| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a nickel sulfate aqueous solution of low zinc concentration by removing zinc from a nickel sulfate aqueous solution by using hydrogen sulfide, by which the zinc is selectively formed and precipitated while preventing co-precipitation with nickel and at the same time, the nickel sulfate aqueous solution from which zinc is removed until the concentration of zinc becomes low is efficiently separated and recovered from slurry of sulfide precipitate containing formed zinc sulfide. SOLUTION: The method for producing the nickel sulfate aqueous solution of low zinc concentration comprises: (1) a neutralization process for controlling the pH of a nickel sulfate aqueous solution (A) containing zinc to 1.0-3.5 by adding a neutralization agent to the solution (A); (2) a sulfurization/precipitation process for forming slurry of the sulfide precipitate containing zinc sulfide by blowing hydrogen sulfide into the pH-controlled aqueous solution (A); and (3) a process for performing solid-liquid separation while maintaining the redox potential (Ag/AgCl electrode as a reference) of the slurry at -50 to -100 mV. COPYRIGHT: (C)2006,JPO&NCIPI
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