CZ2021260A3 - A method of obtaining gold and other rare, noble and strategic metals and rare earths using activated iron nanoparticles in a magnetic field or by dissolving them in natural concentrated mine waters, so-called brines rich in I and Br - Google Patents

Abstract

The method of obtaining gold and other rare and strategic metals, including rare earths (e.g. Ce, La, Nd, etc.) from natural rocks, minerals, secondary products and waste materials is that after concentrating and separating the minerals of the treated rock or waste according to density and particle size when dry by air sorting, removal of impurities in a magnetic field and based on the concentration of Au and rare metals and rare earths according to their electrical conductivity by isolation of coarser gold (boulders, lumps, gold nuggets) by a combination of proposed treatment methods and/or after breaking the aluminosilicate lattice , quartz and sulfides and conglomerates containing Au and other noble and strategic metals, including waste products and materials (e.g. waste from the mining of gold and other noble metals, used electronics, mobile phones, dust collectors, drifts, tablecloths, municipal waste, ashes, products after desulphurisation, sorbents after chemosorption of gaseous products after burning coal, other biomass and RDF, products containing Au and other rare and strategic elements, etc.) by thermal, cryogenic (freezing), chemical, microwave, mechanical or ultrasonic delamination, with the possibility of obtaining gold invisible to the naked eye and other rare and strategic elements by separating the finest nanoparticles and several micron particles of Au, Ag, Pt, but also Cu, Zn, W, Mo, Ge, In, Hg, etc. in a grain size of 0 to 100 µm, using the great adhesion of the used activated nanoparticles of iron and its compounds after placing them in a magnetic field or by dissolving them (grain size most often 0 to 50 µm) in water rich in concentrated amounts of iodine I and bromine Br in so-called natural mine brines. In order to accelerate the dissolution of Au and other rare elements in the concentrate, it is possible to use in mixed and heated continuous, cascade tanks, landfills with spraying, etc. simultaneously mechanical-chemical delamination of dissolved particles by grinding or ultrasound or microwave heating.

Description

The method of obtaining gold and other rare, noble and strategic metals and rare earths using activated iron nanoparticles in a magnetic field or by dissolving them in natural concentrated mine waters, so-called brines rich in I and Br

Field of technology

The subject of the invention is a method of obtaining gold and other rare and strategic metals from natural rocks, minerals, secondary products, including waste products, after concentration by dividing the minerals of the treated rock according to density and particle size in dry air sorting, removing impurities in a magnetic field and on the basis of concentration Au and precious metals according to their electrical conductivity by isolating coarser gold (boulders, lumps, gold bars) and/or breaking the lattice of aluminosilicates, quartz and sulfides and amalgams containing Au and other noble and strategic metals by thermal, cryogenic (freezing), chemical, microwave , mechanical or ultrasonic delamination with the possibility of obtaining gold invisible to the naked eye and other rare and strategic elements by separating the finest and several micron particles of Au, Ag, Pt, but also Cu, W, Mo, Ge, In, Hg, etc., as well as rare earths (e.g. Ce, La, Nd, etc.) by means of the high adhesion of the used activated nanoparticles of iron and its compounds after being placed in a magnetic field or by dissolving them in water rich in concentrated amounts of iodine I and bromine Br in so-called natural mine brines.

Current state of the art

Currently, primary deposits are mined, where the gold is very finely dispersed in the rock and the metal is extracted from the hominy by hydrometallurgy. The process consists of finely grinding the hominy so that most of the microscopic gold grains present can come into contact with the lye solution. The ground rock is then leached either with an acidic solution with a high content of chloride ions and an oxidizing environment (e.g. saturation with chlorine gas or the addition of nitric acid) or, conversely, with a solution of alkaline cyanides while bubbling with air oxygen. From the leaching solution, gold is then obtained by reduction, e.g. by passing an electric current through the solution (electrochemically), when metallic gold is excluded at the negative electrode, the cathode. The reduction can also be carried out chemically by adding a suitable reducing agent (hydrazine, metallic aluminum, etc.).

The amalgamation method of extracting gold from ores was used in the past to extract alluvium, in which gold was present in the form of larger separate grains, but which was already difficult to obtain by panning. For this purpose, the gold-bearing rock was contacted with metallic elemental mercury. The resulting gold amalgam was usually simply pyrolyzed after the hominy was separated, and the mercury was simply evaporated into the atmosphere. Currently, this procedure is hardly used, and if it is, the gold is extracted from the amalgam in a more gentle way without contaminating the atmosphere with mercury vapor.

Less widespread, the most effective, but also the most harmful, is the process of obtaining gold by cyanide leaching, using sodium cyanide NaCN, which is harmful to people and destructive to nature. The leaching technological procedures consist in physical contact (by crushing or crushing and grinding) of the gold in the ore with a leaching solution of sodium cyanide. The concentration of the leaching agent is usually very low, typically 0.1%. The actual isolation of the desired gold is carried out either by precipitation with powdered zinc from the liquid phase or by adsorption on activated carbon directly from the suspension after leaching with subsequent desorption and electrolytic exclusion of the gold from the eluate on the cathode.

The final step usually carried out in a gold ore processing plant is the remelting of zinc precipitate or gold-rich cathodes with slag-like substances into raw gold (Doré). Further necessary gold refining is carried out in specialized refineries. The leaching agent is partially consumed during leaching. The common practice of these treatment plants is that they work with a closed circuit of technological waters. Residual values of cyanide are effectively detoxified into non-toxic products, for example by air oxidation in the presence of sulfur dioxide or hydrogen peroxide oxidation. For the most part, they degrade

-1 CZ 2021 - 260 A3 in the final result to carbonates and ammonium ions and to a lesser extent to complexly bound non-toxic cyano complexes.

The existing methods of obtaining gold by leaching it from the deposits did not do without poisonous solutions of various cyanides, salts of hydrocyanic acid. An environmentally friendly alternative solution has recently been found. It was found that instead of cyanides, a mixture made from corn starch is sufficient for leaching gold (the essential leaching component in this case is the so-called alpha-cyclodextrin). The substances contained in starch are relatively cheap and mainly biologically harmless, unlike cyanides.

Gravity separation procedures take advantage of the large difference between the specific gravity of the gold (19,300 kg/m ³ ) and the specific gravity of the parent hominy (typically 2600 to 3500 kg/m ³ ). With modern separation devices based on the centrifuge principle, in favorable cases, a product with such a high gold content can be obtained that it can be processed directly by smelting into raw gold. These devices are characterized by the fact that, apart from water, no reagents are used in the separation of ores.

Another well-known method is flotation disaggregation, where flotation uses the different wettability of gold, or minerals with which the gold is aggregated from the mother hominy. Compared to the parent rock, gold is hydrophobic and therefore gold particles tend to collect on the surface of air bubbles in the aerated mash, rise with them to the surface and thus concentrate in the mineralized foam. The host rock exhibits hydrophilic properties and its particles thus remain in a gold-depleted suspension. The flotation concentrate can be processed both hydrometallurgically (using cyanide leaching) and non-cyanide, pyrometallurgical processes based on melting or roasting.

Among the most widespread methods of obtaining gold are:

- cyanide leaching in stirred reactors, sorption from mash on activated carbon (Carbon-lnPulp), electrolytic exclusion of gold;

- simultaneous cyanide leaching and sorption in stirred reactors (Carbon-ln-Leach), electrolytic exclusion of gold;

- cyanide leaching in stirred reactors, phase separation (by countercurrent washing or filtration) and cementation of gold with zinc dust;

- heap or percolation leaching, gold cementation with zinc dust;

- heap or percolation cyanide leaching, adsorption of gold from a solution onto activated carbon in a column (Carbon-ln-Column); and

- Au obtained by non-leaching processes, e.g. flotation and/or gravity methods, pyrometallurgical termination.

-2 CZ 2021 - 260 A3

Some new production processes, often with a negative impact on the environment, include, for example:

- obtaining gold from roasted concentrates by the so-called crucible method, when it is melted with soda, clay (PbO) and a reducing additive, while the precious metals (Au and Ag) turn into reduced lead,

- after leaching, gold is obtained from cyanide solutions using ion exchangers, as a substitute for the precipitation of Au with zinc dust, the technology of obtaining gold from the drifts of roasting furnaces, by leaching anode sludge in HC1 in the presence of chlorine with subsequent extraction in liquid with organic solvents /amines/ etc.

The disadvantage of most existing methods of obtaining gold is mainly the ecological problem and the negative effect of the chemicals used on the environment.

The magnetic field is not yet used for gold extraction due to the paramagnetic (non-magnetic) properties of gold and other precious metals. The aim of the present invention is to create a concentrate of Au and other precious metals by air sorting according to the density and particle size of the minerals represented, to get rid of magnetizable impurities such as mica and other magnetizable impurities and to bind gold and other precious metals according to excellent conductivity or using clean and harmless activated nanoparticles iron and its compounds, which are easily magnetizable and thus the magnetic field can be used to obtain concentrates of rare metals and rare earths and elements without the use of dangerous and objectionable chemicals, from which gold and rare metals can already be obtained by conventional technological procedures. It depends on the state of the activated nanoparticle and the conditions in the magnetic field, i.e. in some cases, for example, Fe nanoparticles bind to impurities (e.g. sulfides), other nanoparticles directly to metal, rare elements.

The essence of the invention

The subject of this invention is a method of obtaining gold and other precious metals from natural rocks, minerals and waste products after creating concentrates of gold and other precious metals by air, cascade sorting according to the density and size of the mineral particles in a defined area, removal of magnetizable impurities (e.g. mica, etc.) .) in a magnetic field and selective separation of highly conductive Au particles and other rare metals according to electrical conductivity with obtaining visible Au particles and other strategic elements after individual technological operations or their combination. The raw materials containing gold and/or other precious metals are dry or wet separated into such a particle size that they are separated by an air cascade filter according to density and particle size, obtaining a heavy portion containing Au and other precious metals, which is then subjected to separation in a magnetic fields where free gold (cobbles and gold flakes), gold bound in quartz, sulfides and other minerals or their decomposition products passes into the non-magnetic portion. According to the need to reduce the volume of the obtained concentrate and to concentrate the amount of gold and other precious metals obtained after air sorting and magnetic separation, it is possible to divide the non-magnetic, but possibly even the magnetic part, if it contains Au particles and other rare metals, into optimal granularity on the basis of electrical conductivity, when concentrated, excellent conductive particles of Au, Ag, Cu, Pt and other rare noble and strategic metals (e.g. W and Mo) are captured on a continuous, electrically charged separation drum. The non-magnetic part after dry or wet magnetic separation obtained in a variable magnetic field or the conductive, concentrated part can be further thermally heated (calcined) to break the lattice of aluminosilicate, quartz or sulphides and to release the inclusions of Au and other rare metals at a temperature of 500 to 1000°C or subject to microwave delamination or perform ultrasonic delamination with hard ultrasound at an oscillation frequency of 20 kHz or release Au and other precious metals from inclusions with quartz or sulphides chemically, using

-3 CZ 2021 - 260 A3 natural mine brines rich in I and Br or by using a common combination of chemical reagents of the type KI and I, resp. KBr and Br.

The essence of the invention to obtain coarser Au particles and other strategic elements (boulders, lumps, gold nuggets) after carrying out a combination of technological modifications to obtain a much reduced volume concentrate and/or to the naked eye the finest invisible and micron Au particles and other rare and strategic metals also consists in the fact that magnetizable activated iron nanoparticles, much finer (e.g. 0.100-0.500 μm), with a very large specific surface area than those of several microns up to approx. 100 μm large gold bars, selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds with different electrical charges, after which a mixture, or suspension, of particles of precious and strategic metals created in this way, covered on the surface with a thin layer of nanoparticles subjected to magnetic separation, whereby originally non-magnetic particles of gold or otherc h of precious metals, enveloped by physical forces with an adhesive layer of magnetizable nanoparticles, are captured in the magnetic field on the matrix in the magnetic portion and at the same time are separated from non-magnetic tailings or, conversely, nanoparticles with an affinity for ballast minerals (e.g. sulphides, or sulfur contained in them), or ballast impurities remain in the magnetic part and precious metals remain in the non-magnetic part and are bound by this procedure, and subsequently the concentrated particles of gold or other precious metals are mechanically, chemically or hydrometallurgically separated from the magnetized nanoparticles with ballast according to known procedures, or vice versa, the non-magnetic part with concentrated by the amount of Au and other rare and strategic metals. Another form of obtaining invisible nanoparticles to micron particles of gold and other rare and noble metals, especially in ultra-fine grain size, for example approx. 0-50 μm, is their dissolution in iodides and bromides, after concentration, fine grinding and breaking of the concentrate lattice by heat, freezing, ultrasound , microwave heating, etc., present in natural mine water containing these concentrated dissolved salts in so-called natural brines rich in I and Br. Invisible, ultra-fine Au and other rare metals can then be obtained after their dissolution from the solution by known separation methods (e.g. electrodialysis, precipitation of NaOH, ascorbic acid, hydrazine, etc.).

The activation of nanoparticles of iron and other elements, selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds, consists in the fact that their large surface area is first saturated with iodides or bromides (e.g. Kl, KBr, etc. ), or by sulfur compounds that have a strong affinity for gold and other rare noble and strategic metals and thus direct the nanoparticles of iron and its compounds to particles containing Au and other noble metals. By dissolving or reacting with Au and other noble metals, the aforementioned activators help to capture nanoparticles on a particle with gold and other precious metals (e.g. Hg, Pt, Cu, Ag, W, Mo, In, etc.) in an environmentally friendly way separation (separation) in a variable magnetic field Au and other noble and rare metals can be released from the obtained magnetic fraction by conventional magnetic, gravity, chemical or metallurgical processes.

Surfactants of a cationic, ammonium or non-ionic nature can be added to the separated raw material to increase the adhesion of nanoparticles to the surface of metal particles of gold, platinum, silver and other precious metals. These surface-active substances help to separate hydrophobic particles of gold and other precious metals from hydrophilic tailings or mother hominy and thus facilitate the creation of a composite of microparticles of gold, surrounded by a wall or with a layer of magnetizable iron nanoparticles and its compounds. Examples of anionic surfactants can be surfactants and detergents from the group of sodium and potassium salts of alkylbenzene sulfonic acids, alcohol sulfates and alcohol ethoxysulfates. At the same time, these sulfur compounds can act as an activating agent to direct the iron nanoparticle and its compounds to particles containing Au and other noble and strategic metals.

The induction of the magnetic field in the range from 0.1 to 10 T, preferably can be in the range from about 0.5 to 5 Tesla.

-4 CZ 2021 - 260 A3

The subject of the invention is also a method of binding even the finest, even only a few microns, particles of gold and precious metals using a surface layer of activated nanoparticles of iron and its compounds with a large surface area with admixture of activators such as iodides, bromides or sulfur compounds (e.g. K1 or KBr, etc. ) in aqueous suspension or in dry conditions, when originally non-magnetic (paramagnetic) particles of gold and precious metals, even in a mixture with other non-magnetic or even magnetic minerals, become magnetizable in a magnetic field and can thus be ecologically separated from the original parent rock, raw material, waste, etc. .. In the so-called magnetic portion of a highly intense to superconducting magnetic separator with a magnetic field induction of 0.1 to 10 Tesla, particles of gold and precious metals are concentrated, or also rare earths and elements together with iron compounds, which can already be separated from gold and precious metals by conventional methods (e.g. chemically, mechanically in a magnetic field, etc.). The non-magnetic portion with a predominance of parent rock, tailings and non-magnetic particles (e.g. quartz, feldspar, clay, sulphides, decomposition products, etc.) is usually in this case a waste raw material which, after drainage, can be used for example as a building material, soil with a high sorption capacity , a source of nutrients, silicate components and substances. The proposed, original procedure of using activated nanoparticles selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds with a positive, zero or negative electrostatic charge and saturated with e.g. K1 or KBr or sulfur compounds also enables reverse binding into magnetic proportion of hydrophilic impurities after their fine grinding and activation by heat, ultrasound, freezing, microwave heating, etc. (e.g. below 100 pm), when even micron particles of Au and other rare metals are separated from the tailings (e.g. quartz, residual sulphides, decomposition products arsenopyrite, sphalerite and chalcopyrite, etc.) and remain in the non-magnetic portion. In such a case, as a rule, selected nanoparticles of iron and its compounds do not need to be activated by I or Br.

Similarly, even the finest nanoparticles of up to only a few micron particles of Au and other rare elements up to micron particles of Au and other rare and noble metals (e.g. in grain size 0-50 pm) can be obtained by dissolving them, after previously breaking the lattice of concentrated Au and other rare metals in rock or minerals, or waste products (e.g. electronics, mobile phones, dust removal, flyaways, tablecloths, municipal waste, ash, energy gypsum, sorbents after chemosorption of gaseous products after burning coal, other biomass and RDF, products with Au content, etc.) where they are bound, for example, by heating with heat, by freezing (temperature 0 to -180°C), ultrasound or microwave waves, etc., in concentrated solutions of iodides and bromides (in so-called natural brines) over time, in puddles, mixed and heated tanks.

In the case of the use of extremely fine and activated nanoparticles with an electric (electrostatic) charge for obtaining very fine particles of gold and other precious metals, it involves the creation of composite particles that can be magnetized in a magnetic field, consisting of initially paramagnetic, non-agglomerated microparticles of gold and precious metals suspended in water or in water with organic solvents, or in the form of powder material and very fine nanoparticles and its compounds, which form an electrically charged layer (wall, film) on the surface of much larger particles of gold and precious metals, which enables the separation of such composite material in a magnetic field or an electric field. The synthesis of a composite particle of gold and precious metals with a nanoparticle of iron and its compounds or other nanoparticles is based on the difference of the point of zero electric charge of microparticles of gold and other precious metals and nanoparticles of iron and its compounds or selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds, where by adding a buffer, the pH of the suspension solution is set such that the microparticle of gold and other rare metals is positively charged and the magnetic nanoparticles of iron and its compounds are negatively charged, and this also occurs due to the effect of high adhesion due to the large specific surface area of the nanoparticle and surface attractive forces, especially after the application of a surface-active substance, to create a layer (wall, film) on the surface of a gold particle, and it can then be easily magnetized in a magnetic field with the possibility of its separation from non-magnetic rock or tailings, or in powder or, better, in dusty or sandy form on electrically charged drum (charging voltage 0-30 thousand V). In order for the magnetizable nanoparticle to be better directed and connected to the particle containing Au and other noble and strategic metals, the nanoparticle of iron and its compounds is most often activated by the addition of substances with

-5 CZ 2021 - 260 A3 high affinity to gold and other precious metals selected from the group of iodides, bromides, or sulfur compounds. Concentrated natural solutions of these salts (mine brines containing Br, I, etc.) can also be used to activate iron nanoparticles.

As already mentioned, ionic, cationic or anionic surfactants can favorably increase the surface adhesion of the nanoparticle of iron and its compounds to the surface of the metal particle of gold, platinum, silver and other rare and strategic metals. Microparticles of gold and precious metals such as platinum, silver, etc. have an average size in the range of approximately 1 to 200 pm, and nanoparticles of iron and its compounds have an average size in the interval of 5 to 1000 nm, i.e. 0.005 to 1 pm, most often preferably in the range 0.050 to 0.500 pm, and can be in powder form or in suspension. They have an order of magnitude greater surface area than particles of gold and other rare and strategic metals, and thus also a great ability for surface, physical adhesion.

Nanoparticles of iron and its compounds with, for example, carbon, titanium, silicon, sulfur can be charged positively or negatively or have a zero electric charge and can thus fulfill a function in the sense of electronegativity, that is, being attracted to the surface by a positively charged particle of gold and other precious metals or even, especially after the application of a surface-active substance of an ionic nature, to create a magnetizable or electrically charged wall (layer, film) also by surface attractive forces.

The biggest advantage of the proposed procedure for obtaining concentrates of gold and other precious metals in a coarser form (cobbles, gold flakes, free particles of precious metals), in a fine form (gold flakes and rare particles in the gem area approx. 0.1-500 pm), or in the finest, invisible finely ground form (0-100 pm) is a harmless, ecological process without the use of dangerous or otherwise objectionable chemicals threatening the environment. Air sorting based on the gravitational distribution (separation) of particles according to their density and particle size in a narrow area, magnetic separation of magnetizable impurities, concentration of Au and other rare metals on an electrically charged drum in an electric or electrostatic field, magnetic separation of surface-modified, magnetizable particles, originally non-magnetic (paramagnetic) particles of Au, Ag, Pt and other rare metals using activated nanoparticles or dissolving even the finest particles of Au and other rare, noble and strategic metals in brines rich in Br and I, or a combination of the mentioned technological treatments takes place in an aqueous environment (wet method in suspension) in a closed water recycling flow or dry after air sorting with the application of air filters. Used surface-active nanoparticles of iron oxides and its compounds and other nanoparticles, selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds, with an extremely high specific surface area of the particles and thus with excellent physical adhesion to a larger metal particle or to ballast impurities, additionally carbonated iodides (Γ), bromides (Br ) or sulfur compounds, can be applied advantageously in solution to a concentrated suspension of gold-bearing mash or sorted overflow or overflow sludge fraction from a hydrocyclone or dry in a closed and filtered circuit up to a small amount of finely ground and heat, ultrasound, freezing (cryogenic), microwave heating broken Au concentrate and other precious and strategic metals. The indisputable advantage of the proposed procedure is also the fact that fine grinding, for example below 100 pm, which is the slowest technological operation, is applied only to a small extent, until the creation of the smallest amount of Au concentrate and other rare, noble and strategic metals with the highest concentration of Au and other of rare and strategic elements (e.g. from 1000 tonnes of basic gold-bearing rock to a concentrate of approx. 100 kg, which may or may not be ultra-finely ground in the final extraction of Au and other rare metals). If Au and other noble and rare or strategic metals are bound exclusively in the finest, invisible particles, for example below approx. 30-50 pm and there is a need to release them from amalgams with aluminosilicates, sulphides and quartz, then they must first be broken by heat or freezing , by microwave heating or chemically or biologically or by ultrasound before ultra-fine grinding. In such a case, the finely ground mixture of noble or strategic metals with ballast minerals must be divided into a concentrate of Au and other noble, rare and strategic metals in the magnetic portion (product 1) and industrially usable product No. 2, consisting of mostly fine quartz,

-6 CZ 2021 - 260 A3 aluminosilicates or sulfides or their decomposition products. Its use can be expected after cleaning in the field of building materials (stucco, plaster, sealants, fillers, pigments, paints, abrasives, geopolymers, pastes, etc.), in the chemical and refractory industry, in the production of cement, active pozzolans, etc.

The obtained concentrate of very fine Au and other rare, noble and strategic metals (e.g. 0-50 pm) is preferably further dissolved in a closed cycle in concentrated natural mine waters (brines) after fine grinding and activation by heat, freezing, ultrasound, microwaves, etc. rich in Br and I content, which occur underground, e.g. in Slánek.

Very fine, concentrated particles of Au and other rare metals in volume-reduced quantities with a grain size of approx. 40-100 μm suitable for obtaining after breaking the lattice of ballast minerals and fine grinding with the help of iron nanoparticles, selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds with subsequent separation from ballast minerals in a variable magnetic field or even finer concentrated particles of Au and other rare metals in volume-reduced quantities in a grain size of approx. 0-40 μm] are advantageously obtained after breaking the lattice of ballast minerals and fine grinding using long-term dissolution in leaching tanks with natural or artificial water, brine rich in I and Br. In general, the thus obtained concentrate of very fine Au and other rare, noble and strategic metals can then be obtained by known methods, such as their dissolution in iodides and bromides, in mercury, processed chemically, in heavy liquids or thermally, or by other known methods. It can be advantageous to leach and dissolve Au and other noble and very fine metals, after breaking up the lattice and fusions with heat or microwaves or hard ultrasound, without the use of nanoparticles, with simultaneous delamination by grinding in suspension with the addition of Hg or KBr or Kl, when very fine , sometimes even 0.5 pm to several micron particles of Au and other noble metals, they dissolve well, and after sifting the solid amalgam and heating it is possible to obtain pure gold with further regenerated Hg through the return cooler, or to separate the ballast solid residue from the solution of Au bromides or iodides with by subsequent precipitation of Au compounds and other noble, rare, strategic metals and other elements, e.g. rare earths. Similarly, during the simultaneous grinding in a dense suspension of the smallest concentrate of Au and other rare and strategic metals in a mixture with a concentrated solution of I and/or Br artificially created or better from a natural mine brine rich in I and Br, Au and other compounds of rare and of strategic metals with subsequent precipitation of Au compounds and other rare elements from the solution after sedimentation of the treated concentrate (sediment).

Examples of implementation of the invention

Example 1

The gold-bearing rock of Kašperská Hora was crushed into a fraction of 0-0.50 mm, or 0-0.25 mm sorted repeatedly on an air, cascade sorter with reduction of the original large sample to about one-tenth to one-twentieth. The obtained heavy fraction with particles with a density (specific weight) above approx. 3.5 g/cm ³ was then subjected to dry magnetic separation under the induction of a magnetic field of up to 1.7 Tesla, obtaining a non-magnetic fraction in the amount of about 25 - 35 wt.% containing free Au golds, sulfides and their transformed decomposition products with Au, quartz and other non-magnetic impurities. Biotite and muscovite mica, Fe, iron and titanium minerals, garnet, etc. were found in the magnetic portion. The concentrate of Au and other rare metals was already sorted in very small quantities on an electrically charged continuous drum with a charging voltage of up to 20,000 V, when the highly conductive minerals containing Au and other rare noble and strategic metals were captured on a rotating drum, and non-conductive (quartz, sulfides and decomposition products without gold, etc.) were thrown from the drum in a ratio of about 1:50. In this way, the sample with a concentrate of Au and other rare elements (for example, Mo, W) was very significantly reduced (up to approx. 3000x) and the gold could be finely ground below approx. 40 pm after placing it in a drum mill together with Hg and a little water. After sieving, the resulting amalgam of mercury and gold was heated in a belt dryer to a temperature of up to 1000°C with a return cooler installed, and after condensing in the cooler, the Hg vapors were captured in the form of liquid Hg in a closed, airtight

-7 CZ 2021 - 260 A3 container. Pure gold remained on the waist in the form of a fine powder.

Example 2

Gold-bearing raw material, e.g. waste tailings containing very fine particles of gold, poor raw material with a low yield of gold and other precious metals, products with a bound proportion of gold, etc., is first crushed to a fine fraction of 0-1 mm, resp. 0-0.5 mm, is repeatedly sorted on an air sorter according to the density and size of the particles, obtaining a heavy fraction with a particle density above approx. 3 g/cm ³ . Then this heavy portion, reduced in volume by lOx to lOOx compared to the original volume of the processed raw material, is magnetically separated dry on a belt or drum continuous magnet with a magnetic field intensity of 0.8-1 Tesla, obtaining a non-magnetic portion (significantly reduced volume of the concentrate freed from magnetizable mica and another mineral). A non-magnetic concentrate with a concentrated content of Au and other rare and strategic metals, reduced up to 200-500 times compared to the original, processed gold-bearing rock (e.g. from 1000 tons of original hominy, i.e. from 1000,000 kg, a non-magnetic portion weighing only about 2000 kg is obtained ) is ground very finely (below approximately 63 pm, or below 100 to 200 pm) wet or dry so that particles of gold, platinum, silver and other precious metals are released from the original aggregates of soil, tailings and other products with bound precious metal. After that, the very fine ground product is sorted wet or dry on a hydrocyclone or a cyclone with a suitable diameter (5 to approx. 80100 mm) or on the determined limit of sorting according to particle size (e.g. 10 pm, 20 pm, 40 pm, etc.). An optimal amount of activated nanoparticles of iron and its compounds, containing Kl, with zero or negative with an electric charge (powder or suspension with a particle size of approx. 10-400 nm, for example in a dose of 0.01 to 1 wt.%, the excess does not matter) and each particle fraction (finer overflow and coarser overflow) is magnetically separated on a high-intensity or a superconducting magnetic separator with a magnetic field induction of 0.1 to 10 Tesla under pre-selected conditions for treating the input suspension or powder. The suspension or powder must be mechanically and chemically dispersed so that the individual particles of gold and other precious metals (with a size of, for example, pm to 100 pm) with a positive electric charge are freed from the other particles in the suspension or powder and can agglomerate into larger formations on the surface with oppositely charged and very small nanoparticles of iron and its compounds. A surface-active substance is added to enable easier surface binding of several orders of magnitude smaller nano-iron particles to metal particles (larger particles of Au, Ag, Pt, etc., after the prior introduction of nanoparticles with Kl with a high affinity to Au and other noble and strategic elements, which is coated with a thin layer of much finer nanoparticles of iron and its compounds). This makes an originally paramagnetic particle of gold and other precious metals, surface-modified with particles of nano-iron and its compounds with a larger Kl agglomerate, magnetizable in a magnetic field and can be captured in the so-called magnetic fraction as one of the output fractions of the magnet. The concentrate of the precious metal with bound particles of iron compounds can then be separated from each other in a simple procedure (e.g. in a variable magnetic field or chemically) and thus obtain ecologically very fine particles of gold and other precious metals in a very pure, almost pure state.

The entire process can also be carried out without prior sorting on a hydrocyclone or cyclone. In such a case, however, it is necessary to carry out prior grinding of the concentrated gold-bearing raw material at least below approx. 50 pm. Compared to the parent rock, gold is hydrophobic in suspension, and therefore the gold particles tend to surface coat (clump) with much finer particles of activated nano-iron and its compounds, which can be separated by magnetic separation. For the correct function of the sorption (bonding) of iron nanoparticles to the surface of microscopically coarser particles of gold, amalgams with gold and other rare metals, it is necessary to disperse the gold-bearing soil very finely by grinding, to release the metal particles from the tailings using a suitable dispersant, to reduce the surface tension using surface-active substances of the detergent type (surfactant) and the fineness of the used nanoparticles of iron and its compounds, usually carrying a zero or negative electric charge, or of an order of magnitude difference between a particle of gold (a rare metal) in units to tens, possibly even hundreds of micrometers and the size of a surface-active particle of iron and its compounds capable of binding

-8 CZ 2021 - 260 A3 agglomerate (in nanometers). Potassium iodide K1 contained in the activated nanoparticle is used to guide ("glue") the activated nanoparticle of iron and its compounds to the particle containing Au and other noble and rare metals.

After obtaining a concentrate of the precious metal in the coarser fractions of the hydrocyclone or for fractions of the order of micrometers in size after magnetic separation of the precious metal particles with surface adsorption of nanoparticles of iron and its compounds, it is possible to separate gold and other precious metals from iron minerals in a simple and well-known way mechanically, e.g. again by magnetic separation at a low magnetic field intensity (e.g. 0.1 to 10 T) after releasing surface-bound iron compounds (when the magnetic part will contain iron compounds and the non-magnetic part will contain gold and precious metals), or chemically after dissolving the iron compounds in acid etc.

The magnetic separator actually performs the function of a kind of ultra-fine sieve, typical for gold panning. The so-called magnetic fraction after the demagnetization phase with a high concentration of separated metal particles is interesting for the mentioned separation method. In this case, the non-magnetic portion with a predominance of tailings and non-magnetic particles (e.g. quartz, feldspar, clay, sulphide residues, etc.) is a waste raw material that can be used in industry and agriculture after drainage. The magnetic portion or the gross overflow fraction of the hydrocyclone can be not only a concentrate of gold and precious metals, but also a source of rare earth elements that are also usable (concentrate of rare elements and rare earth elements). By choosing other nanoparticles with the opposite electrical charge, it is possible to concentrate Au and other rare and strategic elements bound, for example, in sulfides or their decomposition products in a non-magnetic portion.

Example 3

The dried rock containing finely dispersed gold particles approximately 12 to 40 µm in size was first dry ground in an agate planetary mill to a fineness below 63 µm. It was then transferred to an aqueous suspension at a concentration of 100 g/liter, after the addition of a water glass dispersant, it was mixed for 3 minutes in a turbo mixer with a few drops of detergent (surfactant). After adding a suspension of active iron nanoparticles (0.1 ml per liter of suspension, fineness of 100 nm activated in Kl solution), adjusting the pH of the suspension in the range of approx. 2 to 7 and mixing, the aqueous suspension was magnetically separated on a high-intensity magnet with a magnetic field strength of 1 .9 T rental die and using a 0.108" (2.74 mm) diameter flow nozzle. A non-magnetic fraction containing mainly tailings and a magnetic fraction j as a concentrate of gold and j other precious metals in an aqueous suspension was obtained. After X-ray fluorescence chemical analysis, a high proportion of gold (Au) was proven in the concentrate.

Example 4

The tailings from the dump after gold mining in a grain size of 0-1 mm and with an Au content of about 1-3 g/ton was first repeatedly sorted in the dry state on an air sorter according to the density and size of the particles, first at the selected optimal air flow speed in the 0-1 m , then at a different speed of the air flow on a 0-0.5 mm air flow composition and then at a different speed on a modified concentrate with a grain size of 0-0.25 mm, obtaining a total heavy fraction with a particle density above approx. 4 g/cm ³ . This reduced the volume or weight of tailings from about 10 tons (10,000 kg) to 0.5-1 ton (5,001,000 kg-concentrate no.l). After that, this reduced dry sample of the concentrate was magnetically separated on a cascade magnet with a magnetic field strength of about 1-1.7 Tesla, obtaining 50-100 kg of a non-magnetic portion containing Au (reduction of concentrate No. 1 about lOx). The thus concentrated part of the No. 2 Au concentrate was finely ground to a fineness of less than 63 pm and subjected to ultra-fine sorting on an ALPINE air sorter according to particle size with the setting of the sorting limit of approximately 5 pm, obtaining a fine overflow (sub mesh), i.e. finer particles below 5 pm with a predominance of mash (clay, sulphide residues, etc.), quartz and other ballast substances and coarser sediment, that is, particles above 5 pm (over-sieve with a granulometry of 5-63 microns) with a concentration of metallic gold particles. The difference in the specific weight and size of gold particles and other tailings particles is visibly manifested by the separation of heavier and larger gold particles (after fine grinding, the original particles

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Au, perhaps even in the size of 1-5 pm, flattens (increases its surface) and enters the zeolite fraction above 5 pm. Dry, coarser overflow fraction (oversieve above approx. 5 pm) without fine dust or of the overflow was mixed in a ratio of 1:10 in a mixer with a natural concentrated solution of brine rich in dissolved iodine and bromine, or a mixture of the mentioned salts in the form of iodides and bromides. After intensive stirring of the resulting suspension (approx. 500 rpm) and heating to a temperature of approx. 40°C, a solution with dissolved gold was obtained in 48 hours after the decantation, which was further processed by known separation methods. In our case, by precipitation of Au using 0.1 M NaOH with a yield of up to 98 0/ /0.

Example 5

The gold-bearing raw material of Kašperská Hora with a metallurgy of about 5 g Au/ton of rock with gold in the zone of about 3-250 pm, containing also a lot of sulfides (molybdenite M0S2, pyrite FeS2, arsenopyrite, chalcopyrite and their decomposition products) and mica, was first crushed to jaw crusher to a fineness of 0-1 mm, or 0-0.5 mm on a hammer crusher. It was then subjected to air separation according to the density and particle size of the represented minerals to a limit of approx. 3 g/cm ³ on a cascade air sorter. In this way, the first Au concentrate was obtained in the so-called heavy fraction above 3 g/cm ³ (reduced from 1000 tons of hominy to approx. 3 tons), which was subjected to continuous dry magnetic separation at the induction of a magnetic field of about 0.8-1 Tesla, obtaining 2 .of Au concentrate in the non-magnetic portion / volume reduction from 3 tons to about 50 kg, i.e. 60x). This already reduced concentrate was heated in the 0-0.5 mm size fraction to a temperature of 800°C and the hot product was leached in a concentrated natural brine (Br content 350 mg/1, 1 content about 250 mg/1) from an underground well in of a ratio of 1:3 (dry matter: water) for about 24 hours with constant, intensive mixing in the storage tank. After sedimentation of the leached suspension, the solution above the sediment containing dissolved gold was transferred to the second storage tank, where Au precipitation was carried out using 0.1 M ascorbic acid at a pH below 2. The Au recovery was about 99%. Another product, in addition to the obtained gold, were I and Br salts obtained by thermal evaporation of the gold-bearing solution and the remaining sediment. The third product after Bral was expelled was a silicate residue (aluminosilicate), usable for its whitening and pozzolanic activity in the construction industry. The waste-free technology was also applied during the previous heating of the gold concentrate to approx. 800°C by capturing the resulting gaseous products (SO2, F, Cl, Hg, etc.) on a dry, powdered sorbent. The advantage of this gold extraction procedure is the fact that the reduced Au concentrate does not have to be finely ground and natural brine with a concentrated amount of I and Br is used for leaching. At the same time, other industrially usable products are obtained, especially medicinal salts Br and I.

Example 6

Zlatá Hora gold-bearing raw material obtained from the maximum reduced concentrate after air sorting and obtaining a heavy fraction above approx. 4 g/cm ³ (concentrate No. 1), magnetic separation to obtain a non-magnetic fraction rich in Au (concentrate No. 2) and electrostatic charge separation of this of the non-magnetic sample (concentrate No. 3), only about 15 kg of concentrate No. 3 was obtained from the original sample of 40 tons of raw material (40,000 kg). The coarse gold was then separated by gravity, and the fine fraction below approx. 0.25 mm was finely ground below 100 pm, transferred to a suspension after the addition of a surfactant. After treatment with the addition of a solution of iron oxide nanoparticles (particle size up to 300 nm), a high-intensity magnetic separation was performed in suspension on a fine matrix and a magnetic field intensity of 1.9 T, after intensive mixing in a turbodissolver. An increased fine gold content was demonstrated in the magnetic portion (Ouch).

Example 7

The gold-bearing raw material from the Mokrsko deposit with a metallicity of only about 1-2 g Au/t and with a predominance of gold particles in the very fine miter area (approx. 0.5-25 pm) was, after a significant concentration of the gold by air and magnetic separation and calcination (calcination) of the resulting concentrate to a temperature of about 800°C+-100°C (from 1000 tons of original raw material volume reduction to about 1-3 tons of concentrate), while wet in suspension ground in a drum mill with grinding bodies to a fineness below 40 to 100 pm in

- 10CZ 2021 - 260 A3 environment with the addition of a concentrated solution of mine water, i.e. natural brine with a high content of Br and I. The thus processed fine concentrate in a thick suspension (1:2) with partially or completely dissolved particles of Au and other rare metals was then leached for about 12-24 hours in mixed (approx. 250 rpm) and heated (approx. 40°C) tanks filled with natural water, i.e. concentrated brine from underground wells with a high content of 1 (125 mg/1) and Br (270 mg/l). Fine metal particles of gold and other metals (0.5-25 pm) passed, thanks to their reactivity given by the ultra-fine zeolite composition, and active dissolution during comminution (delamination) by grinding with reaction with Br and I, respectively. bromides and iodides in natural science into a solution that was pumped out and Au obtained by electrodialysis or reduction, precipitation with 0.1 M ascorbic acid or 0.1 M NaOH with a yield of about 98-99%. Very fine ballast sediment in tanks rich in silicate and the remains of sulphide minerals, but also the Bral compound was used as a building material. After concentration of solutions rich in I and Br salts, e.g. by desalting using heating in an evaporator, medicinal and industrially usable bromine and iodine salts were also obtained. Three products were thus prepared by the proposed procedure: fine gold, Br and I salts and silicate building material.

Example 8

Gold-bearing sand with a grain size of 0-1 mm, after being concentrated on an air sorter according to mineral density and particle size, significantly decreased in volume with the formation of a concentrate of Au and other rare, noble and strategic elements in the so-called heavy proportion above 3.5-4 g/cm ³ after finely grinding it dry, I sorted ultra-fine on an ALPINE-HOSOKAWA air sorter at the sorting limit of approximately 10-20 pm. Metal heavier gold pieces, especially after delamination flattened patties by grinding) were then separated into the mitotic fraction above the specified sorting limit. The fraction above 10 to 20 µm was then converted into a suspension (200 g of dry matter/ liter of suspension) with the addition of a dispersing agent, or buffer. After adding a dose of iron nanoparticles with a size of about 50-100 nm with a high specific surface and thus high surface adhesion and mixing, a high-intensity magnetic separation was performed on a flow magnet with a magnetic field intensity of 1.9 T. A concentrate of metal particles was obtained in the magnetic portion and the non-magnetic fraction was dominated by quartz and other paramagnetic components. Gold or other precious metal was separated from iron compounds from the magnetic portion chemically after dissolving them in acid (for example, in concentrated sulfuric acid H2SO4, in hydrochloric acid HC1, etc.).

Example 9

When obtaining Au and other rare and strategic elements from waste products, e.g. from electronics, mobile phones, dust, flyaways, tablecloths, municipal waste, fly ash, energy gypsum, sorbents after the chemosorption of gaseous products from the combustion of coal and other biomass or other products containing Au etc. the following adjustment procedure was applied. First, the waste material was crushed and ground, sorted according to density (specific weight) and particle size, according to magnetic susceptibility, conductivity properties, etc. Then the significantly reduced concentrate containing Au and other rare, noble and strategic elements was desired in natural mine brine, i.e. in a concentrated solution with a high content of Br and I. The suspension in leaching reaction tanks was continuously stirred at a temperature of 20-40°C in a cascade arrangement of leaching tanks. In order to accelerate the leaching of Au and other important metals, the short-term action of hard ultrasound was also used, which newly enabled a better leaching of Au and the metals of interest into the solution above the sediment, by "living" miniaturized particles containing Au being ultrasonically etched with bromine and iodine ions, or . in a combination of Br and Br, or even I and 1 and Au and other strategic and rare elements went into solution better. After sedimentation of the solid, desired particles of the waste raw material or product, gold, but also Pt, Cu, Zn, In, etc. were precipitated in the last reaction vessel using ascorbic acid or NaOH, etc. Another usable product of the proposed treatment was the healing salts Br and I, but also fine sediment, which, after dewatering in a calopress, provided an industrially processable product, e.g. usable for heat and sound insulation boards and otherwise usable building material (e.g. masonry blocks, sealants, joint compounds, etc.).

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Example 10

The proposed treatment procedure recovered invisible gold from the sludge after gravity sorting 5 by flotation on a vibrating table while wet in suspension. The original rock of Kašperská Hora with a content of about g Au/ton after crushing and coarse grinding in a fineness fraction of 0-0.5 mm was enriched according to the density (specific weight) of gold in the heavy fraction to a metallicity of about 25 g Au/ t. Gold losses of about 1.5 g/t of sludge were detected in the finest and lightest waste sludge fraction (sludge) in an amount of up to 35 wt.%. After it was dried and sorted by floating on meshes ίο 0.05 mm (50 pm), a concentrate of invisible Au with a metallicity of up to 8.5 g Au/t fraction 0- 50 p.m.

Claims (7)

PATENT CLAIMS 1. A method of obtaining gold and other rare and strategic metals and rare earths from natural rocks, minerals, secondary products, including waste, characterized by the fact that, after concentration by dividing minerals, treated rock or waste according to density and particle size in dry air sorting, removal of impurities in a magnetic field and based on the concentration of Au and precious metals according to their electrical conductivity by isolating coarser gold (boulders, lumps, gold bars) and/or after breaking the lattice of aluminosilicates, quartz and sulfides and other conglomerates containing Au and other noble and strategic metals, in zeolite fraction 0-100 pm, thermal, cryogenic (freezing), chemical, microwave, mechanical or ultrasonic delamination with the possibility of obtaining gold invisible to the naked eye and other rare and strategic elements by separating the finest nanoparticles and several micron particles of Au, Ag, Pt, but also Cu, W, Mo, Ge, In, Hg, etc. using the high adhesion of the used activated nanoparticles iron and its compounds after being placed in a magnetic field or by dissolving them in water rich in concentrated amounts of iodine I and bromine Br in so-called natural mine brines. 2. The treatment method according to claim 1, characterized in that magnetizable composite, activated iron nanoparticles, selected from the group of elements including Fe, Ti, C, Si, S, O and their compounds with high surface adhesion, are subjected to magnetic separation, whereby the originally non-magnetic particles of gold or other precious metals, covered by a weak physical force-adherent layer (film) of magnetizable nanoparticles, are captured in the magnetic field on the matrix and at the same time are separated from the non-magnetic tailings or ballast and subsequently the magnetic portion of the concentrate of gold or other precious metals is mechanically or chemically separated from the magnetized nanoparticles. 3. The treatment method according to claim 1 and 2, characterized in that iron nanoparticles selected from the group of elements including Fe, Ti, C, Si, S, O can be activated by the addition of concentrated mine brine with a high content of I and Br or pure KBr solutions or Kl, or by sulfur compounds that have a strong affinity for gold and other rare noble and strategic metals and thus direct the nanoparticles of iron and its compounds to particles containing Au and other noble metals. 4. The method according to claims 1 to 3, characterized in that surfactants of a cationic, anionic or non-ionic nature are added to the separated raw material to increase the adhesion of nanoparticles to the surface of metal particles of gold, platinum, silver and other rare metals and elements, including rare earth. 5. The treatment method according to claim 1, characterized in that another form of obtaining nanoparticles invisible to the eye up to a few microns of gold and other rare and noble metals and rare earths, especially in ultra-fine grain size, for example 0-50 pm, is their dissolution in iodides and bromides concentrated as dissolved salts in so-called mine, natural brines rich in I and Br. Invisible, ultrafine Au and other rare metals and rare earths can then be obtained from the solution after their dissolution by known separation methods (e.g. electrodialysis, precipitation of NaOH, ascorbic acid, hydrazine, etc.). 6. The treatment method according to claims 1 and 5, characterized in that to accelerate the dissolution of Au and other rare elements in the concentrate, it is possible to simultaneously use mechanical-chemical delamination by grinding or ultrasound or microwave heating. 7. The treatment method according to claims 1, 5 and 6, characterized by the fact that gold and other rare, strategic elements and rare earths can also be obtained from waste materials (e.g. waste from the mining of gold and other precious metals, used electronics, mobile phones) , dust removal, drifts, tablecloths, municipal waste, ash, energy gypsum, sorbents after chemosorption of gaseous products from coal combustion, other biomass and RDF, products containing Au and other rare and strategic elements, etc.).