DD210681A1 - Potassium chloride and magnesia compounds containing fertilizer and soil improvers - Google Patents

Abstract

The invention relates to a potassium chloride u. Soil improvers and fertilizers containing magnesium compounds and a process for its production from natural raw materials or secondary raw materials which have scarcely been used for this purpose. The task was to provide the novel fertilizer and soil conditioner and finding a production method under the boundary conditions, use of sufficiently abundant raw materials, high material utilization of the materials contained in these materials and not least significant reduction in environmental impact. The novel fertilizer and soil conditioner provides an intimate mixture (without taking into account the inert materials) from potassium chloride, various crystalline silicates, preferably forsterite resp. forsteritaehnliche phase, a "spinel-like phase", optionally roentgenamorphen material and possibly some magnesium oxide. It is produced according to the invention by calcination of a mixture of carnallite-containing material and clay mineral-containing raw material at a temperature equal to or above the decomposition temperature of the clay minerals of the siliceous raw material, preferably between 700 and 800 degrees Celsius, advantageously in the presence of water vapor. From the reaction product can continue to gain an improved potassium chloride and magnesium compounds containing fertilizer and soil conditioner.

Description

Fertilizer containing potassium chloride and magnesium compounds

Soil conditioners

Field of application of the invention

The invention relates to a fertilizer and soil conditioner containing potassium chloride and magnesium compounds and to a process for its preparation from carn.allithaltigem material.

Characteristic of the known technical solutions

The world's most important raw materials for the production of fertilizers based on potassium chloride represent the salt rocks that occur in powerful deposits, in particular carnallitite, Sylvin.it and hard salt. Among these salt rocks, carnallitite has for years been of major technical importance to the fertilizer industry. The minerally extracted carnallitite consists of a mixture of the mineral carnallite (KCl · MgClI · 6H ₂ O), which forms the actual value of the rock, with rock salt, kieserite or other constituents.

It is known that carnallite is unsuitable as a fertilizer (physiological antagonism in the uptake of almost equal molar proportions Mg " ¹ ""-" and K ⁺ ions, through the roots, the plants); Carnallite resp. As a result, carnallitite must be worked up for potassium chloride ",

Proposals cam alii thai ti ge s material under very high pressure to decompose at about 200 ⁰ C (vgl.zB: DE-PS 281 913) or to digest with liquid NH ^ (cf .: DE-PS 575 914) have for their high apparatus. Effort and their bad

2436 11

Energy balance technically, can not enforce.

It has also been proposed to separate out and separate the MgClp component of the carnallite by means of chemical agents in an aqueous medium. Suitable for this purpose are "alkalis (cf., for example, DE-PS 599.301; DE-PS 609.225) or amines (cf., for example: J ¹ R-PS Ί.116.Ο15; US-PS 2,977,186) is the use of synthetic products of the chemical industry, the recovery of which is known to be energy- and material-consuming, and this is the main disadvantage of their use.

Finally, it has been tried, the above-mentioned, physiological antagonism in the use of Oarnallit as a fertilizer by adding a large excess of. Potassium fertilizers to raw or calcined carnallite (see: DE-AS T.592.818) or dried to pyrohydrolysed carnallite (see: DD-PS 141.018) to avoid «, the disadvantage of both proposals consists essentially, in. the admixture from potassium fertilizers to prepared carnallite. In the case of the use of potassium chloride this means a "technical-economic Circulus vitiosus, since the required KCl are currently produced only from carnallite must,"

In the case of technically introduced carnallite processing, the carnallitically bound KCl is readily soluble in the water, even in the cold. MgCl "component as well as the. Secondary components separated. Apart from that, the not inconsiderable energy requirement and noticeable KCl losses are their main disadvantage in the onset of a large volume of magnesium chloride-containing final leaches, the so-called "potassium lye". Whose comprehensive recovery is despite various Proposals (vgl.zB: DD-PS 146.029; DD-PS 151.056) so far not succeeded.

Although it should be possible to increase the potassium chloride yield in carnallite decomposition by using mixed solvents, for example water / acetone, or by precipitation, with organic solvents, in particular methanol; one

The proposals do not generally contribute to reducing the environmental impact. The recovery of the organic. Substances complicates the procedures, in addition.

It has also been recommended (DE-AS 1,198,802; DE-OS 1,467,293; DE-OS 3,010,755) to carry out the decomposition of carnallite with C. to C. alcohols. In this case, the MgClp component changes into the alcoholic phase; KCl forms the sediment. After that. Separation should be able to recover both the alcohol and the MgClg-G content. In the work-up of the resulting organic phase, a so-called "mixed phase" of alcohol, water and MgClp component, which makes the quantitative recovery of the alcohol and the MgClp component under simple, technical conditions, is known to occur at an early stage. A thereby taking place in general partial hydrolysis of Magnesiumchloridlrydrate more difficult this process. It should be possible to avoid the said "mixed phase" when above about 400 ⁰ C calcined carnallite is used (see, for example: US Patent 3,341,282, US Patent 3,401,011). However, the general disadvantage of these methods is the use of combustible organic solvents which require considerable additional safety measures.

In DD-PS 143.364 finally a method for the production of KCl by pyrohydrolysis of a mixture of carnallite and mechanically and / or chemically activated SiO _? Suggested. During the thermal treatment of said, mixture evaporates, the KCl and can be recovered in this way. The Kachteil this proposal consists in both the use of a synthetic. SiO ^ component as well as in the invention essential evaporation of potassium chloride; the latter is known to require high temperatures,

Object of the invention

It is the object of the invention to find a fertilizer and soil conditioner containing novel potassium chloride and magnesium compounds and a process for its production from carnallitic material.

Presentation of the invention

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It is an object of the present invention to provide a fertilizer and soil conditioner containing novel potassium chloride and magnesium compounds, which further contains KCl, more particularly silicates, which by virtue of their chemical composition do not exert a negative influence on the soil structure and in an advantageous embodiment of the invention act as magnesium-containing long-term fertilizer. , ,

Vifeiterhin the object of the invention was to find a method for producing the novel fertilizer

- from domestic raw materials, in particular carnallite-containing material,

- in case of extensive material use of the recyclables of the raw materials used,

- Only one chemical process step with reaction temperatures below 1050 ⁰ C.

last but not least

- without significant environmental impact.

According to the invention was a. novel potassium chloride and magnesium compounds containing fertilizer and soil conditioner and a process for its preparation found. The characteristics, the fertilizer and soil conditioner and the method can be taken from the claim of the invention.

Dcis found novel potassium chloride and magnesium compounds containing fertilizer and soil conditioner is an intimate mixture of KCl, various crystalline silicates, preferably porsterite, possibly crystalline MgO, optionally X-ray genamorphic material and optionally inert substances. The content of the novel agent to KCl can vary a wide range; In general, it can be adjusted in a targeted manner via the composition of the starting mixture. The novel agent advantageously contains 20 to 75% by mass of KCl. As a component of the inventive agent from the group of different crystalline silicates occurs preferably orsterit resp.

Lk a D 1 ID

  - 5 -

forsterite-like material. Further, usually minor proportions, crystalline silicates may be included in the fertilizer and soil conditioner of the present invention, but the assignment of the observed lines is X-ray to known well crystallized silicates (eg listed in: Ed .: JCPDS: XPDF, Swartmore: JCPDS ) extremely difficult because of the multiplicity of lines and coincidences that occur. Finally, a "spinel-like phase" was observed in the novel agent. Due to the line broadening and systematic line shift of the same, it may be assumed that this is the one doped with MgO, the thermal. Decomposition of clay minerals known per se before mullite formation is. The constituents mentioned, in particular forsterite, "spinel-like phase" and possibly X-ray amorphous material, are basically in-soil soil improvers and depot fertilizers.

Inert material in this description of the invention is understood to mean a predominantly crystalline material which originates from the raw materials used for the production of the novel agent and has not changed practically during the reaction, for example quartz and optionally calcite from the clay mineral-containing raw material; NaCl from the carnallite-containing material. Both. Inert substances are usually fibers of the fertilizer which have no adverse influence on its action. In special cases, NaCl may be advantageous as a fertilizer. The same applies to the included. Sulfates.

The method for the preparation of the novel fertilizer and soil conditioner is to prepare a mixture of a carnallite-containing material with a clay mineral-containing raw material and then calcination of this mixture at a temperature equal to or above the decomposition temperature of the clay minerals (eg kaolinite, mixed layer minerals) in the corresponding Raw material, preferably between 700 and 800 ⁰ C, advantageously in the presence of water vapor, within normal times in. known plants. The mass ratio of advantageous intimate mixtures of carnallite-containing material and mineral-rich raw material is 2 to 1 to 8 to

Z43Ö 1 1

As carnallithaltiges material for the specified method are all natural, possibly prepared and / or dried Oarnallitite resp. Carnallite, but preferably synthetic carnallite, advantageously dried, or mixtures of said materials.

As tonciin.eralhaltiger raw material, according to the invention all Rohkaoline, raw clays, processed kaolins or clays, clays or the like. Or mixtures thereof can be used. In terms of properties, the silicate starting materials listed should contain more than 60% by weight of clay minerals. Also, the use of the known storage compounds of clay minerals or smectite - organic. Complexes alone or in admixture with the other listed siliceous raw materials. is provided according to the invention.

The experiments carried out showed that occur in the calcination of mixtures of standard kaolin, and carnallite at different reaction temperatures and different mixing ratios within the error limits of the measuring methods used as the main crystalline phases (without taking into account the inert materials) KCl and forsterite. In addition, the already described "spinel-like phase" was found. At low calcination temperatures it is only indicated; Here, X-ray-amorphous material increasingly occurs. Furthermore, small amounts of "other silicate phases" which could not be clearly identified were found in the reaction product. They occur in particular at high reaction temperatures.

The results described above can be interpreted to mean that the carnallite is only completely dehydrated (calcined water) during calcination, the mixture first, and then the MgClp component comprising pyrohydrate is lysed, its KCl content being retained almost completely in the fired product. If the pyrohydrolysis of MgOlp component certainly to small extent during the drying of the Oarnallites above 400 ⁰ C., and in the presence of water vapor significantly vigorously above 500 ⁰ C a. It can be assumed that the pyrohydrolysis by the decomposition

Z 4 3 b 1 1 b

- 7 -

the Tonrninerale, preferably of the kaolin! ts, freiwerden.de water is completed; however, the reaction product "MgO" is rapidly chemically bound by the "metastable phases" formed during the decomposition of the clay minerals, preferably forming porsterite as the stable crystalline phase. To what extent the described reaction sequence "Pyrohydrogenysis / Interception of the" MgO "" can be assigned temporally can not be answered as well as a conceivable influence of the KCl and possibly the inert substances.

J) The resulting during the calcination of the mixture of carnallithaltigem material and clay mineral-containing raw material gaseous reaction products of water and HCl can be obtained outside the reaction sraumes, possibly after separation of the pesticides, in per se known quantitatively.

An advantageous embodiment of the method according to the invention consists in removing the soluble. Ingredients of the potassium chloride-containing fertilizer and soil conditioner according to the invention by means of water. From the. obtained solution can be recovered after separation of the residue and purification in known per se KCl. It has proved to be favorable to finely comminute the water-insoluble residue dry or wet, preferably to particle sizes smaller than 0.04 mm. Such activated, preferably forsterite-containing, silicate body is a delayed-release magnesium soil improver. By adding this powder or the corresponding suspension to known fertilizers or their solutions, magnesium-containing fertilizers and soil conditioners can be prepared. Advantageously, however, the finely comminuted forsterithaltige powder or the corresponding suspension in. Optionally selectable proportions, if necessary combined kaliuaichloridhaltigen solution, optionally thoroughly mixed in and then the KCl in known per se eliminated, the pesticides separated and dried. By this operation, an improved potassium chloride-containing fertilizer of the present invention is obtained. Before, during or after the excretion of the potassium chloride, the auxiliaries known per se for improving the granulation, trickling

8sv nj ·, ¹ ^ l r -

ability u. Like. Be added.

The fertilizer according to the invention may be mixed with the known fertilizers, soil improvers and additives. to NK, PK or NKP fertilizers ... '««

A guide example

The invention will be explained in more detail in the following embodiment, wherein it is not limited to this example.

Raw materials:

1. kaolin of chemical composition (in% by mass): 52.6 SiO ₂ ; 34 Al ₀ (X; 0.6 Fe ₂ O- and TiO ₂ with the mineral constituents (in% by mass) 86 kaolin.it and 14 quartz.

2. kaolin of chemical composition (in mass%): 63.4 SiO ₂ ; 21.7 Al ₂ O ₃ ; 1.5 Fe ₃ O ₃ and TiO ₂ ; 2.1 MgOJ 4.5 K ₃ O and the mineral constituents (in% by mass) 58 mixed layer minerals; 22 quartz; 17 kaolin.it; 3 feldspar.

3. Glaze clay of chemical composition (in mass%): 51.7 SiO ₂ ; 10.6 Al ₂ O ₃ ; 11.9 CaO; 5 Fe ₃ O ₃ and TiO ₂ ; 5 MgO; 3.3 alkali oxides and the mineral constituents mixed layer minerals, quartz, calcite, dolomite, kaolinite and others.

4.Carnal with the mineral composition (in% by mass) calculated from the chemical analysis 55 carnallite; Halit; 8 kieserite; 5 anhydrite and 2 sylvite (in the X-ray diagram only carnallite and halite could be identified).

Working Procedure;

From the. Raw materials. 1 or 2 or 3 and raw material 4 were, by intensive mixing and grinding in. An agate mill, the required. Preparing starting mixtures of carnallite-containing material (CM) and clay mineral-containing raw material (TR). These mixtures were calcined in portions in a M 12 laboratory muffle furnace and allowed to cool after termination of the reaction. Thereafter, the predominantly in. Form coarse grains present product is crushed and examined. The results are shown in the table ",

Table; Selected survey results

example 1 Example 2 Example 3 Example 4 Example 5 Example 6 raw materials 1 and 4 2 and 4 1 and 4 2 and 4 3 and 4 1 and 4 Mixing ratio TR to CH 1 to 2 1 to 2 1 to 4 1 to 4 1 to 4 1 to 6 Calcination temperature in K 1000 1000 1075 1075 1075 1250 Calcination time in h 3.5 3.5 3.5 3.5 3.5 2.5

Phases of the reaction product (X-ray graphically):

Main components:

Potassium chloride + sodium chloride + JPorsterite

Neben.bestandteile:

"spinel-like phase" + quartz X-ray amorphous material calcite

"other silicate phases.

traces

X-ray amorphous material

Claims (7)

1. Düngeuiicl Bodenverbesserungsmittel containing potassium chloride and magnesium compounds, characterized in that it is an intimate mixture of (the inert materials are not taken into account here). - 20 to 75% by mass of potassium chloride. - Rest different crystalline silicates, before preferably Forsterit resp. forsterite-like phase, a "spinel-like phase", optionally X-ray amorphous material, possibly magnesium oxide, in which the water-insoluble components should preferably have a particle size of less than 0.1 mm, advantageously less than 0.04 mm. 2. Process for the preparation of a fertilizer and soil conditioner containing potassium chloride and magnesium compounds, gj3kj5nm ^^ that the following steps are carried out successively: a) preparation of a mixture of carnallite-containing material and clay mineral-containing raw material, wherein the mixture should contain 20 to 80% by mass of carnallite-containing material calculated as MgCl ₂ , b) calcining the mixture produced at a temperature equal to or above the decomposition temperature of the clay minerals of the siliceous raw material, preferably between 700 and 800 ⁰ C, advantageously in the presence of. Steam, c) separating the solid from the gaseous reaction products and recovering them. 3. The method according to item 2, characterized in that a carnallitite, a prepared carnallitite, a natural or synthetic carnallite, a pre-shredded and / or dried carnallitite resp. Carnallite or a mixture of said materials is used. 4. The method according to item 2, characterized in that a natural or processed kaolin resp. Clay, a clay ο. Like. Or a mixture of the listed raw materials used becomes. 5. The method according to item 4, characterized in that the clay mineral-containing raw material contains more than 60% by mass of clay minerals, preferably of the kaolinite type or mixed layer minerals or mixtures thereof. 6. The method according to item 2 or 4 or 5, characterized in that the known per se. Intercalationsverbin.dungen of kaolinite or the smectite - organic complexes or mixtures of enumerated substances are used. 7. A process for the preparation of a potassium chloride and magnesium compounds containing fertilizer and soil conditioner according to item 2, characterized in that the following steps are carried out in succession: d) treating, the separated solid reaction product according to item 2c) with water or treated reflux brine, preferably in the heat, e) separating the potassium chloride-containing solution from the residue and washing it to the required extent, f) precipitation of the potassium chloride from the optionally purified liquor in a manner known per se, g) collecting the wash water and / or the potassium chloride-poor lye to the return brine, treating it and, if appropriate, reuse in process step d), όΌ IS h) mixing of the residue after step e), the off (the inert materials are disregarded) - The active ingredient porsterite resp. forest-like phase - The Bodenverbesserüngsmitteln "spinel-like phase", optionally X-ray amorphous material, possibly other crystalline silicates and - If necessary magnesium oxide and preferably has a particle size smaller than 0.1 mm, advantageously less than 0.04 mm should, with solid potassium chloride and / or suspending the said residue in the optionally purified potassium chloride-containing solution after step e) and precipitating the potassium chloride in known and separating the pesticides _e