Sulfuric Acid Leaching of Low-grade Zinc Oxide Ore--A Study

Sulfuric acid leaching of low grade zinc oxide ore is studied in this paper. At pH of 2.0 leaching rate of above 97% can be achieved only by controlling addition of sulfaric acid(ie. dosage and rate). At the same time leaching rates of silico and iron can be reduced to 13% and 0.84% or much less, respectively, and the consamption of sulfuric acid is 1.76 t per ton zinc. Addition of thiobacillus ferrooxidans can enhance the reaching rate of zinc slightly and is favorable for iron precipitation, which can reduce the content of iron in leach solution. Percolation leaching can achieve leaching rates of above 95% Zn, 3.6% Si and 0.6% Fe, respectively.