Abstract: By using the synthetic Indium sulfide to simulate the actual indium sulfide, the leaching effect and leaching process conditions of indium sulfide with the conventional leaching method and the oxidation leaching of potassium permanganate and hydrogen peroxide as the oxidant in sulfuric acid leaching system were studied. The results showed that under conditions of the stirring speed at 800 r/min, particle size of 75 ~ 96 μm, the liquid-solid ratio of 300∶1, the temperature at 80 ℃, and initial concentration of sulfuric acid of 2.0 mol/L for leaching 60 min, the leaching rate of indium arrived at 84.9% by the conventional leaching method. Under the same conditions, the leaching rate reached 94.9% or 92.8% by adding oxidant KMnO₄ or H₂O₂ to realize oxidation leaching only for 20 min. At temperature <70 ℃, the oxidant plays a major role, where the effect of potassium permanganate is more obvious than the that of hydrogen peroxide; At temperature> 70 ℃, the temperature effect plays a leading rule, and the impact of the two oxidants are less different.

Key words: Indium sulfide, Conventional leaching, Oxidation leaching, Leaching rate