| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing a crude nickel sulfate solution by which when a crude nickel sulfate solution is obtained using a lead-freed precipitate as a raw material for nickel sulfate production, the amount of slaked lime consumed in an iron removal step and the amount of emergence of a gypsum-based neutralization precipitate can be reduced. <P>SOLUTION: In a method for obtaining a crude nickel sulfate solution using a lead-freed precipitate as a raw material for nickel sulfate production by sequential treatment at a sulfuric acid dissolution step, a reductive dissolution step, an iron removal step and a cobalt extraction step, a neutralization step is interposed between the reductive dissolution step and the iron removal step, and at the neutralization step, basic nickel sulfate is added as a neutralizing agent to a solution after reductive dissolution and the basic nickel sulfate is thoroughly dissolved to achieve a predetermined pH, and the resulting solution after neutralization is supplied to the iron removal step. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
