Oxidative pressure leaching of sphalerite concentrate with high indium and iron content in sulfuric acid medium

The leaching of a sphalerite concentrate with high indium and iron content in sulfuric acid–oxygen media has been studied in the present paper. The variables considered in the study were particle size, concentration of sulfuric acid, partial pressure of oxygen, leaching temperature, and leaching time. The experimental data indicated that under the conditions employed up to 99% zinc and 90% indium extraction were achieved. The mineralogical analysis of the residue showed that the main minerals are elemental sulphur, unreacted pyrite and quartz, the amount of sulphide sulphur oxidized to sulphate during leaching is 81%.