| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of reducing Ni recovery loss which can suppress sufficiently adhesion of formed sulfide to the inside surface of the reaction vessel for sulfurization reaction, reduce the concentration of fine floating solid in overflow liquid to reduce Ni recovery loss and thus allow improvement of the Ni recovery rate, in a precipitation separation treatment of wet metallurgy for nickel oxide ore and a wet metallurgy method for Ni oxide ore and a sulfurization processing system which employ the method of reducing Ni recovery loss.SOLUTION: Provided is a method of reducing Ni recovery loss in a sulfurization step of blowing hydrogen sulfide gas into an aqueous sulfuric acid solution containing Ni and Co recovered after an exudation step, a solid/liquid separation step and a neutralization step to cause sulfurization reaction which produces Ni-containing sulfide and a barren solution, and the Ni-containing sulfide recovered after the sulfurization step is recycled to the aqueous sulfuric acid solution. The sulfide is classified by a liquid cyclone to obtain a sulfide of an average particle size of 55μm, and the sulfide is added to the aqueous sulfuric acid solution as a seed crystal in such an amount as to give an Ni amount four to six times the Ni amount in the aqueous sulfuric acid solution.</p> |
