Abstract: Provided is a nickel powder manufacturing method capable of efficiently manufacturing a high-quality nickel powder using as little ammonium gas or ammonium water as possible. The nickel powder manufacturing method according to the present invention is characterized by comprising: a first step for generating a post-neutralization slurry including nickel hydroxide by mixing a nickel sulfate aqueous solution and a neutralizing agent; a second step for causing a complex-forming reaction by mixing an ammonium sulfate aqueous solution with the post-neutralization slurry and obtaining a post-complexation slurry including a nickel ammine complex aqueous solution; and a reducing step for obtaining a nickel powder and a post-reduction solution by contacting hydrogen gas with the nickel ammine complex aqueous solution. Further, it is preferable that a post-complexation solution obtained in the reduction step be repeatedly used as the ammonium sulfate aqueous solution to be added to the post-neutralization slurry.

Abstract: Provided is a method for manufacturing coarse particles of a so-called high-purity nickel powder with a small amount of impurities, particularly having a low sulfur grade, from a nickel sulfate amine complex solution using a fine nickel powder. A method for manufacturing a nickel powder includes the following treatment steps (1) to (6) in a process for manufacturing a nickel powder from a nickel sulfate solution: (1) a hydroxylation step; (2) a complexation step; (3) a reduction step; (4) a solid/liquid separation step; (5) a nickel recovery step of repeatedly supplying the recovered nickel powder to step (2) and/or step (3), sulfurating the recovered final reduction solution, and then solid/liquid separating the sulfurated solution to generate nickel sulfide and a nickel post-reduction solution; and (6) a nickel regeneration step of oxidatively leaching the nickel sulfide obtained in step (5) and repeatedly supplying the obtained nickel sulfate solution to step (1).

Abstract: Provided is a production method for maintaining the quality while keeping a high operating rate of the reaction by continuously feeding a solution, seed crystals, and hydrogen gas into a reactor to produce nickel powder, and continuously discharging the resulting powder. The method for producing nickel powder comprises feeding a nickel ammine sulfate complex solution and seed crystals into a reactor, and feeding hydrogen gas into the reactor to subject a nickel complex ion in the nickel ammine sulfate complex solution to a reduction treatment and to thereby produce nickel powder, wherein, in the reduction treatment, while the nickel ammine sulfate complex solution is being continuously fed into the reactor, a temperature inside the reactor is controlled within the range of 150 to 185° C. and the feed rate of hydrogen gas is controlled to maintain an inner pressure of the reactor in the range of 2.5 to 3.5 MPa.

Abstract: Provided is a method for producing high density nickel powder particularly having a median diameter of 100 to 160 ?m by controlling a particle size of nickel powder. The method includes: performing an initial operation by charging a pressure vessel equipped with a stirrer with a nickel ammine complex solution containing nickel in the concentration of 5 to 75 g/L together with seed crystals in the amount of 5 to 200 g per liter of the solution, increasing the temperature of the solution, and performing a reduction reaction with hydrogen by blowing hydrogen gas into the pressure vessel, thereby obtaining the nickel contained in the nickel ammine complex solution as nickel powder; and thereafter, performing a specified operation A repeatedly at least once to obtain the nickel powder having the median diameter of 100 to 160 ?m and a bulk density of 1 to 4.5 g/cm3.

Abstract: A method for producing nickel powder sequentially includes: a mixing step of adding, to a nickel ammine sulfate complex solution, an insoluble solid as seed crystals and a polyacrylate or lignosulfonate as a dispersant to form a mixed slurry; and a reduction and precipitation step of charging a reaction vessel with the mixed slurry and blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions in the mixed slurry to form nickel precipitate on the surface of the insoluble solid, wherein the amount of the dispersant added in the mixing step is controlled to control the number of the nickel powder obtained by formation of the nickel precipitate in the reduction and precipitation step.

Abstract: A nickel sulfate amine complex liquid and nickel powder having a particle diameter of 0.1 ?m to 300 ?m are supplied to a reaction container, hydrogen gas is continuously supplied while the inside of the reaction container is maintained at 150° C. to 250° C., and the pressure is set to 2.5 MPa to 3.5 MPa, whereby nickel ions in the nickel sulfate amine complex liquid are reduced to nickel and deposited on the surfaces of the nickel powder supplied to the reaction container, a reacted slurry including the nickel sulfate amine complex liquid and the nickel powder is then transferred to a pressurized storage container at the same or slightly lower pressure than the internal pressure of the reaction container, and the pressure of the pressurized storage container to which the reacted slurry is transferred is then reduced, after which the reacted slurry is extracted from the pressurized storage container.

Abstract: Provided a production method for reducing the content level of sulfur and carbon which are impurities in nickel powder to improve the quality of nickel powder produced by a complexing reduction method. The method of producing nickel powder having low carbon and sulfur concentrations includes: a complexing treatment of adding a complexing agent to a nickel sulfate aqueous solution to form a solution containing nickel complex ions; maintaining the solution containing nickel complex ions at a solution temperature of 150 to 250° C. in a pressure vessel and blowing hydrogen gas into the solution containing nickel complex ions to perform hydrogen reduction to produce nickel powder; washing the nickel powder with water; and then roasting the nickel powder washed with water in a mixed gas atmosphere of nitrogen and hydrogen.

Abstract: Provided is a method with which it is possible to prevent equipment, such as piping and valves, used to discharge and recover a nickel powder-containing slurry from a high pressure reaction tank from being damaged and trapping the nickel powder therein and to enable continuous operation, thereby improving the productivity. This nickel powder production method comprises a step of reacting a nickel sulfate-amine complex solution with hydrogen gas under high pressure in a reaction tank, thereby obtaining a nickel powder slurry containing nickel powder. The method is characterized in that the nickel powder slurry is discharged and transferred through discharge piping from the reaction tank in which the nickel powder-containing slurry has been produced, and then a washing solution is supplied to the discharge piping at a predetermined pressure to wash the discharge piping.

Abstract: Provided is nickel powder obtained by adding seed crystals to a nickel ammine complex solution and performing hydrogen reduction reaction under high temperatures and high pressures, wherein the nickel powder does not produce dust during handling, and a container can be efficiently filled with the nickel powder. The method for producing nickel powder includes: adding seed crystals and a surfactant having a nonionic or anionic functional group to a solution containing a nickel ammine complex to forma mixed slurry; and subjecting the mixed slurry to hydrogen reduction under high temperature and high pressure conditions in a pressure vessel to obtain nickel powder from the mixed slurry.

Abstract: A nickel sulfate amine complex liquid and nickel powder having a particle diameter of 0.1 ?m to 300 ?m are supplied to a reaction container, hydrogen gas is continuously supplied while the inside of the reaction container is maintained at 150° C. to 250° C., and the pressure is set to 2.5 MPa to 3.5 MPa, whereby nickel ions in the nickel sulfate amine complex liquid are reduced to nickel and deposited on the surfaces of the nickel powder supplied to the reaction container, a reacted slurry including the nickel sulfate amine complex liquid and the nickel powder is then transferred to a pressurized storage container at the same or slightly lower pressure than the internal pressure of the reaction container, and the pressure of the pressurized storage container to which the reacted slurry is transferred is then reduced, after which the reacted slurry is extracted from the pressurized storage container.

Abstract: Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially comprises: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

Abstract: Provided is a method for producing seed crystals of cobalt powder, sequentially including: a complexing step of adding ammonia, an ammonia compound solution, or both of ammonia and an ammonia compound solution to a cobalt sulfate solution to obtain a solution containing a cobalt ammine sulfate complex; a mixing step of adding a solid to the solution containing the cobalt ammine sulfate complex to form a mixture slurry; a reduction and precipitation step of charging a reaction vessel with the mixture slurry, blowing hydrogen gas into the reaction vessel and reducing cobalt contained in the mixture slurry to obtain a cobalt powder slurry containing cobalt precipitate with a cobalt component precipitated on the surface of the solid as cobalt powder; and a solid-liquid separation step of performing solid-liquid separation on the cobalt powder slurry to obtain cobalt precipitate and a solution after reduction.

Abstract: Provided is a method for producing high density nickel powder particularly having a median diameter of 100 to 160 ?m by controlling a particle size of nickel powder. The method includes: performing an initial operation by charging a pressure vessel equipped with a stirrer with a nickel ammine complex solution containing nickel in the concentration of 5 to 75 g/L together with seed crystals in the amount of 5 to 200 g per liter of the solution, increasing the temperature of the solution, and performing a reduction reaction with hydrogen by blowing hydrogen gas into the pressure vessel, thereby obtaining the nickel contained in the nickel ammine complex solution as nickel powder; and thereafter, performing a specified operation A repeatedly at least once to obtain the nickel powder having the median diameter of 100 to 160 ?m and a bulk density of 1 to 4.5 g/cm3.

Abstract: Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially includes: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, a dispersant containing a sulfonate and an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

Abstract: A method for manufacturing nickel powder whereby a reduction in production efficiency due to abrasion of a flash vessel connected to a pressurized container can be suppressed when nickel powder is generated using the pressurized container and subsequently recovered. The method for manufacturing nickel powder comprises charging a pressurized container with a nickel sulfate ammine complex solution and seed crystals, adding hydrogen gas to the pressurized container, and reducing the nickel included in the nickel sulfate ammine complex solution, wherein, when a nickel powder slurry obtained in the pressurized container is extracted to a flash vessel connected to the pressurized container, the slurry is extracted to the flash vessel while the supply rate of the nickel ammine complex solution to the pressurized container and/or the extraction rate of the nickel slurry from the pressurized container is controlled so the liquid level in the pressurized container is in a fixed range.

Abstract: Provided is a method for producing cobalt powder with high reaction efficiency by controlling the amount of added seed crystals when cobalt powder is produced from a solution containing a cobalt ammine sulfate complex. The method sequentially includes: a mixing step of adding, to the solution containing a cobalt ammine sulfate complex, cobalt powder as seed crystals in an amount of 1.5 times or more and 3.0 times or less the amount of cobalt contained in the solution and then adding a dispersant in an amount of 1.5% by weight to 3.0% by weight of the added seed crystals to form a mixture slurry; and a reduction and precipitation step of charging a reaction vessel with the mixture slurry and then blowing hydrogen gas into the mixture slurry to reduce cobalt complex ions contained in the mixture slurry to form cobalt precipitate on the surface of the seed crystals.

Abstract: Provided is a production method for producing coarse particles of high purity Co powder from a cobalt ammine sulfate complex solution using fine Co powder and using industrially inexpensive H2 gas.

Abstract: A method for producing nickel powder sequentially includes: a mixing step of adding, to a nickel ammine sulfate complex solution, an insoluble solid as seed crystals and a polyacrylate or lignosulfonate as a dispersant to form a mixed slurry; and a reduction and precipitation step of charging a reaction vessel with the mixed slurry and blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions in the mixed slurry to form nickel precipitate on the surface of the insoluble solid, wherein the amount of the dispersant added in the mixing step is controlled to control the number of the nickel powder obtained by formation of the nickel precipitate in the reduction and precipitation step.

Abstract: Provided is nickel powder obtained by adding seed crystals to a nickel ammine complex solution and performing hydrogen reduction reaction under high temperatures and high pressures, wherein the nickel powder does not produce dust during handling, and a container can be efficiently filled with the nickel powder. The method for producing nickel powder includes: adding seed crystals and a surfactant having a nonionic or anionic functional group to a solution containing a nickel ammine complex to forma mixed slurry; and subjecting the mixed slurry to hydrogen reduction under high temperature and high pressure conditions in a pressure vessel to obtain nickel powder from the mixed slurry.

Abstract: Provided a production method for reducing the content level of sulfur and carbon which are impurities in nickel powder to improve the quality of nickel powder produced by a complexing reduction method. The method of producing nickel powder having low carbon and sulfur concentrations includes: a complexing treatment of adding a complexing agent to a nickel sulfate aqueous solution to form a solution containing nickel complex ions; maintaining the solution containing nickel complex ions at a solution temperature of 150 to 250° C. in a pressure vessel and blowing hydrogen gas into the solution containing nickel complex ions to perform hydrogen reduction to produce nickel powder; washing the nickel powder with water; and then roasting the nickel powder washed with water in a mixed gas atmosphere of nitrogen and hydrogen.