Research of the Process of Purification of Sulfate Zinc Solution from Iron Ions Using Anodic Oxidation

Abstract

The possibility of using a membrane electrolytic cell for the electrochemical oxidation of Fe(II) and purification from impurities of real industrial solutions obtained by atmospheric leaching of low-grade zinc concentrates is considered. The average indicators for carrying out the electrooxidation process are given. The principal possibility of conditioning a zinc sulfate solution by hydrolytic purification with preliminary oxidation of iron in a membrane electrolytic cell with an anion-exchange membrane MA-41 TU 2255-062-05761695-2009 is considered. Carrying out direct electrooxidation of iron (II) in sulfate zinc solutions in the anode chamber of a flow membrane electrolyzer ensures good filterability of precipitates after hydrolytic precipitation of iron, since this solution does not contain Fe(II) ions, the presence of which leads to significant difficulties in the operations of separating solid and liquid phases. This makes it possible to exclude the thickening operation from the technological scheme. The degree of oxidation of iron during the test period was 99.8–99.9%. The residual concentration of iron after precipitation from solutions obtained after electrochemical oxidation in the form of oxide and hydroxide compounds was less than 0.01 g/dm3.