A HYDROMETALLURGICAL PROCESS FOR LEACHING MANGANESE FROM FURNACE DUST CONTAINING MANGANESE OXIDES.

摘要

The invention relates to a two stage process of leaching Mn-oxide containing furnace dust, for making manganese or MnO2 from comprising the steps of leaching of Mn-oxide containing furnace dust with sulfuric acid in a first stage; said acid being present in an amount effective to dissolve soluble manganese and convert manganese oxide in to manganese sulfate; adding a base to leach solution to raise pH 1.5 to 2 for potassium removal; leaching the residue generated in the first stage with a sulfuric acid solution and a reducing agent, said reducing agent being present in an amount effective to reduce MnO2 to MnO and said sulfuric acid being present in an amount effective to convert MnO to MnSO4; mixing of leach solution from b) and c) ; removing iron from the said solution by adding base to raise pH to 4 to 7; adding a sulfide to said leach solution to heavy metal precipitates; removing said metal precipitates from the solution; treating said leach solution in an electrolytic cell having an anode and cathode to deposit manganese dioxide on anode or manganese metal on cathode; and recovering said manganese dioxide from anode and manganese metal from cathode.