The Direct Leaching of Micro-disseminated Gold Concentrate by Bromide Process and the Characterization of Leaching Products

Gold is an important industry and strategic reserves of metal, but cyanide leaching process have adverse to the environment. In this paper, an absolutely non-cyanide bromide gold-leaching system was puts forward to leaching a kind of micro-disseminated gold concentrate from China. The influence of different reagent concentration and temperature on the bromide leaching process were tested in this research, and various testing methods as X-ray diffraction (XRD), scanning electron microscopy, infrared spectroscopy, and laser particle size analysis were carried to characterize the leaching residue. Results show that the leaching rate of Au is increasing as the concentration of leaching agent and oxidant rising; temperature rise will accelerate the leaching reaction rate, gold-leaching efficiency after 8 h can reach 97.93%; XRD and infrared spectroscopy testing indicate that the mineral structure is destroyed completely, the desulfurization rate of S element can reach 96%.