Method for preparing tungsten trioxide and crude platinum powder by recovering alumina-supported tungsten-platinum catalyst and application of tungsten trioxide and crude platinum powder

Abstract

The invention belongs to the technical field of recycling of rare and noble metal secondary resources, and discloses a method for preparing tungsten trioxide and crude platinum powder by recovering an aluminum oxide tungsten-supported platinum catalyst and application of the method, and the method comprises the following steps: (1) sieving catalyst powder to be treated; (2) firing the crushed catalyst at high temperature, cooling and sieving to obtain catalyst powder; (3) adding sodium hydroxide or potassium hydroxide and pure water into the catalyst powder, and heating and refluxing to obtain an alkaline reaction solution; (4) filtering the alkaline reaction solution to obtain filtrate and black filter residues; (5) acidifying the filtrate with hydrochloric acid or sulfuric acid to obtain an acidic solution; (6) filtering the acidic solution to separate out yellow filter residues, washing with pure water, and drying to obtain yellow tungsten trioxide; and (7) drying the black filter residues in the step (4) to obtain crude platinum powder. Tungsten and platinum are separated from the aluminum oxide supported tungsten-platinum catalyst through the steps, and tungsten trioxide and crude platinum powder are prepared.

Description

Technical Field

[0001] This invention belongs to the field of rare and precious metal secondary resource recycling technology, and in particular, it relates to a method and application for the recovery and preparation of tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst. Background Technology

[0002] There is a wealth of literature on the separation of catalyst supports and the rare and precious metals they support. Most of these studies involve a single support supporting a single rare and precious metal.

[0003] In recent years, composite supports or two or more catalysts mounted on a single support have become increasingly common. However, reports on the separation and recovery of multiple rare and precious metals from the support are relatively rare.

[0004] Existing technologies all involve a single rare or precious metal mounted on a carrier. Examples include ruthenium-supported alumina catalysts, platinum-supported alumina catalysts, rhodium-supported alumina catalysts, and iridium-supported alumina catalysts. The secondary recycling processes for these resources are relatively mature.

[0005] In recent years, with the development of catalyst technology and innovation in applications, composite supports or supports supporting two or more catalysts have emerged in large numbers. Examples include the alumina-supported platinum-tungsten catalyst mentioned in this invention, as well as alumina-supported platinum-ruthenium catalysts, alumina-supported platinum-rhodium catalysts, and so on. However, there are very few reports on the separation of such composite support catalysts in relevant documents. Therefore, a new method for the recovery and preparation of tungsten trioxide and crude platinum powder is urgently needed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and application for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst.

[0007] The technical solution adopted by this invention to solve its technical problem is: A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst includes the following steps: (1) The catalyst is pulverized and passed through a 100-mesh standard sieve; (2) Take the catalyst after crushing and sieving in the above steps, put it into an alumina ceramic boat, put the ceramic boat into a high temperature resistance furnace and calcine it at a constant temperature of 700-900℃ for 3-6 hours. After the furnace is cooled down to below 400℃, take out the ceramic boat and let it cool naturally to room temperature. Then crush the calcined catalyst and pass it through a 100 standard sieve to obtain catalyst powder. (3) Weigh 1 part by weight of the catalyst powder from the previous step and put it into a stainless steel reactor equipped with a mechanical stirrer and a heating reflux condenser. Add 5-10 parts by weight of pure water and 2-4 parts by weight of caustic alkali. Start stirring and heat under reflux for 3-6 hours. Add 5-10 parts by weight of pure water and continue heating under reflux and stirring for 5-15 minutes. Cool to room temperature to obtain an alkaline reaction solution. (4) After filtering the alkaline reaction solution, four layers of filter paper are laid during filtration. The black filter residue is washed repeatedly with pure water until the washing liquid is neutral. The filtrate and washing liquid are combined to obtain a clear filtrate; the black filter residue is retained. (5) The clear filtrate is injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. Under stirring, 12 to 15 parts by weight of inorganic acid are slowly added. Then, under stirring, the mixture is heated for 1 to 4 hours and cooled to room temperature to obtain an acidic solution with a yellow precipitate. (6) Filter the acidic solution to separate the yellow precipitate, and wash the yellow precipitate repeatedly with pure water until the washing solution is neutral. Filter the yellow precipitate again, put it in a drying oven at 120-140℃, dry for 6-8 hours, and cool to room temperature to obtain the yellow tungsten trioxide product. (7) The black filter residue retained in step (4) is placed in an electric oven at 100-110℃ and dried for 6-8 hours. After cooling, the crude platinum powder product is obtained.

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

[0009] Its specific preparation steps and general process are as follows: Figure 1 As shown.

[0010] The optimal process yield after recovery of the tungsten-platinum supported alumina catalyst is 99%. The test results for the required tungsten oxide components are as follows: Tungsten oxide test results % .

[0012] Further, the caustic alkali mentioned in step (3) is sodium hydroxide (NaOH) with a mass concentration of 95-99% or potassium hydroxide (KOH) with a mass concentration of 90-95%.

[0013] Further, the inorganic acid mentioned in step (5) is hydrochloric acid (HCl) with a mass concentration of 36-37% or sulfuric acid (H2SO4) with a mass concentration of 48-52%.

[0014] The method described above is used in the simultaneous recovery and preparation of tungsten and platinum.

[0015] The method described above is used in the simultaneous separation and recovery of tungsten and platinum.

[0016] The method described above is used in the simultaneous preparation of tungsten trioxide and crude platinum powder.

[0017] The advantages and positive effects of this invention are as follows: 1. Traditional extraction methods may generate a lot of byproducts. By using a catalyst, the formation of byproducts can be reduced by adjusting the properties of the catalyst (such as pore size, surface acidity and alkalinity), thereby improving the purity of the product.

[0018] 2. By improving reaction efficiency and product yield, this invention can bring greater economic benefits in long-term use, while reducing raw material waste and catalyst replacement costs.

[0019] 3. Due to the high efficiency and selectivity of the catalyst in this invention, the amount of raw materials and solvents required in the reaction process is small, and less waste and pollutants are generated, which helps to reduce environmental pollution.

[0020] 4. This invention can separate tungsten and platinum from alumina-supported tungsten-platinum catalysts and produce tungsten trioxide and crude platinum powder. This invention separates rare and precious metals from the catalyst support for secondary resource recycling, making rare and precious metals effectively recycled and utilized as secondary resources, which has high economic value.

[0021] 5. In the recycling process of this invention, we employ two schemes. Analytical grade and high-purity reagents are used respectively for product recovery and preparation. Due to the different specifications used, the final tungsten trioxide recovery rate and impurity content are shown in Table 1.

[0022] Table 1

[0023] After considering both options, high-purity reagents were ultimately chosen as the recovery material. This approach resulted in minimal waste generation and byproduct formation, and the product yield and quality met expectations.

[0024] This invention, through experimental verification, demonstrates that using high-purity sodium hydroxide, high-purity hydrochloric acid, and deionized water in the production process yields tungsten trioxide with high yield and good quality. See Table 2.

[0025] Table 2 Oxide Yield and Detection Results

[0026] This recycled tungsten trioxide is widely used in environmental protection and catalysis due to its high quality. It is also used as a stealth material in the defense and military fields due to its simple structure, high shielding ability, and high sensitivity. In recent years, mineral resources have become scarce, and this invention embodies the concept of repeated utilization of mineral resources. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the general process for preparing the alumina-supported tungsten-platinum catalyst used in the method of this invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0029] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0030] A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst includes the following steps: (1) The catalyst is pulverized and passed through a 100-mesh standard sieve; (2) Take the catalyst after crushing and sieving in the above steps, put it into an alumina ceramic boat, put the ceramic boat into a high temperature resistance furnace and calcine it at a constant temperature of 700-900℃ for 3-6 hours. After the furnace is cooled down to below 400℃, take out the ceramic boat and let it cool naturally to room temperature. Then crush the calcined catalyst and pass it through a 100 standard sieve to obtain catalyst powder. (3) Weigh 1 part by weight of the catalyst powder from the previous step and put it into a stainless steel reactor equipped with a mechanical stirrer and a heating reflux condenser. Add 5-10 parts by weight of pure water and 2-4 parts by weight of caustic alkali. Start stirring and heat under reflux for 3-6 hours. Add 5-10 parts by weight of pure water and continue heating under reflux and stirring for 5-15 minutes. Cool to room temperature to obtain an alkaline reaction solution. (4) After filtering the alkaline reaction solution, four layers of filter paper are laid during filtration. The black filter residue is washed repeatedly with pure water until the washing liquid is neutral. The filtrate and washing liquid are combined to obtain a clear filtrate; the black filter residue is retained. (5) The clear filtrate is injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. Under stirring, 12 to 15 parts by weight of inorganic acid are slowly added. Then, under stirring, the mixture is heated for 1 to 4 hours and cooled to room temperature to obtain an acidic solution with a yellow precipitate. (6) Filter the acidic solution to separate the yellow precipitate, and wash the yellow precipitate repeatedly with pure water until the washing solution is neutral. Filter the yellow precipitate again, put it in a drying oven at 120-140℃, dry for 6-8 hours, and cool to room temperature to obtain the yellow tungsten trioxide product. (7) The black filter residue retained in step (4) is placed in an electric oven at 100-110℃ and dried for 6-8 hours. After cooling, the crude platinum powder product is obtained.

[0031] Furthermore, the catalyst mentioned in step (1) is an alumina-supported tungsten-platinum catalyst, and the composition and mass percentage of the alumina-supported tungsten-platinum catalyst are as follows:

[0032] Further, the caustic alkali mentioned in step (3) is sodium hydroxide (NaOH) with a mass concentration of 95-99% or potassium hydroxide (KOH) with a mass concentration of 90-95%.

[0033] Further, the inorganic acid mentioned in step (5) is hydrochloric acid (HCl) with a mass concentration of 36-37% or sulfuric acid (H2SO4) with a mass concentration of 48-52%.

[0034] Furthermore, the optimal process yield after recovering the tungsten-platinum catalyst supported on alumina was 99%, and the mass percentage content of each component in the tungsten trioxide product was as follows: .

[0036] The method described above is used in the simultaneous recovery and preparation of tungsten and platinum.

[0037] The method described above is used in the simultaneous separation and recovery of tungsten and platinum.

[0038] The method described above is used in the simultaneous preparation of tungsten trioxide and crude platinum powder.

[0039] Specifically, the relevant preparation and testing methods are as follows: The catalyst used in step (1) of the method of the present invention is an alumina-supported tungsten-platinum catalyst.

[0040] Approximate content of tungsten-platinum catalyst supported on alumina:

[0041] Its preparation steps and general process are as follows: Figure 1 As shown.

[0042] Example 1 A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst includes the following steps: (1) Crush the catalyst to be treated to pass through a 100-mesh standard sieve.

[0043] (2) Take 1000 grams of the catalyst after crushing and sieving in the previous step and put it into 1000 ml of alumina ceramic boat. Place the ceramic boat in a high-temperature furnace and calcine it at a constant temperature of 800°C for 4 hours. Then, cool the furnace down to about 350°C. Take out the ceramic boat and let it cool naturally to room temperature. Then, crush the calcined catalyst and pass it through a 100-mesh standard sieve to obtain catalyst powder.

[0044] (3) Place 500g of catalyst powder into a stainless steel reactor equipped with mechanical stirring and heating reflux condenser, add 5000g of pure water and 1000g of sodium hydroxide (NaOH≥98%, mass concentration), start stirring and heating reflux for 4 hours, add 5000g of pure water, continue stirring and heating reflux for 10 minutes, cool to room temperature, and obtain alkaline reaction solution.

[0045] (4) Filter the alkaline reaction solution. When filtering, lay four layers of filter paper. Wash the black filter residue with 1000g of pure water several times until the washing solution is neutral. Combine the filtrate and washing solution to obtain a clear filtrate. Keep the black filter residue.

[0046] (5) The clear filtrate was injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. 6000 g of hydrochloric acid (HCl≥37%, mass concentration) was slowly added under stirring. Then the mixture was stirred and heated under reflux for 2 hours. After cooling to room temperature, an acidic solution with a yellow precipitate was obtained.

[0047] (6) Filter the acidic solution to separate the yellow precipitate, wash the yellow precipitate with pure water until neutral. Filter the yellow precipitate again, put it in a drying oven at 120℃, dry for 6 hours, and cool to obtain the yellow tungsten oxide product.

[0048] (7) The black filter residue retained in step (4) is dried in an electric oven at 100°C for 6 hours and then cooled to room temperature to obtain coarse platinum powder.

[0049] Example 2 A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst includes the following steps: (1) Crush the catalyst to be treated to pass through a 100-mesh standard sieve.

[0050] (2) Take 1000 grams of the catalyst after crushing and sieving in the previous step and put it into 1000 ml of alumina ceramic boat. Place the ceramic boat in a high-temperature furnace and calcine it at a constant temperature of 800℃ for 4 hours. Then, cool the furnace down to about 350℃. Take out the ceramic boat and let it cool naturally to room temperature. Then, crush the calcined catalyst and pass it through a 100-mesh standard sieve to obtain catalyst powder.

[0051] (3) Place 500g of catalyst powder into a stainless steel reactor equipped with mechanical stirring and heating reflux condenser, add 5000g of pure water and 1000g of potassium chloride (KOH≥95%, mass concentration), start stirring and heating reflux for 4 hours, add 5000g of pure water, continue stirring and heating reflux for 10 minutes, cool to room temperature, and obtain alkaline reaction solution.

[0052] (4) Filter the alkaline reaction solution. When filtering, lay four layers of filter paper. Wash the black filter residue with 1000g of pure water several times until the washing solution is neutral. Combine the filtrate and washing solution to obtain a clear filtrate. Keep the black filter residue.

[0053] (5) The clear filtrate was injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. 6000 g of hydrochloric acid (HCl≥37%, mass concentration) was slowly added under stirring. Then the mixture was stirred and heated under reflux for 2 hours. After cooling to room temperature, an acidic solution with a yellow precipitate was obtained.

[0054] (6) Filter the acidic solution to separate the yellow precipitate, wash the yellow precipitate with pure water until neutral. Filter the yellow precipitate again, put it in a drying oven at 120℃, dry for 6 hours, and cool to obtain the yellow tungsten oxide product.

[0055] (7) The black filter residue retained in step (4) is dried in an electric oven at 100°C for 6 hours and then cooled to room temperature to obtain coarse platinum powder.

[0056] Example 3 A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst includes the following steps: (1) Crush the catalyst to be treated to pass through a 100-mesh standard sieve.

[0057] (2) Take 1000 grams of the catalyst after crushing and sieving in the previous step and put it into 1000 ml of alumina ceramic boat. Place the ceramic boat in a high-temperature furnace and calcine it at a constant temperature of 800°C for 4 hours. Then, cool the furnace down to about 350°C. Take out the ceramic boat and let it cool naturally to room temperature. Then, crush the calcined catalyst and pass it through a 100-mesh standard sieve to obtain catalyst powder.

[0058] (3) Place 500g of catalyst powder into a stainless steel reactor equipped with mechanical stirring and heating reflux condenser, add 5000g of pure water and 1000g of sodium hydroxide (NaOH≥98%, mass concentration), start stirring and heating reflux for 4 hours, add 5000g of pure water, continue stirring and heating reflux for 10 minutes, cool to room temperature, and obtain alkaline reaction solution.

[0059] (4) Filter the alkaline reaction solution. When filtering, lay four layers of filter paper. Wash the black filter residue with 1000g of pure water several times until the washing solution is neutral. Combine the filtrate and washing solution to obtain a clear filtrate. Keep the black filter residue.

[0060] (5) The clear filtrate is injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. 6000 g of sulfuric acid H2SO4 ≥ 50% (mass concentration) is slowly added under stirring. Then the mixture is stirred and heated under reflux for 2 hours. After cooling to room temperature, an acidic solution with a yellow precipitate is obtained.

[0061] (6) Filter the acidic solution to separate the yellow precipitate, wash the yellow precipitate with pure water until neutral. Filter the yellow precipitate again, put it in a drying oven at 120℃, dry for 6 hours, and cool to obtain the yellow tungsten oxide product.

[0062] (7) The black filter residue retained in step (4) is dried in an electric oven at 100°C for 6 hours and then cooled to room temperature to obtain coarse platinum powder.

[0063] The relevant test results are as follows: In the method of this invention, the optimal process yield after recovery of the alumina-supported tungsten platinum catalyst is 99%. The test results for the required tungsten oxide are as follows: Tungsten oxide test results %

[0064] 2. In the recycling process of this invention, we employ two schemes. Analytical grade and high-purity reagents are used respectively for product recovery and preparation. Due to the different specifications used, the final tungsten trioxide recovery rate and impurity content are shown in Table 1.

[0065] Table 1

[0066] After considering both options, high-purity reagents were ultimately chosen as the recovery material. This approach resulted in minimal waste generation and byproduct formation, and the product yield and quality met expectations.

[0067] 3. Experiments have verified that this invention, using high-purity sodium hydroxide, high-purity hydrochloric acid, and deionized water in the production process, yields tungsten trioxide with high yield and good quality. See Table 2.

[0068] Table 2 Oxide Yield and Detection Results

[0069] This recycled tungsten trioxide is widely used in environmental protection and catalysis due to its high quality. It is also used as a stealth material in the defense and military fields due to its simple structure, high shielding ability, and high sensitivity. In recent years, mineral resources have become scarce, and this invention embodies the concept of repeated utilization of mineral resources.

[0070] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for recovering tungsten trioxide and crude platinum powder from an alumina-supported tungsten platinum catalyst, characterized in that: Includes the following steps: (1) The catalyst is pulverized and passed through a 100-mesh standard sieve; (2) Take the catalyst after crushing and sieving in the above steps, put it into an alumina ceramic boat, put the ceramic boat into a high temperature resistance furnace and calcine it at a constant temperature of 700-900℃ for 3-6 hours. After the furnace is cooled down to below 400℃, take out the ceramic boat and let it cool naturally to room temperature. Then crush the calcined catalyst and pass it through a 100 standard sieve to obtain catalyst powder. (3) Weigh 1 part by weight of the catalyst powder from the previous step and put it into a stainless steel reactor equipped with a mechanical stirrer and a heating reflux condenser. Add 5-10 parts by weight of pure water and 2-4 parts by weight of caustic alkali. Start stirring and heat under reflux for 3-6 hours. Add 5-10 parts by weight of pure water and continue heating under reflux and stirring for 5-15 minutes. Cool to room temperature to obtain an alkaline reaction solution. (4) After filtering the alkaline reaction solution, four layers of filter paper are laid during filtration. The black filter residue is washed with pure water several times until the washing liquid is neutral. The filtrate and washing liquid are combined to obtain a clear filtrate. Retain the black filter residue; (5) The clear filtrate is injected into a glass reactor equipped with a mechanical stirrer and a heating reflux device. Under stirring, 12 to 15 parts by weight of inorganic acid are slowly added. Then, under stirring, the mixture is heated for 1 to 4 hours and cooled to room temperature to obtain an acidic solution with a yellow precipitate. (6) Filter the acidic solution to separate the yellow precipitate, and wash the yellow precipitate repeatedly with pure water until the washing solution is neutral. Filter the yellow precipitate again, put it in a drying oven at 120-140℃, dry for 6-8 hours, and cool to room temperature to obtain the yellow tungsten trioxide product. (7) The black filter residue retained in step (4) is placed in an electric oven at 100-110℃ and dried for 6-8 hours. After cooling, the crude platinum powder product is obtained.

2. The method according to claim 1, characterized in that: The catalyst mentioned in step (1) is an alumina-supported tungsten-platinum catalyst. The composition and mass percentage of the alumina-supported tungsten-platinum catalyst are as follows:

3. The method according to claim 1, characterized in that: The caustic alkali mentioned in step (3) is sodium hydroxide (NaOH) with a mass concentration of 95-99% or potassium hydroxide (KOH) with a mass concentration of 90-95%.

4. The method according to claim 1, characterized in that: The inorganic acid mentioned in step (5) is hydrochloric acid (HCl) with a mass concentration of 36-37% or sulfuric acid (H2SO4) with a mass concentration of 48-52%.

5. The method according to any one of claims 1 to 4, characterized in that: The optimal process yield after recovering the tungsten-platinum catalyst supported on alumina is 99%. The mass percentage content of each component in the finished tungsten trioxide product is as follows: 。 6. The application of the method as described in any one of claims 1 to 5 in the simultaneous recovery and preparation of tungsten and platinum.

7. The application of the method as described in any one of claims 1 to 5 in the simultaneous separation and recovery of tungsten and platinum.

8. The application of the method according to any one of claims 1 to 5 in the simultaneous preparation of tungsten trioxide and crude platinum powder.

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