RU2802033C1 - Method for processing deactivated automobile catalysts - Google Patents

Abstract

FIELD: catalysts.

SUBSTANCE: methods for processing deactivated automotive catalysts, and in particular isolation and purification of rare earth metals contained in secondary raw materials. Waste automotive catalysts are crushed to a particle size of 1-2 mm, fired at t = 780-800°C for 5-5.5 hours, after which they are crushed to a size class of 3-5 microns to obtain a solid sample, into a resulting solid sample with a leaching solution of 6M HCl is added in a ratio of 1:5. The resulting suspension is stirred and heated, aluminum granules are added in an amount of 10% of the sample. After completion of the reduction reaction, the leaching process is carried out for 4 hours at a temperature of 75-80°C. During the entire leaching process, H₂O₂ is dosed into the suspension in an amount of 10% of the solid sample. After completion of the leaching process, the resulting suspension is filtered and washed to a neutral medium, the resulting precipitate is dried to constant weight.

EFFECT: increasing the environmental friendliness of the process of extraction of platinum group metals and rare earth elements while maintaining a high degree of extraction.

5 cl, 1 dwg, 1 tbl, 3 ex

Description

The invention relates to methods for processing deactivated automotive catalysts and, in particular, to the field of isolation and purification of rare earth metals contained in secondary raw materials [C22B11/00, C22B11/04].

An automobile catalyst is a complex technical device. Unlike industrial catalysts, it works in non-stationary conditions. Significant temperature differences in different modes of operation of the internal combustion engine, from a "cold start", in which the exhaust gas temperature is close to the ambient temperature, to forced modes, in which the gas temperature can reach peak values of 1100-1200 ° C. In addition, it is characterized by an extremely rapid change in the composition and volumetric velocity of the gas flow from operation on a "rich" mixture, in which there is an oxygen deficiency in the exhaust gases, to operation on "poor" mixtures, when the excess of oxygen reaches 5% of stoichiometry. All this leads to fairly rapid wear of the catalyst. Not only the applied catalyst layer, which contains γ-alumina doped with oxides of rare earth, alkaline earth elements and zirconium, as well as platinum group metals, undergoes critical structural changes, but also the material of the ceramic block itself, complex magnesium aluminosilicate, synthetic cordierite. Changes in the applied coating are reduced to a phase transition of γ-aluminum oxide to the α-form, accompanied by degradation of the surface with a change in its specific area from 80-120 m ² /g to 25-50 m ² /g. In this case, morphological changes occur in the porous structure, leading to the “collapse” of micro- and mesopores. In turn, this leads to blocking of the platinum group metals and a drop in the catalytic activity of the catalyst. In addition, due to the operation of the engine on “rich” mixtures, the surface of the catalyst is carbonized, due to low-quality fuel, sulfur accumulates, and due to “overshoots” of engine oil, phosphorus accumulates. The influence of sulfur is especially great, which forms sulfides with platinum metals that do not have catalytic activity in reactions taking place on a catalyst. The carrier material undergoes phase changes as a result of operation in critical modes and turns from cordierite into mullite with an additional reduction in surface and blocking of the active centers of the catalyst.

The active components of the catalyst, platinum group metals, are in complex charge states in the initial period of operation, which makes it possible to effectively convert harmful components of engine exhaust gases both in the diffusion and kinetic regions of reactions. Over time, the ongoing morphological changes in the composition of the coating lead to a loss of catalytic properties due to the coarsening of noble metal particles from the initial size of 5-7 nanometers to 2-5 microns. And if the surface layer of active components still somehow continues to function, then the inner layers of agglomerates of platinum group metals are completely blocked.

The proposed method for the processing of deactivated automotive catalysts takes into account all the above features and, in this regard, allows you to qualitatively carry out the process of extracting platinum group metals and rare earth elements with increased environmental friendliness of the processing process.

Known from the prior art METHOD AND DEVICE FOR PROCESSING GROUND SCRAPE OF SPENT AUTOMOBILE CATALYST [RU2364638, publ. 20.08.2009] involving the dissolution of platinum metals with an acid-oxidizing mixture by pulsed geyser supply from above to the scrap of a portion of a boiling solution of an acid-oxidizing mixture with the removal of the resulting productive solution and the supply of another clean portion of the acid-oxidizing mixture until a yellow color appears in the productive solution, followed by washing water flowing from above.

The disadvantage of the analogue is the technical complexity of the implementation of the proposed method due to the need to use a pulsed geyser supply from above to scrap portions of a boiling solution of an acid-oxidizing mixture.

Also known from the prior art is a METHOD FOR EXTRACTING PLATINUM METALS FROM AUTOMOBILE CATALYSTS [RU2209843, publ. 08/10/2003] including dissolution with an acid-oxidizing mixture, characterized in that before dissolution, the catalyst is wetted with an aqueous solution of hydrochloric acid in the ratio of HCl: H2O = 1: 1-5, the dissolution is carried out by subsequent heating with the addition of oxidizing agents at boiling in vapors of oxidizing reagents, and after washing the precipitate with water from the resulting solutions, metals are precipitated by cementation into a collective concentrate.

The disadvantage of analogue is the low environmental friendliness of the proposed method due to the need to add oxidizing agents at the boil in the vapor of oxidizing reagents.

Also known from the prior art is a METHOD FOR RUTENIUM ENRICHMENT OF A SPENT RUTENIUM CATALYST BASED ON ALUMINUM OXIDE [CN114934180, publ. 08/23/2022] which is characterized by the fact that it includes the following steps: in the first step, after acid leaching, the spent ruthenium catalyst based on alumina is finely ground to a particle size of less than 0.149 mm, after grinding, the particles are added to the acid leaching solution and the presence of the required ratio is controlled liquid and solid phase between acid leach solution and spent ruthenium alumina catalyst, the ratio of volume of liquid in ml to mass g of alumina, based on spent ruthenium catalyst should be 3-8:1, stirring speed 300-600 rpm , stirred at room temperature for 0.5-2 h, then add the reducing agent - aluminum powder, the amount of added aluminum powder 0.01-0.02 mass of spent ruthenium catalyst based on aluminum oxide, raise the reaction temperature to 50-95°C and continue the reaction for 1-3 hours; after completion of the reaction, the mixture is filtered and washed, thus obtaining a primary leach solution and a primary leach residue; at the second stage, secondary acid leaching is carried out, the primary leaching residue is subjected to acid leaching with a freshly prepared hydrochloric acid solution with a concentration of 3.0-7.0 mol/l, the liquid-solid ratio is controlled, that is, the ratio of the volume of liquid ml to the mass of primary leaching slag should be 5-10:1, acid leaching is carried out for 0.5-3.0 hours, at a temperature of 50-95°C, with a stirring speed of 300-600 rpm, after completion of the reaction, filtration and washing of the acid leaching solution an acid leach residue is obtained, the acid leach solution is returned to the first stage for reuse, and the acid leach residue is sent to the ruthenium extraction process; at the third stage, sodium hydroxide is added to the primary leaching solution to bring the pH of the solution to 0.5-3.0, after which sodium formaldehyde sulfoxylate is added and its added mass is adjusted in the range from 3 to 10:1 of the mass of ruthenium in the solution, temperature reaction, while, is 60-90°C, reaction time 15-90°C, duration 60 min, stirring speed from 300 to 600 rpm, after completion, filtered, washed and dried, obtaining a precipitate of ruthenium.

The disadvantages of analog are:

- the technical complexity of the implementation of the claimed method due to the long and multi-stage process;

- its limited functionality due to the fact that only such a chemical element as ruthenium can be extracted at the output.

The closest in technical essence is a METHOD OF EXTRACTION OF PLATINUM FROM A CATALYST BASED ON ALUMINUM BY DISSOLVING THE CARRIER [CN108315564, publ. 07/24/2018] which is characterized by the fact that it includes the following steps: at the first stage, the carrier containing the platinum-containing spent catalyst is dissolved, while concentrated sulfuric acid is used as a reagent, the consumption of sulfuric acid is 1% of the platinum spent catalyst and 2-8 times exceeds the amount of added water, 3-10 times the weight of raw materials, the reaction temperature is from 80 to 120°C, and the reaction time is from 2 to 8 hours; at the second stage, a reducing agent is added; at the third stage, clarification and separation of liquid and solid are carried out, for which the solution is diluted with water, after which the volume of the resulting solution becomes from 30 to 80 times more than the spent platinum catalyst, the resulting solution is stirred and allowed to settle for clarification, the liquid is drained and a thick suspension is filtered at the bottom to obtain platinum-containing slag; at the fourth stage, the platinum-containing slag is calcined to remove carbonaceous deposits and organic substances, the calcination temperature is from 500-1000°C; at the fifth stage, platinum is dissolved on calcined slag, hydrochloric acid and an oxidizing agent are used as reagents, the ratio of liquid to solid is 2/1-10/1, the initial acidity, the concentration of hydrochloric acid is 1-10 mol/l, and nitric acid is the oxidizing agent or sodium chlorate; in the sixth step, solid ammonium chloride is slowly added to the platinum-containing solution to obtain ammonium chloroplatinate, precipitated, filtered and washed with a 50 g/l ammonium chloride solution, the ammonium chloroplatinate precipitate is mixed with hot water, the reducing agent hydrazine hydrate is added to reduce, and crude spongy platinum product; at the seventh stage, after dissolving the crude product, platinum sodium salt is added in the amount of 20-200 g/l, then sodium hydroxide solution is added to bring the pH value to 7-10, then the impurities are precipitated, and then they are filtered; in the eighth step, the platinum sodium salt complex solution is adjusted to a pH value of 1 to 3 with analytical pure salt, and analytically pure solid ammonium chloride is added to precipitate platinum, the ammonium precipitate is calcined and decomposed to obtain platinum, while the calcination decomposition temperature is 500- 1000°C, calcination time 1-10 hours.

The main technical problem of the prototype is the low environmental friendliness of the process of extracting rare earth metals, due to the fact that the prototype method uses a large amount of sulfuric, hydrochloric and nitric acid, while the dissolution process occurs at high temperature, over a long period of time and is multi-stage and technically difficult. Thus, the extraction process itself is lengthy and non-environmental, requiring specialized equipment, in addition, after the extraction process, a large number of spent compounds remain that require special storage and disposal.

The objective of the invention is to eliminate the disadvantages of the prototype.

The technical result of the claimed invention is to increase the environmental friendliness of the process of extracting platinum group metals and rare earth elements.

This technical result is achieved due to the fact that the method of processing deactivated automotive catalysts, characterized in that the samples of spent automotive catalysts are initially crushed to a particle size of 1-2 mm, fired at t = 780-800°C for 5-5.5 hours, then the samples of spent automotive catalysts are crushed to a size class of 3-5 microns, then a 6M HCl leaching solution is added to the sample from the obtained solid sample in a ratio of 1:5, the resulting suspension is stirred and heated, aluminum granules are added in an amount of 10% of the sample sample , then after the end of the reduction reaction, the leaching process is carried out for 4 hours at a temperature of 75-80 ° C, during the entire leaching process, H ₂ O ₂ is dosed into the suspension in an amount of 10% of the sample of the solid sample, after the completion of the leaching process, the resulting suspension is filtered through a filter and washed to a neutral medium, the resulting precipitate is dried to constant weight.

In particular, samples of spent automotive catalysts are crushed in a jaw crusher.

In particular, samples of spent automotive catalysts are ground in a planetary mill.

In particular, samples of used automotive catalysts are fired in a muffle furnace.

In particular, the resulting suspension is filtered through a blue ribbon filter.

Brief description of drawings:

In FIG. 1 shows the general scheme of the installation for implementing the claimed method.

The figure shows: 1 - stirrer drive with speed control, 2 - stirrer, 3 - leaching solution, 4 - sampler, 5 - thermometer, 6 - hole for sample and leaching solution, 7 - siphon cover, 8 - thermostat, 9 - solid sample.

Implementation of the invention.

The installation for leaching autocatalysts includes a stirrer drive with speed control 1, in the lower part of which a stirrer 2 is placed in the internal volume of the three-necked flask. Also, the leaching solution 3 is placed in the internal volume of the flask. A sampler 4 is placed in the upper part of the flask. includes a thermometer 5, configured to measure the temperature inside the flask. A hole for the sample and leaching solution 6 is made in the upper part of the flask. A siphon cover 7 is placed above the stirrer in the upper part of the flask. A thermostat 8 is placed along the outer perimeter of the flask. A solid sample 9 is placed in the inner volume of the flask, in its lower part.

The method of processing deactivated automotive catalysts is characterized by the fact that initially samples of spent automotive catalysts are crushed in a jaw crusher to a particle size of 1-2 mm, fired in a muffle furnace at t = 780-800 ° C for 5-5.5 hours. At the same time, During firing, the following chemical reactions take place:

C + O ₂ \u003d CO ₂ ;

PtS + O ₂ \u003d PtO + SO ₂ ;

PdS + O ₂ \u003d PdO + SO ₂ ;

2Ce ₂ O ₃ + O ₂ \u003d 4CeO ₂ .

Next, the catalyst is crushed in a planetary mill to a size class of 3-5 microns. Thus obtaining a solid sample 9, prepared for the stages of reduction and leaching.

The leaching process is carried out in a three-necked flask with a reflux condenser installed at a temperature of 75-80°C and stirring at a speed of 300-600 rpm for 4 hours, with a solid sample weight of 9-25 g.

A portion of the solid sample 9 is loaded into the installation for leaching of autocatalysts (figure 1), 6M HCl is added to it in a ratio of 1:5 (t:g). These operations are carried out using the sample hole and the leaching solution 6. The resulting slurry (consisting of the leaching solution 3 and the solid sample 9) is stirred at a speed of 300 to 600 rpm using a stirrer 2 (which has a variable speed drive 1), heated using a thermostat 8, to a temperature of 75 - 80°C.

Temperature control is carried out using a thermometer 5, samples of the solution for leaching 3, if necessary, are taken using a sampler 4. In the resulting suspension (consisting of a solution for leaching 3 and a solid sample 9), with stirring and heating, aluminum granules are added in an amount of 10 % of the sample weight.

During recovery, the following reactions occur.

Hydrogen release as a result of the reaction between aluminum and hydrochloric acid solution:

2Al + 6HCl \u003d 2AlCl ₃ + 3H ₂ .

Reduction of oxides of platinum metals with hydrogen at the moment of release into a metallic form:

PdO + H ₂ \u003d Pd + H ₂ O;

PtO + H ₂ \u003d Pt + H ₂ O;

2Rh ₂ O ₃ + 6H ₂ \u003d 4Rh + 6H ₂ O.

Recovery of cerium from a higher oxide to a trivalent form:

2CeO ₂ + H ₂ \u003d Ce ₂ O ₃ + H ₂ O.

After the completion of the reduction reaction of platinum group metals (PGM) and rare earth elements (REE) with aluminum granules, the countdown of the process of their extraction begins, which is characterized by the fact that H ₂ O ₂ is dosed into the suspension during the entire leaching process (4 hours) - in amount of 10% of the weighed solid sample 9. The addition of aluminum granules and H ₂ O ₂ is also carried out using the sample hole and leaching solution 6.

During the leaching process, the following reactions take place.

Oxidative leaching of platinum group metals into solution:

Pd + 4HCl + 2H ₂ O ₂ = PdCl ₄ + 4H ₂ O;

Pt + 4HCl + 2H ₂ O ₂ \u003d PtCl ₄ + 4H ₂ O;

2Rh + 6HCl + 3H ₂ O ₂ = 2RhCl ₃ + 6H ₂ O.

Leaching of cerium into solution:

Ce ₂ O ₃ + 6HCl = 2CeCl ₃ + 3H ₂ O;

Partial dissolution of the cordierite base:

Al ₂ O ₃ + 6HCl \u003d 2AlCl ₃ + 3H ₂ O.

Upon completion of the leaching process, the suspension is filtered through a blue ribbon filter. The precipitate filtered and washed to a neutral medium is dried to constant weight and weighed.

The claimed technical result of improving the environmental friendliness of the process of extracting platinum group metals and rare earth elements is achieved due to the fact that the claimed method, based on the use of aluminum granules in the leaching process, is technically simple to implement, while, in comparison with the solutions known from the prior art, less the amount of hydrochloric acid, the leaching process lasts a shorter amount of time, at a lower required temperature. Also, the claimed technical result is achieved due to the ability to subsequently regenerate the working solution, since the basis of the automotive catalyst is cordierite (Mg ₂ Al ₄ Si ₅ O ₁₈ ), which is a magnesium aluminosilicate.

The choice of the crushing range of spent automotive catalysts in a jaw or hammer crusher to a particle size of 1-2 mm is justified by laboratory experiments, during which it was found that: roasting samples crushed to a particle size of less than 1 mm does not lead to an increase in the degree of extraction of PGM and REE in solution at the leaching stage; calcination of samples ground to a particle size of more than 2 mm leads to a decrease in the degree of extraction of PGM and REE in solution at the leaching stage. Also, the choice of the range is justified, by the minimum value, by the technical characteristics of the grinding equipment, by the maximum, by cost savings in the second stage of grinding and the costs associated with processing in the furnace.

The choice of temperature ranges (t = 780-800°C) and firing time in a muffle furnace (for 5-5.5 hours) is justified by laboratory experiments, during which it was found that: at temperatures below 780°C, complete removal of carbon, and an increase in temperature above 800°C leads to a decrease in the degree of extraction of rhodium and cerium in the leaching process; an increase in the roasting time does not lead to an increase in the degree of extraction of PGMs and REEs at the leaching stage, and a decrease in the time below the value specified in the range leads to incomplete removal of sulfur and carbon.

The choice of the range of grinding the catalyst to the size class - 3-5 microns, is justified by laboratory experiments, during which it was found that: reducing the particle size below the lower value of the range does not lead to an increase in the degree of extraction of PGM and REE at the leaching stage, and an increase in particle size above the upper value leads to a decrease in the degree of extraction of rhodium and cerium.

The choice of temperature ranges in the leaching process of 75-80°C and mixing time (for 4 hours) is justified by laboratory experiments, during which it was found that: carrying out reactions at a lower temperature leads to a decrease in the degree of extraction of PGM and REE, and an increase in temperature above 80°C leads to intensive evaporation of the working solution; a decrease in the process time leads to a decrease in the degree of extraction of PGM and REE, and an increase does not lead to an increase in the degree of extraction of PGM and REE.

The choice of the concentration of 6M HCl acid in a ratio of 1:5 (t:l) is justified by laboratory experiments, during which it was found that: a decrease in concentration leads to a decrease in the degree of extraction of the target components of the solution, an increase in concentration does not lead to an increase in the yield of target products. In addition, an increase in the concentration of acid leads to an increase in the environmental load due to increased entrainment of vapors. The ratio t:l was chosen based on the fact that its increase does not lead to an increase in the degree of extraction of the target components into the solution. In addition, an increase in the ratio in production conditions will lead to an increase in the volume of capacitive equipment. Reducing the ratio, as shown by experiments, leads to a change in the rheological properties of the suspension and a deterioration in the ability to mix and filter.

The choice of the ratio of the added aluminum granules in the amount of 10% of the solid sample is substantiated by laboratory experiments, during which it was found that a smaller amount of the reducing agent does not provide a high degree of quality for the extraction of PGM and REE, and an increase does not lead to an improvement in the result.

The choice of the ratio of adding H ₂ O ₂ in the amount of 10% of the solid sample is justified by laboratory experiments, during which it was found that a smaller amount of oxidizing agent does not provide a high degree of extraction of PGM and REE, and an increased amount does not lead to an improvement in the result.

The applicant, in 2022, implemented the claimed method in laboratory conditions.

Examples of the implementation of the claimed method.

Example 1

The spent catalyst from a Mercedes car contains the following platinum group metals and rare earth elements: platinum in the amount of 0.0958%, palladium in the amount of 0.1763%, rhodium in the amount of 0.0328%, cerium in the amount of 2.97% . After crushing in a jaw crusher to a particle size of 1.2 mm, a sample weighing 25 g was taken from the total mass of the catalyst for further processing. The sample was fired in a muffle furnace at a temperature of 800°C for 5 hours. After cooling to room temperature, the sample was ground in a planetary mill to a particle size of 4.7 μm. Particle size measurements were carried out on a laser size analyzer. After grinding, the sample sample was loaded into a three-necked flask equipped with a reflux condenser, a stirrer, and an addition funnel. Then 125 g of hydrochloric acid with a concentration of 6M was poured into the flask. 2.5 g of aluminum granules are added to the resulting suspension with stirring and heating. Every 15 minutes, concentrated hydrogen peroxide was added to the suspension. The total amount of hydrogen peroxide added was 2.5 g. At the end of the leaching process, the slurry was filtered through a blue ribbon filter. The precipitate filtered and washed to a neutral medium was dried to constant weight and weighed. After that, calculations were carried out based on the results of X-ray fluorescence analysis of the initial catalyst powder and the dried precipitate remaining after the leaching process. The degree of extraction into the solution was: Pd-97.6%; Pt-93.1%; Rh-72.9% and Ce-76.7%.

Example 2

The spent catalyst from the Opel car contains the following platinum group metals and rare earth elements: platinum in the amount of 0.2209%, cerium in the amount of 0.066%. After grinding in a jaw crusher to a particle size of 1.7 mm, a sample weighing 9 g was taken from the total mass of the catalyst for further processing. The sample was fired in a muffle furnace at a temperature of 800°C for 5 hours. After cooling to room temperature, the sample was ground in a planetary mill to a particle size of 4.1 μm. Particle size measurements were carried out on a laser size analyzer. After grinding, the sample sample was loaded into a three-necked flask equipped with a reflux condenser, a stirrer, and an addition funnel. Then 45 g of hydrochloric acid with a concentration of 6M was poured into the flask. 0.9 g of aluminum granules are added to the resulting suspension with stirring and heating. Every 15 minutes, concentrated hydrogen peroxide was added to the suspension. The total amount of hydrogen peroxide added was 0.9 g. At the end of the leaching process, the slurry was filtered through a blue ribbon filter. The precipitate filtered and washed to a neutral medium was dried to constant weight and weighed. After that, calculations were carried out based on the results of X-ray fluorescence analysis of the initial catalyst powder and the dried precipitate remaining after the leaching process. The degree of extraction into the solution was: Pt-95.2% and Ce-75.4%.

Example 3

The spent catalyst from the Vesta car contains the following platinum group metals and rare earth elements: palladium in the amount of 0.2116%, rhodium in the amount of 0.0454%, cerium in the amount of 1.848%. After grinding in a jaw crusher to a particle size of 1.4 mm, a sample weighing 16 g was taken from the total mass of the catalyst for further processing. The sample was fired in a muffle furnace at a temperature of 800°C for 5 hours. After cooling to room temperature, the sample was ground in a planetary mill to a particle size of 3.7 μm. Particle size measurements were carried out on a laser size analyzer. After grinding, the sample sample was loaded into a three-necked flask equipped with a reflux condenser, a stirrer, and an addition funnel. Then 80 g of hydrochloric acid with a concentration of 6M was poured into the flask. 1.7 g of aluminum granules are added to the resulting suspension with stirring and heating. Every 15 minutes, concentrated hydrogen peroxide was added to the suspension. The total amount of hydrogen peroxide added was 1.7 g. At the end of the leaching process, the slurry was filtered through a blue ribbon filter. The precipitate filtered and washed to a neutral medium was dried to constant weight and weighed. After that, calculations were carried out based on the results of X-ray fluorescence analysis of the initial catalyst powder and the dried precipitate remaining after the leaching process. The degree of extraction into the solution was: Pd-98.4%; Rh-79.7% and Ce-91.3%.

During the implementation of the claimed method, the claimed technical result was confirmed, increasing the environmental friendliness of the process of extracting platinum group metals and rare earth elements, the estimated volume of non-environmental products remaining after the implementation of the claimed method (compared to the solutions of analogues and prototype) was reduced by 40-80%. Maintaining a high degree of extraction (in comparison with solutions of analogs and prototype) is shown in table 1.

Table 1 PGM/REE Analogue 1 Analogue 2 Analogue 3 Prototype Claimed Solution Degree of extraction, % Platinum 96.8 98.1 98.25 98.6 98 98.2 98.2 93.1 95.2 Palladium 98.2 98.3 98.3 97.8 98.2 97.6 98.4 Cerium 94.4 95.2 76.7 75.4 91.3 Rhodium 96.2 94.8 92.4 94.1 72.9 79.7 Ruthenium 99.84 99.07

As can be seen from the table, 1 the claimed solution allows you to implement a high degree of extraction of PGM and REE is not significantly different from the solutions of analogues and prototype.

The claimed method, taking into account the characteristics of the equipment (replacing a planetary mill with a ball mill, replacing a muffle furnace with a drum one, replacing a three-necked flask with a heated reactor made of polypropylene with a stirrer), can be implemented in pilot production.

Claims (5)

1. A method for processing deactivated automotive catalysts, characterized in that the spent automotive catalysts are crushed to a particle size of 1-2 mm, fired at t = 780-800 ° C for 5-5.5 hours, after which they are crushed to a size class of - 3- 5 μm to obtain a solid sample, a 6M HCl leaching solution is added to a sample from the obtained solid sample in a ratio of 1:5, the resulting suspension is stirred and heated, aluminum granules are added in an amount of 10% of the sample sample, after the reduction reaction is completed, the leaching process is carried out in for 4 hours at a temperature of 75-80°C, during the entire leaching process, H ₂ O ₂ is dosed into the suspension in an amount of 10% of the sample of the solid sample, after the completion of the leaching process, the resulting suspension is filtered through a filter and washed until a neutral medium, the resulting precipitate dried to constant weight. 2. The method according to claim 1, characterized in that the spent automotive catalysts are crushed in a jaw crusher. 3. The method according to claim 1, characterized in that the spent automotive catalysts are crushed in a planetary mill. 4. The method according to claim 1, characterized in that the spent automotive catalysts are fired in a muffle furnace. 5. The method according to claim 1, characterized in that the resulting suspension is filtered through a "blue tape" filter.