In metallurgical process for non-ferrous metals, smelting residue is inevitably generated as secondary product. The smelting residue include some useful metals and undesired toxic materials; Cu, Pb, Ca and As, etc.
In this research, some experimental feasibilities were investigated to recover/remove Cu, Pb, Ca and As from the residue, and to reduce amount of residue. Primarily, the removal of As from the residue was examined by H2SO4 solution as a 1st stage leach H2SO4 mixed with H2O2 to recover Cu from the leach residue. And then, to recover and separate Cu from impurities from the 2nd leached solution, solvent extraction separation method was examined by using LIX-84I as a solvent. Finally, to separate Pb and Ca from the leached residue of 2nd leaching stage, sulfurised flotation was examined by amylxanthic acid potassium salt (PAX) with sodium hydrosulfate (NaSH).
In each experiment, we obtained several optimum experimental conditions to recover/concentrate Cu and Pb, to remove As, and designed the schematic flowsheet to treat the residue. For the 1st stage leaching and 2nd stage leaching, the removal of 90% As and the leaching rate of 85% Cu could be achieved by 0.25 mol/l and 1.0 mol/l H2SO4 solution, respectively. On the other hand, the extraction of over 90% Cu and stripping was carried out by solvent extraction. In case of flotation, the distribution of recovery Pb in float product by sulfurization process was over 60%.
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