Leaching of sulphide ores such as ZnS, PbS etc,, can be done by treating them with hot aqueous sulphuric acid.
2ZnS(s) + 2H2SO4 (aq) + O2 (g) → 2ZnSO4 (aq) + 2S (s) + H2O
In this process the insoluble sulphide is converted into soluble sulphate and elemental sulphur.