摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for separating and removing zinc from an aqueous solution of nickel sulfate containing cobalt and zinc in which, by improving the conventional method where hydrogen sulfide is blown into the aqueous solution to selectively precipitate zinc sulfide, and zinc is separated and removed from the aqueous solution, zinc is almost perfectly separated and removed with hardly losing nickel and cobalt without using a pH conditioner for controlling the production reaction of precipitation. SOLUTION: In the above conventional method, (1) the concentration of zinc in the above aqueous solution is <=0.5 g/l, (2) the pH of the aqueous solution is previously controlled to the range of 2.5 to 3.8, and (3) the ORP(oxidation-reduction potential) of the aqueous solution is controlled to the range of -260 to -120 mVvs.Ag/AgCl in accordance with the amount of hydrogen sulfide to be blown.</p> |