RU2114196C1 - Method of hydrometallurgical recovery of rare metals from technologically persistent raw material - Google Patents

Abstract

FIELD: hydrometallurgy. SUBSTANCE: persistent raw material matrix is disintegrated and placed into sealed vessel containing solution of halide acids, nitrous acid, and complexing agents for rare metals. Into the vessel from outside, oxygen is supplied, and process is carried out at a specified pH value, pressure, and oxidants reduction half-wave potential for a period of time chosen from opening matrix conditions to provide maximum oxidation and recovery of metals from matrix and formation of mother solution containing dissolved rare metal complexes and oxides. Rare metals are isolated from matrix and mother solution by conventional techniques. EFFECT: enhanced process efficiency. 18 cl

Description

 The invention relates to the metallurgy of non-ferrous and rare metals (for example, gold, silver, platinum, palladium, iridium, rhodium, ruthenium, osmium), physically and chemically strongly associated with natural or anthropogenic raw materials, and more specifically to methods of hydrometallurgical extraction of rare metals from technologically persistent raw materials.

 The invention can be used in the metallurgical industry and in the analysis, as well as in conducting geochemical, geological exploration and exploration work, reassessment of balance and off-balance reserves in natural and man-made raw materials.

 The vast majority of raw materials of rare metals consists of crystalline and amorphous inorganic and organic components. These raw material components form a complex matrix, in which rare metals make up a very small fraction, for example, 0.0001% of the total matrix mass. However, even with such small contents, their recovery is of significant industrial interest.

 In some favorable cases, rare metals can be in the matrix of raw materials in the form of compact discrete clusters, for example, in the form of intrinsic minerals or as part of certain carrier minerals as a significant impurity. Such raw materials do not present technological difficulties for industry and analysis.

 Meanwhile, it was established that the compact presence and distribution of rare metals in the matrix of raw materials is the exception rather than the rule. In many types of raw materials, the matrix can include, for example, platinum in an amount up to n • 0.001%, and even with an increase of 20,000 times, it is not possible to detect and identify the form of its presence. It is believed that rare metals in this case are in the form of individual nuclei, subatomic size of clusters and clusters, which are chemically or physically associated with the surrounding condensed inorganic and organic matter of the matrix. Naturally, with such scattering, the extraction of any elements from the matrix of raw materials is an extremely difficult task. In this case, the greatest technological difficulties arise when the concentration and extraction of rare metals is necessary to produce from a matrix of raw materials, consisting of hardly oxidizable and hardly soluble components that determine the degree of technological persistence of the raw materials. For example, granites, clays, metamorphic schists, gneisses, in particular carbon-containing, black sands, graphite, and many others, are technologically resistant. In these rocks, especially carbon-containing, significant amounts of rare metals scattered in the matrix can be found. They are not recoverable during processing by existing technologies, for example, in mild hydrometallurgical conditions. For this reason, the development of hydrometallurgical methods for the cost-effective extraction of rare metals from technologically resistant raw materials is an urgent problem.

In metallurgy and analytical practice, numerous hydrochemical methods for the extraction of rare metals are used. All methods include preliminary physical disintegration in a dry or wet way to the technically and economically maximum possible particle size, at least up to 0.01 - 0.001 cm. This operation allows you to partially expose the inclusion of rare metals in the matrix in the form of native or intermetallic particles, having a size of at least 0.0001 cm. Smaller particles containing rare metals having a size of less than 0.00001 cm can be separated from the matrix of raw materials and extracted into the reaction solution only after further th chemical disintegration of hard particle matrix material. For this purpose, stubborn raw materials after physical grinding are subjected to thermochemical, chemical or more complex processing. For example, refractory raw materials are subjected to oxidative roasting at 500-1000 ^o C, redox melting on lead, copper or other alloy. In this case, non-productive components of the matrix of raw materials, including metals, are destroyed or converted into a solution, useful components are converted into an alloy or into a solution, concentrated and then a marketable product is isolated from them by known methods.

 However, none of the known methods of chemical and thermochemical processing can achieve sufficient completeness of the opening of the resistant part of the matrix of raw materials or its sufficient permeability for oxidizing agents, complexing agents or extractants, which could ensure the maximum extraction of rare metals. In this regard, a significant part of the rare metals is irretrievably lost or accumulated in the tailings, which leads to a decrease in the economic and environmental efficiency of production. The main reasons for these losses are that, at technically feasible and economically reasonable costs, the known methods of mechanical disintegration of the matrix of solid raw materials do not provide grinding below a particle size of 0.001 cm and, therefore, do not open micron inclusions of rare metals, and the known hydrometallurgical and pyrometallurgical processes with a low electrochemical potential half-wave recovery, the level of which does not provide oxidation and conversion of most condensed components of the persistent part of the matrix of raw materials.

 For example, the measured electrochemical potential of the half-wave reduction of such common matrix components as inorganic oxides of silicon, aluminum, manganese, magnesium, titanium, or numerous heteroatomic carbon compounds (peroxides of alkyls, aralkyls, condensed polynuclear arenes, polymer phenyls, and others) is within 1.3 -2.6 V (mainly in the range of 1.9-2.2 V). For example, a complex of gold with aluminum has a half-wave reduction potential of 1.3 V, with titanium silicates - 1.9 V, with silicon - 2.6 V.

 Meanwhile, the oxidative cyanidation process, used, for example, in gold hydrometallurgy, proceeds at a maximum value of the electrochemical potential of the half-wave of reduction equal to 0.9 V, the process using molecular chlorine - 1.35 V, the process of redox smelting by Verckley using as oxidizing agent - 1.65 V. Therefore, none of the above processes ensures the completeness of opening the matrix containing components with the electrochemical potential of the half-wave reconstructed Ia more than 1.4 V and therefore can not provide recovery of rare metals included in such components. In addition, in a number of common technological processes in the processing of refractory raw materials, for example, oxidative roasting or redox smelting is used to remove the refractory component in the form of gases. Moreover, components with a high electrochemical potential of the half-wave of reduction are not destroyed due to the low level of the oxidation process, and the measured losses of micron particles of rare metals with vapors, dusts and reaction gases often reach 95-100%.

 A known hydrometallurgical method for the extraction of rare metals [1, 2], including mechanical grinding of raw materials to fractions with a particle size of about 0.001 cm, placing the raw materials in an open vessel containing a stirred acidic solution heated to boiling, including a mixture of hydrochloric and nitric acids in a ratio of 3: 1. The process is conducted in the presence of atmospheric oxygen. The method is effective for the destruction, dissolution and transformation of the components of the matrix of raw materials, the electrochemical potential of the half-wave recovery of which does not exceed 1.4 V.

The closest in technical essence and the achieved effect is a hydrometallurgical method for the extraction of rare metals (US patent 4752412), which consists in the fact that pre-crushed raw materials are placed in an open vessel containing a stirred, heated to boiling (preferably up to 82 ^o C) acidic aqueous solution with pH value of acidity, equal to 3 and lower, containing acid taken from the series: nitric, hydrochloric, sulfuric, phosphoric, hydrofluoric, acetic. The process is carried out with continuous bubbling into the reaction mixture of a mixture of gaseous oxidizing agents introduced from outside a UV-ozone generator, obtained by irradiating a mixture of molecular oxygen and water vapor with high pressure mercury lamps with a radiation flux with a wavelength of not more than 200 nm, with the following most effective composition taken vol.% ozone 40; hydroxyl 40; hydrogen peroxide 5; hydrogen dioxide 5; high molecular weight peroxides 5; atomic oxygen 5. The specified mixture of oxidizing agents (activated oxygen) has an electrochemical potential of the half-wave of reduction reaching 2.4 V. The process of oxidation using such a mixture of oxidizing agents provides the necessary level of hydration of the feed matrix, breaking of bonds of rare metals with other components, oxidation of rare metals and sufficient permeability of the resistant part of the matrix of raw materials for the reaction solution, oxidizing agents and complexing agents. Next, to isolate the rare metals oxidized in an acidic solution from the matrix and form a mother liquor containing rare metal complexes, increase the pH of the reaction mixture to 11 by adding limestone and alkali and complexing agents for rare metals taken from the series: cyanide, hypochlorite are introduced into the reaction mixture , thiocarbamate, thiourea or iron (II) - hypochlorite, which form water-soluble chelates with oxidized rare metals. After a certain time of leaching of rare metals under the indicated conditions and the formation of a mother liquor saturated with chelate complexes of rare metals, the supply of oxidizing agents is stopped, the mother liquor is separated from insoluble materials and useful components are extracted from the mother liquor using standard technologies.

 According to the data published by the authors, the application of the proposed method on the example of various refractory carbon-containing ores of the states of Alaska and Utah in the USA allowed to increase the extraction, for example, of gold 1.36-30 times depending on the type of refractory raw materials in comparison with the standard method of assay melting carried out without preliminary hydrochemical and oxidative preparation. Achieving the indicated effect also allows us to state that only free compact gold, as well as gold not associated with the refractory component of the feed matrix, is detected and extracted by standard assay analysis.

 According to the proposed method, oxidizing agents are introduced into the reaction mixture in the form of a gas phase, the main components, for example, ozone and oxygen, are poorly soluble in aqueous liquids. The efficiency of such a process in an open vessel is not high due to the low speed of diffuse exchange and the low speed of establishing equilibrium at the gas-liquid interface. In addition, when implementing the method, there are large irretrievable losses of gaseous oxidizing agents under conditions of gas sparging through the liquid reaction mixture in an open vessel and due to the high temperature of the process. Such process management also does not provide a sufficient concentration of oxidizing agents on the reaction surface of the refractory particles of the matrix of raw materials in aqueous solution, due to diffuse restrictions on the solution-matrix interface.

 Reduces the efficiency of the process, increases the number of operations and the duration of the process, the proposed separate maintenance of the oxidation of the matrix and rare metals in an acidic environment and the subsequent, already in an alkaline environment, obtaining a mother liquor and soluble complexes of rare metals.

 In addition, the application of the process control method does not provide, for example, the opening of components resistant to ozone and peroxide oxidation, but essentially even such simple nitrogen-containing compounds that actively coordinate such rare metals as urea, thiourea and cyanides. It is significant that these compounds were used as complexing agents to remove oxidized rare metals from the solid matrix into the mother liquor. For example, it is known that the electrode oxidation process of platinum coordinated to urea nitrogen does not occur until the electrochemical potential of the half-wave of restoration of the level equal to 1.4 - 1.6 V is reached, when oxygen can be introduced between the nitrogen and platinum. Therefore, according to the proposed method, the real level of the electrochemical potential of the half-wave of reduction in the reaction mixture does not reach the desired value and is significantly deviated into the cathode region from the calculated level specified by the ozone mixture.

 The basis of the invention is to create a method of hydrometallurgical extraction of rare metals from refractory raw materials, in which, by changing the process technology, active chemical disintegration and structural transformations of the refractory components of the matrix are carried out, as a result of which breaking of chemical bonds, oxidation of rare metals, their binding into soluble complexes are ensured , the extraction of these complexes and oxides in the mother liquor.

 The problem is solved in that in the method of hydrometallurgical extraction of rare metals from technologically resistant raw materials, namely, the raw material matrix is crushed, the propagation vessel containing an acid solution of a certain chemical composition and concentration is partially filled with crushed raw materials, the resulting mixture is constantly mixed, a certain temperature is maintained , pH of the acidity of the solution in the mixture and the value of the half-wave potential of the reduction of oxidizing agents partially supplied from an external source of the analyzer, and for a certain time, they carry out the process of chemical dissolution and structural transformation of the matrix of raw materials until the matrix is permeable to oxidizing agents and oxidizing rare metals, according to the invention, the process is carried out in an airtight vessel filled with a gas-liquid mixture including crushed raw materials, selected acid solutions, liquid oxidizing agents and complexing components and as a gaseous oxidizing agent supplied from an external source, oxygen is used, while the pressure in the vessel, the acidity of the thieves, the chemical composition of acids and oxidizing agents, the temperature, the half-wave potential of the reduction of oxidizing agents and the reaction mixture, the composition of the complexing components and the process time are selected from the condition of maximum opening of the raw material matrix for the oxidation and extraction of rare metals and the formation of a mother liquor, including dissolved complexes and oxides of rare metals and recovering rare metals from the matrix and mother liquor by known methods.

 It is advisable to use halogen and nitrous acids as acids, and acids containing fluorine, chlorine, iodine, bromine, taken separately or in combination, as halogen acid.

 It is also advisable to obtain nitrous acid directly in the mixture due to the reactions of halogen mineral acids and salts of nitrous acid introduced into the mixture or due to the introduction of nitrogen (II) oxides from the outside into the reaction mixture.

 Such process management ensures the dissolution and structural transformation of most components of the matrix of raw materials and, as a result, an increase in the extraction of rare metals into a marketable product.

It is necessary to maintain the temperature of the reaction mixture equal to 0-20 ^o C, and the pH of the acidity in the mixture is in the range of 0.1-3.

 Such a temperature of the reaction mixture and a pH value of acidity create conditions for the stable existence of nitrous acid in the mixture.

 It is also necessary to maintain pressure in the vessel and the oxidation process by introducing oxygen from the outside.

 In this case, it is desirable to maintain the pressure in the vessel at a level below or equal to atmospheric. Such process conditions are optimal.

 It is also advisable to use components of halogen and nitrous acids and their compounds with each other as complexing agents, as well as products of redox reactions in the reaction mixture, and use halogens, oxygen, nitrogen, peroxides and their compounds activated with each other as oxidizing agents. another, formed in the process of redox mutual reactions and reactions with a matrix of raw materials, while the electrochemical potential of the half-wave reduction of oxidizing agents is AZNO maintained at a level equal to 2.4-2.6 V, and in the reaction mixture at least equal to 1.1 V. At this time, the process flow of calculating the selected maximum recovery of rare metals from a matrix in the mother liquor.

 Such conditions of the process provide a sufficient opening and, the removal of the protective groups and functional centers into the solution from the refractory part of the matrix of raw materials, the achievement of maximum oxidation of rare metals and, as a result, their removal into the mother liquor and a higher percentage of extraction of rare metals from technologically resistant raw materials.

 To remove the soluble non-productive part of the organic components of the raw material matrix, it is advisable to pre-treat the technologically resistant raw material after grinding with organic solvents taken from a number of acyclic, alicyclic and cyclic hydrocarbons, including halogen-containing lower alcohols and ketones taken separately or in a mixture.

 To remove the soluble non-productive part of the inorganic components of the matrix, technologically refractory raw materials after grinding are pretreated with halogen acid.

 It is possible to pre-treat technologically refractory raw materials after grinding before the main process with organic solvents and halogen acid sequentially, each time removing the dissolution products.

 This process management increases the speed and effectiveness of the subsequent extraction of rare metals in the main process, facilitates the separation of the mother liquor from solid particles of raw materials.

 To extract rare metals from the mother liquor, it is advisable to separate the mother liquor from undissolved raw materials and boil them. In this case, dissolved gases and easily boiling oxides and rare metal complexes that are trapped are removed.

 It is advisable to recover the mother liquor after boiling and removing the separated reaction gases and some rare metals to achieve the electrochemical potential of the half-wave of reduction in the mother liquor, equal to 0-0.2 V, and to separate the remaining rare metal complexes and oxides into the precipitate, separate the precipitate and then to extract rare metals from it by known methods, for example, using cyanides and thiourea, or by conducting standard assay melting with the extraction of rare metals in verkble. Such a process ensures the maximum use of existing technologies, technical means and infrastructure of industrial enterprises and reduces the cost of obtaining marketable products.

 It is also advisable to pre-enrich the raw materials, separating the productive soluble and easily oxidizable components from the refractory part of the matrix of raw materials and process them separately.

 This process management reduces the cost of extracting rare metals and increases the profitability of production.

 The proposed method of hydrometallurgical extraction of rare metals from technologically refractory raw materials is that the matrix of refractory raw materials is mechanically, avoiding heating, crushed to the maximum economically acceptable level, for example, to a particle size of not more than 0.001 cm. Crushed raw materials, a solution of acids, oxidizing agents and complexing agents of a certain chemical composition and concentration partially fill, sealed agitation vessel to the design level, providing for each specific type of hard cheese l volume increase with the possible foaming of the reaction mixture due to the released and introduced gases. The process is conducted at a certain pH value of the acidity of the medium and the electrochemical potential of the half-wave recovery. In addition, the calculated amount of oxidizing components and oxygen is introduced into the sealed vessel from the outside, and a certain temperature of the reaction mixture is maintained in it. Upon reaching a certain level of the electrochemical potential of the half-wave of reduction in the reaction mixture, the chemical disintegration of the refractory components of the matrix of the raw material is carried out for a certain time until the matrix is permeable to oxidizing agents and complexing agents, the mother liquor is formed and the rare metals in the form of soluble oxides or complexes are released into the mother liquor. The mother liquor is separated from the unreacted solid matrix of the feed and rare metals are recovered from the mother liquor by known methods.

 The duration of the process of extraction of rare metals for each type of raw material is different and amounts to 1-49 hours. In this case, leaching is carried out at least in one stage until the maximum opening of the matrix of raw materials and extraction of rare metals into the mother liquor.

 During the process, mainly hydrochloric and nitrous acids are used as acids, maintaining an excess of hydrochloric acid. Additionally, depending on the structural, functional and elemental composition of the matrix of refractory raw materials, the calculated amount of ions of other halogens: fluorine, iodine, bromine, both individually and in combination, is introduced into the reaction mixture. The concentration of nitrous acid is maintained by introducing externally its soluble inorganic salts, lithium, sodium, potassium, or cesium nitrites, or when alkaline ions are rich in the reaction mixture, nitric oxide (II), for example, obtained by ammonia conversion, is introduced into the reaction mixture or by other means.

The pH in the reaction mixture is maintained at a pH of 3 or lower, since at most pH 3.3 anion anion exists. $\genfrac{}{}{0ex}{}{\text{-}}{\text{2}}$ and at pH less than 3.3 - nitrous acid (HNO ₂ ). The temperature of the reaction mixture is maintained within the range of 0-20 ^° C., optimally 15 ± 5 ^° C. At lower temperatures, the stability of nitrous acid increases, but the reaction rate decreases and the viscosity of the aqueous reaction mixture increases, and at higher temperatures the concentration of nitrous acid decreases due to for its decay and competing nitric acid formation reactions.

 The pressure in the sealed vessel containing the reaction mixture, until the oxidation reaction is completed, is set at a level lower than or equal to atmospheric, and as the reaction mixture absorbs nitrogen oxides and molecular oxygen, the pressure in the vessel decreases. The decrease in pressure is compensated by a controlled supply of oxygen from outside to atmospheric level. Increasing the pressure in the reaction vessel above atmospheric increases the rate of the oxidation reaction and reduces the time of the oxidation process, however, complicates the technical design, increases the cost of manufacturing and operation of equipment, requires a higher degree of environmental protection of the production.

 The oxidation of various components in the reaction mixture is ensured by the use of the interaction of oxidizing halogen acids, oxygen, nitrogen oxides, atomic halogens, oxygen and nitrogen and radicals arising during the reaction of these oxidizing agents with the organic material of the feed matrix. The half-wave potential of the recovery of such a complex oxidizing system can reach 2.4-2.6 V, which is sufficient for the destruction or structural transformation of most of the protective and functional groups of the resistant components of the feedstock matrix. Moreover, the measured electrochemical potential of the half-wave reduction of the reaction mixture can only increase to the level of the oxygen line of water.

 Some types of refractory raw materials contain valuable, but unproductive to rare metals, organic carbon substances (for example, asphalts, resins, paraffins), soluble in organic solvents. After grinding, such raw materials are preliminarily subjected to treatment with organic solvents, for example, from a number of halogen-containing hydrocarbons, lower alcohols, ketones, taken separately or in combination. The resulting solution was separated, the solvents were distilled off and returned to the process, and the resulting by-products were removed. Such preliminary processing of high-carbon raw materials improves the basic hydrometallurgical process, reduces the cost of oxidizing agents and filtering the undissolved part of the raw material, and facilitates the production of productive components in the final stages of the process.

 In many, especially natural ores, technologically refractory raw materials contain readily soluble inorganic components that are unproductive to rare metals, for example, alkaline earth and ferruginous carbonates. Such raw materials are also processed after grinding, for example, with hydrochloric acid without oxygen. The resulting gases and the filtrate are removed. Such pretreatment improves the basic hydrometallurgical process, reduces the salinization of the mother liquor with ferrous and alkaline earth salts, some of which, for example, by forming sulfates, can crystallize in the mother liquor, dragging along useful components.

To facilitate the extraction of rare metals from the mother liquor obtained by the above method, the mother liquor containing an excess of oxidizing agents and, above all, nitrogen oxides, unstable nitroso complexes and nitro compounds, unreacted nitrous and nitric acids, can be boiled. In this case, the first rapid separation of nitrogen oxides occurs when reaching 45-55 ^o C with a delay period of 0.1-300 s. In this case, the foaming solution increases in volume up to 3-4 times or more, which should be provided for during the implementation of the process. Further heating occurs without side effects and can be continued until boiling. In this interval, after foaming to a boil, complete osmium and ruthenium oxides having low sublimation temperatures of 29 and 99 ^° C, respectively, can be removed together with steam. These oxides are captured in a known manner. The mother liquor remaining after these operations is further treated with reducing agents, reducing the electrochemical potential of the half-wave of the solution recovery stepwise (for selective selection of rare metals precipitates) or immediately to a value of 0-0.2 V. Recovery leads to the intensive destruction of most, for example, nitroso complexes and the formation of sediment containing rare metals. The precipitate is separated and recovered from it commodity metals by known methods.

 In some cases, selective extractants, for example liquid, not miscible with an aqueous solution, should be used. So, for example, butyl mercaptan can be used in the selective recovery of only gold.

 For analytical purposes, for example, to determine gold by the method of assay melting, the mother liquor and the undissolved part of the raw materials obtained by the described method can be not separated, but subjected to drying to dry salts and smelting in a standard way.

 Such conducting sample preparation for analysis in comparison with the conventional method of assay melting, which it has so far conducted without preliminary chemical processing of raw materials, gives more accurate results on the content of rare metals in refractory raw materials.

 Finally, it should be pointed out that it is advisable to conduct a phase analysis of refractory raw materials and their constituent components in order to reveal their productivity on rare metals.

 Separate processing of the phases of raw materials can lead to a significant reduction in processing volumes and lower costs per unit of commodity output.

 The following are aspects of the chemistry of the proposed process.

 The components of the matrix of refractory raw materials can be divided into two classes of inorganic and organic.

 Among inorganic components, anhydrous silicates and aluminosilicates, oxides of titanium, silicon, carbides, and graphite should be classified as particularly resistant components. The decomposition and dissolution of these resistant components, coordinating and / or including rare precious metals, is difficult, since the electrochemical potential of the half-wave of reduction for these components in most cases is higher than 1.6 V. Hydrogen-containing silicates, iron and aluminosilicates slowly dissolve in a medium of strong acids and in the presence of oxidizing agents such as oxygen, nitrogen oxides, and halogens, since their electrochemical potential of the half-wave of reduction is below 1.45 V.

 The main components of the organic part of the matrix of refractory raw materials are heteroatomic condensed compounds and, primarily, nitrogen peroxides and ethers. The organic components of the matrix include functional centers responsible for coordination or chemical bonding with scattered rare metals, and protective groups restricting the access of oxidizing agents, solvents, and complexing agents to the functional centers. Chemical disintegration of the organic part of the matrix of refractory raw materials involves two parallel processes: the removal of the action of protective groups and the destruction or transformation of functional centers.

 It is most difficult to ensure the removal of protective groups from the matrix, the number of which in organic chemistry is known to more than 1200. Some of them can be removed by acid or neutral hydrolysis without the participation of oxidizing agents and are resistant to alkaline treatment, and vice versa. Others require treatment in the presence of mercury, silver, copper, or Lewis salts. For example, silyl and silyl protective groups are common in refractory raw materials of the low-temperature metamorphic and metasomatic class, graphite and carbonaceous shales, siliceous, black and oil shales, and sedimentary rocks. They are capable of retaining complexes and oxides of noble metals on the surface of silicas, silicates and aluminosilicates and are very stable under conditions of acid hydrolysis. For removal and / or separation of the chemical associated precious metals, fluoride ions must be present in the reaction medium. The latter can be drawn from the inorganic part of the raw material during acid treatment, for example, from fluorine-apatite, and if they are deficient, they must be introduced into the process from the outside in the form of soluble salts or hydrofluoric acid.

 The removal of alkylthioprotective groups from the matrix can be carried out under acidic and near-neutral conditions in the presence of mercury, silver or copper salts at low electrochemical potentials of the half-wave of reduction. For example, in the field of stability in an acidic solution of monovalent copper.

 Hydroperoxides, peroxoesters, peroxides of alkyls and aralkyls have high electrochemical potentials of the half-wave of reduction, respectively: 0.6 - 0.9 V, 0.8 - 1.1 V and 1.4 - 2.1 V. For their oxidation, it is necessary to ensure the electrochemical potential half-waves of restoration in solution at the proper level.

To create a sufficient oxidation potential in the reaction medium and remove the most resistant components from the feedstock matrix, nitrogen oxides, halogens, and oxygen are formed or introduced into it, the combined action of which ensures the creation of a sufficient concentration of oxidizing agents on the surface of the solid particles of the matrix and the achievement of a high electrochemical reduction potential up to 2.7 V. For example, in an acidic environment, nitric acid and nitrogen oxides react as follows:
HNO ₂ + H ⁺ + e = NO + H ₂ O - +1.00 V
or 2HNO ₂ + 4H ⁺ + 4e = N ₂ O + 3H ₂ O - +1.29 V
or 2HNO ₂ + 6H ⁺ + 6e = N ₂ + 4H ₂ O - +1.44 V
Where
e - electron
In a neutral environment, the nitrous acid anion acts as a reducing agent, for example
NO $\genfrac{}{}{0ex}{}{\text{-}}{\text{2}}$ + H ₂ O + e = NO + 2OH ^- - -0.46 V
or NO $\genfrac{}{}{0ex}{}{\text{-}}{\text{2}}$ + 6H ₂ O + 6e = NH ₄ OH + 7OH ^- - -0.15 V
or 2NO $\genfrac{}{}{0ex}{}{\text{-}}{\text{2}}$ + 4H ₂ O + 6e = N ₂ + 8OH _- - +0.11 V
Therefore, the oxidation process of the persistent part of the feed matrix is carried out in a region of sufficient acidity, and an excess of unreacted nitrous acid can be used in subsequent reduction reactions.

Nitric oxide (1), for example, in a near-neutral medium reacts with water with a low anode potential
N ₂ O + H ₂ O + 2e = N ₂ + 2OH - +0.94 V,
and in an acidic medium with an anode potential of almost double
N ₂ O + 2H ⁺ = N ₂ + H ₂ O - +1.77 V
Nitric oxide (II) can create the electrochemical potential of the half-wave of reduction in the near-neutral medium, equal, for example
NO + H ₂ O = HNO ₂ + H ⁺ + e - +0.99 V
or 2NO + 2H ₂ O + 4e = N ₂ + 4OH ^- - +0.85 V
and in an acidic environment has a higher anode potential
2NO + 2H ⁺ + 2e = N ₂ + H ₂ O - +1.59 V
or 2NO + 4H ⁺ + 4e = N ₂ + 2H ₂ O - +1.68 V
Bubbling molecular oxygen into a reaction mixture that does not contain other oxidizing agents and organic substances can create the electrochemical potential of the process recovery half-wave at various levels
O ₂ + 2H ₂ O + 4e = 4OH ^- - +0.4 V
or O ₂ + 2H ⁺ + 2e = H ₂ O ₂ - +0.68 V
or O ₂ + 4H ⁺ + 4e = 2H ₂ O - +1.23 V
The highest electrochemical potentials of the half-wave of reduction can be caused by halogen oxidation processes, for example
F ₂ + 2e = 2F ^- - + 2.87 V
Cl + H ₂ O = HClO + H ⁺ + e - +1.63 V
Cl + H ₂ O ₂ + ClO ₂ + 2H ⁺ + e - +1.45 V
The combined action of oxygen, nitrogen oxides, halogens and organic substances with mobile hydrogen in the presence of any neutral molecules leads to the formation of atomic oxygen, ozone, halogens, peroxides and radicals. This can be illustrated in the following reactions:
RCOOH + Cl = RCOO + HCl
RCOO + NO = NO ₂ + RCO
RCO + O ₂ = RC (O) OO
Cl + O ₂ = ClO + O
ClO + O ₂ = Cl + O ₃
O + O ₂ + M = O ₃ + M
where M is any neutral molecule.

The ozone formed in this case creates the highest electrochemical potential of the half-wave of reduction in weakly acidic solutions, for example
O ₃ + 2H ⁺ + 2e = O ₂ + H ₂ O - +2.07 V,
which with increasing and decreasing acidity decreases
O ₃ + 6H ⁺ + 6e = 3H ₂ O - +1.51 V
O ₃ + H ₂ O + 2e = O ₂ + 2OH ^- - +1.24 V
For industrial applications of the proposed process, it is important that in the presence of halogens, the oxidation of nitric oxide (II) by halogens and oxygen easily occurs in the dark conditions of a sealed vessel. Moreover, with an excess of halogens and oxygen, NO is spent on the formation of NOCl, NCl and NO, and with a deficiency, NO is involved in the formation of peroxides, inhibition of radials and ozone, for example, by the reaction
O ₃ + NO = NO ₂ + O ₂
Maintaining a low process temperature in the optimal range of 10 ± 5 ^o C and regulating the pressure in the reactor using the oxygen supplied to the mixture shift the reaction towards the formation of nitrous acid. These reactions proceed with a significant decrease in free energy, the greatest with a lack of oxygen:
4NO + O ₂ + 2H ₂ O = 4HNO ₂ - +304.34 kJ
and less loss of free energy with an excess of oxygen, for example
2NO + O ₂ + H ₂ O = HNO ₃ + HNO ₂ - +228.6 kJ
The energy released during these processes is sufficient for the oxidation reaction to occur without additional heating, which proceed at a faster rate and are practically irreversible. In this case, the reaction of oxidation of NO to NO ₂ is the slowest. The equation of the rate of this reaction is represented as
W = Ka ² b
Where
K is the reaction rate constant, increasing with decreasing temperature;
a is the concentration of nitric oxide (II);
b is the concentration of oxygen in the gas phase.

The decomposition of nitrous acid into nitric acid and nitric oxide (II) comes with heat absorption
3HNO ₂ = HNO ₃ + 2NO + H ₂ O - -75.9 kJ
which contributes to heating and oxygen deficiency.

These complex conditions for the interaction of oxidizing agents require, in order to optimize the process, to observe the predominance of halogens and oxygen over the concentration of NO and NO ₂ and, accordingly, NO ₂ over NO.

Thus, the strong protective groups of the feedstock matrix, for example peroxyacyl, peroxyaroyl, nitrates and esters, can be destroyed in the presence of NO, O ₂ and halogens, for example
RC (O) OONO ₂ + 3NO + 2O ₂ = 4NO ₂ + CO ₂ + RO + OH
and retire or structurally transform. The matrix of raw materials disintegrates or becomes loose, amorphous, opening up access to oxidizing agents and complexing agents to the functional centers of the matrix and the metals associated with them.

Among the functional centers coordinating or chemically bonding transitional, including noble metals, OH, CO are the most typical. COO, NH ₂ , NH, CH, OHN, C = C and many others, including those including hetero elements such as arsenic, sulfur, phosphorus and antimony. Of these, the groups containing nitrogen are the most significant. The opening of this part of the refractory raw materials and the oxidation of the metals associated with them is ensured by the combined action of a complex of oxidizing agents represented by halogens, oxygen, nitrogen oxides and their derivatives. In this case, the removal into the mother liquor, for example, of noble metals occurs in the form of well-known halogen and nitroso complexes. Functional centers containing, for example, alcohol groups are destroyed with the formation of organic peroxide, hydrogen peroxide and ketones. Further, organic peroxides decompose with the formation of radicals, which develop an oxidation chain, the deepening of which leads to the decomposition of ketones to carboxylic acids, carbon monoxide and water.

 Naturally, the oxidation rate of solid phases is usually negligible due to diffusion limitations. It can be increased by increasing the concentration of oxidizing agents in the solution and the depth of disintegration of the solid particles of the matrix. In order to overcome diffusion inhibition caused by the slow supply of oxidizing agents from the gas phase to the liquid phase, the proposed process uses oxidizing agents that are soluble in aqueous solutions, and the temperature increase in the zone of oxidation reactions is achieved due to deoxotation and secondary oxidation processes.

 Excess or lack of oxygen is critical for many reactions to occur on the surface of the feed matrix and in the reaction solution. For example, with a lack of oxygen, alcohols are converted to ketones and water without the formation of organic and inorganic peroxides. The optimal ratio of oxidizing agents, peroxides, and radicals can be realized with a sufficiently energetic supply of oxygen through the reaction mixture. This can be realized if oxygen is supplied with a carrier readily soluble in the reaction solution, as well as easily giving and receiving oxygen at a low activation energy. One of these carriers is nitric oxide (II), which is formed in the process of mutual reactions of nitrous acid, halogen acids and the matrix of raw materials. Nitric oxide (II) is practically insoluble in an aqueous solution. However, easily combining with molecular oxygen in the gas phase with an insignificant thermal effect (+12 kJ), it turns into nitric oxide (IV). The latter is highly soluble in aqueous media, on which the industrial technology for producing nitric acid is based.

 Under conditions of tight process control, the obtained nitric oxide (IV) is transferred from the gas phase to the reaction mixture, dissolved in it and removes the kinetic restrictions on oxygen delivery to the solution and to the surface of the matrix particles. With this process, the concentration of oxidizing agents in the gas phase and the solution is easily controlled, for example, by the pressure supplied to the oxygen reactor.

 To break the bond of metals and functional groups, for example, nitrogen-containing, the use of nitrous acid in the process is especially important. It allows you to conduct the reaction of nitriding resistant materials with high thermal effect. Amides are converted to carboxylic acids, and primary amines to alcohols and aldehydes. In the presence of halogen ions and oxidizing agents, primary, secondary and tertiary amines, being strong bases, easily dissolve in acids. The composition of the products of the interaction of amines with nitrous, nitric acids, and nitrogen oxides depends on the structure of amines. So, for example, primary aliphatic amines with nitrous acid give molecular nitrogen and alcohol; secondary amines form liquid and solid nitro derivatives, while tertiary amines dissolve in nitrous acid and form various oxidation products, in particular aldehyde and secondary amine. Due to weak basic properties, nitroamines do not dissolve in acids, but with prolonged action of oxidizing agents in acidic solutions, they are unstable and are isomerized into hydroxylamines with the further evolution of nitrogen and alcohol. Salts of aromatic diazo hydrates are more stable, but also decompose over time, releasing nitrogen.

Aliphatic and aromatic diazonium ions and amines decompose very quickly. Under suitable process conditions, the oxidation of, for example, amines occurs with a delay period of 0.01 - 2000 s, increasing with decreasing concentration of oxidizing agents. In addition, primary and secondary amines decomposing to nitrogen act as heat generators due to deazotization reactions proceeding with an exothermic effect of more than 300 kJ / mol. This heat is quite enough to stimulate the breaking of bonds in most organic compounds and to overcome the activation barrier in the reaction zone, which is mainly equal to 150-180 kJ / mol. The calculated value of the temperature in the zone of the de-nitration reaction reaches 1000 ^o C, which naturally intensifies the reactions of oxidation, dissolution, chlorination, nitrosation and thermal decomposition of nearby sections of the solid particles of the matrix. It is likely that the heating of the reaction zone is even higher due to adverse oxidation reactions, for example, nitric oxide (II) into nitrous acid. So, if primary amines are easily oxidized by molecular oxygen, forming hydroxylamine and nitro compounds, and secondary amines are soluble nitroso compounds, then tertiary amines form oxides, which require strong heating for further decomposition. The decrease in free energy during de-nitriding during the reaction of primary amines and nitrous acid ensures the destruction of tertiary amines and their oxidation products.

 Carbon compounds of the feedstock matrix having unsaturated bonds are oxidized at these bonds by ozone to aldehydes, carboxylic acids and peroxides, or undergo a gap at the site of such a bond. With hydrogen peroxide they react with the formation of glycols, with carboxylic acids with the formation of epoxides, with halogen acids they are halogenated. Primary, secondary, tertiary arsines are oxidized to diarso compounds, carboxylic acids and oxides, and nitrosyl halides form oximes. Oxidation of mercaptans leads to the formation of sulfenic, sulfinic, sulfonic acids and sulfoxides.

 Most of the organic compounds oxidized in this way either pass into the mother liquor or remain bound to the solid phase of the matrix, without further interfering with the access of oxidizing agents and complexing agents to productive components. The latter also undergo oxidation to higher oxides and, in the form of higher oxides, easily lose touch with the functional centers of the matrix of raw materials and can be removed into the mother liquor in the form of ionic compounds, chelates or complexes.

As a result of this process, the halogen and nitroso complexes of rare metals, including noble and their low-melting oxides, are concentrated in the mother liquor. These complexes are very resistant to reduction, oxidation, and heating and can exist without decomposition and precipitation from the mother liquor over 10 ⁺ s.

 The examples illustrate some of the results obtained by hydrometallurgical extraction of rare metals from refractory raw materials by the proposed method.

Example 1. Taken sulphide black shale ore containing, wt.%: Silicates 82; pyrites 4,5; arsenopyrite 0.5; carbonates 3; heteroatomic carbon compounds 9.8; phosphates 0.2. The organic phase includes, wt.%: Carbon 86; hydrogen 4.5; oxygen 5.2; nitrogen 1.8; sulfur 1.8; arsenic 0.1 and phosphorus 0.2, the rest is impurities. The yield of volatiles upon ignition, wt.%: At 200 ^° C. 0.146, at 500 ^° C. 2.85 and at 850 ^° C. 5.14. Gold content, g / t, according to neutron activation analysis / NAA /: without preliminary calcination 20.8; after calcination at 200 ^° C. 13.2; at 500 ^° C. 13.2; at 850 ^° C. 6.95. The gold content in raw materials according to standard assay analysis 12.1 g / t; silver 96 g / t; no platinoids were found.

 The initial ore was preliminarily crushed in a ball mill in a mixture with water 1: 1 by weight to a particle size of 90% - 0.15 mm.

The resulting mixture was placed in an agitation vessel, a solution of 10% HCl was added to a liquid: solid ratio of 2: 1 by weight and the agitation vessel was filled to 50% by volume. The agitation vessel was sealed and then during the whole process the vessel was cooled, the temperature of the reaction mixture was kept within 10 ± 5 ^o C and the acidity was less than pH 2, by adding an external HCl solution, the reaction mixture was stirred in a turbulent mode.

The process was carried out by introducing from the outside into a sealed agitation vessel technical oxygen and an aqueous solution of alkaline nitrous salt (NaNO ₂ ), which forms nitrogen and NO in the form of a gas phase in an acidic environment, maintaining the ratio in the gas phase of the reaction vessel NO: O ₂ as a ² : a and keeping the total pressure in the sealed vessel at 0.8 ± 0.2 atmosphere. The process was carried out for 14 hours until the oxygen consumption in the reaction mixture was achieved, the half-wave potential index reached 1.1 V in the mixture and the extraction of rare metals into the mother liquor ceased.

Next, the mixture was filtered, the filtrate was heated to 55 ± 5 ^° C, the dissolved gases were removed, osmium and ruthenium oxides were distilled off from the filtrate by blowing with steam under vacuum, the residual mother liquor was separated and useful components were separated from it by known methods. Received, g / t: 96 gold; silver 183; palladium 24; platinum 6.5; osmium 3.5; ruthenium 0.5; rhodium 2 and iridium 6.

Example 2. A sludge fraction was taken for washing the building river sands of a flat river with a content of not less than 0.1 g / m ³ in sands of sludge gold, containing essentially wt%: inorganic silicates 55; carbonates 2.2; sulfides (troilite) 3; iron hydroxides 0.5; bound water 10; organic phase 29.3. The organic phase includes, wt.%: Carbon 52; hydrogen 6; oxygen 35; nitrogen 2,3; sulfur 0.6; phosphorus 0.3; arsenic 0.1; the rest is impurity. The output of volatile components during calcination, wt.%: At 200 ^o C 0.19; at 500 ^° C. 5.82; at 850 ^° C. 6.77. Gold content, g / t, according to HAA: without calcination 3.6; after calcination at 200 ^° C. 2.7; at 500 ^o C 2.5; at 850 ^o C 0.4. The gold content in raw materials according to standard analysis of 0.2 g / t; silver 34.2 g / t; no platinoids.

The feed was leached for 3 hours. The pH of the mixture was maintained equal to 2 ± 0.2 and a temperature of 15 ± 5 ^o C until the complete elimination of the reaction gases at a supply pressure of 600 ± 50 mm Hg. Art. until the complete cessation of oxygen consumption by the reaction mixture and the electrochemical potential of the half-wave of recovery equal to 1.1 B. Then they acted as in example 1. Received, g / t; gold 3.7; silver 115; platinum 4.5; osmium 0.5; ruthenium 0.5; palladium 2; iridium 0.3; Rhodium 0.5.

Example 3. The ore of gold-bearing metamorphic shale was taken, containing essentially wt.%: Silicates 80; carbonates 7.5; pyrite 2.2; phosphates 0.2; stibnite 0.5; organic phase 8.0; the rest is impurity. The organic phase includes, wt.%: Carbon 88; hydrogen 4; nitrogen 1.5; oxygen 4; sulfur 1.5; arsenic 0.1; antimony 0.1; antimony 0.1; phosphorus 0.8. The output of volatiles upon ignition, wt. %: at 200 ^° C 2.7; at 500 ^° C. 1.8; at 850 ^o C 8. Gold content, g / t, according to the NAA: without calcination 21.8; after calcination at 200 ^° C. 20.8; at 500 ^o C 18; at 850 ^° C. 10.2. Content, g / t, according to standard assay analysis: 10.8 gold; silver 78.5; no platinoids were found.

 After grinding, the ore is pretreated with 10% hydrochloric acid for 10 hours to remove carbonates and soluble sulfides. Upon completion of dissolution, the solution was separated, the solid residue was leached by the method as in example 1. Received, g / t: gold 46.8; silver 186.5; platinum 1.6; iridium 0.6; ruthenium 3.2; Rhodium 0.2.

Example 4. Tails taken from the extraction of molybdenum from molybdenum concentrates containing, by weight. %: silicon dioxide 10 ± 2; aluminum oxide 5 ± 0.7; iron oxide 0.3 ± 1; iron oxide - 17 ± 0.5; calcium oxide - 20 ± 5; sodium oxide 1.1 ± 0.5; potassium oxide - 0.2 ± 0.1; sulfate sulfur 20 ± 0.5; sulfide sulfur 1.8 ± 0.5; molybdenum 3.1 ± 0.5; total carbon 20.2 ± 5; nitrogen 3.5 ± 1.2; hydrogen 1.2 ± 0.5; arsenic 0.6 ± 0.1; phosphorus 1.2 ± 0.2, other impurities. The output of volatiles upon ignition, wt. %: at 200 ^o C 5.6; at 500 ^° C. 4.3; at 850 ^° C. 17.35. Gold content, g / t, according to the NAA: without calcination 14.7; after calcination at 200 ^° C. 13.2; at 500 ^° C. 6.2; at 850 ^o C 1.2. Content in raw materials, g / t, according to standard analysis: gold 8.5; silver 78.5. No platinoids found.

 The raw material was leached according to the method as in example 1. Received, g / t: gold 29.6; silver 175; selenium 244; rhenium 42.5; patina 5.6; palladium 2.3; iridium 3.3; rhodium 0.6; no osmium; no ruthenium.

Example 5. The scrubber dust of smelting furnaces of copper production of the following composition was taken, wt.%: Copper 1.7; lead 40.5; sulfur 12.4; zinc 5.6; arsenic 2.9; total carbon 11.5; silicates 0.2; water 25.0; the rest of the impurities, including: silver 148 g / t; no gold; no platinoids. The yield of volatiles upon ignition, wt.%: At 200 ^o C 26.6; at 500 ^° C. 12.7; at 850 ^o C 14.2.

 The raw material was leached according to the method as in example 1, until the electrochemical potential of the half-wave recovery of the mixture reached 1.1 B. The solid part of the raw material completely passed into the mother liquor after 1.5 hours. Received, g / t: 18.1 gold; silver 196; platinum 5; iridium 2; rhodium 2; no ruthenium; no osmium; rhenium 67.

 Below are the results of the effect of pre-treatment of raw materials with organic solvents and hydrochloric acid.

 Example 6. A metamorphic ore was taken with an organic carbon content of 0.55% and a total carbon of 2.5%, in which standard assay melting was determined, g / t: gold 3.3; silver 1,2. The raw material was treated in a Soxhlet apparatus for 2 hours with chloroform at a ratio of liquid to solid in the mixture equal to 2. The filtrate was removed. The solid filter residue was treated for 2 hours with an azeotropic mixture of ethyl alcohol and benzene with a liquid to solid ratio of 2. The filtrate was removed. The solid residue from the last treatment was exposed to a 10% aqueous hydrochloric acid solution for 1 h at reflux until gas evolution ceased. The filtrate was removed. The total weight loss of raw materials from three consecutive stages of processing amounted to 7.5%. The content of organic carbon in the solid residue decreased to 0.25%, and the total carbon to 0.5%. Standard assay melting of the solid residue from three consecutive stages of processing in terms of the initial weight of the sample obtained, g / t: 18.2 gold; silver 42. Further processing was carried out by the method as in example 1.

 Example 7. Taken carbonate carbonate shale with an organic carbon content of 2.4%; total carbon - 6%. Standard assay melting determined, g / t: 4.7 gold; silver 12. The raw material was processed in three successive stages, each lasting 2 hours. In the first stage, the raw material was treated with chloroform in a Soxhlet apparatus with a liquid to solid ratio of 2. The filtrate was removed. In the second stage, the solid residue from the previous treatment with 10% hydrochloric acid was treated at boiling point. The filtrate was removed. In the third stage, the solid residue from previous operations was treated with a mixture of ethyl alcohol and benzene, taken in a ratio of 2. In total, in three stages of processing, the weight loss of the feedstock was 15%. The content of organic carbon in the solid residue decreased to 0.2%, and the total carbon to 0.7%. The standard assay melting of the solid residue from three consecutive treatments in terms of the initial weight of the sample obtained, g / t: 18.8 gold; silver 28.8. Further processing was carried out by the method as in example 1.

 Thus, the proposed method of hydrometallurgical extraction of rare metals from refractory raw materials provides the extraction of rare metals and 1.5-42 times more than in the known methods. In addition, the use of this method for preliminary analysis makes it possible to determine the presence of those components in the ore that previously could not be detected.

 Using the method can lead to a multiple increase in reserves and increase the extraction of rare metals in existing plants, reduce material costs per unit of recovered useful product and involve tails and other raw material sources that were previously considered not promising.

Claims (17)

 1. The method of hydrometallurgical extraction of rare metals from technologically refractory raw materials, including grinding the feedstock, partially filling the agitation vessel with crushed raw materials and an acid solution, stirring the reaction mixture, maintaining a certain temperature, pH and half-wave potential of the recovery of gaseous oxidizing agents with the supply of gaseous oxidizing agents from external source to obtain a mother liquor containing rare metals, characterized in that the process is conducted in a herm the agitation vessel using oxygen as the gaseous oxidizing agent, with the introduction of complexing agents, while the pressure in the vessel, the acidity of the solution, the acid composition, temperature, the half-wave potential of the oxidizing agents and the reaction mixture, the composition of complexing components and the process time are selected from the condition of maximum extraction of rare metals in the mother liquor, followed by extraction of rare metals from the resulting solution by known methods.  2. The method according to p. 1, characterized in that the acid used is halogen and nitrous acid.  3. The method according to claim 2, characterized in that as a halogen acid using acids containing fluorine, chlorine, iodine, bromine, taken individually or in combination.  4. The method according to claim 2, characterized in that the nitrous acid is obtained directly in the mixture due to the reaction of mineral salts of nitrous acid and halogen acid introduced into the reaction mixture or introduced into the reaction mixture of nitric oxide (II) obtained in an external source. 5. The method according to claim 1, characterized in that the temperature of the reaction mixture is maintained equal to 0 - 20 ^o C, and the pH of the acidity in the mixture is in the range of 0.1 - 3.  6. The method according to claim 1, characterized in that the pressure in the vessel and the oxidation process are supported by the supply of oxygen from the outside or its mixture with nitric oxide (II).  7. The method according to claim 6, characterized in that the pressure in the vessel is maintained at a level below or equal to atmospheric.  8. The method according to claim 1, characterized in that as complexing agents use components of halogen and nitrous acids, their compounds with each other and oxygen and the products of redox reactions in the reaction mixture.  9. The method according to claim 1, characterized in that halogens, oxygen, nitrogen and peroxides of their compounds with each other, activated in the reaction mixture and formed in the process of mutual redox reactions and reactions with the matrix of raw materials, are used as oxidizing agents.  10. The method according to PP. 1 and 9, characterized in that the half-wave potential of the reduction of the oxidation process is maintained at 2.4 - 2.6 V, and the electrochemical potential of the half-wave of reduction in the reaction mixture is at least 1.1 V, and the process time is selected based on the achievement maximum extraction of rare metals in the mother liquor.  11. The method according to claim 1, characterized in that the technologically refractory raw materials after grinding are pre-treated with organic solvents taken from a number of acyclic, alicyclic and cyclic hydrocarbons, including halogenated, lower alcohols and ketones, taken separately or in a mixture, and solvents and dissolved components are removed.  12. The method according to claim 1, characterized in that the technologically refractory raw material after grinding is pretreated with halogen acid and the dissolved components are removed.  13. The method according to claim 1, characterized in that the technologically refractory raw material after grinding is pre-treated sequentially with organic solvents and halogen acid, each time removing the products of dissolution and the solvent.  14. The method according to claim 1, characterized in that after completion of the process, the mother liquor is separated from the undissolved raw materials and subjected to boiling, dissolved gases and low-boiling oxides and rare metal complexes that are trapped are removed.  15. The method according to 14, characterized in that the mother liquor after boiling and removal of the separated reaction gases and part of the rare metals is reduced to the half-wave potential of the reduction in the mother liquor 0 - 0.2 V and the rare complexes and rare oxides remaining in the solution are precipitated metals, the precipitate is separated and then rare metals are extracted from it by known methods.  16. The method according to claim 1, characterized in that the raw material is pre-enriched, separating the productive, readily soluble and oxidizable components from the refractory components, and process them separately.  17. The method according to claim 1, characterized in that the duration of the process of leaching and extraction of rare metals is selected for each specific raw material and it is 1 to 48 hours, while leaching is carried out at least in one stage until the maximum extraction of rare metals in stock solution.