Manganese ions removal from zinc sulphate soln. - obtd. during extn. of zinc by oxidising to manganese dioxide and pptn.

摘要

Method of removing soluble manganous ions from a soln. contg. zinc sulphate comprises treatment of (part of) the soln. with an oxidant which can oxidise the manganous ions to insoluble filterable alpha-MnO2, the oxidant being in amount 130-150% of that theoretically required to remove all the Mn ++, and separating off the ppte. The process is effected at between 90 degrees C and the b.pt. of the soln. in 1/2-2 hrs. Used in the recovery of zinc from a concentrate of Zn contg. Mn, the concentrate having been roasted and leached to dissolve the zinc and treated to remove iron. Process may also be used in removing manganese from other metal salt solutions. In the subsequent process of electrolysing the zinc sulphate to extract the zinc, improved yields are obtained of zinc uncontaminated with Mn, having improved physical and chemical properties.