Method for efficiently separating platinum and rhenium in waste aluminum-based platinum-rhenium catalyst and recovering metal aluminum by using microwave technology

Abstract

The invention discloses a method for efficiently separating platinum and rhenium in a waste aluminum-based platinum-rhenium catalyst and recovering metal aluminum by using a microwave technology, and relates to the technical field of comprehensive utilization of metallurgical solid waste resources and recovery of rare and noble metals. The method comprises the following steps: carrying out microwave alkali fusion roasting on the waste aluminum-based platinum-rhenium catalyst, cooling a reaction product, and adding water for leaching to obtain a leachate 1 and leaching residues; dissolving the leaching residues by using aqua regia, centrifuging, precipitating platinum by using ammonium chloride, finally reducing platinum-containing precipitates to obtain platinum powder, promoting meta-aluminate radical hydrolysis of the leaching solution 1 by using an acid adding method, filtering to obtain aluminum hydroxide precipitates and a leaching solution 2, carrying out alkaline anion resin adsorption exchange on the leaching solution 2, and desorbing by using a desorbent to obtain a rhenium-containing solution; and concentrating and crystallizing to obtain ammonium rhenate. The method realizes efficient separation of platinum and rhenium in the waste aluminum-based catalyst and recovery of metal aluminum, has the remarkable advantages of small slag amount, high efficiency and the like, and provides a solution for solving the problem of treatment of the waste aluminum-based catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of comprehensive utilization of metallurgical solid waste resources and recovery of rare and precious metals, and particularly to a method for efficiently separating platinum and rhenium from waste aluminum-based platinum-rhenium catalysts and recovering metallic aluminum by using microwave technology. Background Art

[0002] Platinum-rhenium catalysts are widely used in the catalytic reforming process in the petroleum refining industry and play a crucial role. However, in practical applications, the activity of these catalysts may decline due to various factors and finally become solid waste. Specifically, they include: (1) Overheating effect: A high-temperature environment may cause the crystal grains of the active components of the catalyst to grow or even sinter, thereby reducing its catalytic performance; (2) Catalyst poisoning: The presence of chemical pollutants will cause catalyst poisoning, making it partially or completely lose its activity; (3) Pollution accumulation: Impurities and pollutants may accumulate on the surface of the catalyst or block the pores, further weakening its catalytic effect.

[0003] It is worth noting that waste aluminum-based platinum-rhenium catalysts contain relatively high contents of precious metals, with the platinum content being about 2000 - 4000 g / t and the rhenium content being about 3000 - 4000 g / t, which makes them have significant recycling value. Therefore, from the perspectives of resource utilization and environmental protection, it is necessary to effectively recycle such waste catalysts to realize the reuse of platinum and rhenium. However, due to the unique physical and chemical properties of platinum and rhenium, there are many challenges in efficiently recovering these two metals from waste aluminum-based platinum-rhenium catalysts. In particular, the recovery rate of rhenium is relatively low, and the separation of platinum and rhenium is difficult. To solve these problems, more advanced recovery technologies need to be developed to improve the recovery efficiency and ensure the effective reuse of resources.

[0004] The separation of platinum and rhenium from waste aluminum-based platinum-rhenium catalysts is an important link in resource recovery. Common separation methods mainly include the carrier dissolution method, the active component dissolution method, and the total dissolution method: (1) Carrier dissolution method: This method utilizes the property that alumina is easily soluble in acid or alkali. By selectively dissolving the carrier, platinum remains insoluble and is concentrated in the residue, and then platinum is recovered through further dissolution and refining steps. The recovery process of rhenium depends on the selected solvent system and dissolution conditions. Specifically, the carrier dissolution method includes the alkali method and the acid method. Among them, the alkali method uses an alkaline solution to dissolve the carrier. The advantage is that the enrichment rate of platinum in the residue is relatively high, and NaAlO 2The leaching solution can be used to produce a new catalyst support. However, the alkaline method also has some challenges, such as difficult solid-liquid separation, complex pressure alkaline dissolution operation and high equipment requirements; while the atmospheric pressure alkaline roasting time is longer, the leaching rate of rhenium is low, and it is easy to cause volatilization loss of rhenium; different from the alkaline method, the acid method uses an acidic solution to dissolve the support, and its main advantage is high comprehensive metal recovery efficiency, low treatment cost, and by-products can be sold, but the acid method also faces the problem of complex operation process, especially the difficulty of solid-liquid separation, and the support cannot be reused after being damaged. (2) Dissolving active components method: This method focuses on dissolving the active components (i.e., platinum and rhenium) in the catalyst without directly dissolving the support. Through specific chemical treatment, platinum and rhenium can be selectively extracted from the waste catalyst to achieve efficient separation of the two. This method usually has high selectivity and recovery rate, but more complex process design is required in practical applications. (3) Total dissolution method: The total dissolution method aims to dissolve both the support and the active components simultaneously, thereby completely decomposing the waste catalyst, and then using a variety of separation techniques to recover platinum and rhenium respectively. Although this method can achieve comprehensive element recovery, it often involves more complex process flows and higher cost inputs.

[0005] In view of the above technical problems, the present invention provides a method for efficiently separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum by using microwave technology. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for efficiently separating platinum and rhenium from waste aluminum-based platinum-rhenium catalysts and recovering metallic aluminum by using microwave technology to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above purpose, the present invention provides the following solution:

[0008] The present invention provides a method for separating platinum and rhenium from waste aluminum-based platinum-rhenium catalysts and recovering metallic aluminum by using microwave technology, comprising the following steps:

[0009] (1) Mix the waste aluminum-based platinum-rhenium catalyst with an alkali and then perform microwave roasting. After the microwave roasting is completed, cool the product and add water for leaching treatment to obtain leaching solution 1 and leaching residue;

[0010] (2) Dissolve the leaching residue with aqua regia, precipitate platinum with ammonium chloride from the supernatant after centrifugation, and finally reduce the platinum-containing precipitate to obtain platinum powder;

[0011] (3) Hydrolyze the leaching solution 1 with an acid to promote the hydrolysis of meta-aluminate ions, filter to obtain aluminum hydroxide precipitate and leaching solution 2;

[0012] (4) Adsorb rhenium in the solution of the leaching solution 2 with an alkaline anion resin, desorb with a desorbent to obtain a rhenium-containing solution, concentrate and crystallize the rhenium-containing solution to obtain ammonium perrhenate.

[0013] As a further preference of the present invention, the power of the microwave roasting is 600-800 W; the temperature of the microwave roasting is 500-700 °C, and the time is 10-60 min.

[0014] As a further preference of the present invention, in step (2), the platinum-containing precipitate is reduced in an ascorbic acid solution.

[0015] As a further preference of the present invention, the base used in the microwave roasting is sodium hydroxide.

[0016] As a further preference of the present invention, the mass ratio of the sodium hydroxide to the waste aluminum-based platinum-rhenium catalyst is 1:1-1:2.

[0017] As a further preference of the present invention, the temperature of the leaching treatment is 70-90 °C, the time of the leaching treatment is 30-60 min; the solid-liquid ratio of the leaching treatment is 1 g:(5-7) mL.

[0018] In the ammonium chloride precipitation method, the ammonium chloride is an analytical pure solid or solution, ensuring good quality and no obvious impurities. The temperature is 50-70 °C, and the pH value is 2-4.

[0019] As a further preference of the present invention, the acid used to promote the hydrolysis of meta-aluminate by adding acid for hydrolysis is hydrochloric acid.

[0020] As a further preference of the present invention, the basic anion resin is D296 strong basic anion exchange resin.

[0021] As a further preference of the present invention, the desorbent is a mixed solution of ammonia water and ammonium chloride or an NH 4 SCN solution.

[0022] Aiming at the problems of complex operation and high equipment requirements of traditional pressure alkali leaching, long time of atmospheric pressure alkali roasting, low rhenium leaching rate and easy rhenium volatilization loss, etc., the present invention proposes to adopt the microwave ultra-fast alkali melting reaction technology to efficiently separate platinum and rhenium, effectively reduce the amount of residue generated in the leaching process, and reduce the subsequent treatment burden; at the same time, due to the reduction of the leaching residue amount, the acid consumption for subsequent acid treatment is effectively reduced.

[0023] The present invention adopts the microwave alkali fusion technology, which significantly reduces the slag rate in the waste aluminum-based platinum-rhenium catalyst to only about 5%, far lower than 60% of the conventional alkali fusion method. In addition, the method of the present invention only needs to be calcined for 10 minutes to achieve efficient separation of platinum and rhenium. Specifically, during the water leaching process, the dissolution rate of platinum is about 3%, while the leaching rate of rhenium is as high as 99.95%. The present invention can minimize the slag volume, shorten the treatment time and improve the separation efficiency, not only significantly reducing the subsequent acid consumption and energy consumption, but also providing an efficient and environmentally friendly solution to the problem of separating platinum and rhenium in waste aluminum-based catalysts.

[0024] The present invention provides an innovative and efficient solution to solve the problems existing in the traditional alkali leaching method, which helps to achieve efficient separation and resource utilization of platinum and rhenium in waste aluminum-based platinum-rhenium catalysts, while significantly reducing resource consumption and environmental pollution in the process flow, and achieving remarkable economic and environmental benefits.

[0025] The present invention discloses the following technical effects:

[0026] The microwave alkali fusion technology of the present invention significantly reduces the equipment requirements, avoids corrosion of the equipment, and thus prolongs the service life of the equipment. In addition, this technology significantly improves the separation efficiency of platinum and rhenium, demonstrating excellent process advantages.

[0027] The microwave alkali fusion of the present invention not only greatly shortens the reaction time, realizes an ultra-fast alkali fusion reaction, but also effectively avoids the problem of rhenium volatilization caused by long-term high-temperature treatment. This improvement significantly enhances the separation efficiency of platinum and rhenium and reduces the slag volume. Therefore, the acid consumption and the amount of waste liquid in the subsequent treatment process are greatly reduced, further reducing the environmental burden and treatment cost.

[0028] The present invention not only realizes the efficient separation of platinum and rhenium, but also efficiently recovers metallic aluminum in the same process flow, which not only improves the resource utilization rate, but also provides a more environmentally friendly and economical solution for industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is a process flow chart for the present invention to efficiently separate platinum and rhenium from waste aluminum-based catalysts by using microwave technology and recover metallic aluminum.

[0031] Figure 2 It is the X-ray diffraction pattern of the hydrolysis precipitate in Example 1 of the present invention. Detailed Embodiments

[0032] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be construed as a limitation on the present invention, but rather as a more detailed description of certain aspects, features, and implementation schemes of the present invention.

[0033] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0035] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are merely exemplary.

[0036] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0037] It should be noted that the aspects not described in detail in the present invention are all conventional operating means in the art and are not the focus of the present invention.

[0038] Figure 1 This is the process flow chart of the present invention.

[0039] The spent aluminum-based platinum-rhenium catalyst in the examples and comparative examples of the present invention is from the failed catalyst of petrochemical reforming, where the contents of platinum and rhenium are Pt 1718 g\t and Re 0.23 wt%, respectively, and the content of Al 2 O 3 is 95 wt% and the particle size is 200 mesh.

[0040] Example 1

[0041] A method for efficiently separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum by using microwave technology, the steps are as follows:

[0042] (1) Dry the waste aluminum-based platinum-rhenium catalyst, ball-mill it to a uniform particle size, mix it evenly with sodium hydroxide in a corundum crucible according to a mass ratio of 1:1, place it in a microwave high-temperature reactor, and carry out microwave calcination at a microwave power of 800 W and 600 °C for 60 min. After the reaction ends, slowly cool it to obtain a cooled product.

[0043] (2) Carry out water leaching treatment on the cooled product after the reaction in step (1) according to a solid-liquid ratio of 1:5 (g:mL), a leaching temperature of 90 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, with a pH value of 13) and a leaching residue (a Pt-enriched product), and the residue rate is 5%. The leaching rate of rhenium is 99.95%, and the dissolution rate of platinum in the leaching solution L1 is 2.79%.

[0044] Among them:

[0045] The calculation method of the leaching rate (dissolution rate) is as follows: In the formula, ω 0 is the content (wt%) of the metal (platinum or rhenium) in the waste aluminum-based platinum-rhenium catalyst; m 0 is the mass (g) of the waste aluminum-based platinum-rhenium catalyst; C 1 is the content (g / L) of the metal (platinum or rhenium) in the leaching solution L1; V 1 is the volume (L) of the leaching solution L1.

[0046] (3) Dissolve the leaching residue obtained in step (2) with aqua regia, centrifuge it at 5000 r / min with a bench-top high-speed centrifuge, take the analytical pure solid ammonium chloride, and slowly add it to the supernatant to ensure the uniformity of ammonium chloride in the solution. Carry out precipitation aging, solid-liquid separation, precipitation, washing, and drying operations at 50 °C and a pH value of 4 to obtain a platinum-containing precipitate. Finally, reduce the platinum-containing precipitate in an ascorbic acid solution to obtain platinum powder (purity > 99%, recovery rate of platinum > 97%).

[0047] (4) Add hydrochloric acid to the leaching solution L1 obtained in step (2) to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white precipitate of aluminum hydroxide and a rhenium-containing leaching solution L2 (pH value of 8) can be obtained.

[0048] (5) Exchange the rhenium-containing leaching solution L2 in step (4) with an alkaline anion resin D296, desorb it with a mixed solution of ammonia water and ammonium chloride as a desorbent to obtain a rhenium-containing solution, and then obtain ammonium perrhenate through heating, concentration, cooling, and crystallization (purity of ammonium perrhenate > 99%; recovery rate based on rhenium > 99%).

[0049] Figure 2 X-ray diffraction pattern of the hydrolysis precipitate in Example 1. It can be seen from Figure 2 that the main substance of the hydrolysis precipitate is white aluminum hydroxide precipitate, and through elemental testing, the rhenium content in the white aluminum hydroxide precipitate is lower than 0.0009 wt%, indicating that all rhenium has entered the solution.

[0050] Example 2

[0051] A method for efficiently separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum using microwave technology, the steps are as follows:

[0052] (1) Dry the waste aluminum-based platinum-rhenium catalyst, ball mill it to a uniform particle size, mix it evenly with sodium hydroxide in a corundum crucible according to a mass ratio of 1:1, place it in a microwave high-temperature reactor, and carry out microwave calcination at a microwave power of 700 W and 800 °C for 10 min. After the reaction ends, slowly cool to obtain a cooled product.

[0053] (2) For the cooled product after the reaction in step (1), carry out water leaching treatment according to a solid-liquid ratio of 1:6 (g:mL), a leaching temperature of 85 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, with a pH value of 13) and a leaching residue (containing Pt concentrate), and the residue rate is 5%. Using the same calculation method as in Example 1, the leaching rate of rhenium is 99.93%, and the dissolution rate of platinum is 2.77%.

[0054] (3) Dissolve the leaching residue obtained in step (2) with aqua regia, centrifuge it at 5000 r / min using a bench-top high-speed centrifuge, take the analytical pure solid ammonium chloride, and slowly add it to the supernatant to ensure the uniformity of ammonium chloride in the solution. Carry out precipitation aging, solid-liquid separation, precipitation, washing, and drying operations at 50 °C and a pH value of 4 to obtain a platinum-containing precipitate. Finally, reduce the platinum-containing precipitate in an ascorbic acid solution to obtain platinum powder (purity > 99%, platinum recovery rate > 97%).

[0055] (4) Add hydrochloric acid to the leaching solution L1 obtained in step (2) to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white aluminum hydroxide precipitate and a leaching solution L2 (pH value of 8) can be obtained.

[0056] (5) Exchange the rhenium-containing leaching solution L2 in step (4) using an alkaline anion resin D296, desorb it with a mixed solution of ammonia water and ammonium chloride as a desorbent to obtain a rhenium-containing solution, and then obtain ammonium perrhenate through heating, concentration, cooling, and crystallization (ammonium perrhenate purity > 99%; based on rhenium, the recovery rate > 99%).

[0057] Example 3

[0058] A method for efficiently separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum using microwave technology, the steps are as follows:

[0059] (1) Dry the waste aluminum-based platinum-rhenium catalyst, ball-mill it to a uniform particle size, mix it evenly with sodium hydroxide in a corundum crucible according to a mass ratio of 1:2, place it in a microwave high-temperature reactor, and perform microwave calcination at a microwave power of 600 W and 700 °C for 30 min. After the reaction ends, obtain a cooled product through slow cooling.

[0060] (2) Perform water leaching treatment on the cooled product after the reaction in step (1) according to a solid-liquid ratio of 1:5 (g:mL), a leaching temperature of 90 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, with a pH value of 13) and a leaching residue (a Pt-enriched product), and the residue rate is 5%.

[0061] Using the same calculation method as in Example 1, the leaching rate of rhenium is 99.89%, and the dissolution rate of platinum is 3.10%.

[0062] (3) Dissolve the leaching residue obtained in step (2) with aqua regia, centrifuge it at 5000 r / min using a tabletop high-speed centrifuge, take the analytical pure solid ammonium chloride, and slowly add it to the supernatant to ensure the uniformity of ammonium chloride in the solution. Perform precipitation aging, solid-liquid separation, precipitation, washing, and drying operations at 55 °C and a pH value of 3 to obtain a platinum-containing precipitate. Finally, reduce the platinum-containing precipitate in an ascorbic acid solution to obtain platinum powder (purity > 99%, recovery rate of platinum > 97%).

[0063] (4) Add hydrochloric acid to the leaching solution L1 obtained in step (2) to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white precipitate of aluminum hydroxide and a leaching solution L2 (pH value of 8) can be obtained.

[0064] (5) Exchange the rhenium-containing leaching solution L2 in step (4) using an alkaline anion resin D296, desorb it with a mixed solution of ammonia water and ammonium chloride as a desorbent to obtain a rhenium-containing solution, and then obtain ammonium perrhenate through heating, concentration, cooling, and crystallization (purity of ammonium perrhenate > 99%; recovery rate based on rhenium > 99%).

[0065] Comparative Example 1

[0066] A method for separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum, the steps are as follows:

[0067] (1) Dry the waste aluminum-based platinum-rhenium catalyst, ball-mill it to a uniform particle size, mix it evenly with sodium hydroxide in a corundum crucible according to a mass ratio of 1:1, place it in a muffle furnace, and calcine it at 600 °C for 60 min. After the reaction ends, obtain a cooled product through slow cooling.

[0068] (2) The cooled product after the reaction in step (1) is subjected to water leaching treatment according to a solid-liquid ratio of 1:5 (g:mL), a leaching temperature of 90 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, with a pH value of 13) and a leaching residue (containing Pt concentrate), and the residue rate is approximately 70%.

[0069] Using the same calculation method as in Example 1, the leaching rate of rhenium is approximately 85%, and the dissolution rate of platinum is approximately 1%.

[0070] (3) The leaching residue obtained in step (2) is dissolved in aqua regia, centrifuged at 5000 r / min using a bench-top high-speed centrifuge, and then analytical pure ammonium chloride solid is slowly added to the supernatant to ensure the uniformity of ammonium chloride in the solution. After precipitation aging, solid-liquid separation, precipitation, washing, and drying operations are carried out at 50 °C and a pH value of 4 to obtain a platinum-containing precipitate. Finally, the platinum-containing precipitate is reduced in an ascorbic acid solution to obtain platinum powder.

[0071] (4) The leaching solution L1 obtained in step (2) is treated by adding acid to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white precipitate of aluminum hydroxide can be obtained, and the leaching solution L2 (with a pH value of 8).

[0072] (5) The rhenium-containing leaching solution L2 in step (4) is exchanged using an alkaline anion resin D296, desorbed with a mixed solution of ammonia water and ammonium chloride as a desorbent to obtain a rhenium-containing solution, and then ammonium perrhenate can be obtained through heating, concentration, cooling, and crystallization.

[0073] Comparative Example 2

[0074] A method for separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum, the steps are as follows:

[0075] (1) The waste aluminum-based platinum-rhenium catalyst is dried, ball-milled to a uniform particle size, mixed evenly with sodium hydroxide in a mass ratio of 1:1 in a corundum crucible, placed in a muffle furnace, and calcined at 800 °C for 10 min. After the reaction ends, it is slowly cooled to obtain a cooled product.

[0076] (2) The cooled product after the reaction in step (1) is subjected to water leaching treatment according to a solid-liquid ratio of 1:6 (g:mL), a leaching temperature of 85 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, with a pH value of 13) and a leaching residue (containing Pt concentrate), and the residue rate is approximately 70%.

[0077] Using the same calculation method as in Example 1, the leaching rate of rhenium is 75%, and the dissolution rate of platinum is approximately 1%.

[0078] (3) Dissolve the leaching residue obtained in step (2) with aqua regia. After centrifuging at 5000 r / min with a bench-top high-speed centrifuge, take the analytical pure ammonium chloride solid and slowly add it to the supernatant to ensure the uniformity of ammonium chloride in the solution. Under the conditions of 50 °C and a pH value of 4, carry out precipitation aging, solid-liquid separation, precipitation, washing, and drying operations to obtain a platinum-containing precipitate. Finally, reduce the platinum-containing precipitate in ascorbic acid solution to obtain platinum powder.

[0079] (4) Add hydrochloric acid to the leaching solution L1 obtained in step (2) to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white precipitate of aluminum hydroxide can be obtained, and the leaching solution L2 (pH value is 8)

[0080] (5) Exchange the rhenium-containing leaching solution L2 in step (4) with alkaline anion resin D296. After desorbing with a mixed solution of ammonia water and ammonium chloride as the desorbent, a rhenium-containing solution is obtained. After heating, concentration, cooling, and crystallization, ammonium perrhenate can be obtained.

[0081] Comparative Example 3

[0082] A method for separating platinum and rhenium from waste aluminum-based catalysts and recovering metallic aluminum, the steps are as follows:

[0083] (1) Dry the waste aluminum-based platinum-rhenium catalyst, ball-mill it to a uniform particle size, mix it evenly with sodium hydroxide in a mass ratio of 1:2 in a corundum crucible, place it in a muffle furnace, and calcine it at 700 °C for 30 min. After the reaction ends, slowly cool it to obtain a cooled product.

[0084] (2) For the cooled product after the reaction in step (1), carry out water leaching treatment according to a solid-liquid ratio of 1:5 (g:mL), a leaching temperature of 90 °C, and a leaching time of 30 min to obtain a leaching solution L1 (a leaching solution containing Al and Re, pH value is 13) and a leaching residue (a Pt-enriched product), and the residue rate is about 60%.

[0085] Using the same calculation method as in Example 1, the leaching rate of rhenium is obtained as 80%, and the dissolution rate of platinum is about 1%.

[0086] (3) Dissolve the leaching residue obtained in step (2) with aqua regia. After centrifuging at 5000 r / min with a bench-top high-speed centrifuge, take the analytical pure ammonium chloride solid and slowly add it to the supernatant to ensure the uniformity of ammonium chloride in the solution. Under the conditions of 50 °C and a pH value of 4, carry out precipitation aging, solid-liquid separation, precipitation, washing, and drying operations to obtain a platinum-containing precipitate. Finally, reduce the platinum-containing precipitate in ascorbic acid solution to obtain platinum powder.

[0087] (4) Add hydrochloric acid to the leaching solution L1 obtained in step (2) to promote the hydrolysis of aluminate ions to form a precipitate. After filtration, a white precipitate of aluminum hydroxide can be obtained, and the leaching solution L2 (pH value is 8).

[0088] (5) The rhenium-containing leaching solution L2 in step (4) is exchanged with an alkaline anion resin D296, and the rhenium-containing solution is obtained by desorbing with a mixed solution of ammonia water and ammonium chloride as a desorbent. After heating, concentration, cooling, and crystallization, ammonium perrhenate can be obtained.

[0089] The present invention realizes the efficient separation of platinum and rhenium in the waste aluminum-based catalyst and the recovery of metallic aluminum, and has significant advantages such as less slag volume, short time, and high efficiency, providing an innovative solution for solving the problem of treating waste aluminum-based catalysts.

[0090] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solution of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for separating platinum and rhenium from waste aluminum-based platinum-rhenium catalysts and recovering metallic aluminum using microwave technology, characterized in that: The following steps are involved: (1) mixing a waste aluminum-based platinum-rhenium catalyst with an alkali and then performing microwave roasting, cooling the product after the microwave roasting, adding water and performing leaching treatment to obtain a leachate 1 and a leached residue; (2) dissolving the leached residue with aqua regia, using ammonium chloride to precipitate platinum in the supernatant after centrifugation, and finally reducing the platinum-containing precipitate to obtain platinum powder; (3) hydrolyzing the leachate 1 with acid, filtering, and washing to obtain aluminum hydroxide precipitate and leachate 2; (4) The rhenium in the leachate 2 is adsorbed by an alkaline anion resin, and then desorbed by a desorbent to obtain a rhenium-containing solution, and the rhenium-containing solution is concentrated and crystallized to obtain ammonium rhenate.

2. The method according to claim 1, characterized in that The power of the microwave roasting is 600-800w; the temperature of the microwave roasting is 500-700°C, and the time is 10-60min.

3. The method according to claim 1, characterized in that The alkali used in the microwave roasting is sodium hydroxide.

4. The method according to claim 3, characterized in that The mass ratio of the sodium hydroxide to the waste aluminum-based platinum-rhenium catalyst is 1:1 to 1:

2.

5. The method according to claim 1, characterized in that The leaching temperature is 70-90°C, the leaching time is 30-60min, and the solid-liquid ratio is 1g: (5-7)mL.

6. The method according to claim 1, characterized in that The acid hydrolysis adopts hydrochloric acid.

7. The method according to claim 1, characterized in that The basic anion resin is D296 strong basic anion exchange resin.

8. The method according to claim 1, characterized in that The desorbent is a mixed solution of ammonia water and ammonium chloride or a NH4SCN solution.

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