摘要 |
<p>Ppte. of hydrated cobaltic oxide (I) is mixed with a spent sulphate electrolyte (II) to form a paste, where (I) and/or (II) contain chloride ions. The paste is treated with air so all the Cl ions are evolved as C12 gas; and then a reducing agent (III) is added to dissolve all the Co and to obtain a soln. free from chloride, from which Co is reclaimed by electrolysis. (III) is SO2, H2O2 or an organic cpd. converting Co to its divalent state. When (II) is contaminated by chlorate ions, a reducing agent is pref. added to form chlorides before the liw. (II) is mixed with ppte. (I). Before electrolysis, the soln. is pref. treated to remove Pb, Fe, Zn, Cu, adn Ni.</p> |