Method for extracting valuable metal in high-temperature alloy return scrap through carbonylation metallurgy

Abstract

The invention relates to the technical field of recycling of cast nickel-based high-temperature alloy return scraps, and particularly discloses a method for extracting valuable metals in high-temperature alloy return scraps through carbonylation metallurgy. Comprising the steps of sulfuration smelting of the return scrap, carbonylation nickel extraction of the return scrap, chlorination of the material after nickel extraction, and graded carbonylation tungsten, chromium and molybdenum extraction, and nickel, chromium, tungsten and molybdenum in the cast nickel-based high-temperature alloy return scrap can be prepared into high-purity metal products by utilizing the characteristic of high selectivity of the carbonylation process. The nickel-based high-temperature alloy tailings can be directly sold as products in the forms of nickel carbonyl, chromium carbonyl, tungsten carbonyl and molybdenum carbonyl, meanwhile, the enrichment of rare and precious metals in the nickel-based high-temperature alloy tailings is realized, CO gas and chlorine gas used in the extraction process can be recycled, and the process can ensure the product quality while saving the cost, and is suitable for industrial production. And the method has huge economic benefits and relatively high popularization and implementation values.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling of returned materials of cast nickel-based high-temperature alloys, and specifically discloses a method for extracting valuable metals from returned materials of high-temperature alloys by carbonylation metallurgy. Background Art

[0002] As a nickel-based alloy with a face-centered cubic structure suitable for temperatures above 540°C, cast nickel-based high-temperature alloy has become an indispensable key material for national defense construction and economic development due to its long-term stable operation under high-temperature stress and extreme environments. However, in the production process of cast nickel-based high-temperature alloy, a large amount of high-temperature alloy return materials such as sprues, runners, risers, defective parts, etc. are generated. These return materials are rich in high-value metal elements such as Ni, W, Cr, Mo, Nb, Hf, Al, Ti, and V. Since the yield rate of high-temperature alloy precision castings is generally low, generally less than 30%, and the yield rate of complex-shaped thin-walled blade precision castings is even lower than 20%, a large amount of returned materials are piled up. This not only takes up huge amounts of funds, but also causes serious waste of high-value metal resources such as nickel and cobalt. At present, recycling returned materials through batching will not only reduce product quality, but also have a low recycling rate and cannot handle mixed materials, making the purification and reuse technology of returned materials a common problem that needs to be solved urgently in the high-temperature alloy industry. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a method for extracting valuable metals from high-temperature alloy return materials by carbonylation metallurgy.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows: A method for extracting valuable metals from high-temperature alloy return materials by carbonylation metallurgy comprises the following steps: S1. When smelting and casting nickel-based high-temperature alloy return material, add a vulcanizing agent for vulcanization activation. After vulcanization, the sulfur content of the material is controlled at 3-10%, and then water quenching is performed to form particles with a particle size of 0.5-5 mm. After drying, the material is added to a high-pressure reactor; S2, raising the temperature of the autoclave to 150-230°C and the pressure to 5-10MPa, introducing a mixed gas of H2 and CO to carry out a carbonylation reaction to extract nickel, and the carbonyl nickel generated by the reaction enters the next step to prepare metallic nickel powder and nickel pill products; S3, after nickel extraction, the pressure of the autoclave is reduced to 0.1-3Mpa, the temperature is reduced to 300-700°C, and chlorine is introduced for chlorination reaction, wherein the amount of chlorine introduced is the sum of the molar ratio of tungsten to chlorine of 1:6-10, the molar ratio of chromium to chlorine of 1:3-8, and the molar ratio of molybdenum to chlorine of 1:6-10; S4. After the chlorination is completed, control the temperature of the high-pressure reactor at 30 - 120 °C and the pressure at 3 - 7 Mpa. Introduce CO gas, and add zinc in a ratio of tungsten to zinc molar ratio of 1:3 - 5 using the CO gas to carry out the tungsten extraction reaction by carbonylation, extracting tungsten in the material in the form of tungsten carbonyl, directly making tungsten carbonyl products or entering the next process to decompose into metallic tungsten products; S5. After the tungsten extraction is completed, increase the pressure of the high-pressure reactor to 20 - 30 Mpa and the temperature to 100 - 170 °C. Introduce CO gas, and add aluminum in a ratio of chromium to aluminum molar ratio of 1:1 - 3 using the CO gas to carry out the chromium extraction reaction by carbonylation, extracting chromium in the material in the form of chromium carbonyl, directly preparing chromium carbonyl products or entering the next process to decompose into metallic chromium products; S6. After the chromium is extracted and separated by carbonylation, add diethyl ether in a ratio of molybdenum to diethyl ether mass ratio of 1:3 - 10, add dichloroethane in a ratio of molybdenum to dichloroethane mass ratio of 1:3 - 10, and raise the temperature to 250 - 350 °C and the pressure to 30 - 38 MPa. Introduce CO gas to carry out the molybdenum extraction reaction by carbonylation; S7. After steps S1 - S6, the carbonylation tailings are obtained. The carbonylation tailings are enriched with rare and precious metals in the superalloy return materials, and the rare and precious metals enter the next process for extraction and recovery.

[0005] Further, the sulfurizing agent in step S1 is elemental sulfur or nickel sulfide.

[0006] Further, in the H2 and CO mixed gas introduced in step S2, the introduced amount of H2 is 10 - 100 times the molar ratio of the oxygen content in the water-quenched material.

[0007] Further, after chlorination in step S3, tungsten metal is converted into tungsten hexachloride, chromium is converted into chromium trichloride, and molybdenum is converted into molybdenum hexachloride.

[0008] Further, the zinc added in step S4 is in powder form with an average particle size of 0.1 - 5 mm.

[0009] Further, the aluminum added in step S5 is in powder form with an average particle size of 0.1 - 5 mm.

[0010] Further, when the superalloy nickel-based return material does not contain tungsten or molybdenum, there is no need to perform the operation of tungsten or molybdenum extraction by the carbonylation method.

[0011] The beneficial effects of the present invention are as follows: By taking advantage of the high selectivity of the carbonylation process, through the methods of sulfidizing and smelting the returned materials, carbonylating and nickel-extracting the returned materials, chlorinating the materials after nickel extraction, and fractionally carbonylating to extract tungsten, chromium, and molybdenum, the nickel, chromium, tungsten, and molybdenum in the returned materials of cast nickel-based superalloys can be prepared into high-purity metal products, or directly sold as products in the form of nickel carbonyl, chromium carbonyl, tungsten carbonyl, and molybdenum carbonyl. At the same time, the enrichment of rare and precious metals in the tailings of nickel-based superalloys is realized. The CO gas and chlorine used in the extraction process can be recycled. This process can ensure product quality while saving costs, and has great economic benefits and high promotion and implementation value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the process flow diagram of the present invention. SPECIFIC EMBODIMENTS

[0013] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0014] Example 1: This example provides a method for recycling the returned materials of a cast nickel-based superalloy with the grade of K418B. The composition of the returned materials of K418B alloy is shown in Table 1-1: S1. Add 10 kg of the returned materials of the cast nickel-based superalloy for smelting. During smelting, add sulfur for sulfuration activation. The sulfur content in the materials after sulfuration is 10%. Then, water-quench to form particles with a particle size of 5 mm. After drying, add the materials to a high-pressure reaction kettle. S2. Raise the temperature of the high-pressure reaction kettle to 150 °C and the pressure to 5 MPa. Introduce a mixed gas of H2 and CO, where the amount of H2 is 0.625 mol, to carry out the carbonylation nickel extraction reaction. The nickel carbonyl generated by the reaction enters the next process to prepare metal nickel pellet products. S3. After nickel extraction, lower the pressure of the high-pressure reaction kettle to 3 Mpa, lower the temperature to 300 °C, and introduce 89.74 mol of chlorine for chlorination reaction to convert Cr and Mo in the returned materials into CrCl3 and MoCl6. S4. This returned material does not contain tungsten, so the carbonylation tungsten extraction operation is not carried out. S5. Increase the pressure of the high-pressure reactor to 20 Mpa, lower the temperature to 100 °C, introduce CO gas, and add 21.16 mol of aluminum powder with an average particle size of 0.1 mm in a chromium-to-aluminum molar ratio of 1:1 using the CO gas, and carry out the chromium carbonylation reaction to extract chromium in the material in the form of chromium carbonyl and directly prepare chromium carbonyl products; S6. After the chromium is extracted and separated by carbonylation, add 1260 g of diethyl ether in a molybdenum-to-diethyl ether mass ratio of 1:3, add 1260 g of dichloroethane in a molybdenum-to-dichloroethane mass ratio of 1:3, then raise the temperature to 250 °C and the pressure to 30 MPa, introduce CO gas, and carry out the molybdenum carbonylation reaction; S7. After steps S1 - S6, the carbonylation tailings are obtained. The carbonylation tailings are enriched with rare precious metals in the superalloy return material, and the rare precious metals enter the next process for extraction and recovery.

[0015] Using this carbonylation process to fractionally carbonylate and recover Cr, Ni, and Mo in the cast nickel-based superalloy, the carbonylation rates of Cr are 95.7%, the carbonylation rate of Ni is 98.3%, and the carbonylation rate of Mo is 97.3%.

[0016] The chemical composition of the nickel pellets obtained by the decomposition of nickel carbonyl is shown in Table 1-2: The chemical compositions of the extracted chromium carbonyl and molybdenum carbonyl are shown in Table 1-3: Example 2: This example provides a method for recycling the return material of a cast nickel-based superalloy with the grade K213. The composition of the K213 alloy return material is shown in Table 2-1: S1. When smelting 50 kg of the return material of the cast nickel-based superalloy K213, add nickel sulfide for sulfuration activation. After sulfuration, the sulfur content in the material is controlled at 3%, and then it is water-quenched into particles with a particle size of 0.5 mm. After drying, the material is added to the high-pressure reactor; S2. Raise the temperature of the high-pressure reactor to 230 °C and the pressure to 10 MPa, introduce a mixed gas of H2 and CO, and the amount of H2 added is 100 times the O content in the return material, which is 93.75 mol, to carry out the nickel carbonylation reaction. The nickel carbonyl generated by the reaction enters the next process to prepare metal nickel powder products; S3. After nickel extraction, lower the pressure of the high-pressure reactor to 0.1 Mpa, lower the temperature to 700 °C, and introduce 1270.2 mol of chlorine gas for chlorination reaction to chlorinate all Cr and W in the return material into CrCl3 and WCl6; S4. After the chlorination is completed, control the temperature of the high-pressure reactor at 120 °C and the pressure at 3 Mpa. Introduce CO gas, and add 77.55 mol of zinc powder with an average particle size of 0.1 mm (including aluminum in the return material) in a tungsten-to-zinc molar ratio of 1:5 using the CO gas. Carry out the tungsten extraction reaction by carbonylation to extract tungsten in the material in the form of tungsten carbonyl. The tungsten carbonyl enters the next process and decomposes into tungsten powder products; S5. After the tungsten extraction is completed, increase the pressure of the high-pressure reactor to 30 Mpa and the temperature to 170 °C. Introduce CO gas, and add 441.45 mol of aluminum powder with an average particle size of 5 mm in a chromium-to-aluminum molar ratio of 1:3 using the CO gas. Carry out the chromium extraction reaction by carbonylation to extract chromium in the material in the form of chromium carbonyl. The prepared chromium carbonyl enters the next process and decomposes into chromium powder products; S6. Since there is no molybdenum in the return material, no molybdenum extraction operation is carried out.

[0017] S7. After steps S1 - S6, the carbonylation tailings are obtained. The rare and precious metals in the high-temperature alloy return material are enriched in the carbonylation tailings, and the rare and precious metals enter the next process for extraction and recovery.

[0018] Using this carbonylation process to fractionally carbonylate and recover Cr, Ni, and W in the cast nickel-based superalloy, the carbonylation rates of Cr are 96.3%, the carbonylation rate of Ni is 98.7%, and the carbonylation rate of W is 96.5%.

[0019] After the cast superalloy return material is separated and recovered by the carbonyl method to obtain nickel carbonyl, chromium carbonyl, and tungsten carbonyl, and then decomposed, the chemical compositions of the obtained nickel powder, tungsten powder, and chromium powder products are shown in Table 2-2: Example 3: This example provides a method for recycling the return material of a cast nickel-based superalloy with the grade GH4169. The composition of the GH4169 alloy return material is as follows in the table: S1. When smelting 70 kg of the cast nickel-based superalloy return material, add elemental sulfur for sulfuration activation. After sulfuration, control the sulfur content in the material at 7%, then quench it into particles with a particle size of 3 mm. After drying, add the material to the high-pressure reactor; S2. Raise the temperature of the high-pressure reactor to 180 °C and the pressure to 7 MPa. Introduce a mixed gas of H2 and CO, where the amount of H2 added is 70 times the O content in the return material, which is 33.69 mol. Carry out the nickel extraction reaction by carbonylation. The generated nickel carbonyl enters the next process to prepare metal nickel pellets; S3. After nickel extraction, reduce the pressure of the high-pressure reactor to 2 Mpa, lower the temperature to 500 °C, introduce 1604.94 mol of chlorine for chlorination reaction, and completely chlorinate Cr and Mo in the returned material into CrCl3 and MoCl6; S4. Since the returned material does not contain tungsten, the operation of carbonylation for tungsten extraction is not carried out; S5. Increase the pressure of the high-pressure reactor to 25 Mpa, raise the temperature to 150 °C, introduce CO gas, and add 573.58 mol of aluminum powder with an average particle size of 2 mm in a ratio of 1:2 of chromium to aluminum by mole using CO gas for carbonylation chromium extraction reaction, and extract chromium in the material in the form of chromium carbonyl to directly prepare chromium carbonyl product; S6. After carbonylation extraction and separation of chromium, add 20510 g of ether in a ratio of molybdenum to ether of 1:10, add 20510 g of dichloroethane in a ratio of molybdenum to dichloroethane of 1:10, raise the temperature to 350 °C, the pressure to 38 MPa, introduce CO gas, and carry out carbonylation molybdenum extraction reaction.

[0020] S7. After steps S1 - S6, the carbonylation tailing is obtained. The carbonylation tailing is enriched with rare and precious metals in the superalloy returned material, and the rare and precious metals enter the next process for extraction and recovery.

[0021] Using this carbonylation process to fractionally carbonylate and recover Cr, Ni, and Mo in the cast nickel-based superalloy, the carbonylation rates of Cr are 96.6% respectively, the carbonylation rate of Ni is 98.5%, and the carbonylation rate of Mo is 97.7%.

[0022] The chemical composition of the nickel pellets product obtained by the decomposition of nickel carbonyl is shown in Table 3-2: The chemical compositions of the extracted chromium carbonyl and molybdenum carbonyl are shown in Table 3-3: Example 4: This example provides a method for recycling the mixture of cast nickel-based superalloy returned materials. The composition of the mixture of cast nickel-based superalloy returned materials is shown in Table 4-1: S1. When smelting 50 kg of the mixture of cast nickel-based superalloy returned materials, add nickel sulfide for sulfuration activation. After sulfuration, control the sulfur content in the material at 8%, then water-quench to form particles with a particle size of 2 mm. After drying, add the material to the high-pressure reactor; S2. Raise the temperature of the high-pressure reactor to 200 °C and the pressure to 6 MPa. Introduce a mixed gas of H2 and CO. The amount of H2 added is 50 times the O content in the returned material, which is 781.25 mol. Carry out the nickel carbonylation reaction. The nickel carbonyl generated by the reaction enters the next process to prepare metallic nickel pellet products. S3. After nickel extraction, lower the pressure of the high-pressure reactor to 0.6 Mpa and the temperature to 400 °C. Introduce 1610.02 mol of chlorine gas for chlorination reaction to completely chlorinate Cr, Mo, and W in the returned material into CrCl3, MoCl6, and WCl6. S4. After chlorination, control the temperature of the high-pressure reactor at 30 °C and the pressure at 7 Mpa. Introduce CO gas and add 44.88 mol of zinc powder with an average particle size of 5 mm in a ratio of tungsten to zinc molar ratio of 1:3.5 using CO gas to carry out the tungsten carbonylation reaction to extract tungsten in the material in the form of tungsten carbonyl and directly produce tungsten carbonyl products. S5. After tungsten extraction, raise the pressure of the high-pressure reactor to 28 Mpa and the temperature to 120 °C. Introduce CO gas and add 489.28 mol of aluminum powder with an average particle size of 0.6 mm in a ratio of chromium to aluminum molar ratio of 1:2.5 using CO gas to carry out the chromium carbonylation reaction to extract chromium in the material in the form of chromium carbonyl. The chromium carbonyl enters the next process to decompose into metallic chromium pellet products. S6. After chromium extraction by carbonylation separation, add 11550 g of ether in a ratio of molybdenum to ether mass ratio of 1:7 and add 6600 g of dichloroethane in a ratio of molybdenum to dichloroethane mass ratio of 1:4. Raise the temperature to 300 °C and the pressure to 35 MPa. Introduce CO gas to carry out the molybdenum carbonylation reaction. S7. After steps S1 - S6, the carbonylation tailings are obtained. The rare and precious metals in the superalloy returned material are enriched in the carbonylation tailings and enter the next process for extraction and recovery.

[0023] The chemical compositions of the nickel pellet and chromium pellet products obtained by the decomposition of nickel carbonyl and chromium carbonyl are shown in Table 4-2: The chemical compositions of the extracted tungsten carbonyl and molybdenum carbonyl are shown in Table 4-3: It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modification examples that fall within the scope and boundary of the appended claims or equivalent forms of such scope and boundary.

Claims

1. A method for extracting valuable metals from superalloy return materials by carbonylation metallurgy, characterized in that, It includes the following steps: S1. When smelting and casting the nickel-based superalloy return material, a sulfiding agent is added for sulfiding activation. After sulfiding, the sulfur content in the material is controlled at 3-10%, and then it is quenched with water to form particles with a particle size of 0.5-5 mm. After drying, the material is added to a high-pressure reactor; S2. The temperature of the high-pressure reactor is raised to 150-230 °C and the pressure is 5-10 MPa. A mixed gas of H2 and CO is introduced to carry out the carbonylation nickel extraction reaction. The nickel carbonyl generated by the reaction enters the next process to prepare metal nickel powder and nickel pellet products; S3. After nickel extraction, the pressure of the high-pressure reactor is reduced to 0.1-3 Mpa, the temperature is reduced to 300-700 °C, and chlorine gas is introduced for chlorination reaction. The input amount of chlorine gas is the sum of the molar ratios of tungsten to chlorine of 1:6-10, chromium to chlorine of 1:3-8, and molybdenum to chlorine of 1:6-10; S4. After chlorination, the temperature of the high-pressure reactor is controlled at 30-120 °C and the pressure is 3-7 Mpa. CO gas is introduced, and zinc is added in a ratio of tungsten to zinc molar ratio of 1:3-5 using CO gas. The carbonylation tungsten extraction reaction is carried out to extract the tungsten in the material in the form of tungsten carbonyl, and directly make tungsten carbonyl products or enter the next process to decompose into metal tungsten products; S5. After tungsten extraction, the pressure of the high-pressure reactor is increased to 20-30 Mpa and the temperature is raised to 100-170 °C. CO gas is introduced, and aluminum is added in a ratio of chromium to aluminum molar ratio of 1:1-3 using CO gas. The carbonylation chromium extraction reaction is carried out to extract the chromium in the material in the form of chromium carbonyl, and directly prepare chromium carbonyl products or enter the next process to decompose into metal chromium products; S6. After carbonylation extraction and separation of chromium, ether is added in a ratio of molybdenum to ether mass ratio of 1:3-10, and dichloroethane is added in a ratio of molybdenum to dichloroethane mass ratio of 1:3-10. The temperature is raised to 250-350 °C and the pressure is 30-38 MPa. CO gas is introduced to carry out the carbonylation molybdenum extraction reaction; S7. After steps S1 - S6, carbonylation tailings are obtained. The carbonylation tailings are enriched with rare and precious metals in the nickel-based superalloy return material, and the rare and precious metals enter the next process for extraction and recovery.

2. The method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, characterized in that: The sulfiding agent in step S1 is elemental sulfur or nickel sulfide.

3. The method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, characterized in that: In the mixed gas of H2 and CO introduced in step S2, the input amount of H2 is 10-100 times the molar ratio of the oxygen content in the water-quenched material.

4. A method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, characterized in that: After chlorination in step S3, tungsten metal is converted into tungsten hexachloride, chromium is converted into chromium trichloride, and molybdenum is converted into molybdenum hexachloride.

5. A method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, characterized in that: The zinc added in step S4 is in powder form with an average particle size of 0.1-5 mm.

6. The method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, wherein: The aluminum added in step S5 is in powder form with an average particle size of 0.1-5 mm.

7. A method for extracting valuable metals from superalloy return materials by carbonylation metallurgy according to claim 1, characterized in that: When the nickel-based superalloy return material for casting does not contain tungsten or molybdenum, the operation of carbonylation tungsten or molybdenum extraction is not required.

Images