On one hand, high-sulphur and high-arsenic refractory gold concentrate (HGC) leads to regional ecological damage. On the other hand, it contains a lot of valuable elements. So utilization of it can bring social and environmental benefits. In this paper, the kinetics of HGC oxidation by dilute nitric acid under mild conditions was investigated. The effects of particle size (50-335 mu m), reaction temperature (25-85 degrees C), initial acid concentration (10-30 wt.%) and stirring speed (400-800 rpm) on the iron extraction rate (C(r)) were determined. It is obvious that C(r) increases with the rise of initial nitric acid concentration, reaction time and stirring speed, but decreases with the increase of particle size. Oxidation kinetics indicates that the rate of reaction is diffusion controlled. The activation energies were determined to be 10.70 kJ/mol in the 10% HNO(3) and 12.25 kJ/mol in the 25% HNO(3). (C) 2008 Elsevier Ltd. All rights reserved.