Method for preparing tungsten compound and chloroplatinate from waste catalyst and application of tungsten compound and chloroplatinate

Abstract

The invention belongs to the technical field of recycling of rare and noble metal secondary resources, and discloses a method for preparing a tungsten compound and chloroplatinate from a waste catalyst and application of the method. The method comprises the following steps: (1) firing and crushing the waste catalyst, (2) reacting the waste catalyst with acid, (3) filtering and discarding filtrate, (4) reacting the precipitate with ammonia water, filtering to obtain an ammonium tungstate solution, and retaining filter residues; (5) concentrating the ammonium tungstate solution, crystallizing, separating and drying to obtain an ammonium paratungstate finished product; and (6) reacting the filter residues retained in the step (4) with aqua regia to prepare chloroplatinate. And (7) firing the ammonium paratungstate at a high temperature to obtain tungsten trioxide. According to the method, tungsten and platinum can be effectively separated from the carrier, and the recovery rate of rare and precious metals is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of recycling of secondary resources of rare and precious metals, in particular to a method for preparing tungsten compounds and chloroplatinic acid salts from waste catalysts and applications. BACKGROUND

[0002] During the manufacturing process, some unqualified waste products and scrapped catalysts will be produced, and these catalysts will contain a considerable amount of rare and precious metals, which have high recycling value.

[0003] There are few reports on the recovery of tungsten and platinum from waste catalysts with alumina supporting tungsten and platinum.

[0004] The existing technology is a kind of carrier supporting a kind of rare and precious metal. For example, alumina supporting ruthenium, alumina supporting platinum, alumina supporting rhodium, and alumina supporting iridium. Most of them are a kind of carrier supporting a kind of rare and precious metal. The secondary recovery process of these resources is relatively mature.

[0005] In recent years, with the development of technology in the field of catalysts and the innovation in application, a large number of composite carriers or carriers supporting two or more than two kinds of catalysts have emerged, such as alumina supporting platinum and tungsten catalysts, alumina supporting platinum and ruthenium catalysts, alumina supporting platinum and rhodium catalysts, etc. The separation of such composite carrier catalysts is rarely reported according to relevant documents. In addition, the resources of precious metals are decreasing with each year's exploitation, and are dependent on imports. Therefore, a new method for recovering tungsten compounds and chloroplatinic acid salts from waste catalysts is urgently needed. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and provide a method for preparing tungsten compounds and chloroplatinic acid salts from waste catalysts and applications.

[0007] The technical solution adopted by the present application to solve its technical problems is as follows: A method for preparing tungsten compounds and chloroplatinic acid salts from waste catalysts, comprising the following steps: (1) burning the waste catalyst at 600-700℃ for 3-6 hours, and then crushing and passing through a 100-mesh standard sieve to obtain catalyst powder; the purpose of this step is to remove volatile impurities carried by the waste catalyst; (2) adding the catalyst powder, hydrochloric acid and pure water into a reactor equipped with a mechanical stirring rod and a reflux condenser, heating to 120℃, and stirring and refluxing for 3-6 hours, and then cooling to room temperature to obtain an acidic reaction liquid with precipitate; the purpose of this step is to dissolve the alumina carrier to form an aluminum chloride solution, and the precipitate contains tungsten and platinum; (3) The acidic reaction solution with precipitate in the previous step is allowed to stand and precipitate, and the supernatant is siphoned off and discarded. The remaining precipitate is washed with pure water at 70-90°C until neutral, and then filtered to obtain the precipitate, and the weight of the precipitate is measured. This step separates tungsten and platinum from the aluminum chloride solution; (4) The precipitate obtained in the previous step is mixed with 1-3 times its weight of pure water, and stirred to form a uniform slurry. The slurry is slowly added to an equal weight of ammonia water under stirring, and the mixture is kept at a uniform speed. Then the mixture is heated and controlled at a temperature of 60-70°C, and the temperature is gradually increased to 60-70°C and maintained in this temperature range. The stirring reaction is continued for 3-5 hours. After the reaction is completed, the mixture is naturally cooled to room temperature, and then filtered to obtain the filtrate and residue. The residue is washed with pure water for 2-3 times to ensure that the effective components are fully recovered. Finally, the filtrate and the washing liquid are combined to obtain an ammonium tungstate solution, and the residue is sealed and stored for later use. This step separates tungsten and platinum; (5) The ammonium tungstate solution obtained in the previous step is placed in a boiling water bath, and evaporated and concentrated to 3% of the original filtrate volume. The solution is cooled to room temperature, and the crystals are filtered and washed with pure water for 2-3 times. The filtered and washed crystals are placed in an oven and dried at 100-110°C for 3-6 hours to obtain the final product of ammonium paratungstate. (6) The residue retained in step (4) is repeatedly washed with pure water until neutral, and then filtered to obtain a wet cake and record its weight. The wet cake is transferred to a reaction vessel, and aqua regia is added in an amount of 3-5 times the weight of the wet cake, and the initial solution volume is recorded. Then the mixture is stirred and dissolved in a constant temperature water bath at 60-80°C for 2-4 hours. After the material is completely dissolved, the temperature is increased to boiling, and the solution is evaporated and concentrated to 20%-25% of the initial volume. Then, an amount of concentrated hydrochloric acid (HCl) with a mass concentration of 36%-38% equal to the current volume is added to the concentrated solution, and the heating and concentration process is continued until the solution volume returns to the state before the addition of acid. This operation of adding concentrated hydrochloric acid and concentrating to the original volume is repeated 3-5 times, and finally a chloroplatinic acid solution is obtained. (7) The chloroplatinic acid solution obtained in the previous step is diluted with 4-6 times its volume of pure water and filtered. The filtrate is heated to 80-90°C for later use. Another amount of ammonium chloride with the same weight as the wet cake mentioned in step (6) is heated and dissolved in 2-3 times its weight of pure water, and the temperature is brought to 80-95°C. At this time, the hot ammonium chloride solution is added to the chloroplatinic acid hot solution which has been kept at 80-95°C under stirring, and a large amount of yellow crystalline precipitate appears. The stirring is continued for 5-10 minutes, and the mixture is naturally cooled to room temperature. The yellow precipitate is separated from the mother liquor by filtration, and the precipitate is washed with 95% ethanol by volume for 2-3 times. Finally, the precipitate is placed in a drying oven at 90-95°C to obtain the final product of ammonium chloroplatinate.

[0008] Further, the waste catalyst in step (1) is an alumina-supported tungsten and platinum catalyst, and the composition and percentage content of the alumina-supported tungsten and platinum catalyst are as follows:

[0009] The general process of the preparation step route is shown in Figure 1 .

[0010] Further, the weight ratio of the catalyst powder, hydrochloric acid and pure water in step (2) is 1:7-10:1-2; wherein the hydrochloric acid is HCl with a mass concentration of ≥36%.

[0011] Further, the ammonia water concentration in step (4) is 25-28% ammonia water with a mass concentration.

[0012] The application of the method as described above in the simultaneous recovery of tungsten compounds and chloroplatinic acid salts.

[0013] The application of the method as described above in the simultaneous separation and recovery of tungsten compounds and chloroplatinic acid salts.

[0014] The application of the method as described above in the simultaneous preparation of tungsten compounds and chloroplatinic acid salts.

[0015] The advantages and positive effects obtained by the present application are as follows: 1. In the present application, the "multiple hydrochloric acid supplementing-concentrating" cycle is adopted in the preparation of chloroplatinic acid, which effectively removes nitrate impurities (avoids interference of subsequent precipitation), and at the same time, the target product is gradually enriched through volume control, and the platinum recovery rate can reach more than 95%.

[0016] 2. The method of the present application comprises the following steps: (1) calcination and crushing of waste catalyst (2) reaction of waste catalyst with acid (3) filtration, discarding the filtrate, and washing and filtering the precipitate (4) reaction of the precipitate with ammonia water, followed by filtration to obtain an ammonium tungstate solution, and retaining the filter residue (5) concentration of the ammonium tungstate solution for crystallization, separation and drying to obtain ammonium tungstate product (6) preparation of chloroplatinic acid salt after reaction and treatment of the filter residue retained in the above (4) with aqua regia (7) preparation of tungsten trioxide by calcination of ammonium tungstate at high temperature. The method of the present application can effectively separate tungsten and platinum from the carrier, and improve the recovery rate of rare and precious metals.

[0017] 3. The present application precisely utilizes the chemical property difference of tungsten and platinum, combines wet metallurgy and crystallization kinetics control, and realizes efficient, low-consumption and high-purity preparation of metal compounds. The modular design of the present application is not only suitable for laboratory small tests, but also can be quickly adapted to industrial production through parameter amplification (such as replacing batch concentration with continuous extraction), and has significant technical and economic value in the field of precious metal recovery and fine chemical industry. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1A general flow chart of the preparation procedure for the tungsten and platinum on alumina catalyst used in the process of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further illustrated by the following examples, which are illustrative, but not limiting, and should not be construed to limit the scope of the present invention.

[0020] The various experimental operations involved in the specific examples are all conventional techniques in the art, and the parts not specifically noted in this text can be implemented by referring to various commonly used tool books, scientific and technical literature or related instructions, manuals, etc. before the application date of the present invention.

[0021] A method for preparing tungsten compounds and chloroplatinic acid salts from spent catalysts, comprising the following steps: (1) burning the spent catalyst at 600-700°C for 3-6 hours, and after cooling, crushing through a 100 mesh standard sieve to obtain catalyst powder; the purpose of this step is to remove volatile impurities carried by the spent catalyst; (2) adding the catalyst powder, hydrochloric acid and pure water into a reactor equipped with a mechanical stirring rod and a reflux condenser, heating to 120°C, and after stirring and refluxing for 3-6 hours, cooling to room temperature to obtain an acidic reaction liquid with precipitate; the purpose of this step is to dissolve the alumina carrier to form an aluminum chloride solution, and the precipitate contains tungsten and platinum; (3) after the acidic reaction liquid with precipitate from the previous step is allowed to stand and precipitate, the supernatant is siphoned off and discarded, and the remaining precipitate is washed to neutral with 70-90°C pure water, and then filtered to obtain the precipitate and weigh it; this step is to separate tungsten and platinum from the aluminum chloride solution; (4) mixing the precipitate obtained by filtration in the above step with 1-3 times its weight of pure water, and whipping it into a uniform slurry; under stirring, slowly add the slurry into an equal weight of ammonia water, and keep mixing at a uniform speed; then heat and control the temperature of the mixture, gradually increasing the temperature to 60-70°C and maintaining the temperature range, and continue stirring for 3-5 hours; after the reaction is completed, naturally cool to room temperature, and separate the filtrate and residue by vacuum filtration; wash the residue with pure water for 2-3 times to ensure full recovery of the effective components, and finally combine the filtrate and washing liquid to prepare an ammonium tungstate solution, and seal and store the residue for later use; this step allows tungsten and platinum to be separated; (5) place the ammonium tungstate solution obtained in the previous step in a boiling water bath, evaporate and concentrate to 3% of the original filtrate volume, cool to room temperature, filter out the crystals, and wash the crystals with pure water for 2-3 times, place the filtered and washed crystals in an oven, and dry them at 100-110°C for 3-6 hours to obtain the final product of ammonium paratungstate; (6) The filter residue reserved in step (4) is repeatedly washed with pure water until neutral, and then filtered to obtain a wet filter cake and record its mass; the wet filter cake is transferred to a reaction container, aqua regia is added in a proportion of 3-5 times the weight of the wet filter cake, and the initial solution volume is recorded; then the solution is stirred and dissolved in a constant-temperature water bath at 60-80°C for 2-4 hours, and after the material is completely dissolved, the temperature is raised to boiling, and evaporation and concentration are continued until the solution volume is 20%-25% of the initial volume; Then, an amount of concentrated hydrochloric acid HCl with a mass concentration of 36%-38% equal to the current volume is added to the concentrated solution, and heating and concentration are continued until the solution volume returns to the state before the acid was added; this operation of adding concentrated hydrochloric acid and concentrating to the original volume is repeated 3-5 times, and finally a chloroplatinic acid solution is obtained; (7) The chloroplatinic acid solution obtained in the above step is diluted with 4-6 times its volume of pure water and filtered, and the filtrate is heated to 80-90°C for standby use; the same weight of ammonium chloride as the wet filter cake mentioned in step (6) is taken, and 2-3 times its weight of pure water is added and heated to dissolve it, and the temperature is raised to 80-95°C; at this time, the hot ammonium chloride solution is added to the chloroplatinic acid hot solution which has been kept at 80-95°C under stirring, a large amount of yellow crystalline precipitate appears, and stirring is continued for 5-10 minutes, and then the solution is naturally cooled to room temperature; the yellow precipitate is filtered off from the mother liquor, and the precipitate is washed with 95% ethanol by volume and filtered 2-3 times, and finally the precipitate is dried in a drying oven at 90-95°C to obtain the finished product of ammonium chloroplatinate.

[0022] Preferably, the waste catalyst in step (1) is an alumina-supported tungsten and platinum catalyst, and the composition and approximate percentage of the alumina-supported tungsten and platinum catalyst are as follows:

[0023] The general process of the preparation step route is shown in Figure 1 .

[0024] Preferably, the weight ratio of the catalyst powder, hydrochloric acid and pure water in step (2) is 1:7-10:1-2; wherein the hydrochloric acid is HCl with a mass concentration of ≥36%.

[0025] Preferably, the ammonia water concentration in step (4) is 25-28% ammonia water.

[0026] The method as described above is used for simultaneously recovering and preparing tungsten compounds and chloroplatinic acid salts.

[0027] The method as described above is used for simultaneously separating and recovering tungsten compounds and chloroplatinic acid salts.

[0028] The method as described above is used for simultaneously preparing tungsten compounds and chloroplatinic acid salts.

[0029] Specifically, the related preparation and detection are as follows: The waste catalyst used in the following examples is an alumina-supported tungsten and platinum catalyst, and the composition and approximate percentage of the alumina-supported tungsten and platinum catalyst are as follows:

[0030] The general process of the preparation step route is shown in Figure 1 .

[0031] Example 1 A method for preparing tungsten compounds and chloroplatinates from waste catalysts includes the following steps: (1) 1000 grams of waste catalyst is loaded into a 1000 ML porcelain crucible and placed in a high-temperature electric furnace for calcination at 700°C for 4 hours, and then the furnace is cooled down. The next day, the crucible is taken out of the high-temperature furnace and cooled to room temperature. The calcined catalyst is then crushed and passed through a 100-mesh standard sieve. The catalyst powder is obtained.

[0032] (2) 500 grams of the catalyst powder from the previous step, 4000 grams of 36% hydrochloric acid, and 1000 grams of pure water are added to a glass reactor equipped with mechanical stirring and a reflux condenser. The stirring is started and the temperature is raised to 120°C. After refluxing for 3 hours, the temperature is cooled to room temperature, and an acidic reaction solution with precipitates is obtained.

[0033] (3) The acidic reaction solution with precipitates from the previous step is allowed to stand and settle. The supernatant is siphoned off and discarded. The remaining precipitate is washed repeatedly with hot pure water at 70-90°C until it is neutral. Then, the precipitate is filtered and weighed.

[0034] (4) The precipitate from the previous step is stirred with 2 times its weight of pure water to form a slurry. Then, the slurry is added to an equal weight of ammonia water (containing 25-28% NH3) under stirring. The temperature is then raised to about 60°C under stirring, and the reaction is allowed to proceed for 3 hours at this temperature. To reduce the loss of NH3, the reaction is preferably carried out in a closed reactor. After the reaction is completed, the temperature is cooled to room temperature, the volume of the filtrate is measured, and the filter residue is washed with a small amount of pure water three times. The filtrate and washings are combined to obtain an ammonium tungstate solution, and the filter residue is retained.

[0035] (5) The ammonium tungstate solution obtained in the previous step is transferred to a graduated beaker for convenient volume measurement. The solution is evaporated and concentrated in a boiling water bath until the volume is reduced to 3% of the original filtrate volume. The crystals are filtered and washed with a small amount of pure water three times. The crystals are dried at 110°C for 4 hours to obtain the finished ammonium tungstate product. The recovery rate of the finished ammonium tungstate product is 99%, and the purity is 99.9%.

[0036] (6) The residue from step (4) is washed with pure water until neutral, filtered and weighed. The residue is put into a solution of aqua regia with a weight of five times that of the residue, and the volume is measured. After 2 hours of dissolution at about 75°C, the solution is boiled and concentrated to 25% of the original volume, and an amount of concentrated hydrochloric acid (HCl with a mass concentration of 36%) equal to the volume of the solution at this time is added. The solution is further concentrated to the volume before the addition of the concentrated hydrochloric acid, and the same amount of concentrated hydrochloric acid is added again for concentration. This process is repeated three times to remove excess nitric acid. A chloroplatinic acid solution is obtained.

[0037] (7) The chloroplatinic acid solution obtained in the above step is diluted with 4 times the volume of pure water and filtered. The filtrate is heated to about 90°C and kept ready for use. An amount of ammonium chloride equal to the weight of the residue in the above step is dissolved in 2 times the weight of the residue in pure water and heated to about 90°C. At this time, the hot solution of ammonium chloride is added to the chloroplatinic acid solution kept at about 90°C with stirring. A large amount of yellow crystalline precipitate appears, and the stirring is continued for 5 minutes. The yellow precipitate is separated from the mother liquor by filtration, and the yellow precipitate is washed twice with a small amount of 90% ethanol. The ammonium chloroplatinate product is obtained by drying the precipitate at 90°C for 4 hours.

[0038] The platinum recovery rate is 99.2%.

[0039] Example 2 The ammonium paratungstate product of step (5) in Example 1 is calcined in a high-temperature electric furnace at 500°C for 2 hours, cooled, and ground. The ground product is calcined at 650°C for 2 hours and cooled to room temperature to obtain a tungsten trioxide product. The tungsten trioxide product has a recovery rate of 99% and a purity of 99.9%.

[0040] Example 3 The ammonium chloride in step (7) of Example 1 is replaced with an equal amount of potassium chloride, and the same operation is performed to obtain a potassium chloroplatinate product. The platinum recovery rate is 95.9% or more.

[0041] Example 4 The 36% hydrochloric acid in step (2) of Example 1 is replaced with an equal amount of 55% sulfuric acid, and the same operation is performed. The platinum recovery rate is 95.4% or more.

[0042] Comparative Examples 1-3 The preparation method is the same as that of Example 1, and the differences are shown in Table 1. The amount of hydrochloric acid refers to the amount of hydrochloric acid added in step (6) in the preparation of chloroplatinic acid.

[0043] The platinum recovery and related matters in the preparation of chloroplatinic acid with different amounts of hydrochloric acid are shown in Table 1. Table 1

[0044] Conclusion of Table 1; 500g of 4L of platinum-containing residue is the optimal amount when 4100ML of hydrochloric acid is added during the chloroplatinic acid recovery process. The platinum recovery rate and other indicators are qualified.

[0045] Comparative Examples 4-11 The preparation method is the same as Example 1, except that the addition of ammonia water refers to the step (4) in the preparation of ammonium tungstate, and the different temperatures and pH values of the ammonia water are shown in Table 2.

[0046] The influence of different temperatures and pH values of ammonia water on the tungsten yield in the preparation of ammonium tungstate is shown in Table 2: Table 2

[0047] From the high yield of ammonium tungstate, it is concluded that the optimal scheme is to add 105ML to 110ML of ammonia water at a temperature of 60℃ to 70℃ and a pH value of 9.5 to 10.9.

[0048] At the same time, by comparing Example 1 and Comparative Examples 1-11, it can be seen that there is a synergistic effect between the addition of 4100ML of hydrochloric acid to 500g of 4L of platinum-containing residue during the chloroplatinic acid recovery process in step (6) and the addition of 105ML to 110ML of ammonia water at a temperature of 60℃ to 70℃ and a pH value of 9.5 to 10.9 to 3000ML of water and 1000g of residue in a 5L beaker during the preparation of ammonium tungstate in step (4), which can synergistically improve the yield of the prepared product.

[0049] Although the examples of the present application are disclosed for illustrative purposes, those skilled in the art can understand that various alternatives, changes and modifications are possible without departing from the spirit and scope of the present application and the appended claims, therefore, the scope of the present application is not limited to the disclosed content of the examples.

Claims

1. A method for preparing tungsten compounds and chloroplatinates from spent catalysts, characterized in that: Includes the following steps: (1) The spent catalyst is calcined at 600-700℃ for 3-6 hours, cooled, and then crushed through a 100-mesh standard sieve to obtain catalyst powder; the purpose of this step is to remove volatile impurities carried in the spent catalyst. (2) The catalyst powder, hydrochloric acid and pure water are added together to a reactor equipped with a mechanical stir bar and a reflux condenser. The mixture is heated to 120°C and stirred under reflux for 3 to 6 hours. After cooling to room temperature, an acidic reaction solution with precipitate is obtained. The purpose of this step is to dissolve the alumina support to generate an aluminum chloride solution. The precipitate contains tungsten and platinum. (3) After the acidic reaction solution with precipitate from the previous step is allowed to stand and precipitate, the supernatant is siphoned out and discarded. The remaining precipitate is washed with pure water at 70-90℃ until neutral, then filtered out and weighed. This step involves separating tungsten and platinum from an aluminum chloride solution; (4) Mix the precipitate obtained by filtration in the above steps with 1 to 3 times its weight of pure water and stir to form a uniform slurry. Under stirring conditions, slowly add the slurry to an equal weight of ammonia water and keep the mixing at a constant speed. Then heat the mixture and control the temperature, gradually raising it to 60-70°C and maintaining this temperature range, and continue stirring the reaction for 3-5 hours. After the reaction is completed, cool it naturally to room temperature and separate the filtrate and filter residue by vacuum filtration. Wash the filter residue with pure water 2-3 times to ensure full recovery of the effective components. Finally, combine the filtrate and washing liquid to prepare an ammonium tungstate solution, and seal and store the filter residue for later use. This step allows tungsten and platinum to be separated. (5) Place the ammonium tungstate solution obtained in the above step in a boiling water bath, evaporate and concentrate to 3% of the original filtrate volume, cool to room temperature, filter out the crystals, and wash the crystals with pure water 2 to 3 times. Place the filtered and washed crystals in an oven and dry at 100-110℃ for 3 to 6 hours to obtain the ammonium paratungstate product. (6) Wash the filter residue retained in step (4) repeatedly with pure water until neutral, obtain a wet filter cake by vacuum filtration and record its mass; Transfer the wet filter cake to a reaction vessel, add aqua regia at a ratio of 3-5 times the weight of the wet filter cake, and record the initial solution volume; then stir and dissolve in a constant temperature water bath at 60-80℃ for 2-4 hours. After the material is completely dissolved, raise the temperature to boiling and continue to evaporate and concentrate until the solution volume is 20%-25% of the initial volume; Then, add an equal volume of concentrated hydrochloric acid (HCl) with a mass concentration of 36%-38% to the concentrate, and continue heating and concentrating until the solution volume returns to the state before acid addition. Repeat this cycle of quantitative addition of concentrated hydrochloric acid and concentration to the original volume 3-5 times to finally obtain chloroplatinic acid solution. (7) Dilute the chloroplatinic acid solution obtained in the above step with 4 to 6 times its volume of pure water and filter it. Heat the filtrate to 80 to 90°C for later use. Take ammonium chloride of the same weight as the wet filter cake mentioned in step (6) and dissolve it with 2 to 3 times its weight of pure water. Heat the solution to 80 to 95°C. Add the hot ammonium chloride solution to the chloroplatinic acid hot solution that has been maintained at 80 to 95°C with stirring. A large amount of yellow crystalline precipitate will appear. Continue stirring for 5 to 10 minutes and let it cool naturally to room temperature. Filter the yellow precipitate to separate it from the mother liquor and wash the precipitate with 95% ethanol 2 to 3 times. Finally, dry the precipitate in a drying oven at 90 to 95°C to obtain the ammonium chloroplatinate product.

2. The method according to claim 1, characterized in that: The spent catalyst mentioned in step (1) is an alumina-supported tungsten and platinum catalyst. The composition and percentage content of the alumina-supported tungsten and platinum catalyst are approximately as follows: 。 3. The method according to claim 1, characterized in that: In step (2), the weight ratio of catalyst powder, hydrochloric acid, and pure water is 1:7 to 10:1 to 2; wherein the hydrochloric acid is HCl with a mass concentration ≥36%.

4. The method according to claim 1, characterized in that: In step (4), the ammonia concentration is 25-28% by mass.

5. The use of the method according to any one of claims 1 to 4 in the simultaneous recovery and preparation of tungsten compounds and chloroplatinates.

6. The application of the method according to any one of claims 1 to 4 in the simultaneous separation and recovery of tungsten compounds and chloroplatinates.

7. The use of the method according to any one of claims 1 to 4 in the simultaneous preparation of tungsten compounds and chloroplatinates.

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