Production method of 4n high-purity nickel carbonyl pellets

Abstract

This invention discloses a method for producing 4N-grade high-purity carbonyl nickel pellets, comprising the following steps: S1, adding nickel-containing raw materials to a reactor, introducing high-temperature and high-pressure CO gas, and carbonylating to synthesize a carbonyl nickel-iron mixed liquid, wherein the carbonylation synthesis reaction conditions are a pressure of 10 MPa and a temperature above 150°C; S2, passing the carbonyl nickel-iron mixed liquid into a distillation column for distillation purification to obtain high-purity carbonyl nickel liquid; S3, heating and evaporating the high-purity carbonyl nickel liquid, and then mixing it with CO gas at a volume ratio of 1:2 or 1:1; S4, passing the mixed gas into a reactor, where it undergoes countercurrent heat exchange with carbonyl nickel pellet seed crystals heated by a heater, and the carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, with nickel atoms deposited on the surface of the carbonyl nickel pellet seed crystals; S5, when the particle size of the carbonyl nickel pellet seed crystals increases to 10 mm, the carbonyl nickel pellets will form a cone at the top of the reactor.

Description

Technical Field

[0001] This invention relates to the field of gasification metallurgical process technology, and in particular to a method for producing 4N-grade high-purity carbonyl nickel pellets. Background Technology

[0002] Nickel, with atomic number 28 and atomic weight 58.6934, is a hard, ductile, ferromagnetic, silvery-white transition metal located in Group VIII of the fourth period. It possesses excellent thermal and electrical conductivity, high ductility, high temperature resistance, corrosion resistance, chemical stability, and strong oxidation resistance. 4N-grade high-purity carbonyl nickel pellets are near-spherical nickel metal with a purity of over 99.99% produced through a carbonylation process. These pellets have extremely low impurity content (≤100ppm), significantly reducing the interference of impurities on performance and exhibiting good electrical and thermal conductivity. High purity reduces impurities and galvanic cell effects, effectively delaying electrochemical corrosion. High purity also reduces brittle phases at nickel grain boundaries (such as Ni3S2), decreasing dislocation movement resistance; at low temperatures, the face-centered cubic (FCC) structure maintains slip system activity, resulting in good ductility, strength, and low-temperature toughness. High-purity nickel is widely used in the electronics industry, new energy fields, high-temperature alloys for aerospace, precision instruments, and high-end manufacturing. In recent years, with the development of high-tech industries, the application fields of high-purity nickel have become increasingly widespread.

[0003] Currently, the main methods for smelting nickel metal are electrolysis and smelting. However, these methods still cannot effectively reduce impurities, especially metallic impurities, in nickel metal. Nickel metal products produced industrially using traditional electrolysis / smelting methods cannot meet the 4N quality requirements. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for producing 4N-grade high-purity carbonyl nickel pellets.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for producing 4N grade high-purity carbonyl nickel pellets includes the following steps: S1. Add nickel-containing raw materials to the reactor, introduce high-temperature and high-pressure CO gas, and prepare carbonyl nickel-iron mixed liquid by carbonylation synthesis. The carbonylation synthesis reaction conditions are pressure 10 MPa and temperature above 150℃. S2. The carbonyl nickel-iron mixed liquid is passed into a distillation column for distillation and purification to prepare high-purity carbonyl nickel liquid; S3. Heat and evaporate the high-purity nickel carbonyl liquid, then mix it with CO gas at a volume ratio of 1:2 or 1:1 to obtain a mixed gas. S4. The mixed gas is introduced into the reactor and undergoes countercurrent heat exchange with the carbonyl nickel pellet seed crystals heated by the heater. The carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by the elevator and continuously circulated in the reactor for gas phase deposition reaction, and the particle size of the carbonyl nickel pellet seed crystals gradually increases. S5. When the particle size of the carbonyl nickel pellet seed crystals increases to 10 mm, the carbonyl nickel pellets will form a cone at the top of the reactor. Due to the large weight and sufficient kinetic energy of the >10 mm carbonyl nickel pellets, they will break through the set baffle curtain and enter the outer ring of the top distributor of the reactor and then enter the screening equipment for screening. The carbonyl nickel pellets that meet the particle size requirements are separated and then disinfected and replaced. After the replacement is completed, they are released to prepare 4N grade high-purity carbonyl nickel pellets. The fine carbonyl nickel pellets that do not meet the particle size requirements continue to enter the reactor through the pipeline to participate in the carbonyl nickel vapor deposition reaction for growth.

[0006] In step S1, the CO gas is high-purity CO gas with a purity of 99.8% or higher.

[0007] In step S2, the carbonyl nickel-iron mixed liquid is purified and separated by distillation, and the reflux ratio of the distillation column is controlled at (7-1):1 to produce high-purity carbonyl nickel liquid.

[0008] In step S3, the high-purity carbonyl nickel liquid is heated and evaporated by heating with hot water at 60-90°C.

[0009] In step S4, the heater is a tubular heat exchanger, which uses a heat-stable heating medium such as high-temperature flue gas / high-temperature air / heat transfer oil to heat the carbonyl nickel pellet seed crystals to 200-250°C before sending them into the reactor.

[0010] In step S5, the screening equipment is an overflow grading device and a screening machine.

[0011] In step S5, disinfection and replacement involves introducing nitrogen gas for 12 hours.

[0012] The beneficial effects of this invention are: 1. In this invention, nickel-containing raw materials are placed in a reaction vessel, and high-temperature, high-pressure pure CO gas is introduced into the reaction vessel. The Ni and Fe in the raw materials undergo a selective carbonylation complexation reaction with the CO gas to generate nickel carbonyl / iron gas. This nickel carbonyl / iron gas is cooled into a liquid and then introduced into a distillation column. Utilizing the difference in boiling points between iron carbonyl and nickel carbonyl, nickel carbonyl is purified from the nickel carbonyl / iron mixture to obtain high-purity nickel carbonyl liquid. This liquid is then introduced into a heat exchanger for heating and evaporation. The vaporized nickel carbonyl gas is mixed with pure carbon monoxide gas, and the process is controlled... The concentration of nickel carbonyl gas is determined, and then introduced into the nickel carbonyl pellet reactor. The nickel carbonyl gas is thermally decomposed by the heated nickel carbonyl pellet seed crystals. After decomposition, nickel atoms are vapor-deposited onto the surface of the nickel carbonyl pellet seed crystals. The nickel carbonyl pellets discharged from the reactor are lifted to the top of the reactor by an elevator and reintroduced into the reactor for heating and reaction with the nickel carbonyl gas. As the material continuously circulates in the reactor, participating in the thermal decomposition and vapor deposition reaction of nickel carbonyl, nickel atoms are continuously deposited on the seed crystal surface, and the nickel carbonyl pellet seed crystals gradually grow, producing nickel carbonyl pellets of the required particle size. Nickel carbonyl pellet seed crystals that do not meet the particle size requirements are returned to the reactor by an elevator to continue participating in the thermal decomposition and vapor deposition reaction of nickel carbonyl, thus growing nickel carbonyl pellets through vapor deposition.

[0013] 2. In this invention, the sterilization and replacement of carbonyl nickel pellets is carried out by nitrogen pressure replacement. While replacing the toxic and harmful gases carried on the surface of the carbonyl nickel pellets, the carbonyl nickel pellets are cooled. The carbonyl nickel pellets cooled by this method can effectively control the O content on the surface of the carbonyl nickel pellets at a low level.

[0014] 3. Compared with traditional electrolytic / smelting methods for preparing nickel metal, the method for preparing 4N-grade high-purity carbonyl nickel pellets of this invention utilizes the selective reaction of Group VIII metals with CO gas to effectively remove difficult-to-remove impurities.

[0015] 4. Compared with traditional electrolytic / smelting methods for preparing nickel metal, this invention has the advantages of a short production process, reusable CO gas, and no toxic or harmful gas emissions. The entire process only includes the preparation, purification, and carbonyl nickel decomposition vapor deposition to prepare carbonyl nickel pellets. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0018] Example 1 like Figure 1 As shown, nickel-containing raw materials are added to a reactor, and high-temperature, high-pressure CO gas is introduced at a pressure of 10 MPa and a temperature of 150°C to produce a carbonyl nickel-iron mixed liquid through carbonylation synthesis. The carbonyl nickel-iron mixed liquid is then passed through a distillation column for carbonyl nickel purification, with the reflux ratio controlled at 2:1, to obtain high-purity carbonyl nickel liquid. The high-purity carbonyl nickel liquid is then heated and evaporated with 60°C hot water, and mixed with CO gas at a volume ratio of 1:1. The mixed carbonyl nickel / CO gas is then introduced into a reactor, where it is heated to 200°C... Carbonyl nickel pellet seed crystals undergo countercurrent heat exchange, where the carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by an elevator and continuously circulated in the reactor for gas-phase deposition reaction, and the carbonyl nickel pellet seed crystals gradually grow. When the particle size increases to 10 mm, the carbonyl nickel pellets are screened multiple times by an overflow classifier and a sieve. The carbonyl nickel pellets that meet the particle size requirements are separated and then sterilized and replaced with nitrogen gas for 12 hours. After the replacement is completed, the pellets are released, and 4N grade high-purity carbonyl nickel pellets are obtained.

[0019] The carbonyl nickel-iron mixed liquid has a composition of wt. (Ni+Fe) > 99.99%, and the contents of other metallic and non-metallic impurities are all at the ppb level. The control conditions of the carbonyl nickel-iron mixed liquid distillation purification column are: the column top pressure is slightly positive pressure and the column top temperature is the boiling point temperature of carbonyl nickel.

[0020] Example 2 like Figure 1 As shown, nickel-containing raw materials are added to a reactor, and high-temperature, high-pressure CO gas is introduced at a pressure of 10 MPa and a temperature of 170°C to produce a carbonyl nickel-iron mixed liquid through carbonylation synthesis. The carbonyl nickel-iron mixed liquid is then passed through a distillation column for carbonyl nickel purification, with the reflux ratio controlled at 1:1, to obtain high-purity carbonyl nickel liquid. The high-purity carbonyl nickel liquid is then heated and evaporated with 80°C hot water, and mixed with CO gas at a volume ratio of 1:1. The mixed carbonyl nickel / CO gas is then introduced into a reactor, where it is heated to 250°C... Carbonyl nickel pellet seed crystals undergo countercurrent heat exchange, where the carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by an elevator and continuously circulated in the reactor for gas-phase deposition reaction, and the carbonyl nickel pellet seed crystals gradually grow. When the particle size increases to 10 mm, the carbonyl nickel pellets are screened multiple times by an overflow classifier and a sieve. The carbonyl nickel pellets that meet the particle size requirements are separated and then sterilized and replaced with nitrogen gas for 12 hours. After the replacement is completed, the pellets are released, and 4N grade high-purity carbonyl nickel pellets are obtained.

[0021] Example 3 like Figure 1As shown, nickel-containing raw materials are added to a reactor, and high-temperature, high-pressure CO gas is introduced at a pressure of 10 MPa and a temperature of 180°C to produce a carbonyl nickel-iron mixed liquid through carbonylation synthesis. The carbonyl nickel-iron mixed liquid is then passed through a distillation column for carbonyl nickel purification, with the reflux ratio controlled at 1:1, to obtain high-purity carbonyl nickel liquid. The high-purity carbonyl nickel liquid is then heated and evaporated with 90°C hot water, and mixed with CO gas at a volume ratio of 1:2. The mixed carbonyl nickel / CO gas is then introduced into a reactor, where it is heated to 250°C... Carbonyl nickel pellet seed crystals undergo countercurrent heat exchange, where the carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by an elevator and continuously circulated in the reactor for gas-phase deposition reaction, and the carbonyl nickel pellet seed crystals gradually grow. When the particle size increases to 10 mm, the carbonyl nickel pellets are screened multiple times by an overflow classifier and a sieve. The carbonyl nickel pellets that meet the particle size requirements are separated and then sterilized and replaced with nitrogen gas for 12 hours. After the replacement is completed, the pellets are released, and 4N grade high-purity carbonyl nickel pellets are obtained.

[0022] Example 4 like Figure 1 As shown, nickel-containing raw materials are added to a reactor, and high-temperature, high-pressure CO gas is introduced at a pressure of 10 MPa and a temperature of 170°C to produce a carbonyl nickel-iron mixed liquid through carbonylation synthesis. The carbonyl nickel-iron mixed liquid is then passed through a distillation column for carbonyl nickel purification, with the reflux ratio controlled at 7:1, to obtain high-purity carbonyl nickel liquid. The high-purity carbonyl nickel liquid is then heated and evaporated with 80°C hot water, and mixed with CO gas at a volume ratio of 1:1. The mixed carbonyl nickel / CO gas is then introduced into a reactor, where it is heated to 250°C... Carbonyl nickel pellet seed crystals undergo countercurrent heat exchange, where the carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by an elevator and continuously circulated in the reactor for gas-phase deposition reaction, and the carbonyl nickel pellet seed crystals gradually grow. When the particle size increases to 10 mm, the carbonyl nickel pellets are screened multiple times by an overflow classifier and a sieve. The carbonyl nickel pellets that meet the particle size requirements are separated and then sterilized and replaced with nitrogen gas for 12 hours. After the replacement is completed, the pellets are released, and 4N grade high-purity carbonyl nickel pellets are obtained.

[0023] The prepared 4N-grade high-purity carbonyl nickel pellets were sampled and sent for testing. Metallic impurities and some non-metallic impurities were analyzed by GDMS, C and S impurities were analyzed by infrared carbon-sulfur analyzer, and H, O, N impurities were analyzed by oxygen-nitrogen analyzer.

[0024] Table 1 shows the chemical composition of the 4N-grade high-purity carbonyl nickel pellets produced in this example: .

[0025] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for producing high-purity nickel carbonyl pellets of grade 4N, characterized in that, Includes the following steps: S1. Add nickel-containing raw materials to the reactor, introduce high-temperature and high-pressure CO gas, and prepare carbonyl nickel-iron mixed liquid by carbonylation synthesis. The carbonylation synthesis reaction conditions are pressure 10MPa and temperature above 150℃. S2. The carbonyl nickel-iron mixed liquid is passed into a distillation column for distillation and purification to obtain high-purity carbonyl nickel liquid; S3. Heat and evaporate the high-purity nickel carbonyl liquid, then mix it with CO gas at a volume ratio of 1:2 or 1:1 to obtain a mixed gas. S4. The mixed gas is introduced into the reactor and undergoes countercurrent heat exchange with the carbonyl nickel pellet seed crystals heated by the heater. The carbonyl nickel gas is decomposed by the heat carried by the carbonyl nickel pellet seed crystals, and nickel atoms are deposited on the surface of the carbonyl nickel pellet seed crystals. The material is lifted by the elevator and continuously circulated in the reactor for gas phase deposition reaction, and the particle size of the carbonyl nickel pellet seed crystals gradually increases. S5. When the particle size of the carbonyl nickel pellet seed crystals increases to 10 mm, the carbonyl nickel pellets will form a cone at the top of the reactor. Due to the large weight and sufficient kinetic energy of the >10 mm carbonyl nickel pellets, they will break through the set baffle curtain and enter the outer ring of the top distributor of the reactor and then enter the screening equipment for screening. The carbonyl nickel pellets that meet the particle size requirements are separated and then disinfected and replaced. After the replacement is completed, they are released to prepare 4N grade high-purity carbonyl nickel pellets. The fine carbonyl nickel pellets that do not meet the particle size requirements continue to enter the reactor through the pipeline to participate in the carbonyl nickel vapor deposition reaction for growth.

2. The production method of 4N-grade high-purity nickel carbonyl pellets according to claim 1, characterized by, In step S1, the CO gas is high-purity CO gas, with a purity of 99.8% or higher.

3. The method for producing 4N-grade high-purity carbonyl nickel pellets according to claim 1, characterized in that, In step S2, the carbonyl nickel-iron mixed liquid is purified and separated by distillation, and the reflux ratio of the distillation column is controlled at (7-1):1 to produce high-purity carbonyl nickel liquid.

4. The method for producing 4N-grade high-purity carbonyl nickel pellets according to claim 1, characterized in that, In step S3, the high-purity carbonyl nickel liquid is heated and evaporated by heating with hot water at 60-90°C.

5. The method for producing 4N-grade high-purity carbonyl nickel pellets according to claim 1, characterized in that, In step S4, the heater is a tubular heat exchanger. The tubular heat exchanger uses a heat-stable heating medium such as high-temperature flue gas / high-temperature air / heat transfer oil to heat the carbonyl nickel pellet seed crystals to 200-250°C before sending them into the reactor.

6. The method for producing 4N-grade high-purity carbonyl nickel pellets according to claim 1, characterized in that, In step S5, the screening equipment is an overflow grading device and a screening machine.

7. The method for producing 4N-grade high-purity carbonyl nickel pellets according to claim 1, characterized in that, In step S5, disinfection and replacement are carried out by introducing nitrogen gas for 12 hours.

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