Gold leaching for a gold concentrate was difficult due to the fine disseminated grain sizes and large amounts of the gold mineral wrapped by pyrite and arsenopyrite. Some of tests regarding acidic oxidation pretreatment in the systems of HCl?H2O2 and the mechanism and reaction kinetic analysis were carried out. The results showed that under the conditions of dosage of HCl 0.7 mol/L, pulp contentation of 40 g/L, particle size of less than 48 μm accounted for more than 90%, stirring speed of 400 r/min, reaction temperature of 60℃, dosage of H2O2 0.5 mol/L, the dissolution rates of iron and arsenic were 45.9% and 99.6%, respectively, acidic oxidation pretreatment benefited the gold leaching. Under acidic conditions, pyrite and arsenopyrite in gold concentrate could be oxidized by H2O2, the process conforms to the shrinking core model (SCM), and the reaction velocity was controlled by the products layer diffusion.
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