EA039758B1 - Potassium-releasing material - Google Patents

Abstract

The invention relates to a composition for soil remediation, comprising a K-feldspar phase and a calcium silicate hydrate phase comprising at least one phase selected from the group consisting of a dicalcium silicate hydrate phase, tobermorite phase and a hydrogarnet phase. The invention also relates to the use of a composition for soil remediation and to a fertilizer comprising said composition.

Description

Link to related applications

This application claims priority under U.S. Provisional Application No. 62/447,657, filed January 18, 2017, and U.S. Provisional Application No. 62/520,976, filed June 16, 2017, the disclosure of which incorporated by reference in their entirety for all purposes.

Background of the Invention

Minerals, including those that release soluble potassium, silica, and other salts, are useful for a variety of purposes. For example, sources of soluble potassium (potash) are suitable for supporting productive agriculture, particularly in tropical regions where large populations rely on poor soil fertility.

The essence of the invention

The present invention relates to a soil remediation composition comprising a K-feldspar phase and a calcium silicate hydrate phase comprising at least one phase selected from the group consisting of a dicalcium silicate hydrate phase, a tobermorite phase and a hydrogarnet phase in the amounts of the invention. The invention also relates to the use of the composition according to the invention for soil reclamation. In addition, the invention relates to a fertilizer containing the composition according to the invention.

Brief description of the figures

The figures are presented primarily for illustrative purposes and are not intended to limit the scope of the subject matter described herein.

In FIG. 1 is a graph showing the amount of potassium present in various processed syenites. The material was processed at 200°C for 5 h.

In FIG. 2 is a table showing an overview of naturally occurring potassium-containing materials with existing or potential applications in global agriculture.

In FIG. 3 is a flow diagram showing an overview of the various non-limiting steps in a process that provides materials, including dried hydrothermally modified materials of the present disclosure.

In FIG. 4A-4C show variants of the post-processing and drying steps of various embodiments of the methods of the present disclosure.

In FIG. 4A shows a modified drying step using a reactive gas.

In FIG. 4B shows embodiments of the method where various solutions may be introduced into the hydrothermal treatment step in addition to the post-treatment.

In FIG. 4C shows alternative embodiments with the gradual addition of an alkaline earth metal solution in the hydrothermal treatment step in addition to post-treatment.

In FIG. 4D is a schematic representation of the hydrothermal reactor used in preparing the dried hydrothermally modified material of Example 1.

In FIG. 4E shows the mineralogical composition of (a) the raw mix calculated from the data reported for the ultrapotassic syenite MCA41, assuming 100 wt% Ca(OH) ₂ as the source of Ca, and (b) the dried hydrothermally modified material, where K2O was recalculated as 11.7 wt%.

In FIG. 5 shows the composition of dried hydrothermally modified materials under different treatment atmospheres for the hydrothermal treatment step and the drying step. Data are presented for Ar-Ar, Ar-air, air-air and CO2-CO2, where the first indicated atmosphere is for the hydrothermal treatment step and the second indicated atmosphere is used for the drying step.

In FIG. 6 is a series of bar graphs showing the effect of the treatment atmosphere on the leaching of elements from the dried hydrothermally modified material. The hydrothermal treatment step was carried out at 200°C for 5 h.

In FIG. 7A is a schematic representation of the reaction paths and conditions for mineralogical composition in leaching, which is obtained by drying hydrothermally modified materials in an atmosphere of carbon dioxide.

In FIG. 7B, 7D show the leaching of potassium, calcium, and aluminum in either air, argon (Ar), carbon dioxide (CO2), or vacuum drying, for which data has been presented to show the difference between drying with the supernatant phase versus drying after removal supernatant phase.

In FIG. 8 is a schematic representation of the hydrothermal treatment variables (atmosphere, time and/or temperature) used to control the mineralogical composition of the hydrothermally modified material.

In FIG. 9A-9D show the effect of hydrothermal treatment time and temperature in the hydrothermal treatment step on mineralogical composition and leaching; (A) shows the effect of treatment time (t) and temperature (T) on the mineral phases of the dried hydrothermally modified material according to XRD; (B) are bar graphs (units g/kg) showing that K leaching from dried hydrothermally modified material exposed to nitric acid leaching solution is independent of treatment time and temperature when evaluated at 0.5-3 h at 200 , 220 and 230°C; Al leaching does not depend on the treatment time, but decreases with increasing temperature; and Na leaching increases with both time and treatment temperature; (C) shows the change in the mass fraction of the alkali feldspar phase, the tobermorite phase and the amorphous phase in the dried hydrothermally modified material with increasing processing time; (D) shows the dependence of K release and Ca release when a hydrothermal treatment time >5 h is used. This relationship is not observed when a treatment time of 0.5-3 h is used (see Fig. 9B)

In FIG. 10 is a graph of the relationship between K-feldspar conversion (Kfs) and the Ca/Si ratio of the feedstock.

In FIG. 11A is a graph showing the effect of K-feldspar (Kfs) conversion on the mineralogical composition of dried hydrothermally modified material when the Ca/Si ratio in the feed is increased from 0.075 to 0.9.

In FIG. 11B-11D are bar graphs showing the release of elements K+ (B and C), Ca ²⁺ (C and D), Na ⁺ (D) and Al ³⁺ (D) from dried hydrothermally modified material when the Ca/Si ratio is raw material rises from 0.075 to 0.9. In graph (D), the pH was controlled at each of the specific ratios.

In FIG. 11E is a graph showing pH after 24 hours for dried hydrothermally modified material obtained at various processing times using a feedstock with a Ca/Si ratio of 0.3.

In FIG. 11F shows a series of graphs comparing the particle size distribution of raw material mixtures for producing dried hydrothermally modified material at various Ca/Si ratios (0.3, 0.6, 0.15, and 0.075).

In FIG. 12 shows an XRPD pattern of (a) a sample of dried hydrothermally modified material and (b) a sample injected with 50 wt% Si (NIST SRM 640) to determine the amorphous component. The numbers in the database of inorganic crystal structures (ICSD) are as follows: orthoclase (no. 159347); myrocline (no. 34790); plasolite (no. 31250); α-calcium silicate hydrate (No. 75277); 11 A tobermorite (No. 40048); albite (no. 16744); panuncite (No. 30951).

In FIG. 13 is an overview of SEM micrographs of dried hydrothermally modified material, where: (a) and (b) modified K-feldspar; round hydrogarnet particles are clearly visible; the white arrow points to the side of the feldspar surface where fine needles of calcium silicate phases are especially visible as a bryophyte coating, (c) white arrows point to round agglomerates (probably tobermorite); (d) an increase in one of the formations shown in (c); round hydrogarnet particles are clearly visible. Images were obtained by rubbing a pinch of powder on a conductive paint (Carbon Conductive Adhesive 502, Electron Microscopy Sciences).

In FIG. 14 is an overview of SEM micrographs of dried hydrothermally modified material set in thin section, where (a) and (b) show modified K-feldspar particles with obvious internal cracking, and a rim of fine Ca minerals likely to nucleate at the grain edge; small round particles (hydrogarnet) and oblong crystals (α-dicalcium silicate hydrate and tobermorite) are visible. Arrows in (b) indicate elongated tobermorite particles located outside the margin of calcium minerals; (c) and (d) show highly heterogeneous clods. The lump is bounded by a rim of small particles of Ca minerals that encapsulates altered K-feldspar, α-dicalcium silicate hydrate, and tobermorite. A whitish clouding of the background was observed in the lump, which can be explained by small tobermorite crystals. In (d), the arrows indicate thick oblong crystals of α-dicalcium silicate hydrate. Such a crystal differs from the tobermorite crystals shown in (b), which appears to be much thinner. (e) shows a strong increase in oblong and filamentous crystals. Some round hydrogarnet particles are also a visible (f) clump. The arrow points to the edge of the cluster to highlight its overall size and shape, (g) Strong magnification of round hydrogarnet crystals. The arrow points to an area where many crystals appear to coalesce together, (h) Limiting case of a relatively large mass of coalesced hydrogarnet.

In FIG. 15 shows X-ray elemental maps from an electron probe microanalyzer (EPMA) of (a) altered K-feldspar and (b) clods. Hot colors correspond to higher concentrations of the element; cool colors correspond to lower concentrations.

In FIG. 16 shows X-ray elemental maps from an electron probe microanalyzer (EPMA), where (a), (b), (c) modified K-feldspar particles in three different size ranges,

- 2 039758 d<50 µm, 50<d<100 µm and d>100 µm, respectively; (d) lumpy formation in the dried hydrothermally modified material; (e) a large mass of hydrogarnet and (f) a lumpy formation with a central particle of altered K-feldspar containing a distinct inclusion of albite.

In FIG. 17 is a photograph showing the physical properties of ultrapotassium syenite powder rock (left) and dried hydrothermally modified material, NT-1 (right).

In FIG. 18 is an electron probe view of the zeolites that formed in the dried hydrothermally modified material.

In FIG. 19 shows electron backscatter images taken with an electron probe microanalyzer of (a) an amorphous compound and (b) carbonaceous particles.

In FIG. 20 is a titration curve of dried hydrothermally modified material (0.3067 g) suspended in 25 ml of DI water with standardized HNO3 0.1M.

In FIG. 21(a)-(c) show the arrangement, idea, and results for a carbonate spot test by dropping concentrated nitric acid on dried hydrothermally modified material; (a) presents a schematic of the experimental apparatus along with the chemical equation that provides the basis for the test for carbonates; (b) shows the results of a blank test; and (c) shows test results with dried hydrothermally modified material.

In FIG. 22 shows the particle size distribution (PSD) based on both volume percent (V%, base) and particle percentage (N%, inset) for HT-1, dried hydrothermally modified material.

In FIG. 23 shows adsorption and desorption isotherms (-196°C) of gaseous N ₂ on the surface of the dried hydrothermally modified material.

In FIG. 24 shows the release of elements from powdered rock (ultrapotassium syenite) and dried hydrothermally modified material. Leaching conditions: Batch spin test, 24 hours, mS:mL=1:10. HNO3 at a nominal initial pH of 5 as a leaching solution. All values (ppm) refer to mg of element analyzed in solution by ICP-MS per kg of solid material.

In FIG. 25 shows the difference in leaching ratios for bulk powder under standard conditions (pH 5 HNO3), acetate buffering conditions (acetate/HNO ₃ , pH 5.3), and microfluidic conditions at pH 5 and pH 1.

In FIG. 26 is a graph comparing K ⁺ , Ca ²⁺ , Al ³⁺ and Si leaching under microfluidic conditions at various pH values for dried hydrothermally modified material prepared according to the parameters described in FIG. 34A.

In FIG. 27 is a plot of the spontaneous change in pH of an HNO3 solution at an initial nominal pH of 5, which is in contact with either powdered rock (ultrapotassium syenite) or dried hydrothermally modified material at mS.mL=0.1 and room temperature.

In FIG. 28 shows that supernatant water removed from hydrothermally modified material treated at 220° C. for 5 hours is enriched in leachable potassium (K).

In FIG. 29 is a graph of the temperature profile of the hydrothermal processing steps that produce the hydrothermally modified material.

In FIG. 30 is a graph showing the particle size distributions (PSD) of K-feldspar raw material ground for 1 min and then dry sieved using an ASTM #70 (212 µm), 100 (150 µm), 140 (106 µm) sieve. ) and 325 (45 µm) to give the four fractions shown. Raw mixtures were obtained by mixing ground K-feldspar with the desired amount of CaO, rather than co-grinding.

In FIG. 31A, 31B are graphs of the particle size distribution of dried hydrothermally modified materials obtained from each of the four raw materials whose PSD values are shown in FIG. thirty; (A) is a combined graph showing particle size distributions of four separate dried hydrothermally modified materials; (B) shows separate graphs where each of the individual dried hydrothermally modified materials (dashed lines) is superimposed on its respective raw mix (solid lines) used in production.

In FIG. 31C, 31D show the leaching properties of potassium (C), sodium (D), aluminum (D), and calcium (D) from dried hydrothermally modified material as a function of average particle size.

In FIG. 32 is a schematic diagram showing that soluble K ⁺ can be removed from the dried hydrothermally modified material by washing with water. The resulting composition is a solid phase, called washed HT, dried with X, where X represents the drying atmosphere used.

In FIG. 33A is a graph showing particle size distributions of washed and

- 3 039758 unwashed dried hydrothermally modified materials that have been dried under either argon or carbon dioxide conditions.

In FIG. 33B-33F are scanning electron microscopy images comparing washed HT dried with Ar with washed HT dried with CO2. (B) washed with HT dried with Ar; (C) washed HT air dried (thin section); (D) washed HT dried with CO2; (E) washed HT dried with CO ₂ (thin section); (F) Washed HT, dried with air, with marked features. Carbonization has been shown to have a strong influence on the particle morphology of the dried hydrothermally modified material.

In FIG. 33G is a schematic diagram showing an alternative embodiment of the process of the present disclosure in which the decalcification reaction route under flow conditions produces SiO2 and Al2O ₃ from calcium silicate hydrate (CSH) and hydrogen garnet, respectively. Drying/post-treatment is carried out with CO2, which accelerates the decalcification of the hydrothermally modified material after the hydrothermal treatment.

In FIG. 33H is a schematic diagram showing an alternative embodiment of the process of the present disclosure in which the alkaline solution flows through a dense bed of immobile mineral powder.

In FIG. 34A is a schematic representation of an exemplary general process according to the present disclosure, showing the feedstock, processing parameters, and drying conditions used to produce the dried hydrothermally modified material.

In FIG. 34B, 34C show examples of a hydrothermal reactor (B) and a dryer (C) used to make materials of the present disclosure on a laboratory scale.

In FIG. 35A-35D are scanning electron microscopy images showing the dissolution behavior of dried hydrothermally modified material under flow (microfluidic) conditions. Direct comparisons before and after leaching are presented.

In FIG. 36 is a graph showing the release of K from dried hydrothermally modified materials further refluxed at 90° C. for either 24 hours or 96 hours at ambient pressure.

In FIG. 37A-37F show pH and concentration dependent leaching and dissolution; (A) is a graph showing the release of K from each of three leaching solutions (HNO3 pH 5, 33.33 mM CsNO ₃ in HNO3 pH 5 or tetramethylammonium hydroxide pH 12.5) for dried hydrothermally modified material that was dried in argon (Ar); (B) is a graph showing the effect of buffered leaching conditions on element release. Each of K, Na, Al, and Ca was evaluated and compared to an unbuffered control; (C) is a schematic diagram showing that soluble K+ can be removed from the dried hydrothermally modified material by washing with water. The resulting composition is a solid phase, called washed HT, dried with X, where X represents the atmosphere used for drying. Leaching was carried out in one of three solutions: HNO3 pH 5, 33.33 mM CsNO ₃ in HNO ₃ pH 5 or tetramethylammonium hydroxide pH 12.5 (not shown); (D) is a graph showing the change in K release for dried hydrothermally modified materials obtained under various drying conditions (Ar or CO ₂ ) and either washed with water or left unwashed. The experiments were carried out in an HNO3 solution with pH 5; (E) is a graph showing the difference between the release of K from washed and unwashed samples that were dried with either Ar or CO2. The difference between washed and unwashed samples gave the instant release soluble K/K fraction in the dried hydrothermally modified material; (F) is a graph similar to (D), except that the leaching was carried out in a solution of CsNO ₃ /HNO ₃ (33.3 mM) pH 5 for HT dried with Ar, washed with HT, dried with Ar, and washed HT dried with CO2. HT dried with CO ₂ (CsNO ₃ ) was dried in CO ₂ in the presence of CsNO ₃ and the leaching was carried out in a pH 5 HNO3 solution. FIG. 38 shows a detailed overview of the reaction pathways that can occur in the hydrothermal treatment of raw materials based on CaO and feldspar. A chemical rationale is provided that explains the formation of various established mineral phases, including the effect of certain conditions (eg Ca/Si ratio, Al/Si ratio) on product distribution.

Detailed disclosure of the present invention

Disclosed herein are materials that exhibit useful properties in a wide range of industries and applications, including, but not limited to, soil fertility, soil reclamation, geopolymer materials, soluble glass, colloidal silica, and cement manufacture. In some embodiments, the materials of the present disclosure are metal ion releasing materials (including alkali metals such as potassium, alkaline earth metals such as calcium and magnesium, other metals such as aluminum, and additional elements such as silicon), which in some cases (eg potassium, calcium, magnesium and/or silicon) are suitable for use as, for example, fertilizers for agriculture in tropical climates. In some cases, such materials may provide an alternative to known fertilizers such as, for example, KCl.

According to the present disclosure, some technological ways of obtaining materials have been developed. In some embodiments, the technology pathways take into account soil science and/or economic principles to reduce and/or prevent undesirable excess of soluble (e.g., potassium) particles, waste or by-product generation, and/or high processing and environmental costs, while overcoming one or more disadvantages, which may be associated with some known process, such as the known process associated with KCl. In addition or alternatively, the process paths may be of a modular nature, which may lead to direct adaptation to any of the above applications.

When used as a potash fertilizer, the materials disclosed herein can provide a number of advantageous properties such as i) continuous and controlled release of potassium to meet the needs of crops at various stages of growth and avoid both unexpected soil saturation and excessive leaching; ii) a strong aftereffect (eg by providing a supply of available potassium) that improves plant nutrition over many agronomic cycles; iii) the ability to buffer soil pH at optimal levels for a given crop and microbiome; iv) synergistic delivery of micronutrients (eg magnesium); vi) maintaining and improving the mechanical strength and porosity of the soil; vii) improved cation exchange capacity (CEC); viii) low salinity; ix) increasing water holding capacity (WHC) and carbon sequestration; x) relatively low cost; xi) minimal barriers to adoption by farmers; and/or xii) a sustainable way of production implemented at an industrial level and with local resources.

In some embodiments, the methods of the present disclosure use feedstocks such as ultrapotassium syenite (see, for example, FIGS. 1 and 2 for other non-limiting examples of K-bearing ores), CaO (including hydrated and other forms of CaO), and water, which is widespread and/or available. Ultrapotassium syenites are commonly available worldwide in large quantities and can be a relatively readily available source of relatively inexpensive K ₂ O. CaO can be produced by roasting limestone in rotary kilns and is a raw material for several industries (e.g. glass and cement), many of which operate based on already optimized costs and logistics. Dolomite (CaMg(CO ₃ ) ₂ ) and other calcium containing materials are also competitive alternatives. In some embodiments, the implementation of the present disclosure provides for the design and installation of suitable hydrothermal reactors (eg, autoclaves).

In some embodiments, the present disclosure provides methods that are environmentally friendly because they can reduce (e.g., minimize) the generation of waste and/or by-products, especially when compared to some other manufacturing technologies where waste and saline wastewater disposal along with the use of chemical additives such as alkylamine blowing agents provide a process that is less environmentally friendly. The materials disclosed herein can, for example, be applied directly to soils. In some cases, this means that the hydrothermally modified material derived from the raw mineral (eg, K-feldspar) does not need to be separated from the rest of the solid material. In some embodiments, K-feldspar, hydrogarnet, and tobermorite are naturally occurring mineral phases, while α-dicalcium silicate hydrate and non-stoichiometric calcium silicate hydrate are components of concrete and do not involve creating serious environmental hazards. Since, in some embodiments, a portion of the original (e.g., K-feldspar) feedstock is converted into new mineral phases, process parameters such as reaction temperature (T) and reaction time (t) can be chosen to minimize the scale of the environmental impact of the process. . In addition, CO2 emissions from transport can be reduced because the materials disclosed herein can be produced locally and from local resources.

The materials (eg, hydrothermally modified or dried hydrothermally modified materials) disclosed herein may be of value in improving soil mechanics, for example, by increasing soil porosity. For example, the water holding capacity of oxide soils is often low due to the lack of mesopores, which are responsible for storing water for sustained release. However, the volume occupied by the mineral particles disclosed herein may be in a range that is suitable for increasing the number of mesopores and reducing seepage rates. This may serve to reduce (eg prevent) the dispersion of soil colloids and/or to reduce (eg prevent) the dispersion of other fertilizers applied to the soil. In addition, it has been shown that cured pastes of fine hydrogen garnet and calcium silicate hydrates, such as those that make up at least some of the materials disclosed herein, can have a flexural strength of 20 MPa, which is suitable for reducing erosion and for increasing soil strength without obtaining microaggregates, which

- 5 039758 too large (>1 mm) to provide undesirable seepage rates. Ordinary potassium salts (KCl or K2SO4) usually do not provide these improvements in soil mechanics.

The methods described herein can be used to produce materials, such as dried hydrothermally modified materials, that have distinct, unexpected, and improved metal release properties (as described herein) compared to previously known materials.

In various embodiments, the disclosure provides materials, including dried hydrothermally modified materials, providing both an initial, relatively fast potassium release and a relatively sustained potassium release. In some embodiments, the initial potassium release (eg, as measured by the 1 minute potassium release test) may be greater than the sustained release (eg, as measured by the 24 hour potassium release test). In general, it is believed that the sustained release of potassium can be redistributed between several phases formed by hydrothermal treatment, and thus potassium can be released more slowly over a longer period of time compared to some known materials. In various embodiments, the dried hydrothermally modified materials of the present disclosure have the added benefit of releasing micronutrients such as, for example, Si, Ca, Na, and Mg, which may also be beneficial to infertile soils. In addition, dried hydrothermally modified materials according to some embodiments of the present disclosure may have alkalinity levels that may partially replace the need to add lime to the soil. However, the mineralogy of the dried hydrothermally modified materials of the present disclosure may be particularly suitable for tropical soils.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination that contains water and a second composition (eg, a hydrothermally modified material); and removing at least some of the water from the combination, while providing a third composition (for example, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the potassium release test after 24 hours, the amount of potassium released from the third composition is at least about twice as much as the amount of potassium released from the first composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); and removing at least some of the water from the combination, while providing a third composition (for example, dried hydrothermally modified material), and the first composition contains alkali metal silicate in the first amount; the third composition contains an alkali metal silicate in a second amount, which is less than the first amount; and according to the potassium release test after 24 hours, the amount of potassium released from the third composition is at least about twice as much as the amount of potassium released from the first composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition, wherein the second composition (eg, a hydrothermally modified material) contains a K-feldspar phase; and removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the third composition contains a phase of K-feldspar in an amount of at most about 65 wt.%; and at least one of the following is met: the third composition further comprises at least about 1 wt.% of the dicalcium silicate hydrate phase; the third composition further comprises at least about 1% by weight of tobermorite phase; and the third composition further comprises at least about 1% by weight of a hydrogen garnet phase.

In some embodiments, according to the 24 hour potassium release test, the amount of potassium released from the third composition is at least about three (e.g., at least about four, at least about five, at least about 10, at least at least about 25, at least about 50, at least about 100) times greater than the amount of potassium released from the first composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), wherein the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the potassium release test after 24 hours, the amount of potassium released from the third composition is at least about 5000 mg of potassium per 1 kg of the third composition.

In some embodiments, the method includes subjecting the first composition to conditions selected from heat and pressure, thereby obtaining a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination that contains a) water and b) the second composition, while providing a third composition (for example, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the calcium release test after 24 hours, the amount of calcium released from the third composition is at least about 15 mg of calcium per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the aluminum release test after 24 hours, the amount of aluminum released from the third composition is at least about 50 mg of aluminum per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the aluminum release test after 24 hours, the amount of aluminum released from the third composition is at least about 10 mg of aluminum per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the silicon release test after 24 hours, the amount of silicon released from the third composition is at least about 40 mg of silicon per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the sodium release test after 24 hours, the amount of sodium released from the third composition is at least about 5 mg of sodium per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the magnesium release test after 24 hours, the amount of magnesium released from the third composition is at least about 5 mg of magnesium per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removing at least some of the water from the combination, while providing a third composition (eg, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and according to the potassium release test after 1 minute, the amount of potassium released from the third composition is at least about 5000 mg of potassium per 1 kg of the third composition.

In some embodiments, the method includes exposing the first composition to water and conditions selected from heat and pressure, thereby producing a combination containing water and a second composition (eg, a hydrothermally modified material); removal of at least

- 7 039758 some part of the water from the combination, while providing a third composition (for example, dried hydrothermally modified material), and the first composition contains the first alkali metal silicate; the third composition contains a second alkali metal silicate; and the third composition has a relative potassium release of at least about five.

In some embodiments, the first alkali metal silicate contains at least one member selected from K-feldspar, kalsilite, phlogopite, muscovite, biotite, trachyte, rhyolite, micas, ultrapotassium syenite, leucite, nepheline, syenite, phonolite, fenite, ugrandite , sanidine, aplite and pegmatite, and combinations thereof.

In some embodiments, the second alkali metal silicate contains at least one member selected from K-feldspar, kalsilite, phlogopite, muscovite, biotite, trachyte, rhyolite, micas, ultrapotassium syenite, leucite, nepheline, syenite, phonolite, fenite, ugrandite , sanidine, aplite and pegmatite, and combinations thereof.

In some embodiments, the third composition has a higher potassium content than the second composition.

In some embodiments, the implementation of the third composition contains a phase of K-feldspar; and a calcium silicate hydrate phase comprising at least one phase selected from a dicalcium silicate hydrate phase, a tobermorite phase, and a hydrogarnet phase, the third composition comprising a K-feldspar phase in an amount of at most about 65% by weight; and at least one of the following is observed: the third composition contains at least about 1 wt.% of the dicalcium silicate hydrate phase; the third composition contains at least about 1 wt.% phase tobermorite; and the third composition contains at least about 1% by weight of the hydrogen garnet phase.

In some embodiments, the amount of aluminum released from the third composition is at most about 25 mg (eg, at most about 10 mg) of aluminum per kg of the third composition.

In some embodiments, the amount of magnesium released from the third composition is at least about 100 mg of magnesium per 1 kg of the third composition.

In some embodiments, removing water from the combination includes drying the combination.

In some embodiments, removing water from the combination includes flash drying the combination.

In some embodiments, removing water from the combination includes vacuum drying the combination.

In some embodiments, the combination is exposed for at least about 5 minutes.

In some embodiments, removal of at least a portion of the water from the combination occurs within at least about 15 minutes (e.g., at least about 30 minutes, at least about 1 hour, at least about 2 hours, at least about 3 h, at least about 5 h, at least about 16 h) and/or at most about 20 h.

In some embodiments, removing at least a portion of the water from the combination comprises heating the combination to at least about 50°C (e.g., at least about 100°C, at least about 150°C) and/or at most about 200°C. C.

In some embodiments, removing at least a portion of the water from the combination includes exposing the combination to atmospheric pressure.

In some embodiments, removing at least a portion of the water from the combination includes exposing the combination to a pressure of at least about 5 atm (e.g., at least about 30 atm, at least about 50 atm) and/or at most about 80 atm. .

In some embodiments, removal of at least a portion of the water from the combination occurs under a pressure of less than one atmosphere (eg, under vacuum).

In some embodiments, when at least some of the water is removed from the combination, the combination is exposed to a reactive atmosphere. The reactive atmosphere may contain at least one member selected from air, oxygen, ammonia, carbon monoxide and carbon dioxide.

In some embodiments, when at least a portion of the water is removed from the combination, the combination is exposed to an atmosphere containing air.

In some embodiments, when at least some of the water is removed from the combination, the combination is exposed to an inert atmosphere. The inert atmosphere may contain at least one member selected from argon and nitrogen.

In some embodiments, the alkali metal silicate contains at least

- 8 039758 one member selected from K-feldspar, kalsilite, phlogopite, muscovite, biotite, trachyte, rhyolite, micas, ultrapotassium syenite, leucite, nepheline, syenite, phonolite, fenite, ugrandite, sanidine, aplite and pegmatite and combinations thereof .

In some embodiments, the method further comprises grinding a precombination that contains a) an alkali metal silicate and b) at least one member selected from an alkali metal oxide, an alkali metal hydroxide, an alkaline earth metal oxide, and an alkaline earth metal hydroxide, while providing the first composition .

In some embodiments, the conditions to which the first composition is subjected include a temperature of at least about 150°C (e.g., at least about 200°C, at least about 220°C, at least about 230°C) and/or at most approximately 300°C.

In some embodiments, the conditions to which the first composition is subjected include a pressure of at least about 5 atm (eg, at least about 30 atm, at least about 50 atm) and/or at most about 80 atm. In some embodiments, the conditions to which the first composition is subjected include a pressure of less than one atmosphere (eg, vacuum).

In some embodiments, the first composition is exposed for at least about 5 minutes (e.g., at least about 5 minutes, at least about 10 minutes, at least about 15 minutes, at least about 20 minutes, at least at least about 30 minutes, at least about 1 hour, at least about 2 hours, at least about 5 hours, at least about 10 hours), and/or at most about 20 hours.

In some embodiments, the first composition comprises a ratio of calcium to silicon of at least about 0.075 (eg, at least about 0.15, at least about 0.3) and/or at most about 0.6.

In some embodiments, grinding includes ball milling or rod milling.

In some embodiments, the pre-combination contains at least one member selected from potassium hydroxide, potassium oxide, potassium carbonate, calcium oxide, calcium hydroxide, calcium carbonate, sodium carbonate, magnesium carbonate, and combinations thereof.

In some embodiments, the implementation of the third composition contains a zeolite.

In some embodiments, the third composition is a fertilizer, such as, for example, a potassium fertilizer, a calcium fertilizer, a silicon fertilizer, a sodium fertilizer, and/or a magnesium fertilizer. In some embodiments, the fertilizer is a multi-nutrient fertilizer.

In some embodiments, the process produces a material useful in cement chemistry.

In some embodiments, the third composition is suitable for making alkaline solutions for at least one industry selected from the geopolymer industry, the water glass industry, and the colloidal silica industry.

In some embodiments, the implementation of the third composition is suitable for soil reclamation.

In some embodiments, the method further comprises using the third composition as a fertilizer (eg, potash fertilizer, calcium fertilizer, silicon fertilizer, sodium fertilizer, and/or magnesium fertilizer).

In some embodiments, the implementation of the third composition is a soil improver.

In some embodiments, the method further comprises using the second caustic composition for at least one industry selected from the geopolymer industry, the water glass industry, and the colloidal silica industry.

In some embodiments, the method further comprises using the second composition in soil remediation.

In some embodiments, the composition (eg, hydrothermally modified material or dried hydrothermally modified material) contains a K-feldspar phase; and a calcium silicate hydrate phase comprising at least one phase selected from a dicalcium silicate hydrate phase, a tobermorite phase, and a hydrogarnet phase, wherein the composition comprises a K-feldspar phase in an amount of at most about 65% by weight; and at least one of the following is observed: the composition contains at least about 1 wt.% of the dicalcium silicate hydrate phase; the composition contains at least about 1 wt.% phase tobermorite; and the composition contains at least about 1% by weight of the hydrogen garnet phase.

In some embodiments, the composition contains at most about 60% by weight (e.g., at most about 55, at most about 50, at most about 45, at most about 40, at most about 34.9, at most

- 9 039758 more than approximately 32.3 wt.%) of the K-feldspar phase and/or at least approximately wt.% (at least approximately 5, at least approximately 10 wt.%) of the phase

K-feldspar.

In some embodiments, the composition contains at least about 1 wt.% (for example, at least about 2, at least about 3, at least about 5, at least about 10, at least about 15, at least about 20%, at least about 25% by weight of a calcium silicate hydrate phase and/or at most about 30% by weight (e.g., at most about 25%, at most about 20%, at most about 15% by weight) of a silicate hydrate phase calcium.

In some embodiments, the implementation of the composition contains from about 1 to about 30 wt.% phase of calcium silicate hydrate.

In some embodiments, the composition contains a dicalcium silicate hydrate phase in an amount of at least about 1 wt % (at least about 5, at least about 10, at least about 15, at least about 20, at least about 25 , at least about 30, at least about 25, at least about 40 wt.%) and / or at most about 38.6 wt.% (for example, at most about 37.7, at most about 35, at most greater than about 30 wt.%).

In some embodiments, the composition contains a tobermorite phase in an amount of at least about 1% by weight (e.g., at least about 2, at least about 3, at least about 4, at least about 5, at least about 6 , at least about 7, at least about 8, at least about 9, at least about 10 wt.%) and/or at most about 10 wt.% (for example, at most about 9, at most about 8 wt.%).

In some embodiments, the composition contains a hydrogen garnet phase in an amount of at least about 1% by weight (e.g., at least about 5, at least about 8, at least about 9, at least about 10, at least about 11 , at least about 12, at least about 13 wt.%) and/or at most about 15 wt.% (e.g., at most about 13.2, at most about 12.7, at most about 12, at most about 11, at most about 10, at most about 9, at most about 8, at most about 5, at most about 1% by weight.

In some embodiments, the hydrogarnet phase comprises plasolite or hydrogrossular.

In some embodiments, the composition further comprises an amorphous phase.

In some embodiments, the composition contains at most about 51.1 wt.% (e.g., at most about 50, at most about 49, at most about 48, at most about 47, at most about 46, at most about 45 wt.% ) an amorphous phase and/or at least about 18.2% by weight of an amorphous phase.

In some embodiments, the implementation of the amorphous phase contains a zeolite.

In some embodiments, the implementation of the amorphous phase contains at least one member selected from silicon dioxide and calcium silicate hydrates.

In some embodiments, the composition further comprises a zeolite.

In some embodiments, the composition further comprises carbonates.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a potassium release of at least about 5000 mg (e.g., at least about 6502, at least at least about 6763, at least about 7,500, at least about 10,000, at least about 10,377, at least about 11,648, at least about 15,000 mg) of potassium per kg of composition according to a 24 hour potassium release test, and/or at most about 15,000 mg of potassium per 1 kg of composition according to the potassium release test after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a calcium release of at least about 15 mg (e.g., at least about 16, at least about 34, at least about 50, at least about 63, at least about 100, at least about 250, at least about 315, at least about 355, at least about 500 mg) calcium per 1 kg of the composition according to the calcium release through 24 hours and/or at most approximately 657 mg of calcium per 1 kg of composition according to the release test

- 10 039758 calcium after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) comprises a K-feldspar phase, wherein the composition has an aluminum release of at most 50 m (e.g., at most about 41, at most about 40, at most about 28, at most about 25, at most approximately 10 mg) of aluminum per gram of 1 kg of composition according to the aluminum release test after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition is characterized by a silicon release of at least about 40 mg (e.g., at least about 100, at least about 500, at least about 1000, at least about 1388, at least about 1500, at least about 1652 mg) silicon per 1 kg of composition according to the silicon release test after 24 hours and/or at most about 1700 mg silicon per 1 kg of composition according to the test for release of silicon after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a sodium release of at least about 6.2 mg (e.g., at least about 6.4, at least about 10, at least about 15, at least about 20, at least about 30, at least about 40, at least about 50, at least about 60, at least about 70, at least about 80, at least at least about 90, at least about 100 mg) sodium per 1 kg of composition according to the 24 hour sodium release test and/or at most about 100 mg sodium per 1 kg of the composition according to the 24 hour sodium release test.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a magnesium release of at least about 5 mg (e.g., at least about 7, at least about 10, at least about 20, at least about 30, at least about 40, at least about 50, at least about 75, at least about 100, at least about 500, at least about 1000, at least about 2000, at least about 5000 mg) magnesium per 1 kg of the composition according to the magnesium release test after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a potassium release of at least about 5000 mg (e.g., at least about 6000, at least about 7000, at least about 8,000, at least about 9,000, at least about 10,000, at least about 11,000 mg) of potassium per kg of composition according to the potassium release test after 1 minute.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition has a relative potassium release of at least about 5 (e.g., at least about 6, at least about 7, at least about 8, at least about 9, at least about 10), and/or at most about 20.

In some embodiments, the composition further comprises a calcium silicate hydrate phase. The calcium silicate hydrate phase may comprise at least one phase selected from a dicalcium silicate hydrate phase, a tobermorite phase and a hydrogarnet phase.

In some embodiments, the composition further comprises at least one member selected from potassium hydroxide, potassium oxide, potassium carbonate, calcium oxide, calcium hydroxide, calcium carbonate, sodium carbonate, magnesium carbonate, and combinations thereof.

In some embodiments, the composition further comprises panuncite, portlandite, albite, or combinations thereof.

In some embodiments, the composition (eg, dried hydrothermally modified material) contains a K-feldspar phase, wherein the composition contains a K-feldspar phase in an amount of at most about 65% by weight; the composition is obtained from the original composition containing more than about 65 wt.% K-feldspar; and according to the potassium release test after 24 hours, the amount of potassium released from the composition is at least about two times (for example, at least about 3 times, at least about 4 times, at least about 5 times, at least at least about 10 times, at least about 25 times, at least about 50 times, at least about 100 times) more than the amount of potassium released from

- 11 039758 of the original composition.

In some embodiments, the composition (eg, dried hydrothermally modified material) contains an alkali metal silicate phase; and the calcium silicate hydrate phase comprises at least one phase selected from a dicalcium silicate hydrate phase, a tobermorite phase, and a hydrogarnet phase, the composition comprising an alkali metal silicate phase in an amount of at most about 65% by weight; and at least one of the following is observed: the composition contains at least about 1 wt.% of the dicalcium silicate hydrate phase; the composition contains at least about 1 wt.% phase tobermorite; and the composition contains at least about 1% by weight of the hydrogen garnet phase.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by potassium release of at least about 5000 mg of potassium per 1 kg of composition according to a potassium release test after 24 hours.

In some embodiments, the composition (e.g., the dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by a calcium release of at least about 15 mg of calcium per 1 kg of the composition according to a calcium release test after 24 hours.

In some embodiments, the composition (e.g., the dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition exhibits an aluminum release of at most about 10 mg of aluminum per 1 kg of the composition, according to a 24 hour aluminum release test.

In some embodiments, the composition (e.g., the dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by silicon release of at least about 40 mg of silicon per 1 kg of composition according to a 24 hour silicon release test.

In some embodiments, the composition (e.g., the dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by a sodium release of at least about 6.2 mg of sodium per 1 kg of the composition according to a 24 hour sodium release test.

In some embodiments, the composition (e.g., the dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by a magnesium release of at least about 5 mg of magnesium per 1 kg of the composition according to a magnesium release test after 24 hours.

In some embodiments, the composition (e.g., dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition is characterized by potassium release of at least about 5000 mg of potassium per 1 kg of composition according to the potassium release test after 1 minute.

In some embodiments, the composition (eg, the dried hydrothermally modified material) comprises an alkali metal silicate phase, wherein the composition comprises an alkali metal silicate phase in an amount of at most about 65% by weight; the composition is obtained from the original composition containing more than about 65 wt.% alkali metal silicate; and according to the potassium release test after 24 hours, the amount of potassium released from the composition is at least about twice as much as the amount of potassium released from the original composition (eg, hydrothermally modified material).

In some embodiments, the composition (eg, dried hydrothermally modified material) contains an alkali metal silicate phase, wherein the composition has a relative potassium release of at least about five.

In some embodiments, the alkali metal silicate contains at least one member selected from K-feldspar, kalsilite, phlogopite, muscovite, biotite, trachyte, rhyolite, micas, ultrapotassium syenite, leucite, nepheline, syenite, phonolite, fenite, ugrandite, sanidine, aplite and pegmatite; and combinations thereof.

In some embodiments, the composition further comprises a carbonaceous material. The carbonaceous material may contain at least one material selected from KOH, NaOH, Mg(OH) ₂ , Ca(OH) ₂ , K ₂ CO ₃ , Na ₂ CO ₃ , MgCO ₃ and CaCO ₃ .

In some embodiments, the implementation of the composition has a multimodal distribution of particle sizes, including particles with a diameter of from about 1 to about 1000 microns.

In some embodiments, the implementation of the composition contains aggregated particles with a size of from about 100 to about 1000 microns.

In some embodiments, the composition comprises particles with a BET specific surface area of from about 15.1 to about 46.9 m ² /g.

In some embodiments, the composition has a particle size distribution from about 0.01 to about 100 microns (for example, from about 0.1 to about

- 12 039758

100 µm).

In some embodiments, the composition is useful in cement chemistry.

In some embodiments, the composition is useful in the preparation of alkaline solutions for at least one industry selected from the geopolymer industry, the water glass industry, and the colloidal silica industry.

In some embodiments, the implementation of the composition is suitable for soil reclamation.

In some embodiments, the implementation of the fertilizer contains the composition disclosed in this document. The fertilizer may, for example, be a potassium fertilizer, a calcium fertilizer, a silicon fertilizer, a sodium fertilizer and/or a magnesium fertilizer. The fertilizer may be a multi-nutrient fertilizer.

In some embodiments, the implementation of the soil improver contains the composition disclosed in this document.

Disclosed herein are various embodiments of hydrothermally modified materials, dried hydrothermally modified materials, and methods for making the same. In some embodiments, the properties of the materials described herein can be controlled by modifying a number of specific parameters (including, but not limited to, processing time and temperature, drying conditions, processing atmosphere, ratio of raw materials in the raw mixture, surface area of raw materials, etc. ), so that the properties of hydrothermally modified materials or dried hydrothermally modified materials can meet the requirements of a wide range of industrial applications. The various ideas expressed above and discussed in more detail below, which are covered by the methods of the present disclosure, may be implemented in any of a number of ways, as the disclosed ideas are not limited to any particular method of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

In various embodiments, the methods disclosed herein produce minimal or no waste or by-products. This is a departure from some of the conventional manufacturing techniques that aim to convert raw materials such as K-feldspar as well as KCl treatment, where recycling of waste and saline wastewater along with the use of alkylamine blowing agents results in a process that is less environmentally friendly. In some embodiments, hydrothermally modified materials and/or dried hydrothermally modified materials are suitable for direct application to soils. In such embodiments, in general, the modified fraction of the hydrothermally modified potassium-containing mineral (eg, the hydrothermally modified portion of the K-feldspar raw material) is not separated from the remainder of the solid material. In such embodiments, the hydrothermally modified material and/or the dried hydrothermally modified material may contain some unmodified K-feldspar, hydrogarnet, and tobermorite, which are naturally occurring mineral phases, as well as α-dicalcium silicate hydrate and non-stoichiometric calcium silicate hydrate, which are components of concrete and do not pose a significant environmental hazard. Furthermore, in some embodiments of the present disclosure, since only a portion of the original raw material (e.g., K-feldspar) is converted into new mineral phases, the process temperatures (T) and process time (t) are set to minimize the scale of the process impact on environment. Finally, in some embodiments, the methods disclosed herein can reduce (e.g., minimize) CO2 emissions because the hydrothermally modified materials and/or dried hydrothermally modified materials of the present disclosure can be readily produced locally and from local resources.

A flowchart providing a non-limiting, general overview of the process of the present disclosure, which ultimately produces a dried hydrothermally modified material, is shown in FIG. 3. The raw mix contains one or more first raw materials (a1) and one or more second raw materials (a2). The first raw materials (a1) include materials such as alkaline earth metal-containing raw materials (ie CaO) and/or other related metal-containing materials described herein. The second raw materials (a2) include naturally occurring minerals such as alkali metal silicates (eg, K-feldspar) described herein. The appropriate raw material components of the raw mix can then be crushed, ground, crushed, pulverized, etc., using any number of techniques known in the art, a non-limiting list of which is provided herein. The person skilled in the art will recognize that the first and second raw materials (a1, a2) may be milled individually or together, or in some combination thereof. After completion of this step, the raw mixture can be transferred to a hydrothermal reactor such as an autoclave or the like, where the hydrothermal treatment step takes place. Without specifying any particular sequence of events, the materials in the hydrothermal reactor may be contacted with water (in liquid or vapor form, or some combination thereof) in step (b), and the resulting mixture may then be subjected to temperature, pressure, and/or atmospheric conditions as described herein for a period of time sufficient to provide the hydrothermally modified material and the supernatant aqueous phase as represented by step (c). The drying step (d) can be carried out using conventional means such as commercially available dryers (or may be air drying) and carried out according to any of the non-limiting methods described herein. The hydrothermally modified material of step (c) may be dried together with at least some (or all) of the supernatant, or the supernatant may be removed (partially or completely) from the hydrothermally modified material so that each component is dried separately. In either case, the dried hydrothermally modified material is obtained from the general process. Although we refer to step (d) as a drying step, it should be understood that this step does not require the complete removal of all water. It should also be understood that although the dried hydrothermally modified material will be subjected to the drying step (d), this does not require that the dried hydrothermally modified material be subjected to complete removal of all water.

The method described above takes into account (but is not necessarily limited to) both soil science and economic principles to reduce (e.g., prevent) the production of undesirable excess of soluble metal ion particles (e.g., potassium) as well as waste and/or by-products.

Various embodiments of the method shown in FIG. 1 are described in more detail below. 3. The method disclosed herein can be carried out in a batch, semi-continuous or continuous mode, starting from the raw materials that make up the raw mix. In some embodiments of the present disclosure, the raw material (a2) may be selected from among the K-bearing ores indicated in FIG. 2. In other embodiments of the present disclosure, the raw material (a2) is one or more alkali metal silicate materials selected from a non-limiting group of minerals including K-feldspar, kalsilite, phlogopite, muscovite, biotite, trachyte, rhyolite, micas, ultrapotassium syenite, leucite, nepheline, syenite, phonolite, fenite, ugrandite, sanidine, aplite, pegmatite, and combinations thereof.

Any of the above alkali metal containing minerals are suitable for combination with one or more raw materials (a2). In various embodiments of the present disclosure, one or more raw materials (a1) include calcium oxide, calcium hydroxide, or mixtures thereof. In other non-limiting embodiments, the one or more raw materials (a1) include lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, or mixtures thereof. In still other embodiments, the one or more raw materials (a1) include magnesium oxide, calcium oxide, calcium carbonate, beryllium oxide, strontium oxide, radium oxide, magnesium hydroxide, calcium hydroxide, beryllium hydroxide, strontium hydroxide, radium hydroxide, or mixtures thereof. In some embodiments, one or more compounds (a2) include calcium hydroxide. In some embodiments, one or more compounds (a2) include calcium oxide.

Step (a) forming a mixture of particles of raw materials (a1) and (a2) described herein above may include co-grinding or grinding separately (a1) and (a2) using methods known in the field, such as crushing , crushing, grinding and other dry or suspended materials, for example using jaw crushers, grease crushers, cone crushers, ball mills, rod mills, etc., as described in this document.

In various embodiments of the present disclosure, step (a) of forming the mixture occurs by grinding (ie grinding, grinding, powdering, etc.) particles (a1) and (a2) either individually or together. In some embodiments, the non-crushed particles (a1) and (a2) are first combined and then subsequently crushed to form the desired feed mixture (co-grinding). In other embodiments, each component (a1) and (a2) is ground separately before combining the components. In some embodiments, only one of (a1) or (a2) is separately ground prior to combining the components, such that the ground component is combined with the non-ground component. In some embodiments of the present disclosure, the grinding may be ball milling, fluidized bed grinding, wet grinding, media grinding, high pressure homogenizer grinding, cryogenic grinding, rod milling, self-grinding, semi-autonomous grinding, burr grinding, vertical shaft hammer mill, tower mill, or any combination thereof. In some embodiments, the grinding of the mixture (a1) and (a2) is carried out by co-grinding in a ball mill. In some embodiments, co-grinding in a ball mill is carried out on a mixture containing an alkali metal silicate (ie, K-feldspar) and an oxide or hydroxide of an alkaline earth metal (ie, CaO and Ca(OH) ₂ ).

Step (a) of forming a mixture of particles (a1) and (a2) described herein above may include co-grinding or grinding separately (a1) and (a2) using methods from

- 14 039758 known in the art, such as crushing, grinding, grinding and other dry or suspended materials, for example, using jaw crushers, grease crushers, cone crushers, ball mills, rod mills, etc., as described herein. Each component, (a1) or (a2), as well as the resulting mixture, can be sorted, if necessary, by means of, for example, sieves, grids and/or other known methods. In various embodiments, a suitable average particle size for (a1), (a2) or the resulting mixture is independently in the range of about 10 to about 250 microns. In some embodiments, the average particle size of (a1), (a2) or a mixture of (a1) and (a2) is independently about 10 µm, about 20 µm, about 30 µm, about 40 µm, about 50 µm, about 60 µm, about 70 µm, approx. 80 µm, approx. 90 µm, approx. 100 µm, approx. 110 µm, approx. 120 µm, approx. 130 µm, approx. , approx. 200 µm, approx. 210 µm, approx. 220 µm, approx. 230 µm, approx. 240 µm, approx. 250 µm, approx. 260 µm, approx. between any of these values. In some embodiments, (a1), (a2) or the resulting mixture independently has an average particle size of about 17 microns, about 85 microns, about 151 microns, or about 220 microns. If necessary, components (a1) and (a2) may have similar particle sizes or different particle sizes, as described above. Namely, component (a1) may have a similar, larger or smaller average particle size compared to component (a2).

In various embodiments of the method described herein, the mixture (ie, raw material) from step (a) is contacted with water in step (b). The contact of the raw material of step (a) with the water of step (b) can be carried out by any suitable method, such as adding water to the raw material of step (a), or by adding the raw material of step (a) to water, or by sequentially or simultaneously adding water and raw material. step (a) into a suitable vessel, such as a reactor vessel, in which the combination of water and the feedstock of step (a) can be heated to a temperature, optionally under pressure and/or in a suitable atmosphere, as described herein, to obtain a hydrothermally modified material. In any of these embodiments, water may be added as a liquid, vapor, or some combination thereof.

In some embodiments, contact in step (b) of the process is carried out with a mass excess of water relative to feedstock (a2) (eg, the alkali metal silicate described herein). In some embodiments, the mass excess of water relative to feed (a2), expressed as a ratio, is about 1:1, about 2:1, about 3:1, about 4:1, about 5:1, about 6:1, about 7 :1, approximately 8:1, approximately 9:1, approximately 10:1, approximately 11:1, approximately 12:1, approximately 13:1, approximately 14:1, approximately 15:1, 1 approximately 6:1, approximately 17:1, approximately 18:1, approximately 19:1 and approximately 20:1; where, for example, a ratio of 4:1 means that water is present in an amount by weight 4 times greater than the raw material used (a2). In some embodiments, contact in step (b) of the process occurs with a weight ratio of alkali metal silicate feedstock (a2) to water of about 1:1, about 2:1, about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1, about 10:1, about 11:1, about 12:1, about 13:1, about 14:1, about 15:1, 1 about 6:1, about 17:1, about 18:1, about 19:1, and about 20:1; where, for example, a ratio of 4:1 means that the alkali metal silicate raw material is in an amount by weight 4 times greater than the water used.

In some embodiments, the ground feed mixture that is in contact with water is introduced into an autoclave or other suitable container or reaction vessel known in the art to obtain the hydrothermally modified material formed in step (c). In other embodiments, reaction conditions such as atmosphere, time, temperature, and pressure can be varied to control product properties. In some embodiments, modification of these parameters can be used to control the relative amounts of constituent phases, including, but not limited to, amorphous phase, calcium silicate hydrate, hydrogarnet, tobermorite, and K-feldspar. In some embodiments, these parameters can be controlled to promote conversion of the alkali aluminosilicate (e.g., K-feldspar) specifically to other phases, such as amorphous phase(s) and/or calcium silicate hydrate (C-S-H; tobermorite) phase(s). In some embodiments, the leaching properties of the hydrothermally modified materials and/or dried hydrothermally modified materials provided herein are controlled by adjusting the above parameters.

In some embodiments, the pressure used in step (c) of the hydrothermal treatment is in the range of about 5-85 atm. In some embodiments, the step

- 15 039758 (c) hydrothermal treatment is carried out at pressures of about 5 atm, about 10 atm, about 15 atm, about 20 atm, about 25 atm, about 30 atm, about 35 atm, about 40 atm, about 45 atm, about 50 atm , about 55 atm, about 60 atm, about 65 atm, about 70 atm, about 75 atm, about 80 atm, about 85 atm, and any range of values between any of these values.

In some embodiments, step (c) of the hydrothermal treatment is carried out in temperature ranges of approximately 120°C-300°C. In some embodiments, step (c) of the hydrothermal treatment is carried out at a temperature of about 120°C, about 130°C, about 140°C, about 150°C, about 160°C, about 170°C, about 180°C, about 190 °C, approximately 200°C, approximately 210°C, approximately 220°C, approximately 230°C, approximately 240°C, approximately 250°C, approximately 260°C, approximately 270°C, approximately 280°C, approximately 290 °C, approximately 300°C and all ranges between any of these values.

In some embodiments, the duration of process step (c) (i.e., the hydrothermal treatment step) is in the range of about 0.1-20 hours. In some embodiments, the duration of process step (c) is about 0.1 hour, about 0. 25 hours, approximately 0.5 hours, approximately 0.75 hours, approximately 1 hour, approximately 2 hours, approximately 3 hours, approximately 4 hours, approximately 5 hours, approximately 6 hours, approximately 7 hours, approximately 8 hours, approximately 9 hours, approximately 10 o'clock, approximately 11 o'clock, approximately 12 o'clock, approximately 13 o'clock, approximately 2 o'clock, approximately 15 o'clock, approximately 16 o'clock, approximately 17 o'clock, approximately 18 o'clock, approximately 19 o'clock, approximately 20 o'clock and all ranges of values between them.

In some embodiments, step (c) of the hydrothermal treatment is carried out at a pressure in the range of about 5-85 atm, at a temperature in the range of about 120-300° C., for a time in the range of about 0.1-20 hours. In general, step ( c) the hydrothermal treatment can be carried out in any suitable atmosphere such as, for example, a reactive atmosphere or an inert atmosphere. In some embodiments, the atmospheric composition of step (c) of the hydrothermal treatment includes, but is not limited to, argon (Ar), nitrogen (N), air, carbon dioxide (CO2), or mixtures thereof.

The hydrothermally modified material formed in step (c) may include, for example, a modified form of the alkali metal aluminosilicate relative to the form of the alkali metal aluminosilicate in the raw material. The altered form of the alkali metal aluminosilicate may contain some alkali metal, alkaline earth metal, or other metallic or ionic species exchanged with other materials (e.g., CaO, Ca(OH) ₂ , etc.) in a mixture heated in the presence of water, optionally under pressure. and/or in a modified atmosphere as described in various embodiments herein). Exemplary alkali metal aluminosilicates may include potassium aluminosilicates (eg, K-feldspar, ultrapotassium syenite, or any of the other such materials disclosed herein).

In some embodiments, the method includes a drying step (d) where the hydrothermally modified material formed in step (c) and at least a portion of the supernatant aqueous phase formed in the hydrothermal treatment (e.g., water added in step (b) of contacting the hydrothermally modified material), dried together. In some embodiments, the drying of step (d) is carried out at a temperature of from about 20 to about 300°C (e.g., from about 30 to about 290°C, from about 40 to about 280°C, from about 50 to about 270°C, about 60 to about 260°C, about 70 to about 250°C, about 80 to about 240°C, about 90 to about 230°C, about 100 to about 220°C, about 110 to about 210°C, about 120 to about 200°C, about 130 to about 190°C, about 140 to about 180°C, or about 150 to about 170°C).

In some embodiments, the drying step is carried out at a temperature of from about 50 to about 160°C (e.g., from about 60 to about 150°C, from about 70 to about 140°C, from about 80 to about 130°C, from about 90 to about 120°C or from about 100 to about 110°C).

In some embodiments, the drying step is carried out at a temperature of at least about 20°C (e.g., at least about 25°C, at least about 30°C, at least about 40°C, at least about 50°C , at least about 60°C, at least about 70°C, at least about 80°C, at least about 90°C, at least about 100°C,

- 16 039758

on lesser measure approximately 110°C on lesser measure approximately 120°C on lesser measure approximately 130°C on lesser measure approximately 140°C on lesser measure approximately 150°C on lesser measure approximately 160°C on lesser measure approximately 170°C, at least approximately 180° C or on lesser measure approximately 190°C) and/or most more approximately 300°C

(e.g. at most about 290°C, at most about 280°C, at most about 270°C, at most about 260°C, at most about 250°C, at most about 240°C, about 230°C, at most about 220°C or at most about 210°C).

In some embodiments, the implementation of the drying is carried out at ambient temperatures, for example, allowing the supernatant water to evaporate. In some embodiments, step (d) of drying is carried out by flash drying. In some embodiments, step (d) of drying occurs for about 1 minute to about 24 hours (e.g., about 5 minutes to about 23 hours, about 10 minutes to about 22 hours, about 20 minutes to about 21 hours, from about 30 minutes to about 20 hours, from about 40 minutes to about 19 hours, from about 50 minutes to about 18 hours, from about 1 to about 17 hours, from about 2 to about 16 hours, from about 3 to about 15 hours , from about 4 to about 14 hours, from about 5 to about 13 hours, from about 6 to about 12 hours, from about 7 to about 11 hours, or from about 8 to about 10 hours).

In some embodiments, the drying step occurs for about 12 to about 24 hours (e.g., about 13 to about 23 hours, about 14 to about 22 hours, about 15 to about 21 hours, about 16 to about 20 hours or from about 17 to about 19 hours).

In some aspects, step (d) of drying is carried out for at least about 1 minute (e.g., at least about 5 minutes, at least about 10 minutes, at least about 20 minutes, at least about minutes, at least about 40 minutes, at least about minutes, at least about 1 hour, at least about 2 hours, at least about 3 hours, at least about an hour, at least about 5 hours, at least about 6 hours , at least about 7 hours, at least about 8 hours, or at least about 9 hours) and/or at most about 24 hours (e.g., at most about 23 hours, at most about 22 hours, at most about 21 hours). , at most about 8 pm, at most about 7 pm, at most about 6 pm, at most about 5 pm, at most about 4 pm, at most e, about 3 pm, at most about 2 pm, at most about 1 pm, at most about 12 pm, or at most about 11 am).

In some embodiments, the drying of step (d) is carried out at a pressure of from about 1 bar to about 30 bar (e.g., from about 2 bar to about 29 bar, from about 3 bar to about 28 bar, from about 4 to about 27 bar, from about 5 to about 26 bar, about 6 to about 25 bar, about 7 to about 24 bar, about 8 to about 23 bar, about 9 to about 22 bar, about 10 to about 21 bar, about 11 to about about 20 bar, about 12 to about 19 bar, about 13 to about 18 bar, about 14 to about 17 bar, or about 15 to about 16 bar). In some embodiments, step (d) of drying is carried out at a pressure of at least about 1 bar (e.g., at least about 2 bar, at least about 3 bar, at least about 4 bar, at least about 5 bar, at least about 6 bar, at least about 7 bar, at least about 8 bar, at least about 9 bar, or at least about 10 bar) and/or at most about 30 bar (e.g., at most about 25 bar , at most about 20 bar, at most about 15 bar, at most about 14 bar, at most about 13 bar, at most about 12 bar, or at most about 11 bar). In some embodiments, step (d) of drying is carried out at ambient pressure (eg, about 1 bar). In some embodiments, drying is carried out at two or more different temperatures (e.g., for a period of time at a particular temperature, then for another period of time at a different temperature), at two or more different pressures, and/or for two or more different intervals. time. It should be understood that various combinations of the above process parameters for stage (d) drying can be used if necessary.

- 17 039758

In some embodiments, step (c) of the hydrothermal treatment and drying of step (d) are independently carried out under an inert atmosphere or a reactive atmosphere. By way of example, in some embodiments, step (c) is carried out under an inert atmosphere and step (d) is carried out under an inert atmosphere. As another example, in some embodiments, step (c) is carried out in a reactive atmosphere and step (d) is carried out in an inert atmosphere. As a further example, in some embodiments, step (c) is carried out under an inert atmosphere and step (d) is carried out under a reactive atmosphere. As another example, in some embodiments, step (c) is carried out in a reactive atmosphere and step (d) is carried out in a reactive atmosphere. In some embodiments, the implementation of the inert atmosphere contains Ar and/or N ₂ . In some embodiments, the implementation of the reactive atmosphere contains air, oxygen, carbon dioxide, carbon monoxide and/or ammonia. In some embodiments, step (c) of the process is carried out in an inert atmosphere containing Ar or a reactive atmosphere containing air or carbon dioxide. In some embodiments, step (d) of drying the process is carried out in an inert atmosphere containing Ar or a reactive atmosphere containing air or carbon dioxide. In some embodiments, step (c) and/or step (d) is carried out in air.

In some embodiments, the implementation of the reactive atmosphere may contain an inert gas, such as Ar or N ₂ , provided that other components of the atmosphere are reactive. For example, air is a mixture of N2, which is normally inert, and oxygen and traces of CO2, which are reactive. The term reactive atmosphere thus does not exclude gaseous compositions that include inert gases, provided that at least one of the gases in the atmosphere is reactive. The percentage of reactive gas, as described herein, in a reactive atmosphere can be at least about 10%, and can be up to 100% (by volume), including about vol%, about vol%, about vol%, about vol%, approximately vol%, approximately 20 vol%, approximately vol%, approximately 40 vol%, approximately vol%, approximately 60 vol%, approximately vol%, approximately 80 vol% .%, approximately vol.%, approximately vol.%, approximately vol.%, approximately vol.%, approximately 95 vol.% or approximately 100 vol.%, including all ranges and subranges between any of these values. Any combination of reactive and inert gases described herein can be used.

The conditions used to dry the hydrothermally modified material formed in step (c) can affect the basic properties (e.g., mineralogical composition) of the dried hydrothermally modified material, such as, for example, element leaching properties and/or the porosity of the dried hydrothermally modified material. In some embodiments, step (d) of drying the hydrothermally modified material of step (c) may include drying the hydrothermally modified material in the presence of a supernatant (e.g., an aqueous phase) present in step (c) such that any particles dissolved in the supernatant can potentially be recovered as part of the dried hydrothermally modified material. In some embodiments, at least a portion of the supernatant can be separated from the hydrothermally modified material prior to step (d) of drying the material, for example, by decanting or filtering some (or substantially all) of the water from the reactor that produces the hydrothermally modified material from step ( c), then drying the obtained material. When the hydrothermally modified material from step (c) is dried without first removing/decanting the supernatant, drying can be carried out by any suitable means, such as a stream of the desired gas, so that the gas flows through the slurry obtained in step (c) (i.e. a mixture of hydrothermally modified material suspended in a supernatant). In some embodiments, drying the hydrothermally modified material from step (c) in the presence of a supernatant may be carried out by any suitable method known in the art, including, but not limited to, bubbling gas directly through the slurry. In some embodiments, drying step (d) comprises adiabatic drying or non-adiabatic drying. With adiabatic dryers, solid materials can be exposed to heated gases through methods such as blowing gas over the surface (cross circulation), blowing gas through solid layers (through circulation), dripping solids slowly through a slowly moving gas stream (as in a rotary dryer) , blowing gases through a bed of solids that liquefies the particles (i.e., a fluid bed dryer), and by passing solids through a stream of hot gas at high speed (flash drying). Drying can occur by any suitable heat transfer mechanism, including but not limited to: direct (convection), indirect (transfer), radiation, or dielectric. In some embodiments, the resulting hydrothermally modified materials are, for example, dried in an oven to produce dried hydrothermally modified materials. In some embodiments, oven drying is carried out at approximately 90°C for 18 hours.

- 18 039758

In various embodiments, step (d) drying is carried out either in the presence of the supernatant (water), or after at least a portion of the supernatant has been removed as described above using air, argon, carbon dioxide, vacuum, or any of them. combination. In some embodiments, drying step (d) is carried out with one or more reactive gases including ammonia, carbon dioxide, carbon monoxide, oxygen, air, or combinations thereof. In some embodiments, step (d) of drying is carried out with one or more inert gases such as argon or nitrogen. In some embodiments, step (d) of drying is carried out with air. In some embodiments, step (d) of drying is carried out with Ar. In some embodiments, step (d) of drying is carried out with carbon dioxide. In some embodiments, step (d) of drying is carried out under vacuum. In some embodiments, the implementation of the material is flash dried in stage (d) drying.

In various embodiments, the present disclosure provides methods for producing hydrothermally modified material and/or dried hydrothermally modified material that readily releases ions (eg, alkali metal ions such as K+).

In step (a), the methods may include the formation of a raw mixture (or raw materials) containing particles of one or more raw materials (a1), which may in various embodiments be one or more compounds selected, for example, from alkali metal oxide, hydroxide alkali metal, alkaline earth metal oxide and alkaline earth metal hydroxide and combinations thereof; and raw material (a2) which may include one or more alkali metal silicate starting materials.

In step (b), the mixture of step (a) may be contacted with water.

In step (c), the feed mixture of step (b) can be subjected to temperature and pressure for a time sufficient to form a hydrothermally modified material in which the alkali metal silicate starting material (a2) is modified, for example, by exchanging ions present in component (a1), with ions present in the original component (a2). The resulting hydrothermally modified material may contain, for example, (c1) an altered and/or unchanged form of an alkali metal silicate (a2) containing up to about 15% by weight of an alkali metal and/or alkaline earth metal of one or more compounds (a1), and (c2 ) one or more alkali metal and/or alkaline earth metal silicate phases substantially enriched in alkaline earth metal ions. In various other embodiments of the present disclosure, the hydrothermally modified material comprises (c1) an altered and/or unchanged form of the alkali metal silicate of (a2) containing up to about 1 wt%, up to about 2 wt%, up to about 3 wt% , up to about 4 wt.%, up to about 5 wt.%, up to about 6 wt.%, up to about 7 wt.%, up to about 8 wt.%, up to about 9 wt.%, up to about 10 wt.%, up to about 11 wt.%, up to about 12 wt.%, up to about 13 wt.%, up to about 14 wt.%, up to about 15 wt.% alkali metal and/or alkaline earth metal of one or more compounds (a1), including all ranges of values in between.

In step (d), the hydrothermally modified material is dried to obtain a dried hydrothermally modified material that more readily releases ionic species such as, for example, alkali metal ions (K ⁺ , Na ⁺ , etc.) or other ionic species such as silicates, including silicate salts, Mg ²⁺ , Ca ²⁺ etc.

In some embodiments, the present disclosure provides a process for preparing a dried hydrothermally modified material that has improved release of alkali metal (or other) ions compared to the alkali metal silicate (e.g., containing potassium aluminosilicates) starting material(s) from which it was derived. .

In various embodiments of the present disclosure, the hydrothermally modified material and/or the dried hydrothermally modified material is an ion releasing material, such as, for example, an alkali metal ion releasing material (e.g., a K ⁺ ion releasing material and/or a Na ⁺ ion releasing material). In some embodiments, the dried hydrothermally modified material is an alkaline earth metal ion releasing material (eg, a Ca ²⁺ ion releasing material and/or a Mg ²⁺ ion releasing material). In some embodiments, the dried hydrothermally modified material is an aluminum ion (eg, Al ³⁺ ) releasing material. In some embodiments, the implementation of the dried hydrothermally modified material releases Si, for example, in the form of a silicate salt.

In various embodiments, as described above, the raw mix contains one or more compounds from (a1) and one or more compounds from (a2). In some embodiments, the mixture contains a calcium-containing compound and a silicon-containing compound. In various embodiments of the present disclosure, the ratio of calcium-containing component (i.e., CaO, Ca(OH) ₂ , CaCO ₃ ) to silicon-containing material (i.e., alkaline aluminosilicates such as potassium aluminosilicates) can be used to change the mineralogical composition, leaching, buffering, as well as other properties of the dried hydrothermally modified material.

Without wishing to be bound by theory, it is believed that in some embodiments, an increase in the Ca/Si ratio in the feed activates the formation of products towards the formation of dicalcium silicate hydrate and/or an amorphous phase. In some embodiments, increasing the Ca/Si ratio in the feed had the parallel effect of decreasing the tobermorite phase. In some embodiments, the dicalcium silicate hydrate phase can be produced at higher levels than the tobermorite phase by increasing the Ca/Si ratio in the raw mix.

In various embodiments, the Ca/Si ratio is from about 0.025 to about about about about about about about about about about about

0.9. At 0.025, 0.125, 0.225, 0.325, 0.425, 0.525, 0.625, 0.725, in some embodiments approximately approximately approximately approximately approximately approximately approximately

0.05, 0.150, 0.250, 0.350, 0.450, 0.550, 0.650, 0.750

0.075, 0.175, 0.275, 0.375, 0.475, 0.575, 0.675, 0.775, approximately approximately approximately approximately approximately approximately approximately

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8, approximately 0.825, approximately 0.850, approximately 0.875, approximately 0.90, including all ranges between any of these values.

In some disclosures, the dried hydrothermally modified material contains about 15-65 wt% K-feldspar phase, about 0-5 wt% tobermorite phase, about 0-20 wt% hydrogarnet phase, about 5-30 wt% hydrate phase dicalcium silicate, approximately 15-35 wt.% amorphous phase. In some embodiments, the dried hydrothermally modified material contains about 15 wt% K-feldspar phase, about 18 wt% hydrogen garnet phase, about 30 wt% dicalcium silicate hydrate phase, and about 35 wt% amorphous phase.

In various embodiments, the hydrothermally modified or dried hydrothermally modified material of the present disclosure contains about 45-65 wt% K-feldspar phase, about 1-10 wt% tobermorite phase, about 1-10 wt% hydrogarnet phase, about 1- 10% by weight of the dicalcium silicate hydrate phase and about 20-40% by weight of the amorphous phase.

modified dried or the material contains hydrothermally modified

In material implementation hydrothermally some options

approximately 35 wt%, approximately 36 wt%, approximately 37 wt%, approximately 38 wt%, approximately 39 wt%, approximately 40 wt%, approximately 41 wt%, approximately 42 wt%, approximately 43 wt%, about 44 mas .%, approximately 45 wt.% phase K- feldspar, approximately 46 wt.%, approximately 47 wt%, approximately 48 wt%, approximately 49 wt%, approximately fifty wt%, approximately 51 wt%, approximately 52 wt%, approximately 53 wt%, approximately 54 wt%, approximately 55 wt%, approximately 56 wt%, approximately 57 wt%, approximately 58 wt%, approximately 59 wt%, approximately 60 wt%, approximately 61 wt%, approximately 62 wt%, approximately 63 wt%, approximately 64 wt%, approximately 65 wt%, approximately 66 wt%, approximately 67 wt%, approximately 68 wt%, approximately 69 wt%, approximately 70 wt%, approximately 71 wt%, approximately 72 wt%, approximately 73 wt%, approximately 74 mas :.%, approximately 75 wt.% of the modified phase of K-feldspar (those. changed-

compared to the K-feldspar phases present in the feed), including all ranges and values in between.

In other embodiments, the hydrothermally modified or dried hydrothermally modified material contains about 1 wt.%, about 2 wt.%, about 3 wt.%, about 4 wt.%, about 5 wt.%, about 6 wt.%, about 7 wt.%, approximately 8 wt.%, approximately 9 wt.%, approximately 10 wt.%, approximately approximately approximately wt.%, wt.%, wt.%, approximately approximately approximately wt.%, wt.%, wt. %, approximately approximately approximately wt.%, wt.%, wt.%, approximately 20 wt.% of the tobermorite phase, including all ranges between any of these values.

In various other embodiments, the hydrothermally modified or dried hydrothermally modified material comprises about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt.%, about 8 wt.%, about 9 wt.%, about

- 20 039758 wt.%, 11 wt.%, about 12 wt.%, about 13 wt.%, about wt.%, about 15 wt.%, about 16 wt.%, about 17 wt.%, about 18 wt. .%, approximately 19 wt.%, approximately 20 wt.% of the hydrogarnet phase, including all ranges between any of these values.

In some embodiments, the hydrothermally modified or dried hydrothermally modified material contains about 1 wt.%, about 2 wt.%, about 3 wt.%, about 4 wt.%, about 5 wt.%, about 6 wt.%, about 7 wt.%, approximately 8 wt.%, approximately 9 wt.%, approximately 10 wt.%, approximately 11 wt.%, approximately 12 wt.%, approximately 13 wt.%, approximately 14 wt.%, approximately 15 wt. %, approximately 16 wt.%, approximately 17 wt.%, approximately 18 wt.%, approximately 19 wt.%, approximately 20 wt.% of the dicalcium silicate hydrate phase, including all ranges between any of these values.

In some in other embodiments, hydrothermally modified bathroom or dried hydrothermally modified material contains approximately 10 wt%, approximately 12 wt.%, about 14 wt.%, about 16 wt%, approximately eighteen wt.%, about 20 wt.%, about 22 wt%, approximately 24 wt.%, about 26 wt.%, about 28 wt%, approximately thirty wt.%, approximately 32 wt.%, approximately 34 wt%, approximately 36 wt.%, approximately 38 wt.%, approximately 40 wt%, approximately 42 wt.%, approximately 44 wt.%, approximately 46 wt%, approximately 48 masses of these values. .%, approximately 50 wt.% of the amorphous phase, including all ranges between any

In some embodiments, the hydrothermally modified or dried hydrothermally modified material further comprises carbonaceous particles. In some embodiments, the hydrothermally modified or dried hydrothermally modified material contains about 0-20 weight percent carbonaceous particles. In some embodiments, the hydrothermally modified or dried hydrothermally modified material comprises about 0 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt.%, about 7 wt.%, about 8 wt.%, about 9 wt.%, about 10 wt.%, about 11 wt.%, about 12 wt.%, about 13 wt.%, about 14 wt. .%, about 15 wt.%, about 16 wt.%, about 17 wt.%, about 18 wt.%, about 19 wt.%, or about 20 wt.% carbonaceous particles, including all ranges and values between any of these values. The carbonaceous particles may include, for example, K ₂ CO ₃ , Na ₂ CO ₃ , MgCO ₃ and/or CaCO ₃ . In some embodiments, the hydrothermally modified or dried hydrothermally modified material further comprises potassium carbonates, calcium carbonates, sodium carbonates, and any combinations thereof. In various embodiments, the hydrothermally modified or dried hydrothermally modified material further comprises potassium carbonates, calcium carbonates, and combinations thereof. In some embodiments, combinations of potassium carbonates and calcium carbonates include buchiliite and/or fairchildite. Without wishing to be bound by theory, it is believed that carbonates can help control the pH properties of the material and can be used to capture atmospheric CO2. In various embodiments, the implementation of the carbonaceous particles are a phase of calcite. In some embodiments, the calcite phase is present in an amount of about 0 wt.% (e.g., present at most only a trace amount), about 1 wt.%, about 2 wt.%, about 3 wt.%, about 4 wt.% , approximately 5 wt.%, approximately 6 wt.%, approximately 7 wt.%, approximately 8 wt.%, approximately 9 wt.%, approximately 10 wt.%, approximately 11 wt.%, approximately 12 wt.%, approximately 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, about 20 wt%, including all ranges between any of these values. In some embodiments, the hydrothermally modified or dried hydrothermally modified material raises the pH of the aqueous solution to a range of about 10 to about 12. This feature of the hydrothermally modified or dried hydrothermally modified materials can improve soil conditions and/or reduce acidity levels that can be detrimental to agriculture. economy. Thus, hydrothermally modified or dried hydrothermally modified materials of the present disclosure may replace or reduce the need for lime or other pH modifying soil improvers.

Without wishing to be bound by theory, it is believed that the use of a gas containing CO ₂ in step (d) of drying can facilitate the decalcification reaction that occurs when the calcium silicate hydrate (CSH) phases are exposed to CO 2 . In some embodiments, decalcification that occurs in an atmosphere containing CO2 results in a calcite phase (ie, a stable polymorphic form of CaCO ₃ ) provided by calcium decalcification in the CSH phase. In some embodiments, the calcite phase is considered to be responsible for trapping potassium, resulting in a dried hydrothermally modified material that has a relatively slow or continuous release of potassium. In some embodiments, the modified release of potassium is slower than the release of potassium when compared to an otherwise identical material that has not been exposed to CO ₂ upon drying, and occurs over a longer period of time. In some embodiments, the implementation is considered that the decalcification of CSH leads to the production of silicon dioxide (SiO ₂ ). In some embodiments, the decalcification of the CSH phase is believed to be accompanied by decalcification of the hydrogarnet in the dried hydrothermally modified material, resulting in additional production of alumina (Al2O3).

The disclosed methods can be carried out as batch processes or in a continuous mode. In some embodiments, the alkali metal and/or alkaline earth metal (c2) silicate phase contains up to about 23% by weight of alkaline earth metal ions.

In some embodiments, the alkali metal and/or alkaline earth metal silicate phase comprises up to about up to up to up to up to up to about about about about about about wt.%, wt.%, wt.%, wt.%, wt.%, wt. .%, up to up to up to up to wt.%, up to about 2 wt.%, up to about 3 wt.%, approximately approximately approximately approximately approximately approximately wt.%, wt.%, wt.%, wt.%, wt. .%, wt.%, up to up to up to up to approximately approximately approximately approximately approximately approximately wt.%, wt.%, wt.%, wt.%, wt.%, wt.%, approximately 22 wt.%, up to approximately 23% alkaline earth metal ions, including all ranges between any of these values.

In some embodiments, the alkali metal and/or alkaline earth metal (c2) silicate phase contains, on average, about 1 wt.%, about 2 wt.%, about 3 wt.%, about 4 wt.%, about 5 wt.% alkaline earth ions. metal, including all ranges of values in between. In some embodiments, the alkali metal and/or alkaline earth metal (c2) silicate phase contains, on average, about 3% by weight of alkaline earth metal ions.

Many of the materials disclosed herein have been characterized by X-ray powder diffractometry (XRPD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), particle size distribution (PSD), specific surface area (according to the BET method ; BET-SSA), and batch leaching tests (as well as other techniques known to the skilled person) do indeed have the aforementioned desired properties. Understanding the mineralogical composition of the materials of the present invention was obtained from the results of XRPD (eg, Fig. 4E) and imaging (eg, Fig. 14 and 15), so that the mineral phases that make up the hydrothermally modified or dried hydrothermally modified material can be identified and quantified, as well as the degree of inclusion of elements in them relative to stoichiometric chemical formulas. It has been observed that the feldspar lattice, as a typical alkali metal silicate starting material, undergoes structural and chemical changes, a phenomenon referred to herein as change or change.

From characterization, the material was found to exhibit complex mineralogical composition and chemical properties. In some embodiments, the particle size distribution spans particle diameters from ~0.1 to ~100 microns. In other embodiments, the constituent mineral phases are altered K-feldspar, hydrogarnet, α-dicalcium silicate hydrate, 11A tobermorite, and amorphous calcium aluminosilicate hydrate compounds. In some embodiments, the implementation of the phase containing the nuclei of crystallization in situ, have a non-stoichiometric content of Ca, Al and Si; with the exception of hydrogarnet, a high degree of inclusion of K is observed in all mineral structures. In some embodiments, traces of carbonaceous particles with varying levels of K and Ca are also constituents of the material. In various embodiments, the modified K-feldspar is replaced with Ca. In some embodiments, upon leaching, the availability of K, Si, Al, and Ca in the dried hydrothermally modified material is increased relative to the original ultrapotassium syenite feedstock, where the amount of potassium released from the dried hydrothermally modified material after 24 hours has been shown to be two orders of magnitude greater, than in the corresponding raw material ultrapotassium syenite.

In some embodiments of the present disclosure, the hydrothermally modified or dried hydrothermally modified material provided by the methods described herein comprises a multimodal particle size distribution comprising particles in the diameter range of approximately 5-1000 microns. In yet another embodiment of the present disclosure, the hydrothermally modified or dried hydrothermally modified material of the present disclosure contains aggregated particles in the size range of approximately 100-1000 microns. In some embodiments, the specific surface area according to the BET method (BET-SSA) was 15.1 m ² /g for the dried hydrothermally modified material and 46.9 m ² /g for the raw mix.

In various embodiments, the disclosed hydrothermally modified or dried hydrothermally modified materials have an average particle size in the range of about 0.5 to about 250 microns. In some embodiments, the average particle size is about 0.5 µm, about 1 µm, about 1.5 µm, about 2 µm, about 2.5 µm, about 3 µm, about 3.5 µm, about 4 µm, about 4 .5 microns, approximately 5 microns, approximately 5.5 microns, approximately 6 microns, approximately 6.5 microns, approximately 7 microns, approximately 7.5 microns, approximately 8 microns, approximately 8.5 microns, approximately 9 microns, approximately 9 .5 µm, approx. 10 µm, approx. 20 µm, approx. 30 µm, approx. 40 µm, approx. 50 µm, approx. 60 µm, approx. 70 µm, approx. µm, approx. 130 µm, approx. 140 µm, approx. 150 µm, approx. 160 µm, approx. 170 µm, approx. 180 µm, approx. , approximately 220 µm, approximately 230 µm, approximately 240 µm, approximately 250 µm, approximately 260 µm, approximately 270 µm, approximately 280 µm, approximately 290 µm, approximately 330 µm, including all ranges between any of these values.

It is recognized herein that complex mineralogical composition, in addition to other recently understood features, can be used to control the leaching abilities of dried hydrothermally modified material. In particular, leaching experiments (eg, Fig. 24, 9B) were used to evaluate the chemical stability of mineral phases in contact with water. Chemical stability in this area is understood in relation to the ability to release nutrients to the plant and must be consistent with the agronomic context. With this understanding, dried hydrothermally modified materials can be designed and produced to meet an even wider variety of soil needs, also with applications available in other industries.

As described in detail in this disclosure and in the following examples, a prominent feature of the dried hydrothermally modified material is the availability of potassium (K+), as confirmed by leaching tests (see FIG. 24 for a typical example).

Without wishing to be bound by any theory, the evidence presented herein shows that the mechanism for this increased availability of K is Ca-mediated hydrothermal alteration of K-feldspar, i.e. hydrolytic dissolution of the K-feldspar lattice together with the inclusion of Ca ²⁺ instead of K ⁺ . In some embodiments, the hydrothermally modified or dried hydrothermally modified material releases metal ions, such as, for example, K ⁺ .

As used herein, the 24 hour potassium release test is performed as follows. The amount of material is exposed to a 10-fold excess of 10 ^-5 M HNO3 for 24 hours. The amount of potassium ion released from the material over a period of 24 hours represents the release of potassium from the material according to the potassium release test after 24 hours. potassium according to the potassium release test after 24 hours, the amount of material tested for each of the different materials is the same.

In some embodiments, according to the potassium release test after 24 h, the amount of K ⁺ released from the dried hydrothermally modified material is at least 2 times greater than the amount of K ⁺ _; released from one or more alkali metal silicate starting materials from (a2). In various embodiments, according to the potassium release test after 24 hours, the amount of K ⁺ released from the dried hydrothermally modified material, relative to the amount of K ⁺ released from one or more alkali metal silicate starting materials from (a2), was 2 times more , 3 times more, 4 times more, 5 times more, 6 times more, 7 times more, 8 times more, 9 times more, 10 times more, 15 times more, 20 times more, in 25 times more 30 times more 35 times more 40 times more 45 times more 50 times more 55 times more 60 times more 65 times more 70 times more 75 times more 80 times more 85 times more 90 times more 95 times more 100 times more 150 times more 200 times more 250 times more 300 times more 350 times greater, 400 times greater, 450 times greater, or 500 times greater, including everything in between.

In some embodiments, the amount of K ⁺ released from the dried hydrothermally modified material in a 24 hour potassium release test is in the range of about 5 to about 25 g K ⁺ /kg of dried hydrothermally modified material. In some embodiments, the amount of K ⁺ released according to the potassium release test after 24 hours is approximately 5 g K ⁺ /kg dried hydrothermally modified material, approximately 6 g K ⁺ /kg dried hydrothermally modified material, approximately 7 g K ⁺ /kg dried hydrothermally modified material, approximately 8 g K ⁺ /kg dried hydrothermally modified

material, approximately nine G K ⁺ /kg dried hydrothermally modified material, approximately ten G K ⁺ /kg dried hydrothermally modified material, approximately eleven G K ⁺ /kg dried hydrothermally modified material, approximately 12 G K ⁺ /kg dried hydrothermally modified material, approximately thirteen G K ⁺ /kg dried hydrothermally modified material, approximately fourteen G K ⁺ /kg dried hydrothermally modified material, approximately fifteen G K ⁺ /kg dried hydrothermally modified material, approximately fourteen G K ⁺ /kg dried hydrothermally modified material, approximately sixteen G K ⁺ /kg dried hydrothermally modified material, approximately fourteen G K ⁺ /kg dried hydrothermally modified material, approximately 17 G K ⁺ /kg dried hydrothermally modified material, approximately eighteen G K ⁺ /kg dried hydrothermally modified material, approximately nineteen G K ⁺ /kg dried hydrothermally modified material, approximately 20 G K ⁺ /kg dried hydrothermally modified material, approximately 21 G K ⁺ /kg dried hydrothermally modified material, approximately 22 G K ⁺ /kg dried hydrothermally modified material, approximately 23 G K ⁺ /kg dried hydrothermally modified material, approximately 24 G K ⁺ /kg dried hydrothermally modified material or approximately 25 g K ⁺ /kg dried hydrothermally modified

material, including all values and ranges in between.

In some embodiments, the release of K from the dried hydrothermally modified material is enhanced by using a CsNO ₃ /HNO ₃ solution of pH 5. In various embodiments, the release of K from the dried hydrothermally modified material after 24 hours exposure to a 10-fold excess of 10 ^-5 M CsNO ₃ /HNO ₃ about 1.1 times - about 2 times more than the release of K from the same material in the HNO 3 leach solution at pH 5. In some embodiments, the leaching is about 1.1 times greater, about 1.2 about 1.3 times more, about 1.4 times more, about 1.5 times more, about 1.6 times more, about 1.7 times more, about 1.8 times more , approximately 1.9 times larger, approximately 2 times larger, including all ranges and values in between. Without being limited by any particular theory, it is believed that the components of the solid contribute to the absorption of Cs ⁺ and the release of K ⁺ .

As used herein, the 1 minute potassium release test is performed as follows. The amount of material is subjected to a 10-fold excess of 10 ^-5 M HNO ₃ for 1 min. The amount of potassium ion released from the material over a period of 1 minute represents the release of potassium from the material according to the potassium release test after 1 minute. In some embodiments, according to the potassium release test, after 1 minute, the dried hydrothermally modified material releases at least 5000 mg (e.g., at least 6000 mg, at least 7000 mg, at least 8000 mg, at least 9000 mg, at least 10,000 mg, at least 11,000 mg) of potassium per 1 kg of dried hydrothermally modified material.

In some embodiments, a relatively large amount of potassium is initially released from the dried hydrothermally modified material, followed by a relatively small amount of potassium released over an extended period of time. This can be quantified, for example, by measuring the relative release of potassium, which is defined as X/Y, where X is the amount of potassium released by the material according to the potassium release test after 1 min, and Y is the amount of potassium released by the material according to the potassium release test after 24 hours, which is less than the amount of potassium released by the material according to the potassium release test after 1 minute. In some embodiments, the dried hydrothermally modified material has a relative potassium release of about 5 to about 20 (eg, about 7 to about 15, about 9 to about 12). In some embodiments, the dried hydrothermally modified material has a relative potassium release of at least about 5 (e.g., at least about 6, at least about 7, at least about 8, at least about 9, at least

- 24 039758 at least about 10, at least about 11, at least about 12, at least about 13) and/or at most about 20 (e.g., at most about 19, at most about 18, at most about 17, at most about 16, at most about 15, at most about 14).

In some embodiments, the dried hydrothermally modified material is capable of releasing elements other than K. In various embodiments, additional elements that may be released from the material include Al, Si, Ca, Na, and Mg (e.g., as soluble salts that may contain indicated elements in ionic form).

As used herein, the 24 hour calcium release test is performed as follows. The amount of material is exposed to a 10-fold excess of 10 ^-5 M HNO3 for 24 hours. The amount of calcium ion released from the material over a period of 24 hours represents the release of calcium from the material according to the calcium release test after 24 hours. calcium according to the calcium release test after 24 hours, the amount of material tested for each of the different materials is the same.

In some embodiments of the present disclosure, according to the 24 hour calcium release test, the amount of Ca ²⁺ released from the hydrothermally modified or dried hydrothermally modified material ranges from about

0.01 to about 0.35 g Ca ²⁺ /kg dried hydrothermally modified material. In some embodiments, the amount of Ca ²⁺ released according to the 24 hour calcium release test is approximately 0.01 modified modified modified modified modified modified modified modified modified modified modified modified modified material, approximately 0.025 g of material, approximately 0.05 g material, approximately 0.075 g material, approximately 0.1 g material, approximately 0.125 g material, approximately 0.15 g material, approximately 0.175 g material, approximately 0.2 g material, approximately 0.225 g material, approximately 0.25 g material , approximately 0.275 g of material, approximately 0.3 g of material, approximately 0.325 g of material, approximately 0.35 g g Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ^{2 +} /kg dried Ca ²⁺ /kg dry dry Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried Ca ²⁺ /kg dried modified material, including all values and ranges in between.

hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally

As used herein, the 24 hour aluminum release test is performed as follows. The amount of material is exposed to a 10-fold excess of 10 ^-5 M HNO3 for 24 hours. The amount of aluminum ion released from the material over a period of 24 hours represents the release of aluminum from the material according to the aluminum release test after 24 hours. aluminum according to the aluminum release test after 24 hours, the amount of material tested for each of the different materials is the same.

In some embodiments of the present disclosure, according to the 24 hour aluminum release test, the amount of Al ³⁺ released from the hydrothermally modified or dried hydrothermally modified material is in the range of about 0.02 to about 0.35 g Al ³⁺ /kg hydrothermally dried modified material. In some embodiments, the amount of Al ³⁺ released according to the aluminum release test after 24 hours was approximately 0.02 g Al ³⁺ /kg dried modified modified modified modified modified modified modified modified modified modified modified modified modified material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately material, approximately

0.05 0.075 0.1

0.125 0.15 0.175 0.2

0.225 0.25 0.275 0.3

0.325 0.35 g

g g

g g

g g

g g

g g

g g

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

А1 ³⁺ /kg

A1 ³⁺ /kg dried dried dried dried dried dried dried dried dried dried dried modified material, including all values and ranges therebetween.

hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally

- 25 039758

As used herein, the 24 hour silicon release test is performed as follows. The amount of material is exposed to a 10-fold excess of 10 ^-5 M HNO3 for 24 hours. The amount of silicon released from the material over a period of 24 hours represents the release of silicon (for example, in the form of soluble silicates, including orthosilicic acid and its oligomeric or polymeric form) from the material according to the silicon release test after 24 hours. When comparing the amount of silicon release according to the silicon release test after 24 hours, the amount of material tested for each of the different materials is the same.

In some embodiments, according to the 24 hour silicon release test, the amount of silicon released from the hydrothermally modified or dried hydrothermally modified material is in the range of about 0.1 to about 1.5 g silicon/kg dried hydrothermally modified material. In some embodiments, the amount of silicon released according to the 24 hour silicon release test was approximately 0.1 g silicon/kg dried hydrothermally modified material, approximately 0.2 g silicon/kg dried hydrothermally modified material, approximately 0.3 g silicon/kg dried hydrothermally modified material, approximately 0.4 g silicon/kg dried hydrothermally modified material, approximately 0.5 g silicon/kg dried hydrothermally modified material, approximately 0.6 g silicon/kg dried hydrothermally modified material, approximately 0, 7 g silicon/kg dried hydrothermally modified material, approximately 0.8 g silicon/kg dried hydrothermally modified material, approximately 0.9 g silicon/kg dried hydrothermally modified material, approximately 1 g silicon/kg dried hydrothermally modified material 1.1 g silicon/kg dried hydrothermally modified material, approximately 1.2 g silicon/kg dried hydrothermally modified material, approximately 1.3 g silicon/kg dried hydrothermally modified material, approximately 1.4 g silicon/kg dried hydrothermally modified material, approximately 1.5 g silicon/kg dried hydrothermally modified material, including all values and ranges in between.

As used herein, the 24 hour sodium release test is performed as follows. The amount of hydrothermally modified material or dried hydrothermally modified material is subjected to a 10-fold excess of 10 ^-5 M HNO3 for 24 hours. 24 hours When comparing the sodium release value according to the sodium release test after 24 hours, the amount of material tested for each of the different materials is the same.

In yet another embodiment of the present disclosure, according to the sodium release test after 24 hours, the amount of Na ⁺ released from the hydrothermally modified or dried hydrothermally modified material is in the range of from about 0.01 to about 0.1 g Na ⁺ /kg of dried hydrothermally modified material. In yet another embodiment, the amount of Na ⁺ released according to the sodium release test after one hour was approximately 0.01 material, material, material, material, material, material, approximately approximately approximately approximately approximately approximately material, approximately material, approximately material, approximately material , approximately

0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05

0.055

0.06 g Na ⁺ /kg hydrothermally dried

Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg

Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg dried dried dried dried dried dried dried dried dried approximately approximately approximately approximately approximately approximately

0.065 0.07 0.075 0.08 0.085 0.09 0.095

Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg Na ⁺ /kg

Na ⁺ /kg releasing ion hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally modified modified modified modified modified modified modified modified alkali metal dried dried dried dried dried dried dried dried hydrothermally hydrothermally hydrothermally hydrothermally modified modified hydrothermally modified approximately modified hydrothermally modified approximately .1 g Na ⁺ /kg dried hydrothermally modified material, material, material, material, material, material, material, material, material, including all values and ranges in between.

As used herein, the magnesium release test after 24 hours is performed

- 26 039758 as follows. The amount of hydrothermally modified material or dried hydrothermally modified material is subjected to a 10-fold excess of 10 ^-5 M

HNO ₃ over 24 hours. The amount of magnesium ion released from the material over a period of 24 hours represents the release of magnesium from the material according to the magnesium release test after 24 hours.

When comparing the magnitude of magnesium release according to the magnesium release test after 24 hours, the amount of material tested for each of the different materials is the same.

In some embodiments of the present disclosure, according to the magnesium release test after 24 hours, the amount of magnesium released from the hydrothermally modified or dried hydrothermally modified material is in the range of from about 0.01 to about 0.1 g Mg ²⁺ /kg of dried hydrothermally modified material . In some embodiments, the amount of Mg ²⁺ released according to the magnesium release test through the modified modified modified modified modified modified modified modified modified h was approximately 0.01 g Mg ²⁺ /kg dried material, approximately 0.015 g Mg ²⁺ /kg dried material, approximately 0.02 g Mg ²⁺ /kg dried material, approximately 0.025 g Mg ²⁺ /kg dried material, approximately 0.03 g Mg ²⁺ /kg dried material, approximately 0.035 g Mg ²⁺ /kg dried material approx. 0.04 g Mg ²⁺ /kg dried material, approx. 0.045 g Mg ²⁺ /kg dried material, approx. 0.05 g Mg ²⁺ /kg dried material, approx ^. approx. 0.06 g Mg ²⁺ /kg releasing hydrothermally hydrothermally hydrothermally hydrothermally hydrothermally hydrot thermally hydrothermally hydrothermally hydrothermally hydrothermally alkali metal ion material, approximately 0.065 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.07 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.075 g Mg ²⁺ /kg dried hydrothermally modified material , approximately 0.08 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.085 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.09 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.095 g Mg ²⁺ /kg dried hydrothermally modified material, approximately 0.1 g Mg ²⁺ /kg dried hydrothermally modified material, including all values and ranges in between.

Based on the foregoing, and without being bound by any theory, the mineralogical composition of the hydrothermally modified or dried hydrothermally modified material is believed to be suitable for tropical soils. In various embodiments, modified K-feldspar as described herein is a potential reservoir of nutrients and positively contributes to soil mechanics. It is believed that hydrogarnet effectively stabilizes Al, while α-dicalcium silicate hydrate, 11 A tobermorite, and amorphous calcium silicate hydrate are a source of K, Si, Ca, and alkalinity. At higher alkalinity, substitution of lime treatment may be available. Tobermorite can act as an ion exchanger, especially if isomorphic inclusions occur, such as those confirmed in this test (Table 1; ESI-EPMA). In addition, Al-substituted tobermorites may show higher selectivity for Cs and probably other heavy metals, which may be particularly useful for remediation of contaminated soils. The charge of such mineral phases is considered as an additional benefit for soils. At low pH, soil colloids are positively charged, holding anions such as nitrate and phosphate, while at higher pH, negative charges hold cations. The bulk of the mineral phases of the dried hydrothermally modified material is expected to have a negative surface charge, except in the case of very low pH. The feldspar itself has a negative surface charge above pH ~2. Although this value is affected by the ionic strength of the soil solution, the altered feldspar fraction alone can help limit the loss of immediately available K ⁺ , contributing also to the active sequestration of Al ³⁺ and Fe ^2+/3+ .

In some embodiments, the dried hydrothermally modified material described herein has the ability to release the first portion of element(s) (e.g., K, Ca, Mg, Na, Al, and/or Si) relatively quickly (e.g., readily soluble in water and dissolves within minutes or hours upon contact with water), while one or more additional portions are released in a relatively slow and/or continuous manner over a long period of time (for example, is in a less soluble form and is released more slowly over a period of days, weeks or months). Thus, in some embodiments, the dried hydrothermally modified materials disclosed herein have the desired property of having both relatively fast-release K and relatively slow-release K, as discussed above.

In some embodiments, dried hydrothermally modified materials having primarily relatively slow release K can be obtained by washing the dried material with inert gas purged water. This treatment is believed to remove soluble K, leaving potassium to be released in a slow and continuous manner. In some embodiments, the washed materials release from about 1% to about 20% of the potassium available in the unwashed material. In some embodiments, the washed materials release about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11% , approximately 12%, approximately 13%, approximately 14%, approximately 15%, approximately 16%, approximately 17%, approximately 18%, approximately 19%, approximately 20% of potassium available in unwashed material, including all values and ranges in between .

In some embodiments, the dried hydrothermally modified material is considered to have an instantaneous carbonaceous or hydroxide component (eg, potassium hydroxide) that can, for example, provide crops with a direct, chlorine-free source of K. However, it is believed that in some embodiments, the relatively small, relatively sustained release portion of K released from the dried hydrothermally modified material is redistributed between multiple phases, and thus is likely to be available at a slower rate.

In various embodiments, the dried hydrothermally modified material is a fertilizer. In some embodiments, the implementation of the fertilizer is a K ⁺ -fertilizer. In some embodiments, the implementation of the fertilizer is a Ca ²⁺ -fertilizer. In some embodiments, the implementation of the fertilizer is a Na ⁺ -fertilizer. In some embodiments, the fertilizer is a Mg ²⁺ fertilizer. In some embodiments, the implementation of the fertilizer is a silicon fertilizer. In some embodiments, the fertilizer is a multi-nutrient fertilizer (eg, by releasing one or more of the particles identified in this paragraph).

It has also been shown in various embodiments of the present disclosure that the releasable cationic element can be replaced in one or more steps, such as drying in step (d) or step (c). These ion exchange characteristics may be useful in tailoring the metal ion releasing material to a particular application, including but not limited to soil remediation (Cs ⁺ or Cd ²⁺ ) and slow release N fertilizers (NH4+). In some embodiments, dried hydrothermally modified materials that are slow release fertilizers can respond to plant signals (eg, exudates) that result in the release of specific nutrients through mineral metabolism. In various embodiments, the beneficial and unexpected modest release of metal ions is due in part to the above ion exchange properties of the dried hydrothermally modified material.

The controlled nature of the process described herein allows for the formation of any number of separate compositions with different ranges of mineralogical phases described in the disclosure, through modification of the reaction, processing and drying conditions.

In various embodiments, the hydrothermally modified or dried hydrothermally modified materials comprise: modified potassium aluminosilicate (e.g., potassium aluminosilicate in which at least about 5%, about 10%, about 15%, about 20%, about 25%, or about 30% potassium originally present in the raw material aluminosilicate lattice is replaced by another cation such as Ca ²⁺ ); calcium aluminum silicate and calcium silicate hydrate; moreover, the amount of available potassium in the hydrothermally modified or dried hydrothermally modified material is at least about 10 wt.% of the total potassium content in the material, and available potassium represents the amount of potassium dissolved when the material is subjected to leaching conditions, including stirring 1 wt.h. powdered material in 10 wt.h. HNO ₃ with an initial pH of 5 for 24 hours. In some embodiments, the amount of available potassium is

makes at least about 1 wt.%, at least about 2 wt%, on lesser measure approximately 3 wt%, on lesser measure approximately 4 wt%, on lesser measure approximately 5 wt%, on lesser measure approximately 6 wt%, on lesser measure approximately 7 wt%, on lesser measure approximately eight wt%, on lesser measure approximately nine wt%, on lesser measure approximately ten wt%, on lesser measure approximately eleven wt%, on lesser measure approximately 12 wt%, on lesser measure approximately thirteen wt%, on lesser measure approximately fourteen wt%, on lesser measure approximately fifteen wt%, on lesser measure approximately sixteen wt%, on lesser measure approximately 17 wt%, on lesser measure approximately eighteen wt%, on at least about 19 wt.% or by at least about 20 wt.% Total content-

- 28 039758 potassium content in the material. In some embodiments, the hydrothermally modified or dried hydrothermally modified material comprises an ultrapotassium syenite in which at least about 1-10% by weight of potassium in the lattice has been replaced by calcium. In some embodiments, the hydrothermally modified or dried hydrothermally modified material contains ultrapotassium syenite with at least about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, approximately 9% or approximately 10%, including all ranges and values in between.

In some embodiments, dried hydrothermally modified materials are provided that contain about 45-65 wt.% modified potassium feldspar phase, about 1-10 wt.% tobermorite phase, about 1-10 wt.% hydrogarnet phase, about 1-10 wt. .% of the dicalcium silicate hydrate phase and approximately 20-40 wt.% of the amorphous phase. In some embodiments, the dried hydrothermally modified

material contains approximately 45 wt% phase K-field spar, approximately 46 wt%, approximately 47 wt%, approximately 48 wt%, approximately 49 wt%, approximately fifty wt%, approximately 51 wt%, approximately 52 wt%, approximately 53 wt%, approximately 54 wt%, approximately 55 wt%, approximately 56 wt%, approximately 57 wt%, approximately 58 wt%, approximately 59 wt%, approximately 60 wt%, approximately 61 wt%, approximately 62 wt%, approximately 63 wt%,

about 64 wt.%, about 65 wt.%, including all ranges and values in between. In other embodiments, the dried hydrothermally modified material contains about 1 wt.% tobermorite phase, about 2 wt.%, about 3 wt.%, about 4 wt.%, about 5 wt.%, about 6 wt.%, about 7 wt. .%, approximately 8 wt.%, approximately 9 wt.%, approximately 10 wt.%, including all ranges and values in between. In some embodiments, the dried hydrothermally modified material contains about 1 wt% of a hydrogen garnet phase, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%. .%, approximately 8 wt.%, approximately 9 wt.%, approximately 10 wt.%, including all ranges and values in between. In some embodiments, the dried hydrothermally modified material contains about 1 wt% dicalcium silicate hydrate phase, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%. , about 7 wt.%, about 8 wt.%, about 9 wt.%, about 10 wt.%, including all ranges and values in between. In some other embodiments, the dried hydrothermally modified material contains about 20 wt% amorphous phase, about 22 wt%, about 24 wt%, about 26 wt%, about 28 wt%, about 30 wt%, about 32 wt.%, approximately 34 wt.%, approximately 36 wt.%, approximately 38 wt.%, approximately 40 wt.%, including all ranges and values in between.

In some embodiments, the hydrothermally modified or dried hydrothermally modified materials disclosed herein further comprise one or more carbonates, such as K ₂ CO ₃ , Na ₂ CO ₃ , MgCO ₃ , CaCO ₃ , and combinations thereof. In some embodiments, the hydrothermally modified or dried hydrothermally modified materials further comprise potassium carbonates, calcium carbonates, sodium carbonates, and any combinations thereof. In some embodiments, the hydrothermally modified or dried hydrothermally modified materials further comprise potassium carbonates, calcium carbonates, and combinations thereof. In some embodiments, combinations of potassium carbonates and calcium carbonates include buchiliite and/or fairchildite.

In some embodiments, hydrothermally modified or dried hydrothermally modified materials are provided, wherein one or more of the following elements are dissolved when the materials are subjected to the specified leaching conditions: at least about 1000 ppm Si; at least about 200 ppm Al; at least about 200 ppm Ca, about 5 ppm Na, and at least about 5 ppm Mg. In some embodiments, at least about 50 ppm Si, at least about 100 ppm Si, at least about 150 ppm Si, at least about 200 ppm Si, at least at least about 250 ppm Si, at least about 300 ppm Si, at least about 350 ppm Si, at least about 400 ppm Si, at least about 450 ppm Si, at least about 500 ppm Si, at least about 550 ppm Si, at least about 600 ppm Si, at least about 650 ppm Si, at least about 700 hours/ ppm Si, at least about 750 ppm Si,

- 29 039758 at least about 800 ppm Si, at least about 850 ppm Si, at least about 900 ppm Si, at least about 950 ppm Si, at least about 1000 ppm Si, at least about 1050 ppm Si, at least about 1100 ppm Si, at least about 1150 ppm Si, at least about 1200 ppm Si at least about 1250 ppm Si at least about 1300 ppm Si at least about 1350 ppm Si at least about 1400 ppm Si at least about 1450 ppm Si, at least about 1500 ppm Si, at least about 1550 ppm Si, including everything in between, dissolve when the materials are subjected to the specified conditions.

In various embodiments, at least about 10 ppm Al, at least about 20 ppm Al, at least about 30 ppm Al, at least about 40 ppm Al, at least about 50 ppm Al, at least about 60 ppm Al, at least about 70 ppm Al, at least about 80 ppm Al, at least about 90 ppm Al, at least about 100 ppm Al, at least about 110 ppm Al, at least about 120 ppm Al, at least about 130 ppm Al, at least about 140 ppm Al, at least about 150 ppm Al, at least about 160 ppm Al, at least about 170 ppm Al, at least about 180 ppm Al, at least about 190 hours ./million Al, at least about 200 ppm Al, at least about 210 ppm Al, at least n about 220 ppm Al, at least about 230 ppm Al, at least about 240 ppm Al, at least about 250 ppm Al, at least about 260 ppm Al, at least about 270 ppm Al, at least about 280 ppm Al, at least about 290 ppm Al, or at least about 300 ppm Al, including everything in between, dissolve when the materials of the composition are subjected to the specified conditions.

In some embodiments, at least about 10 ppm Ca, at least about 20 ppm Ca, at least about 30 ppm Ca, at least about 40 ppm Ca, at least at least about 50 ppm Ca, at least about 60 ppm Ca, at least about 70 ppm Ca, at least about 80 ppm Ca, at least about 90 ppm ppm Ca, at least about 100 ppm Ca, at least about 110 ppm Ca, at least about 120 ppm Ca, at least about 130 ppm Ca, at least about 140 h ./ppm Ca, at least about 150 ppm Ca, at least about 160 ppm Ca, at least about 170 ppm Ca, at least about 180 ppm Ca, at least about 190 ppm Ca, at least about 200 ppm Ca, at least about 210 ppm Ca, at least e about 220 ppm Ca, at least about 230 ppm Ca, at least about 240 ppm Ca, at least about 250 ppm Ca, at least about 260 ppm Ca , at least about 270 ppm Ca, at least about 280 ppm Ca, at least about 290 ppm Ca, at least about 300 ppm Ca, at least about 310 ppm /million Ca, at least about 320 ppm Ca, at least about 330 ppm Ca, at least about 340 ppm Ca, at least about 350 ppm Ca, at least about 360 ppm Ca, at least about 370 ppm Ca, at least about 380 ppm Ca, at least about 390 ppm Ca, or at least about 400 ppm Ca, including all values in between, dissolve when the materials are subjected to the specified conditions.

In some embodiments, at least about 0.25 ppm Mg, at least about 0.5 ppm Mg, at least about 0.75 ppm Mg, at least about 1 ppm ppm Mg, at least about 1.25 ppm Mg, at least about 1.5 ppm Mg, at least about 1.75 ppm Mg, at least about 2 ppm Mg , at least about 2.25 ppm Mg, at least about 2.50 ppm Mg, at least about 2.75 ppm Mg, at least about 3 ppm Mg, at least about 3.25 ppm Mg, at least about 3.5 ppm Mg, at least about 3.75 ppm Mg, at least about 4 ppm Mg, at least about 4.25 ppm Mg, at least about 4.50 ppm Mg, at least about 4.75 ppm Mg, at least about 5 ppm Mg, at least about 5 .25 ppmMg, by me at least about 5.50 ppm Mg, at least about 5.75 ppm Mg, at least about 6 ppm Mg, at least about 6.75 ppm Mg, at least about 7 ppm Mg, at least about 7.25 ppm Mg,

- 30 039758 at least about 7.5 ppm Mg, at least about 7.75 ppm Mg, or at least about 8 ppm Mg, including everything in between, dissolve when the materials subject to the specified conditions.

In some other embodiments, at least about 0.25 ppm Na, at least about 0.5 ppm Na, at least about 0.75 ppm Na, at least about 1 hour ./million Na, at least about 1.25 ppm Na, at least about 1.5 ppm Na, at least about 1.75 ppm Na, at least about 2 hours ./million Na, at least about 2.25 ppm Na, at least about 2.50 ppm Na, at least about 2.75 ppm Na, at least about 3 hours ./million Na, at least about 3.25 ppm Na, at least about 3.5 ppm Na, at least about 3.75 ppm Na, at least about 4 hours ./million Na, at least about 4.25 ppm Na, at least about 4.50 ppm Na, at least about 4.75 ppm Na, at least about 5 hours ./million Na, at least about 5.25 ppm Na, at least about 5.50 ppm Na, at least about 5.75 ppm Na, at least about 6 ppm Na, at least about 6.75 ppm Na, at least about 7 ppm Na, at least about 7.25 ppm Na, at least about 7.5 ppm Na, at least about 7.75 hours/million Na or at least about 8 hours/million Na, including all values between them, dissolve when the materials are subjected to the specified conditions.

In various embodiments, hydrothermally modified or dried hydrothermally modified materials may be useful as (tropical) fertilizers for reasons that include, but are not limited to i) continuous release of potassium to meet the needs of crops at various stages of growth, and preventing both sudden saturation of the soil , and excess leaching; ii) a strong aftereffect (eg by providing a supply of available potassium) that improves plant nutrition over many agronomic cycles; iii) the ability to buffer soil pH at optimal levels for a given crop and microbiome; iv) synergistic delivery of micronutrients (eg magnesium); vi) maintaining and improving the mechanical strength and porosity of the soil; vii) improved cation exchange capacity (CEC); viii) low salinity; ix) increasing water holding capacity (WHC) and carbon sequestration; x) relatively low cost; xi) minimal barriers to adoption by farmers; and/or xii) a sustainable way of production implemented at an industrial level and with local resources.

In various embodiments, hydrothermally modified or dried hydrothermally modified materials may be of value in improving soil porosity. In oxide soil, both macropores (>75 µm; cannot hold water that is lost due to gravity) and micropores (5-30 µm; hold water too much due to capillary forces) exist, but no intermediate mesopores ( 30-75 µm) which are those capable of retaining water for sustained release. Thus, the water holding capacity is too low. In some embodiments, the volume occupied by the mineral particles is in a suitable range for increasing the number of mesopores and reducing seepage rates (eg, FIG. 18). It will also reduce (eg prevent) the dispersion of soil colloids and other fertilizers. In some embodiments, cured pastes of fine hydrogen garnet and calcium silicate hydrates, such as constituents of dried hydrothermally modified material, have been shown to have a good flexural strength of 20 MPa. This characteristic will reduce erosion and induce soil strength without resulting in too large micro-aggregates (>1 mm) that would give undesirable seepage rates. It is unlikely that any potassium salt (KCl or K ₂ SO ₄ ) would be expected to offer a similar improvement in soil mechanics.

While the characteristics of dried hydrothermally modified material may make it a high quality fertilizer for tropical soils, the ability to adjust properties by modifying various processing parameters facilitates new materials to be used additionally or alternatively in soil remediation, soluble glass applications, geopolymer applications, cement applications and applications. colloidal silicon dioxide. Without wishing to be bound by any particular theory, the utility of these new materials can be better understood by any number of separate mineralogical compositions possibly generated by the reaction pathways of FIG. 38. In some embodiments, processing parameters may be adjusted according to the paths shown by the alternative methods shown in FIG. 33G and 33H. For example, from the method covered by FIG. 33H, a variety of differentiated products can be obtained by passing an alkaline solution through a fixed mineral layer (eg, K-feldspar) and further processing the resulting dissolution products in separate streams of different composition.

- 31 039758

The analysis of the dried hydrothermally modified material that follows provides new insights into the process described herein, filling gaps in knowledge of materials science, manufacturing technology, and their applications in agriculture. In general, the general discussion is structured around the overarching goal of developing an environmentally friendly chemical process, scalable to industrial scale, that can actually benefit nutrient-poor and marginal soils. It has surprisingly been recognized that the composition (ie mineralogical composition) and leaching properties of the dried hydrothermally modified material disclosed herein can be controlled by varying the processing conditions. The following examples offer support for this idea while emphasizing that the hydrothermally modified or dried hydrothermally modified materials disclosed herein can be tailored for a number of important applications.

Examples

A block diagram of the general processing route used to produce dried hydrothermally modified materials is shown in FIG. 3. In the examples below, except where noted, the dried hydrothermally modified materials were treated at 200°C and dried under special conditions at 90°C.

Included in the overall process flow is an additional post-treatment block after the hydrothermal treatment (heating in the presence of water) block, but before or simultaneously with drying, and three additional components that include 1) soluble alkaline solutions; 2) additives or salt solutions; and 3) reactive gases. These modifications affect 1) ion exchange capacity; 2) sensitivity to decalcification; and 3) pH-dependent leaching and dissolution of the final product. Process parameters such as the relative amount of CaO in the feed mixture and the surface area of the feed material affect these properties (eg, as shown for element release) of the dried hydrothermally modified material. The modifications are methods that increase the versatility of the dried hydrothermally modified material (FIGS. 4A-4C). For example, the particle size reduction step (eg grinding) can be carried out under wet or dry conditions. In the hydrothermal or drying steps, an alkaline earth ion solution (eg, Ca ²⁺ ) may be added gradually (eg, to change the Ca ²⁺ /Si ratio in the hydrothermal treatment), or solutions of salts or other nutrients may be added.

Example 1 Synthesis and Characterization of Dried Hydrothermally Modified Material (HT-1).

The ultrapotassium syenite used herein was obtained from the Triunfo batholith, located in the state of Pernambuco, Brazil. The content of K-feldspar was 94.5 wt.%. The content of SiO ₂ , Al ₂ O ₃ and K ₂ O was 62.4 wt.%, 17.0 wt.% and 14.3 wt.%, respectively. Palm-sized soil samples were crushed in a jaw crusher and sieved to obtain particles with a size of <2 mm. CaO (chemically pure, Alfa Aesar) was used as received. Due to storage at the time of the experiments, it was hydrated in Ca(OH) ₂ . The XRPD scan showed that the actual composition at the time of the experiments was as follows: CaO: 5.5 wt%; Ca(OH) ₂ : 93.7% by weight; CaCO3: 0.8 wt%. According to the manufacturer, the level of impurities in the resulting material was as follows: 0.005% Cl max.; 0.05% NO3 max; 0.1% Fe max; 0.1% SO4 max; insoluble material: 1.5% max. and represented acetic acid and ammonium hydroxide.

Co-grinding dry.

The raw material mixture for hydrothermal treatment was obtained by co-grinding in dry conditions 21.28 g of ultrapotassium syenite (<2 mm) and 3.72 g of Ca(OH) ₂ , i.e. hydrated form of purchased CaO. The nominal Ca/Si mole ratio was 0.23 based on the assumption that 100% Ca(OH)2 and 0 wt% Ca is in the ultrapotassium syenite. Grinding was carried out in a 50 ml ceramic grinding vessel pre-filled with Ar (Airgas, pre-cleaning grade 4.8). Stainless steel balls were loaded into the container and evacuated. The ball mill (High Energy Vibrating Ball Mill VQ-N, Across International) was operated for 1 minute. The ground powder (raw mix) was then transferred to a plastic container and temporarily stored under an Ar atmosphere. Processing took place within 20 min after grinding operations.

Water (Ricca Chemical Company®, high quality reagent for laboratory use) was boiled and cooled to room temperature in a stream of sparging Ar. The initial amount was stored in an Ar atmosphere. Loading a hydrothermal tank cannot completely avoid contact of both the raw mixture and water with air.

Hydrothermal treatment and isolation.

A diagram of the hydrothermal reactor used in this test (Parker, EZE-Seal®, 300 ml) is given in FIG. 4D. The reactor was loaded with 25 g of the raw mixture and 100 ml of water. The reactor was sealed and the stirrer rotation was set to 400 rpm. The temperature setpoint of 200°C was reached in

- 32 039758 ~40 min and kept for 5 hours. The internal pressure of the reactor was ~14 atm. (Table 1). The general temperature profile for the hydrothermal process is given in FIG. 29. The reactor was then cooled with a water recycle system until the internal T reached ~60° C. (~15 min). The reactor was quickly opened and the slurry (ie the mixture of hydrothermally modified material suspended in the supernatant) was quantitatively transferred to a glass beaker (SA ~44 cm ^-2 ). The solid component was deposited on the bottom of the beaker, and the excess solution (supernatant) was separated from the top of it. The potassium leachable supernatant (FIG. 28) was dried on top of the solids overnight (18 hours) in a laboratory oven set at 90±5°C. The dried hydrothermally modified material was ground uniformly in an agate mortar to obtain a powder which was labeled HT-1 (FIG. 17). The weight of the dried hydrothermally modified material was not measured. However, loss on ignition (LOI) experiments at 1000° C. for 1 hour (repeated three times) showed a loss of 4.4±0.5 wt%, most likely due to water and/or carbonaceous content. Therefore, the recalculated weight of the dried hydrothermally modified material was 26.1 g. Long-term storage of the material took place in an Ar atmosphere.

Table 1

Change in temperature (T) and pressure (P) during hydrothermal treatment of the raw mixture t (hours) ______ T (°C) ______ P (atm.)

0.0 200 14.0 0.1 200 14.0 0.3 199 13.8 1.0 200 13.9 1.2 200 14.0 1.7 200 14.0 h, o 200 13.8 4.0 200 14.0 5.0 200 14.0

Determination of the mineralogical composition of NT-1.

X-ray powder diffractometry (XRPD).

In FIG. 4E describes the mineralogical composition of the raw mix (a) and the dried hydrothermally modified material (b). The mineralogical composition of the dried hydrothermally modified material in FIG. 4E was determined by X-ray powder diffraction (XRPD). The sample was micronized, loaded into a bowl and placed in a diffractometer (Panalytical X'Pert MPD) which was used as an X-ray source emitting CuKa at 45 kV and 40 mA. Scans were acquired in the 2Θ range of 6-90°, with a step size of 0.0131° and a counting time of 250 s-step' ¹ . Once established, the mineral phases were quantified by structure refinement by the Rietveld method. Several small peaks (1% of all diffractograms) could not be accurately determined and were ignored. An additional 1.1 wt% was attributed to panuncite, but this phase was not independently confirmed. Amorphous content was quantified by adding and thoroughly mixing with a sample of the equivalent weight fraction of Si powder (NIST SRM 640). A second XRPD scan was obtained under the same conditions as the original scan. A new Rietveld structure refinement was carried out, providing a comparison, corrected for differences in scattering power, between the integrated intensity of the Si peaks and the integrated intensity of the known crystalline phases determined in the original analysis. The difference between these values as part of the whole was assumed to be due to the amorphous content of the sample. The final amount of each crystalline component is the result of the original Rietveld structure refinement, normalized to take into account the estimated amorphous content.

The diffraction pattern of the dried hydrothermally modified material is shown in FIG. 12. XRPD analysis detected K-feldspar (KAlSi ₃ O ₈ ) and new mineral phases formed in situ during hydrothermal treatment and/or drying, namely hydrogarnet (Ca ₃ Al ₂ (SiO ₄ ) ₃ - _x (OH) _4x ), α-dicalcium silicate hydrate (Ca ₂ SiO ₃ (OH) ₂ ), 11 A tobermorite (Ca ₅ Si ₆ O ₁₆ (OH) ₂ -4H ₂ O) and amorphous material(s). Some of these mineral phases were observed earlier in studies in the literature for CaO-Al2O3-SiO2-H2O hydrothermal systems (Table 2).

- 33 039758

table 2

Overview of hydrothermal reactivity of CaO-Al ₂ O ₃ -SiO ₂ -H ₂ O systems

Reagents molar ratios T t solvent S.L mixing observed phases ⁱⁿ link AV(Si+Al) Ca/(Si+Al) °C h - mass ratio ^A - - - Ca(OH) ₂ S1O2 gel y-AO3 (amorphous) 0.67 1.00 150 6 water+KOH 1:10 but Ca(OH) ₂ hydro grossular CaCO3 46 Cao S1O2 (amorphous) ΑΙ2Ο3 (amorphous) 0.15 0.83 150 0-190 water+NaOH 1:10; 1:5 No C-S-H 11 A tobermorite 47 CaO coal ash A1(OH)s or ACO3 (sol) 0.57 0.86 100-180 fifteen water 1:6 Yes hydro grossular 11 A tobermorite CaCO3 48 CaO (meta)kaolinite SiO ₂ (precipitated) ΑΙ2Ο3 0.10-0.13 6.50-1.00 175 0.5-24 water 2:1 No quartz Ca(OH) ₂ CSH; aC ₂ SH 11 A tobermorite CaCO3 38 K-feldspar 0.25 0.22 190-220 20 water+NaOH water+KOH water+Ca(OH)2 1:6 No modified K-feldspar hydro grossular CSH; CASH; aC2SH tobermorite CaCO3; K2CO3; K ₂ Ca (CO3) 2 thirty Ca (OH) ₂ ultrapotassium 0.24 0.17 200 5 water 1:4 Yes modified K-feldspar This research

syenite hydrogrossularization

CASH; aC ₂ SH 11 A tobermorite indeterminate ________________________________________________________________________________________________________________________________ carbonates __________________

K-feldspar is the main mineral component of the ultra-potassium syenite used in the raw mix. In the dried hydrothermally modified material, residual K-feldspar, still detectable by XRPD, is 66.5 wt.%, indicating a conversion of 17.4 wt.% of the original mineral. It is shown here that after hydrothermal treatment, the remaining part of the K-feldspar was subjected to modifications, i.e. is modified. The hydrogen garnet was 6.5% by weight and, based on the molecular formula, is probably the only calcium aluminosilicate hydrate. It was identified as a plasolite (x=1.47) in the Rietveld refinement (Fig. 12), but was most likely a solid solution of phases with varying levels of substitution of hydroxyl ions (0<x<3), as shown later with ERMA analysis. The α-dicalcium silicate hydrate and 11 A tobermorite accounted for 3.3 and 3.2% by weight, respectively, and, based on the molecular formula, are calcium silicate hydrate phases. Finally, an amorphous component corresponding to 18.2 wt% was also detected in the dried hydrothermally modified material. In addition to these main components, 1.2 wt.% albite and 1.1 wt.% panuncite were also detected using XRPD.

Determination of the structure and chemical composition of NT-1.

Dried hydrothermally modified material placed in thin sections (27x46 mm, 30 µm thick, 0.5 µm double-sided diamond polish, borosilicate glass, acrylic resin; Spectrum Petrographies Inc.) was observed using a scanning electron microscope (JEOL 6610 LV) operating in high vacuum mode (<10 ^-3 Pa). The accelerating voltage was 10-20 kV, the spot size was 45-60, and the working distance was 9-10 mm. Sections were coated with carbon before observation (Quorum, EMS 150T ES). In the long term, thin sections were stored under vacuum.

The chemical composition of the dried hydrothermally modified material placed in a thin section was determined using an electron probe microanalyzer (EPMA) (JEOL JXA-8200) using an accelerating voltage of 15 kV, an electron beam current of 10 nA, and a beam diameter of 1 μm. The mineral phases were analyzed with a counting time of 20–40 s. From the 1σ count statistics, the standard deviations of the concentration values were 0.3-1.0% for major elements and 1.0-5.0% for non-major elements. Backscattered electron (BSE) images and X-ray elemental maps (4.5 x 2.7 cm) were obtained using a voltage of 15 kV, an electron beam current of 1 nA, and a resolution of 10 μm. The use of such settings, as well as operation in the pattern-raster mode with a fixed beam, prevented signal loss and defocusing of the X-ray beam. Due to possible damage to the mounting epoxy of thin sections, EPMA analysis was performed after SEM imaging. A thin section was inserted into a custom-made holder, which allowed any particle to be positioned and analyzed using a variety of techniques.

Preliminary SEM observations of the dried hydrothermally modified material were made on the powder as is (FIG. 13). Then it was placed in a thin section for detailed study of elements of the morphological structure (SEM) and chemical analysis (EPMA).

- 34 039758

The results (FIGS. 14, 15, Table 3, ESI-EPMA) confirmed the XRPD data, although a high degree of heterogeneity was confirmed.

Table 3

Average concentration of oxide and elements (F and Cl) per mineral phase in dried hydrothermally modified material

Mineral phase K ₂ O ALOS _SiO2 NajO Cao MgO Р2О5 T1O2 MNO FeO SO ₃ F Cl Total Altered K-feldspar (< 50 µm) 13.4 17.1 59.8 0.5 0.3 0.0 0.0 0.1 0.0 0.4 0.0 0.0 0.1 92.8 Altered K-feldspar (50 µm < x < 100 µm) 14.6 18.4 64.3 0.6 0.1 0.0 0.0 0.1 0.0 0.4 0.0 0.0 0.0 98.5 Altered K-feldspar (> 100 µm) 15.0 18.3 64.1 0.6 0.1 0.0 0.0 0.1 0.0 0.5 0.0 0.0 0.0 98.6 Hydrogrossular 0.6 13.4 17.2 0.0 27.4 0.3 0.0 0.0 0.0 0.6 0.1 0.2 0.6 66.1 Dicalcium silicate hydrate 1.1 1.0 12.8 0.2 20.0 0.1 0.0 0.0 0.0 0.1 0.0 0.0 0.7 40.5 11 A tobermorite 1.2 2.9 16.4 0.2 17.1 0.1 0.0 0.0 0.0 0.3 0.0 0.0 0.7 41.2 amorphous 6.7 9.9 30.2 0.3 6.1 0.0 0.0 0.0 0.0 0.2 0.0 0.1 0.8 59.9

All numbers are wt%. Data were obtained by EPMA analysis with a large number of observations (ESI-EPMA). Residue up to 100% by weight, probably due to the water content.

In thin section, the K-feldspar crystals could be clearly distinguished (FIGS. 14a, b, 15) and showed clear changes relative to powder rock. Such changes were confirmed by heterogeneous formations (FIGS. 14a-d) and EPMA chemical analysis (FIG. 16, Table 3, ESI-EPMA). The chemical composition varied between feldspar size classes (d<50 µm; 50 µm<d<100 µm; d>100 µm), with smaller crystals containing more Ca and less K, Si, and Al (Table 3, ESI-EPMA ). Note that mechanical activation of the solid phase can replace Ca both with potassium from the surface and with potassium from the lattice at the grinding stage, and this possibility cannot be completely excluded, especially for the smallest grains (Fig. 16; ESI-EPMA). However, in the dried hydrothermally modified material, a distinguishing characteristic was that some grains of medium size K-feldspar (50 µm<d<100 µm) were unusually enriched in Ca (Fig. 16; ESI-EPMA), which was not the case for the equivalent crystals. size in the raw mix. This was evidence for the incorporation of Ca atoms into the feldspar lattice during the hydrothermal treatment. Note that such conclusions do not directly follow from the average concentration values (Table 3), emphasizing the high degree of composition inhomogeneity. K-feldspar crystals are often surrounded by hydrothermal phases such as hydrogarnet, α-dicalcium silicate hydrate, and 11A tobermorite (FIGS. 14a-d). Splitting and cracking were additional common features of K-feldspar, and there was evidence of pitting (Fig. 14a, b).

Hydrogarnet crystals are mostly spherical with ~1 µm in diameter, although some crystals were ~5 µm in diameter (Fig. 14g). Hydrogarnet has been found to either surround K-feldspar or be dispersed throughout the material. Less commonly, it appears as aggregates of larger mass up to ~30 µm and with a colloidal appearance (Figs. 14h, 16). It was difficult to distinguish 11 A tobermorite from α-dicalcium silicate hydrate on the basis of morphology and textural characteristics alone. Tobermorite occurred in two main forms: i) as many individual crystals, more developed, up to 20 µm long and 1 µm wide (Fig. 14b) or ii) as an aggregate in lumps and clusters, each making up a crystal again <1 µm (Fig. 14c-f). In both cases, tobermorite has a fibrous structure, usually appearing as small needles. The texture of α-dicalcium silicate hydrate was similar to the first type of tobermorite, but was more developed and well formed. In addition, the difference between the two minerals was that for tobermorite, analysis at some points showed an enrichment in potassium up to 5.3 wt.%, and for α-dicalcium silicate hydrate, the total oxide content tended to decrease (ESI-EPMA).

An additional morphological signature of the dried hydrothermally modified material was given by some large structures on the order of 2 mm. Such structures are called clusters (Fig. 14f). They were often round, and richer in Ca and K substituted aluminosilicate hydrates than the rest of the dried hydrothermally modified material. Sometimes they had outer rims enriched with α-dicalcium silicate hydrate and tobermorite. It is likely that such formations arise due to the binding nature of calcium silicate hydrates. Of course, C2S phases are often observed as agglomerated phenocrystal in concrete. Exact quantitative determination of the density of the dried hydrothermally modified material was not carried out. However, visual assessments of the clusters (FIG. 14f) showed a large amount of empty space and suggest low density for such formations. This may explain, at least in part, the macroscopic appearance of dried hydrothermally modified material compared to powdered rocks (FIG. 17).

Electron microprobe analysis also revealed small amounts of zeolites that are present in the dried hydrothermally modified material (FIG. 18). Education, as found, occurs at any time during hydrothermal treatment, but only at temperatures above 220°C.

Finally, various mineral phases will contribute to what is detected as amorphous.

- 35 039758 using XRPD, for example, i) highly modified K-feldspar, ii) crystalline but very small particles, iii) truly amorphous compounds, for example, poorly crystallized non-stoichiometric calcium silicate hydrate (C-S-H). However, examination of the sample with EPMA showed that the amorphous phase occurs in two main forms: i) as a material obtained from raw K-feldspar, from which it retains similar mass proportions of K, Al and Si, but which has been so heavily modified, that the total oxide content is much lower; such material has a pronounced Ca content, ii) as fully anhedral forms, with no evidence of crystallinity or oxide stoichiometric ratios associated with known silicates, oxides, chlorides, carbonates or sulfides (ESI-EPMA). Detailed examination of the thin sections also revealed the presence of carbonaceous phases in the dried hydrothermally modified material, which are not detectable by XRPD (FIG. 19b) and which are not associated with impurities in the CaO reagent. This is probably due to a concentration below the detection limit. Such carbonates appeared additionally and were mainly non-stoichiometric K-Ca-carbonates (Ca/K atomic ratio 7 to 28; ESI-EPMA) in crystal aggregates 5-10 µm in diameter (Fig. 19b). Crystals had two main types, tabular forms or prisms. Carbonates were independently confirmed by acid-base titration (FIG. 20) as well as a qualitative carbonate stain test (FIG. 21).

Characteristics of NT-1 particles.

The particle size distribution (PSD) of the powder samples was determined using a laser diffraction particle size analyzer (Beckman Coulter Inc., LS 13 320) equipped with a custom sample injection module. Samples were suspended in water for analysis and were not sonicated.

Brunauer, Emmett and Teller specific surface area (BET-SSA) was determined using a Micromeritics ASAP 2020 surface area and porosity analyzer. The gas used for adsorption was N2. Samples (˜0.5 g) were degassed at 200° C. until a constant degassing rate of 10 ⁻⁵ mm Hg min ⁻¹ was reached in the sample tube (12 h). SSA was determined at the site of the adsorption isotherm using a multi-point method in the range of p/p ₀ 0.08-0.35. However, the full isotherms of adsorption (up to p/p ₀ =0.99) and desorption were recorded.

The particle size distribution (PSD) of the feed mixture (Ca(OH) ₂ + ultrapotassium syenite) was compared to that of the dried hydrothermally modified material in FIG. 22. It is shown that after hydrothermal treatment and drying, the particles are smaller. Based on the volume, three main groups were observed with ~30, ~10 and ~1 µm, respectively. Thus, the treatment shifts the peak of the main group by one order of magnitude, from ~100 µm in the raw mixture to ~10 µm in the dried hydrothermally modified material. The same shift was observed based on the number of particles, from -1 µm in the raw mix to -0.1 µm in the dried hydrothermally modified material. These observations are consistent with the particle size observed by SEM (FIG. 14). In general, PSD can be used as a fast, efficient, and inexpensive way to assess the effectiveness of a process, since the number of particles of the main size in the powder rock and in the dried hydrothermally modified material decreases and increases, respectively, with the gradual transformation of K-feldspar.

The specific surface area according to the BET method (BET-SSA) was 15.1 m ² -g ^-1 for the dried hydrothermally modified material and 46.9 m ² /g for the raw mixture, which was especially high due to the fine Ca( OH) ₂ . This value is only partly relevant, since the raw mix reacts immediately upon contact with water, changing its surface area over time. BET-SSA due to the rock fraction in the raw mix is unknown, but can be correctly considered as ~1 m ² /g as reported by Ciceri et al. (D. Ciceri, M. de Oliveira, RM Stokes, T. Skorina and A. Allanore, Miner. Eng., 2017, 102, 42-57, incorporated herein by reference in its entirety for all purposes). Comparison of the surface areas of the dried hydrothermally modified material and the rock fraction is then consistent with the amount of smaller particles in the treated material. The N2 adsorption isotherm of the dried hydrothermally modified material (BET type III) shows no noticeable hysteresis (FIG. 23).

Leaching experiments and inductively coupled plasma mass spectroscopy (ICP-MS).

Leaching experiments for both ultrapotassium syenite and dried hydrothermally modified material were carried out in batch mode, meaning that 0.3 g of solid material was brought into contact with 3 ml of leaching solution (mS:mL=0.1), and rotated continuously in for 24 hours in a closed container. Before the start of rotation, the containers were preliminarily filled with Ar. Mass transfer limitations were considered negligible under given mixing conditions. HNO3 at initial pH 5 was used as the leaching solution, and an acidic soil solution was simulated. The initial leach solution was prepared by appropriately diluting standardized 0.1 M HNO ₃ (Alfa Aesar) in boiled water followed by vigorous sparging of Ar for ~15 min. At the end of the experiment, the suspension was filtered (Whatman 13 mm

- 36 039758

GD/X, 0.45 μm) and diluted 1:100 in standardized 0.1 M HNO ₃ . Filtration took place within 15 min after the rotator was stopped. Each of the leaching experiments was repeated three times. The error bars represent the scatter of experimental data between three replicates (FIGS. 24 and 9B). The experiments were carried out at room temperature (20±3°C). The temperature of the leaching solution remained constant when in contact with the dried hydrothermally modified material, as shown by an independent test (not shown).

Inductively coupled plasma mass spectroscopy (ICP-MS) determined the concentration of K, Al, Si, Na, Ca, and Mg in the dilute filtrate (ICP MS, Agilent Tec HNOlogies 7700 series). The instrument used an octopole reaction system (ORS) that was run in He mode (He = 4.0 ml/min), except for Ca, which was determined in no gas mode. A 1 ppm In solution was used as an internal standard.

The results of leaching tests for both ultrapotassium syenite and dried hydrothermally modified material are shown in FIG. 24 (leaching conditions: spinning batch test, 24 h, mS:mL=1:10. HNO ₃ at nominal initial pH 5 as leaching solution. All values (ppm) refer to mg of element analyzed in solution using ICP-MS, per kg of solid material Note that the original BET-SSA and PSD differed for two materials: powder rock (original pH 5, BET-SSA = 17.3 m ² /g, the powder was obtained by grinding in a ball mill <2 mm fraction as described under Reagents for 1 min) dried hydrothermally modified material (initial pH 5, BET-SSA = 15.1 m ² /g, PSD shown in Fig. 19). pH, PSD and BET-SSA are different for the two solid materials, the results are compared only for qualitative visualization of the order of magnitude of the availability of elements In the dried hydrothermally modified material there is 14065±744 ppm K available for dissolution, which is equivalent to 14.5% of the total K content raw materials howl mixture. Thus, after 24 h, potassium is two orders of magnitude more available than in the initial ultrapotassium syenite leached at the same initial pH. For Si, Al, and Ca, the availability was 1520±132 ppm Si, 222±38 ppm Al, and 335±20 ppm Ca, respectively (FIG. 24), corresponding to 0.6, 0.3 and 0.2% of the total content of Si, Al and Ca in the raw mixture, respectively. Ca leaching has been controlled in part because of its role as a macronutrient for plants and because of its ability to adjust soil pH. Ca in the accompanying composition of ultrapotassium syenite is taken into account in this calculation. Na and Mg were also controlled due to the fact that they are the main component of the accompanying composition and important elements for soil scientists. Na can lead to possible soil salinization and Mg is a micronutrient for plants. The dried hydrothermally modified material has 6.5±0.3 ppm Na and 6±1 ppm Mg available for dissolution, which is equivalent to 0.2% for both total Na and Mg in the feed mix . The overall availability of Na is low and decreases in dried hydrothermally modified material relative to ultrapotassium syenite.

The fact that the fraction of available nutrients Si, Al and Ca in the dried hydrothermally modified material was very small in absolute terms is proof of the chemical stability of all calcium silicate phases under given leaching conditions. However, the absolute amount of available nutrients can be noticeable to plants. For reference, in the soil solution, Si concentrations are on the order of 0.09-23.4 mg Si l ^-1 , compared to the value of 152 mg Si l ^-1 in the leach solution reported herein. Note also that in the leaching experiment, the Si concentration corresponds to the solubility limit of amorphous SiO ₂ at very low pH. This is because the actual leach solution was diluted in concentrated HNO ₃ prior to ICP-MS analysis. Thus, it is possible that the Si in the actual leach tank is even greater than what was measured.

Acid-base titration of dried hydrothermally modified material.

Acid-base titration of the dried hydrothermally modified material was carried out as follows.

(a) First, 0.3 g of the dried hydrothermally modified material was suspended in 10 ml of DI water with stirring.

(b) Second, standardized 0.1 M HNO ₃ (Alfa Aesar) was added to the beaker. After each addition of acid (2.5 ml), the system was allowed to stabilize for 15 minutes before reading. Note that the pH did not stabilize due to the reactivity of the surface of the dried hydrothermally modified material.

(c) Third, the titration curve was plotted as shown in FIG. 20 and the equivalence points were used to back-calculate the base content of the dried hydrothermally modified material.

Two separate equivalence points were observed, at pH 10.0 (3.0 ml) and pH 5.8 (12.0 ml). The first equivalence point can reasonably be attributed to carbonates, since the tabulated pKa ₂ value for H ₂ CO ₃ is 10.33 (25°C). Difference between experimental and theoretical values

- 37 039758 can be explained by interference caused by the surface reactivity of other mineral phases such as K-feldspar, hydrogarnet and tobermorite. The second equivalence point seems further away from the table pKa1 value for H2CO3, which is 6.35 (25°C). Assuming that the first equivalence point is indeed due to carbonates, this would correspond to 0.3 mmol CO ₃ ^2- , which is equivalent to 4.3 wt% CO 2 in the dried hydrothermally modified material. This amount was not detected by XRPD, but is in excellent agreement with the LOI data (see section on hydrothermal treatment above). The carbonates were anhedral crystals, but were not amorphous, so XRPD does not detect them, most likely because they are present below the limit of detection. If all carbonate determined by titration at the first equivalence point was K2CO3, then the expected K leaching test would be 78,000 ppm K, well above the experimental data (FIG. 19). The carbonates in the dried hydrothermally modified material are thus an indeterminate mixture that probably contains K2CO3, Na2CO3, MgCO3, CaCO3, but possibly also other double carbonate species such as K2Ca(CO3)2 (buchilyite and/or fairchildite). The second equivalence point does not match the carbonate content found at the first equivalence point. Assuming that the second equivalence point is due to the HCO ^3- + H+ θ H2CO ₃ equilibrium, then in addition to the 0.3 mmol CO ₃ ² ' an additional 0.6 mmol HCO3 ^- bicarbonate particles are present in the dried hydrothermally modified material. This amount would correspond to an additional 8.6 wt.% CO2 content in the dried hydrothermally modified material, for a total of 12.9 wt.% CO2, which is unlikely to go unnoticed by XRPD. These data indicate the effective presence of carbonates in the dried hydrothermally modified material. Such high pH values are important in materials used to improve soil quality and soil health, especially where low pH soils are a problem.

Qualitative Spot Analysis for Carbonate Determination Concentrated nitric acid (15.6 M) was dropped on top of the material using the apparatus shown in FIG. 21(a)-(c). If carbonates were present, they formed CO2, which flowed into the second compartment of the apparatus and precipitated as BaCO ₃ from the Ba(OH) ₂ solution. Panel (b) shows the result of a blank test where the material is ultrapotassium syenite (BaCO ₃ is not formed). Panel (c) shows the test result with dried hydrothermally modified material. A whitish cloud of BaCO ₃ formed, confirming the presence of carbonates.

Relationship between mineralogical composition and leaching.

The basic potassium aluminosilicate (KAS) detected by XRPD in the dried hydrothermally modified material was K-feldspar (KAlSi ₃ O8) (FIG. 4E). XRPD showed that 14.0 g of K-feldspar was converted during the hydrothermal treatment (FIG. 14). PSD analysis confirmed that the particle size population associated with K-feldspar decreased in the dried hydrothermally modified material relative to the raw mix (FIG. 22). However, this mineral phase remains the main component of the dried hydrothermally modified material (66.5% by weight) and thus also the main K-containing phase. This is a carefully designed and intended feature of the material. Complete conversion of K-feldspar would be too costly and would create a large amount of soluble K instantly available in soil solution, contrary to the desired features of dried hydrothermally modified materials disclosed herein, i.e. designing a fertilizer for tropical soils with a K release rate that matches the needs of crops. However, note that what XRPD detects as K-feldspar is actually an altered mineral phase. The structural change was confirmed by examination of the images (FIGS. 14a-d). In addition, the N2 adsorption isotherm had no hysteresis (Fig. 23), which can be explained considering that fractures, cracks or other porous structures do not produce hysteresis behavior if they are on the order of micrometers in size (Fig. 14a, b), although their contribution to surface area is still included in the BET-SSA value. The chemical change was confirmed by elemental maps (FIG. 15), point concentrations (Table 3, ESI-EPMA), as well as by detailed examination of the sample (FIGS. 13, 16). Distortions in the unit cells of Kfeldspar due to the insertion of Ca are the likely cause of the cracking effect noted above. Of course, a hallmark of the dried hydrothermally modified material is that the finest grains of modified K-feldspar particles showed non-stoichiometric elemental abundances, highly depleted in K and enriched in Ca (FIG. 15, FIG. 16, ESI-EPMA). Despite their size, none of the K-feldspar grains retained their original composition, and calcium minerals were observed at the interface between the K-feldspar grains and the hydrothermal solution. Without wishing to be bound by any particular theory, such phases may result from the insertion of Ca into the feldspar or from reprecipitation from solution due to local saturation. In the absence of an alkaline environment, much higher temperatures (600°C) will be involved to see a significant exchange between the K in the feldspar and the alkali ions from the hydrothermal solution. The data presented in this paper thus provide evidence that environments with

- 38 039758 high pH is necessary for the successful conversion and exchange of K ions for Ca ions. Assuming the same dissolution rate for both altered and unaltered K-feldspar, and an actual leaching pH of 12 units (Figure 27), then the amount of available K would be on the order of 10-200 ppm K depending on the actual surface area of the altered K - feldspar. This amount is negligible compared to the data shown in FIG. 24 and confirms that altered K-feldspar acts as a major nutrient reservoir for possible long-term release, but is unlikely to be responsible for short-term release of K. Conversely, material balance calculations (e.g. based on the conversion shown in Fig. 4E ) have shown that the K-feldspar fraction that is completely converted can provide all of the leachable K. Such K is likely located in K-substituted phases other than altered K-feldspar, or in the soluble carbonate fraction (K ₂ CO ₃ solubility (25°C) is 1110 g l ^-1 ) not detected by XRPD but confirmed by EPMA analysis (FIG. 15, ESI-EPMA).

The main phase of calcium aluminosilicate hydrate (CASH) detected by XRPD in the dried hydrothermally modified material was hydrogen garnet (Ca ₃ Al ₂ (SiO ₄ ) ₃ . _x (OH) _4x ; C ₃ A ₂ S ₃ _ _x H _x ). In a wider group of hydrogarnets, hydrogarnet determines the class of minerals, where the inclusion of 4OH instead of the SiO ₄ ^4- tetrahedron occurs, creating grossular (x=0), gibbsite (x=0.2-1.5), cathoite (x=1.5-3 ) and their solid solutions. In artificial systems, hydrogarnet has been observed in cement as the only calcium aluminosilicate hydrate and is often found as a hydration product of autoclaved materials (Table 2). It appears as small octahedral round crystals (1.5-4 µm). Comparison of the micrographs of the dried hydrothermally modified material (FIG. 14) with the PSD data (FIG. 22) shows that in these experiments the hydrogarnet phase was mainly in the form of small and round particles of the order of ~1 µm. EPMA analysis showed a ~30 wt% SiO ₂ content (Table 3; ESI-EPMA), suggesting gibbite rather than cathoite, and consistent with the predominance of round crystals (Fig. 14g). Note that the content of SiO ₂ is also in relatively good agreement with the theoretical value of 22 wt.% in the plasolite phase used in the structure refinement by the Rietveld method. Together with K-feldspar, hydrogarnet is the main Al-bearing mineral. In the leaching test, the availability of Al from the dried hydrothermally modified material is increased relative to ultrapotassium syenite, although it remains comparable. Note, however, that the actual leaching pH of the powdered rock is ~6, while that of the dried hydrothermally modified material is ~12 (FIG. 27). In this latter case, the availability of Al is thus maximal, indicating that in soils buffered at acidic pH, Al will be almost completely unavailable. The level of K incorporation into hydrogarnet crystals was low (Table 3).

Calcium silicate hydrates (CSH) were α-dicalcium silicate hydrate (a-Ca ₂ (SiO ₃ OH)(OH); aC ₂ SH) and 11 A tobermorite (Ca ₅ Si ₆ O ₁₆ (OH) ₂ 4H ₂ O; C ₅ Si ₆ H ₅ ). The hydrothermal synthesis of α-dicalcium silicate hydrate has been previously reported. It usually occurs in the form of rectangular tablets, which are formed over ~150°C. The Ca/Si molar ratio of the raw mix influences the formation of crystalline aC ₂ SH (Ca/Si=2) relative to another weakly crystalline and non-stoichiometric calcium silicate hydrate (Ca/Si<1.75). Thus, aC ₂ SH is most likely formed in calcium-enriched media at the beginning of the reaction, while tobermorite will form later as a phase separating from metastable calcium silicate hydrates. Tobermorite was observed in the artificial system CaO-SiO ₂ -H ₂ O in the temperature range from ~80 to ~150°C, the initial bulk molar composition at Ca/Si=0.8-1.0 and processing time of the order of days. The higher the solubility of the Si source, the lower the crystallinity of the resulting tobermorite. Tobermorite can exist as a metastable mineral above 200°C, although xonolite (Ca ₆ Si ₆ O ₁₇ (OH) ₂ ; C ₆ S ₆ H ₂ ) becomes the thermodynamically preferred phase. Al accelerates the transformation of calcium silicate hydrates into tobermorite and prevents its transformation into xonolite. The inclusion of Al ³⁺ instead of Si ⁴⁺ involves the introduction of interlayer ions to maintain electrical neutrality, usually Na ⁺ , K ⁺ or Ca ²⁺ , giving tobermorites with a high CEC of ~70 meq/100 g. Several crystal forms have been reported for tobermorites, including lamellar, splinter-like and fibrous crystals. This latter type was confirmed in this test (Fig. 14b, Fig. 14e). However, K-substituted tobermorites (potassium tobermorite) are very rare in nature. In the dried hydrothermally modified material, tobermorite was 3 wt% (FIG. 4E) and contained both K and Al (Table 3, ESI-EPMA). In general, the absolute amount of potassium in tobermorite was small, and was probably masked in the leaching experiment by the immediately available K component. XRPD. This amorphous phase has been shown to have a very variable composition (ESI-EPMA). Although the content of K and Al has been found to be high, its ion-releasing capacity has not been established at present.

In addition to the XRPD phases, it has been shown that the dried hydrothermally modified mother

- 39 039758 al also contains carbonaceous particles (Fig. 19, ESI-EPMA). Carbonates are important because they help regulate the pH properties of the material and can be used to capture atmospheric CO2. In this work, there are only three possible sources of carbon: i) impurities in the raw material (0.8 wt.% CaCO ₃ in reagent Ca(OH)2, which is equivalent to 0.12 wt.% in the raw mixture; see Experimental section) , ii) atmospheric CO2 in the hydrothermal reactor (negligible), iii) atmospheric CO2 during the drying stage (assumed to be 400 ppm during the entire drying stage). It is possible that the carbonization of some phases, for example, KOH, formed during the drying of the supernatant after treatment, occurs ex situ during the preparation and placement of the powder in a thin section. However, it is more likely that it is, of course, the drying step that regulates the formation of carbonates. Given the mineralogical complexity of the material, it is unlikely that the K available in solution comes from a single phase, such as soluble carbonates. However, the amount of K ₂ CO ₃ that will confirm the experimental value of FIG. 24, equivalent to 2.50 wt.%, low enough that it might not be determined by XRPD. As shown in ESI-EPMA, the carbonates formed during processing are in fact complex particles with variable K/Ca atomic ratios and with solubility values not immediately available in the literature. In general, leaching plants do not distinguish the origin of available K, although the data presented in this test suggest carbonaceous particles as likely to be responsible. Other nutrient reservoirs such as altered K-feldspar, tobermorite or amorphous phases are expected to release K at a slower and probably more controlled rate than soluble ionic species.

The leaching data presented here (FIG. 24) highlights the importance of relating nutrient availability to mineral phases in predicting the agricultural performance of a material. These data show that, with the exception of Na and Mg, the availability of elements from the dried hydrothermally modified material is higher than in ultrapotassium syenite leached at the same initial pH. For Ca, the availability cannot be immediately compared, since in the raw material it was available from associated minerals, while in the dried hydrothermally modified material it was artificially introduced by adding Ca(OH) ₂ to the system. A comprehensive review of the dried hydrothermally modified material shows that K-feldspar was characterized by pozzolanic activity, which is a behavior unique to the [K ₂ O-Al ₂ O ₃ -SiO ₂ ]K-feldspar-CaO-H ₂ O system. the system is far from thermodynamic equilibrium, it can be directed to a deliberate redistribution of structural elements in the mineral phases, which release beneficial nutrients to improve soil fertility.

The following examples (2-8) were run under microfluidic conditions according to the parameters and settings indicated in FIG. 34A-34C. Hydrothermal treatment time (5, 16 or 24 h), drying conditions (Ar, air, CO2 and vacuum) and Ca/Si ratios in the feed (0.075, 0.15, 0.3, 0.45, 0.6 and 0 ,9) have been extensively studied for their effect on mineralogical composition, leaching, pH and other important properties (i.e. particle size distribution) of the dried hydrothermally modified material. As determined, the hydrothermally modified material was dried with or without a supernatant using the dryer shown in FIG. 34C.

Example 2 Dissolution of dried hydrothermally modified material under flow conditions (microfluidic).

Fig. 35A-35D show the dissolution properties of the dried hydrothermally modified material under microfluidic conditions. The dried hydrothermally modified material was evaluated before and after leaching. Scanning electron microscope (SEM) images showed that the calcium aluminosilicate (CASH) hydrate phases are dissolved in the flow, while the K-feldspar phase is not. Without wishing to be bound by any particular theory, this is believed to be due to the buffered pH and not to the flow itself.

Leaching of hydrothermal powders in volume relative to flow.

In FIG. 25 compares bulk leaching (HNO ₃ pH 5) with microfluidic leaching for dried hydrothermally modified materials. At pH 5, the K/Al and K/Ca ratios under flow conditions are significantly reduced compared to the leaching that occurs from the bulk of the powder in the standard leach solution. Microfluidic setups also facilitate the release of key elements (Al, Si, K, and Ca), which has been investigated in various sections and pH environments (FIG. 26). These data show how the release of each element varies depending on the leaching conditions and the initial mineralogical composition. In general, it can be concluded that the release of elements under bulk conditions is different from leaching under flow conditions.

Example 3 Effect of Processing and Drying Conditions on Dried Hydrothermally Modified Material.

Release of K from dried hydrothermally modified material under various drying conditions.

- 40 039758

Leaching experiments were carried out as follows: 300 mg of hydrothermally modified material was suspended in 3 ml of HNO3 pH 5 solution (performed three times). The samples were then stirred at ambient temperature for 24 hours. Mineral leaching was determined by ICP-MS under acidic conditions (0.1N HNO3). The pH measurements were carried out three times in containers separate from the leaching samples, which were prepared under the same conditions as the above leaching experiment. pHt= ₀ was recorded within 3 min from the moment of contact of the liquid with the material. pHt= ₂₄ was recorded after 24 hours of stirring. Except where noted, hydrothermally modified materials were processed at 200°C and dried under special conditions at 110-120°C.

A number of dried hydrothermally modified materials were obtained using four separate sets of atmospheric conditions (Ar-Ar, Ar-air, air-air and CO2-CO2) to react the raw materials and subsequently dry the resulting products.

Obviously in Fig. 5 (and from Table 4 below) that changing the processing and drying atmosphere markedly affects the composition of the resulting dried hydrothermally modified material. In particular, the amount of amorphous phase, dicalcium silicate hydrate, hydrogarnet, tobermorite, and K-feldspar changes under each set of conditions. Under an Ar-Ar atmosphere, K-feldspar (Kfs) has the highest conversion to products, with only 56% Kfs remaining after the process is completed. This leaves about 29% of the composition defined as an amorphous phase. Both Ar-Ar and Ar-air also contain 89% of the dicalcium silicate hydrate phase, a phase that is notably absent under the other two sets of conditions. CO2-CO2 gives the lowest Kfs conversion and dried hydrothermally modified material with substantially reduced amorphous content.

Table 4

Composition of dried hydrothermally modified materials at different treatment atmospheres for the hydrothermal treatment stage and the drying stage

Atmosphere Ag-Ag Ag-air Air to air CO ₂ -CO ₂ Kfs 56.1 68.2 66.5 68.1 Tobermorite 7.2 hydro grenade 6.1 7.1 6.5 Dicalcium silicate hydrate 8.2 8.7 Calcite 23.8 Amorphous phase content 28.7 fourteen 18.2 5.6

In addition, hydrothermally treating and drying atmospheres alter the leaching properties of dried hydrothermally modified materials (FIG. 6). At 200° C. for 5 hours, air-to-air conditions provide higher levels of release of potassium, aluminium, silicon and calcium. For sodium alone, release is reduced compared to other options.

Additional studies were performed to isolate the effect of drying conditions on potassium leaching from two sets of dried hydrothermally modified materials. For the first set, the dried hydrothermally modified material was dried with the supernatant using separately air, Ar, CO ₂ and vacuum. As shown in FIG. 7B, K release is highest under Ar conditions and lowest when CO2 is used. The use of a vacuum of 10 ^-2 -10 ^-3 torr also provides a significant release of K + from the dried hydrothermally modified material. Air drying provides an intermediate value, clearly showing that the small amount of CO ₂ that is naturally present has little effect on leaching. In these experiments, the release of K, as found to depend on the drying temperature (<90°C).

A similar trend was observed in solid samples dried after removal of the supernatant (FIG. 7B). Potassium leaching was again lowest when CO2 was used to dry the dried hydrothermally modified material. Aggregate data indicate that solid samples are sensitive to carbonation, so CO ₂ /carbonate equilibrium in the soil is likely to be important for the long-term performance of working samples.

In FIG. 7A provides an explanation for the above behavior. Without wishing to be bound by any particular theory, the dissolution of CO ₂ in the drying solution may likely co-precipitate potassium with CaCO ₃ (probably substituted with K CaCO ₃ ). Potassium sequestration in mineral phases ultimately reduces the degree of possible leaching.

Confirmation for the possible capture of K is provided by examination of the hydrothermally modified material dried in air, Ar or CO2 (Table 5). In contrast to other atmospheric conditions, a significant calcite phase (14% by weight) precipitates when the samples are dried with CO2. Since the lattice parameters in the dried hydrothermally modified material are larger than the reference ones (ionic radius K ⁺ >Ca ²⁺ ), it is reasonable that potassium co-precipitates with CaCO ₃ in a poorly soluble phase, designated as K _2x Ca( _1-x )CO ₃ . In addition, the presence of a larger fraction of the amorphous phase may indicate the occurrence of amorphous CaCO ₃ .

- 41 039758

Table 5

Mineralogical composition of dried hydrothermally modified materials obtained through various drying conditions

Mass fraction of the phase

Phase air Ag from ₂ Alkali feldspar 0.57 0.64 0.51 Tobermorite 0.06 0.03 0.03 aC ₂ S 0.00 0.06 0.00 hydrogrossular 0.12 0.09 0.08 Euomum+COz** 0.07 0.07 0.00 Calcite 0.01 0.00 0.14 amorphous 0.16 0D1 0.2 G

*Possible occurrence of amorphous CaCO ₃ .

** Mass of CO2 obtained from calcite in a CO2 dried sample.

In contrast to potassium, Ca release is significantly increased in hydrothermally modified materials dried without supernatant (FIG. 1C). The largest amount of leaching occurs when using vacuum to dry the material, although similar levels were obtained with argon. There is no measurable leaching of calcium from the CO ₂ -dried material, probably due to the limited solubility of the CaCO ₃ -containing phase.

Aluminum leaching was also determined for hydrothermally modified material dried in various atmospheres (FIG. 7D). In all sets of conditions, leaching was highest for the material dried with the supernatant, although the difference in magnitude varied. Drying under vacuum gave the highest release of Al, followed by air, argon and CO ₂ .

Effect of drying conditions on sample pH.

Whereas the hydrothermally modified samples that were dried with the supernatant showed no change in pH at 24 h when dried with air, Ar, CO ₂ or vacuum, pH changes were observed for samples of the hydrothermally modified materials dried after removal of the supernatant. liquids by vacuum filtration. Interestingly, basicity tended to increase with air, Ar, and vacuum, but tended to decrease when the hydrothermally modified material was dried with CO2 (Table 6).

Table 6 pH of samples dried under various conditions with and without supernatant Samples dried with air Ar CO ₂ Vacuum supernatant

Leaching pHt=o Leaching pH _t = ₂ 4 ₄ 12.2 12.4 12.3 12.4 12.3 12.2 12.3 12.3 Samples dried without air-solid Ag-solid C O ₂ - solid Vacuum solid supernatant substance substance substance substance Leaching pHt=o 11.3 11.6 11.8 11.5 Leaching pH _t=2 4 ₄ H.9 12.3 10.8 12.1

These pH and potassium leaching results are consistent with the proposed calcium silicate hydrate (CSH) reaction shown in FIG. 7A (upper reaction). When the Ca1, ₆₇ SiO ₂ (OH) ₃ , ₃₃ -0.43 H ₂ O phase was dissolved, hydroxide ions were obtained, which effectively increase the pH level. At the same time, potassium is released from the CSH phase, resulting in observed leaching levels. In contrast, in the presence of CO2, the carbonization reaction of CSH occurs (FIG. 7A, lower reaction). Decalcification of the CSH phase provides a mechanism for the release of potassium, although it also causes a tendency to decrease in basicity (pH 11.8 ^ pH 10.8). The formation of xCaCO3 also explains why calcium leaching is minimized or does not occur when solid samples are dried with CO2 (FIG. 1C).

The leaching of other minerals is also affected by pH. The release of aluminum, for example, correlates with pH in samples dried without a supernatant. Ar at pH 12.3 provides the highest release of Al, while CO2 at pH 10.8 releases the lowest amount of Al (FIG. 7D).

In general, the solid phase appears to be quite sensitive to carbonation. Carbonization has many effects on dried hydrothermally modified material. Leaching is possibly reduced by capturing K in the K _2x Ca( _1-X )CO ₃ phases. Drying with CO2 also causes a decrease in alkalinity, possibly reducing the buffering capacity of the dried hydrothermally modified material. Under these conditions, calcium is released into solution through the dissolution of minerals. When air, Ar or vacuum is used for drying, the dried hydrothermally modified material has the ability to buffer pH. Thus, compatibility with additives and composite materials is considered. However, the ability to adjust the pH depending on the drying atmosphere

- 42 039758 facilitates the use of these dried hydrothermally modified materials for soil remediation or for the production of alkaline solutions for certain industries/applications including but not limited to geopolymer, water glass, colloidal silica and KOH/K2CO ₃ solutions.

Example 4 Time and Temperature Dependence of Dried Hydrothermally Modified Material.

Both time (t) and temperature (T) are hydrothermal processing variables that have been found to affect the composition of the dried hydrothermally modified material (FIG. 8). For example, raising the temperature from 200 to 230°C for 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 hours not only increases the degree of K-feldspar conversion, but also increases the amount the amorphous phase present (FIG. 9A). The content of tobermorite, a calcium silicate that is substituted with K, was also found to increase with increasing treatment time. Hydrogarnet content, on the other hand, remains constant despite changes in variables. The minor component, which is the sum of the minor phases, i.e. albite, biotite, panuncite, usually present in an amount of less than 10%.

Mineral leaching was also evaluated as a function of time and temperature. After a time in the range of 0.5-3.0 h and at temperatures of 200, 220 and 230° C., the leaching of K remains relatively constant. Thus, it was concluded that the amount of potassium leaching is independent of treatment time and temperature (FIG. 9B). Al leaching, on the other hand, is relatively constant over any treatment time, but has been found to drop significantly with increasing treatment temperature. Although Si and Ca leaching are not easily displayed within the given ranges, Na release correlates with both treatment time and temperature (FIG. 9B).

The question whether it is possible to increase the degree of conversion of K-feldspar in the dried hydrothermally modified material for a longer processing time was also resolved (Table 7). Tested treatment time 5, 16 and 24 hours, the temperature was maintained at 200°C. It should be noted that Kfs decreased by approximately 13.6% from 5 to 16 hours (FIG. 9C), indicating that the degree of conversion can indeed be increased. The relatively small change of 2.4% observed during the last 8 hours (16-24 hours) may be partly due to an increase in tobermorite during the same period (FIG. 9C). The content of tobermorite remains mostly constant during the first 11 hours of treatment, only to pass from 7 to 9.2 wt.% of the fraction during the last 8 hours. Considering the content of the amorphous phase, a significant increase in this phase is clearly visible from 5 to 16 hours, hitting a plateau thereafter to completion at 24 hours. Based on the intended use of dried hydrothermally modified material, slight variations in mineralogical composition may be important and should be taken into account in the composition. According to the lattice parameters and chemical compositions obtained from XRPD and WDS, respectively, crystalline phases exist in solid solutions. Such changes may be important in leaching. Such changes may be important in leaching. For example, in 1 g of dried hydrothermally modified material, which typically releases 10 mg K/kg of material, there are 2.6 x 10 ^-7 mol K and 2.3 x 10 ^-5 mol tobermorite (based on 2.4 wt.% tobermorite). Only 1.1 mol% of silicon in tobermorite needs to be co-substituted for Al and K to account for the mass of K observed in leaching, reinforcing that small changes in phase redistribution can have a significant effect on the properties of the dried hydrothermally modified material.

Table 7

Influence of Long Processing Time on the Composition of Dried Hydrothermally Modified Material

Phase 5 h 16 h 24 hours Alkali feldspar 0.631 0.552 0.528 Tobermorite 0.061 0.07 0.092 aC ₂ S 0 0 0 hydrogrossular 0.127 0.112 0.114 Biotite 0.002 0 0 Calcite 0.007 0 0 amorphous 0.172 0.266 0.266

Surprisingly, the release of K does not coincide with the decrease in the mass fraction of Kfs. In fact, increased hydrothermal treatment time actually reduces K leaching, likely because K is sequestered in one or more phases of the dried hydrothermally modified material (FIG. 9D). In contrast, Ca leaching is markedly increased in dried hydrothermally modified material treated for 24 h at 200° C. compared to less time treated (FIG. 9D). It is found that the change in pH is proportional to the release of Ca, so that when the alkalinity decreases over time, the leaching of Ca increases significantly. Despite changes in pH at each time point, the data support

- 43 039758 the idea that the dried hydrothermally modified material has a suitable buffering capacity, since the alkalinity in all cases not only remains, but actually tends to a slight increase in basicity when leaching occurs over a period of 24 hours (Table 8).

Table 8 Filtrate pH measured for dried hydrothermally modified materials treated at 200°C for various times _____________________________5 h________16 h_______24 h Leaching pHt=o 12.2 11.6 11.2

Leaching pHt=24 ₄ 12.4 12.2 11.8

Example 5 Effect of the Ca/Si Ratio in Raw Material on the Properties of a Dried Hydrothermally Modified Material

Effect of Ca/Si on the Kfs Conversion.

A number of experiments have shown that the ratio of Ca/Si in the feed affects the degree of conversion Kfs [(Kfs _initial -Kfs _final )/Kfs _initial ], mineralogical composition, release of minerals, particle size distribution (PSD) and buffering. Therefore, modulation of this parameter can be usefully used to match the properties of the dried hydrothermally modified material for a particular application.

To answer the question of whether it is possible to determine the minimum CaO/Kfs that provides the desired dried hydrothermally modified material, studies were carried out with various proportions of Ca/Si. It is clear from the initial data that a change in the Ca/Si ratio in the raw material affects the mass fractions of various components in the dried hydrothermally modified material (Table 9). In particular, when the Ca/Si ratio was increased, the amount of Kfs remaining in the composition of the product became smaller and smaller. At the same time, both the hydrogarnet phase and the amorphous phase are present in much higher mass fractions, shifting from Ca/Si = 0.075 to the maximum tested value, where Ca/Si = 0.3. Tobermorite, on the contrary, has a peak at Ca/Si = 0.15, while at the same time somewhat decreasing at Ca/Si = 0.3 (Table 9).

Table 9

Mass fractions of phases of various components in the dried hydrothermally modified material at different ratios of Ca/Si in the raw material

Mass fraction of the phase

Phase Ca/Si = 0.075 Ca/Si = 0.15 Ca/Si = 0.3 Alkali feldspar 0.868 0.728 0.631 tobermorite 0.024 0.075 0.061 hydrogrossular 0.028 0.062 0.127 amorphous 0.08 0.129 0.172

Biotite omitted for clarity

The graphical representation of K-feldspar conversion as a function of Ca/Si in the feed mixture (driving force) highlights that there is a most promising range that can be used (FIG. 10). Although the amount of K-feldspar jumps a lot at the first doubling of the Ca/Si ratio in the feed, a plateau is essentially reached when increasing to Ca/Si=0.30. Thus, the effect on conversion beyond the intermediate ratio shown in FIG. 10 turns out to be the minimum.

Influence of Ca/Si on the mineralogical composition of dried hydrothermally modified material.

In FIG. 11A shows that Kfs conversion correlates with Ca/Si in the feed mixture for mass fractions from 0.075 to 0.9 (bar graph). In this test, the mass fraction of the fraction is normalized to Ca/Si = 0.9, i.e. fraction of the artificial phase corresponding to the difference between CaO in Ca/Si = 0.9, and a sample with lower Ca/Si were added to the XRD results for samples with Ca/Si<0.9. The analytical error of phase quantification by XRD for dried hydrothermally modified material is typically in the range of 5-20% for a given phase. The calculated value of the degree of conversion for Ca/Si = 0.075 was negative and was considered unphysical. Thus, no value for the degree of conversion Kfs is given for Ca/Si = 0.075.

The amorphous dicalcium silicate hydrate and hydrogen garnet phases correlate with % Kfs conversion such that the wt % of each increases as Ca/Si in the feed mixture rises from 0.075 to 0.9. On the contrary, tobermorite remains quite stable, actually starting to decrease in wt.% at Ca/Si = 0.45. Thus, it is shown from the data that it is possible to obtain dicalcium silicate hydrate, rather than tobermorite, by increasing the Ca/Si in the mixture. In general, the change of K-feldspar into a significant amorphous phase can also be activated by simply increasing Ca/Si in the feed mixture. The ability to shift products in the direction of forming a dicalcium silicate hydrate phase and an amorphous phase simply by modifying the Ca/Si ratio is expected to have a positive effect on cement chemistry and is consistent with a variety of cement applications in general.

Effect of Ca/Si on the release of minerals.

The release of K can be modulated by changing the Ca/Si in the raw mix. An increase in Ca/Si causes more K to be released by the dried hydrothermally modified material, where the maximum value is reached when Ca/Si = 0.45 (FIG. 11B). Thus, the release of K was found to be proportional to Ca/Si.

Leaching for Ca differs from K due to the lack of a linear relationship, as well as the effect of changing pH. In fact, Ca release levels are quite similar when Ca/Si is 0.15, 0.30 and 0.6 (FIG. 11C). This correlates with dried hydrothermally modified materials where the pH buffering capacity remains unchanged or mostly unchanged (Table 10). At the lowest feed ratio, the alkalinity drops to 11.0, in which case the release of Ca is much higher (FIG. 11C). Based on the Ca/Si feed data, the alkalinity of the dried hydrothermally modified material is affected (i.e., buffering decreases at low Ca/Si), which in turn can have an effect on the release of minerals such as Ca. Unexpectedly, the Ca leaching peak occurs when the Ca/Si feed blend ratio = 0.45, so that the value is comparable to that observed in low Ca/Si feed blends (FIG. 11D). An even larger peak was observed at Ca/Si = 0.9, probably showing unreacted Ca(OH)2 from the hydrothermal process.

Table 10 Filtrate pH Measured for Dried Hydrothermally Modified Materials Produced with Different Ca/Si Ratios in the Feed _______________________________0.075 0.15 0.3 0.6

Leaching pHt=o 10.9 11.2 12.2 12.3

Leaching pHt=244 11.0 11.5 12.3 12.3

The release of sodium (Na) and aluminum (Al) can also be modulated by changing the Ca/Si in the raw mix (FIG. 11D). Al leaching increases over the entire Ca/Si range, possibly forming a plateau at the highest ratio tested (0.9). A similar observation applies to Na leaching, except that a slight decrease is noted at 0.6, the highest tested Ca/Si in the raw mix.

In general, the Ca/Si ratio controls the degree of hydrothermal reaction and needs to be optimized for the desired working time (t), temperature (T), feedstock composition, and desired mineralogical composition in the dried hydrothermally modified material. It should be noted that low Ca/Si reduces the buffering capacity of the material, which, in turn, can affect the leaching of minerals. As discussed earlier, the ability to adjust pH in response to the drying atmosphere facilitates the use of these dried hydrothermally modified materials for soil remediation or alkaline solutions for some industries/applications, including but not limited to geopolymer, water glass, colloidal silica, and KOH solutions. /K2CO3.

Effect of Ca/Si on Particle Size Distribution (PSD) for Dried Hydrothermally Modified Materials.

The PSD was evaluated for each of the Ca/Si ratios used in the study, with comparisons made between the raw mix and the dried hydrothermally modified material. Particle size analysis was performed with water as the dispersion medium in the absence of sonication. For raw mixes with lower Ca/Si, the plot of effective diameter versus differential volume shows little difference between materials before and after treatment. Only at Ca/Si = 0.3 and 0.6 significant changes were observed (FIG. 11F). For raw mixes with Ca/Si = 0.6, it is possible that particle agglomeration gives a shoulder <20 µm. Found that the degree of conversion of K-feldspar increased when increased the ratio of Ca/Si. In addition, the increased conversion of K-feldspar is also reflected in an increase in the amount of small particles.

In general, the Ca/Si ratio plays a significant role in processing. The alkaline earth component in the feed mix controls the alkalinity/pH of the hydrothermal process, which in turn determines the dissolution kinetics of the alkali aluminosilicate lattice and potentially the course of the entire reaction. The phase distribution is sensitive to the concentration of Ca/Si in water, for example, a Ca-enriched environment preferentially accelerates the growth of dicalcium silicate hydrate, a Ca-enriched stoichiometry compound. The alkali cation uptake by the newly formed calcium silicate phases depends on the Ca/Si in solution, eg low Ca/Si solutions increase the alkali lattice distribution in the solid phase as part of the calcium silicate phases. These observations indicate that the chemistry and phase distribution of the dried hydrothermally modified material can be tailored by controlling the alkaline earth/Si and/or alkaline earth/alkaline element ratios in the hydrothermal process solution.

- 45 039758

Example 6 Understanding the Role of Raw Blend PSD in Processing.

Raw material containing K-feldspar (<2 mm) was ground (50 g/pass) for min. The ground material was then dry sieved using ASTM E11 No. 70 (212 µm), 100 (150 µm), 140 (106 µm), and 325 (45 µm) sieves to obtain the four fractions shown in

PSD (Fig. 30).

Raw mixtures were then obtained by physically mixing these fractions with the desired amount of CaO, rather than co-grinding. Dried hydrothermally modified materials were obtained from four fractions. The PSD of the dried hydrothermally modified materials was measured (FIG. 31A) and superimposed on the PSD of the corresponding raw material (FIG. 31B) to note similarities and deviations. In general, there was a strong similarity of materials before and after treatment with only some minor differences noted at 7=85 µm and 7=17 µm. Therefore, the PSD of the dried hydrothermally modified material can be controlled by changing the PSD of the raw material.

The effect of raw mix PSD on element leaching was investigated. The release of K was maximum for an average particle size of 85 μm. The larger particle sizes of 151 and 220 µm produced substantially equivalent amounts of released K, with the smallest particles giving an intermediate value (FIG. 31C). For Na and Al, the largest release of elements occurred at the smallest average particle size. Leaching generally decreased with increasing particle size. Calcium leaching was maximum when the raw mix PSD was 220 µm, with no leaching being detected at either 85 µm or 17 µm (FIG. 31D).

According to the data, the reactivity of the raw material can be controlled by changing the grinding ratio of the raw material. Thus, the surface area of the raw material can be increased to activate the reactivity of the raw material. Because of the strong correlation, the PSD of the raw material can be adjusted to obtain the desired PSD of the dried hydrothermally modified material.

Example 7 Sensitivity of dried hydrothermally modified material to decalcification.

As shown in FIG. 7A, drying the dried hydrothermally modified material with CO2 resulted in a decalcification reaction that eliminated the α-dicalcium silicate hydrate phase and replaced it with a calcite phase (Table 11). The amorphous phase is still present and somewhat enlarged. To achieve the data in Table 1, the mass fraction of the air-dried HT fraction was normalized to CO2-dried HT, i.e. an artificial phase fraction was added to quantify the air-dried HT phases corresponding to the amount of CO2 included in the CO2-dried HT as determined from the mass fraction of CaCO ₃ .

Table 11

Quantification of phases by XRD using CO2 or air based drying atmosphere

Atmosphere for drying

Phase CO2 air K-feldspar 50.2 51.9 Tobermorite 3.3 4.1 α-dicalcium silicate hydrate 0 5.5 Hydrogarnet 8.4 10.9 Albite 0.6 3.1 Panuncite 2.1 2.5 Biotite 0 0.3 Calcite 14.2 0 "SOg" but 6.5 Amorphous phase content 21.2 15.2

The following experimental setups were performed to further investigate the effect of CO2 drying on the structure and composition of the dried hydrothermally modified material:

1) the hydrothermal (HT) material was dried with the supernatant in an X (Ar or CO2) atmosphere;

2) the dried HT material was washed with Ar-purged water to remove soluble K (FIG. 27; eg KOH or K ₂ CO ₃ );

3) after filtration to remove water, the washed material (retentate) was dried under vacuum in a Schlenk flask (~ ^10-2 Torr) for 24-36 h;

4) The dried washed material was subjected to leaching experiments. Once the dried hydrothermally modified material was washed and dried (Ar or CO ₂ ), XRD was used to determine the mineralogical composition of each of the phases (Table 12). It should be noted that

- 46 039758 the calcite phase in the washed material dried with CO2 increased from 14.2 to 18.2, while the content of the amorphous phase decreased from 21.2 to 13.0. Other composition changes are also detectable.

Table 12

Quantification by XRD of washed phases using CO2 or air based drying atmosphere

Atmosphere for drying

Phase CO2 air K-feldspar 55.5 52.0 tobermorite 4.0 4.8 α-dicalcium silicate hydrate 0 5.1 Hydrogarnet 6.8 I,6 Albite 2.5 2.8 Panuncite 0 2.1 Biotite 0 oh, s Calcite 18.2 0 "CO ₂ " but 6.5 Amorphous phase content 13.0 14.9

The number of large particles is less in washed than in unwashed dried hydrothermally modified material (Fig. 33A). Superposition of HT dried with CO2 and washed HT dried with CO2 shows that the effective particle diameter remains the same.

Scanning electron microscope (SEM) images of Ar-washed HT dried with Ar confirm that sheets of calcium aluminosilicate hydrate (C-A-S-H) surrounding K-feldspar can be detected. In addition, hydrogarnet globular phases are embedded in a C-A-S-H matrix (FIGS. 33B and 33C). The biotite phase is also defined.

SEM images of washed HT dried with CO2 provide additional evidence that carbonization leads to compaction and decalcification of C-A-S-H sheets. Decalcified hydrogarnet is also clearly depicted. Carbonization accelerates the growth of Ca-rich polyhedral particles, providing another structurally different feature (FIGS. 33D and 33E).

An SEM micrograph of washed HT dried with Ar is shown in FIG. 33F. The numbers in the image refer to features typical of the respective phase, which were defined as follows: 1) K-feldspar (myrocline and orthoclase), 2) CASH (tobermorite, α-dicalcium silicate hydrate and amorphous), 3) hydrogarnet and 4 ) CaOH ₃ /Ca(OH) ₂ . Similar features were used to identify the phases in washed HT dried with CO2.

Dispersive X-ray spectrometry (EDS) was used to quantify the nominal atomic fraction of the elements K, Ca, Al, and Si in each phase (Table 13). Although there are no strong differences for the three elements, the Ca-containing phases are characterized by lower Ca/(Al+Si) in CO2-dried samples than when dried in Ar. Thus, CO2 can extract Ca from minerals during processing. Therefore, the effect of CO2 on the mineralogical composition of the material also showed the possibility of a decalcification process that results in the formation of SiO ₂ and Al ₂ O ₃ from K feldspar, as depicted in FIG. 33g. The conversion of K-feldspar to its constituents serves to further illuminate the suitability of the disclosed methods in a host of industries and applications.

Table 13

Nominal atomic fraction of phases determined by SEM and EDS

Nominal atomic fraction

K/ Ca/ ΑΪ7 Si7 ______________________(M ^a +Al+Si) (M+Al+Si) (M+Al+Si) (M+Al+Si) Hydrothermally treated material

Washed, dried with Ag NT

K-feldspar 0.18(2) but 0.22(2) 0.6(1) C-A-S-H 0.01(1) 0.47(4) 0.09(2) 0.43(3) hydro grenade but 0.54(3) 0.16(3) 0.30(2) CaCO3 / Ca (OH) ₂ but 0.97(1) but 0.3(2) Washed, dried with CO ₂ HT K-feldspar 0.22(3) but 0.17(3) 0.61(2) C-A-S-H 0.05(4) 0.08(5) 0.14(3) 0.73(4) hydro grenade but 0.23(3) 0.26(4) 0.51(2) CaCO3 / Ca (OH) ₂ 0.01(1) 0.96(1) 0.01(1) 0.01(1)

^and M corresponds to K, or Ca, or the sum of K and Ca

Example 8 pH and concentration dependent leaching and dissolution.

- 47 039758

Comparison of leaching in CsNO ₃ /HNO ₃ and tetramethylammonium hydroxide.

It is possible that the degree of leaching can be increased by efficient exchange of the cation with potassium in the appropriate phases. Based on the assumption that cation exchange occurs in the hydrated interlayers of the tobermorite phase and/or the amorphous CASH phase, there should be a limit to the size of the cation that the putative exchange sites can meet. Thus, leaching was evaluated in a variety of leaching solutions to gain insight into the size of the cation capable of exchanging and then releasing potassium (K). In particular, we compared Cs ⁺ and NMe4 ⁺ (TMA) with cation radii of 1.67 A and ~4.5 A, respectively. Using a CsNO3/HNO ₃ leaching solution (pH 5), the amount of K released was significantly increased compared to HNO ₃ pH 5 (FIG. 37A). Found that Cs ⁺ , based on its corresponding size, is very effective in cation exchange with K ⁺ . On the other hand, the large TMA cation from tetramethylammonium hydroxide (TMAOH) is inefficient at ion exchange with K ⁺ containing sites. It is also clear from the results that hydroxide-mediated lattice dissolution is not the primary mechanism for the release of K from the solid phase. In addition, the dried hydrothermally modified material has been shown to be stable under basic conditions of ~pH 12.

Release of minerals in acetate buffer.

The leaching conditions in the buffer were compared with a standard HNO ₃ solution (pH 5). The release of K in the presence of acetate buffer (pH 5.3) only slightly increased, but slightly acidic buffer conditions greatly accelerated the dissolution of Ca-containing phases (Fig. 37B). As shown in pH 5.3 buffer solutions, components of the dried hydrothermally modified material can dissolve when the material is subjected to acidic pH. Additionally, the material can serve as a useful source of soluble Al under acidic conditions (see FIGS. 37B and 26 for data).

Leaching of elements in CsNO3 in washed dried hydrothermally modified material

Similar to the conditions used in Example 7 (FIG. 32), the dried hydrothermally modified material was washed with water to separate the K release contribution from the solid phase from the soluble components. The main difference in this test was that a CSNO ₃ /HNO ₃ leaching solution was used to see if the release of K from the solid phase could also be increased by efficient cation exchange with Cs ⁺ (FIG. 37C).

K from the solid phase contains a fraction of the total K available for release, thus washed materials dried with either Ar or CO2 have lower K release than the corresponding unwashed samples in the HNO ₃ leach solution (FIG. 37D). This difference gives the proportion of soluble/fast-released K in the dried hydrothermally modified material. In the case of CO2 drying, the mass balance dictates that the loss of K in CO2 dried HT occurs in the solid phase (ie, K redistributed by carbonization, see FIG. 37E).

In FIG. 37D and 37F, a comparison is made between K leaching in dried hydrothermally modified material, subsequently washed with water, and then re-dried under different atmospheres. Based on the data, solid phase components were found to promote Cs uptake and K release. This was confirmed by three materials (Ar-dried HT, Ar-dried HT-washed, and CO2-dried HT-washed), each _of which subjected to leaching in CsNO ₃ /HNO ₃ which in all cases showed a greater release of K than when the HNO ₃ solution was used alone (Fig. 37F vs. Fig. 37D). In addition, drying in CO2 in the presence of CsNO3 has been found to have the same effect as leaching in CsNO3, providing a different approach to increasing soluble K.

Example 9 Effect of Additional Refluxing of Dried Hydrothermally Modified Material.

The dried hydrothermally modified material was obtained as follows:

1) 25 g of raw mix (Ca/Si=0.3) in 100 g of water;

2) hydrothermal treatment was carried out at 200°C for 5 h;

3) The combined solids/supernatant was dried in air at 100-110°C for 18 hours.

The dried hydrothermally modified material was then further refluxed at 90° C. to study the effects of this treatment. With a treatment time of 5 h and using an atmosphere of air, a complex mineralogical composition was achieved, summarized in table. 14. The main components were Kfs (44.5% for combined orthoclase/myrocline), amorphous phase (26.7%) and tobermorite (17%). Tobermorite was present in a significantly higher amount than in the dried hydrothermally modified material obtained without additional reflux.

- 48 039758

Table 14

Mineralogical composition of refluxed material

Air-air-5h-96h_ reflux 90°C KAlSi ₃ O ₈ (Orthoclase/feldspar) 12.2 KAlSi ₃ O ₈ (Microclean) 32.3 Ca ₅ Si ₆ Oi ₆ (OH) ₂ -4H ₂ O (Tobermorite) 17 Ca ₂ SiO ₃ (OH) ₂ (A-dicalcium silicate hydrate) 0 Ca ₃ Al ₂ (SiO ₄ ) ₃ -x (OH) ₄ x (Plazolite/Hydrogrossular) 7.3 NaAlSi ₃ O ₈ (albite) 2 (K,Na)AlSiO ₄ (Panuncite) 2.5 K(Mg,Fe) ₃ (AlSi ₃ Oio)(F,OH) ₂ (Biotite) 0 _CaCO3 (Calcite) 0 Amorphous phase content 26.7 KFS (no panuncitis) 44.5 KFS (with panuncitis) 47 Total 100

The refluxed dried hydrothermally modified material was also studied for its K release properties (FIG. 36). Comparing the conditions tested, leaching was found to be greater when reflux was carried out for 24 hours. Increasing the amount of time to 96 hours significantly reduced the K release capacity of the material. results.

All references, articles, publications, patents, patent publications and patent applications cited herein are incorporated by reference in their entirety for all purposes. However, mention of any reference, article, publication, patent, patent publication and patent application cited herein does not constitute and should not be taken as knowledge or any form of suggestion that they constitute prior art or form part of the common knowledge in any country in the world. .

CLAIM

Claims (15)

CLAIM 1. A soil remediation composition comprising a K-feldspar phase and a calcium silicate hydrate phase, comprising at least one phase selected from the group consisting of a dicalcium silicate hydrate phase, a tobermorite phase, and a hydrogarnet phase; moreover, the composition contains a phase of K-feldspar in an amount of not more than 65 wt.%; and at least one of the following is met: the composition contains at least 1 wt.% of the dicalcium silicate hydrate phase; the composition contains at least 1 wt.% of the tobermorite phase or the composition contains at least 1 wt.% of the hydrogarnet phase. 2. The composition of claim 1, wherein the composition contains at least about 1% by weight of the K-feldspar phase. 3. Composition according to any one of claims 1, 2, wherein the composition contains from 1 to 30% by weight of the calcium silicate hydrate phase. 4. A composition according to any one of claims 1 to 3, wherein the hydrogarnet phase contains plasolite or hydrogrossular. 5. A composition according to any one of claims 1 to 4, further comprising an amorphous phase resulting from the conversion of K-feldspar. 6. Composition according to claim 5, wherein the amorphous phase contains zeolite. 7. The composition of claim 5, wherein the amorphous phase contains at least one member selected from the group consisting of silica and calcium silicate hydrates. 8. Composition according to any one of claims 1 to 7, additionally containing one or more carbonates. 9. The composition of claim 8 wherein the one or more carbonates are selected from the group consisting of K ₂ CO ₃ , YCO3, MgCO3 and CaCO3. 10. Composition according to any one of claims 1 to 9, wherein the composition is characterized by a release rate after 24 hours per 1 kg of composition of at least one of: at least 5000 mg of potassium according to the potassium release test after 24 hours; at least 15 mg of calcium according to the calcium release test after 24 hours; no more than 10 mg of aluminum according to the test for the release of aluminum after 24 hours; not less than 40 mg of silicon according to the test for the release of silicon after 24 hours; - 49 039758 at least 5 mg sodium according to the sodium release test after 24 hours or at least 5 mg magnesium according to the magnesium release test after 24 hours. 11. A composition according to any one of claims 1 to 10, wherein the composition contains aggregated particles ranging in size from 100 to 1000 microns. 12. A composition according to any one of claims 1 to 11, wherein the composition comprises particles with a BET specific surface area of 15.1 to 46.9 m ² /g. 13. Composition according to any one of claims 1 to 12, wherein the composition is characterized by a particle size distribution from 0.01 to 1000 µm. 14. Use of a composition according to any one of claims 1 to 13 for soil reclamation. 15. A fertilizer containing a composition according to any one of claims 1 to 13.