Nickel powder manufacturing method

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.

1 . A nickel powder manufacturing method, the method comprising:
 a first step for generating a post-neutralization slurry containing 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 obtained in the first step and obtaining a post-complexation slurry containing a nickel ammine complex aqueous solution; and   a reduction step for obtaining nickel powder and a post-reduction solution by bringing hydrogen gas into contact with the nickel ammine complex aqueous solution obtained in the second step.   
     
     
         2 . The nickel powder manufacturing method according to  claim 1 , wherein in the second step, the post-reduction solution obtained in the reduction step is used as the ammonium sulfate aqueous solution to be mixed with the post-neutralization slurry. 
     
     
         3 . The nickel powder manufacturing method according to  claim 1 , the method further comprising a third step for subjecting the post-complexation slurry obtained in the second step to solid-liquid separation into a nickel ammine complex aqueous solution and a post-complexation sediment and supplying the nickel ammine complex aqueous solution to the reduction step. 
     
     
         4 . The nickel powder manufacturing method according to  claim 1 , wherein in the first step, slaked lime and/or sodium hydroxide is used as the neutralizing agent. 
     
     
         5 . The nickel powder manufacturing method according to  claim 1 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         6 . The nickel powder manufacturing method according to  claim 2 , the method further comprising a third step for subjecting the post-complexation slurry obtained in the second step to solid-liquid separation into a nickel ammine complex aqueous solution and a post-complexation sediment and supplying the nickel ammine complex aqueous solution to the reduction step. 
     
     
         7 . The nickel powder manufacturing method according to  claim 2 , wherein in the first step, slaked lime and/or sodium hydroxide is used as the neutralizing agent. 
     
     
         8 . The nickel powder manufacturing method according to  claim 3 , wherein in the first step, slaked lime and/or sodium hydroxide is used as the neutralizing agent. 
     
     
         9 . The nickel powder manufacturing method according to  claim 6 , wherein in the first step, slaked lime and/or sodium hydroxide is used as the neutralizing agent. 
     
     
         10 . The nickel powder manufacturing method according to  claim 2 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         11 . The nickel powder manufacturing method according to  claim 3 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         12 . The nickel powder manufacturing method according to  claim 4 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         13 . The nickel powder manufacturing method according to  claim 6 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         14 . The nickel powder manufacturing method according to  claim 7 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         15 . The nickel powder manufacturing method according to  claim 8 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution. 
     
     
         16 . The nickel powder manufacturing method according to  claim 9 , wherein in the reduction step, the nickel powder is obtained by adding ammonia water to the nickel ammine complex aqueous solution and then bringing the hydrogen gas into contact with the nickel ammine complex aqueous solution.