The Experimental Studies On HQ0211 Bacteria Oxidation Of Refractory Gold Complex

At present, rational, efficient and environmental friendly exploitation and utilization of refractory gold mineral resource has become one of the main challenge faced by every gold producing country. Many refractory ores are utilized efficiently and their reconvenes are improved remarkably because of better pretreatment, especially biooxidation pretreatment. In this paper, the arsenic and antimony bearing double refractory gold ores concentrate is Studied. Leaching bacteria called HQ0211 is used as test bacteria. The shake flask leaching, 3 L bio-oxidation-Cyanide Leaching of this gold ores, and continuous bio-oxidation test are carried out to study the oxidation of HQ0211, increase the oxidation rate of the gold, and improve the gold recovery.The shaking leaching of the gold ore containing arsenic shows that with increase of pulp density the mineral oxidation decreases. When the pulp density is 10%, the desulfurization degree and arsenic removal degree reach to 68.88% and 64.07% respectively; with pH increasing, the oxidation effect of the gold ore containing arsenic and antimony increases and then decreases, the optimal initial pH of oxiding refractory gold by HQ0211 bacteria is 2.1. At this time, the desulfurization degree and arsenic removal degree reach 80.56% and 78.06%, respectively.3 L bio-oxidation -Cyanide Leaching of this gold ores indicates that HQ0211 bacteria suit for the refractory gold ore.When the pulp concentration is 10%, after 16d, the rate of weight loss is 41.47%, the arsenic removal degree is 78.77%, the desulfurization rate is 88.01%, and the gold leachingefficiency is 96.69%.Different oxidation cycle of continuous bacterial oxidation shows:the lag phase of bacterial leaching is shortened effectively and the oxide efficiency of mineral is improved. Compared with the single bioleaching tank with 10% pulp density, potentials reach 624～643 mV after 84 hours’continuous oxidation in the first stage oxidation tank. The dearsenization degree, the desulfurization rate and the weight loss rate are 81.759%,71.07% and 43.10% respectively. After 84 hours’continuous oxidation, the first stage oxidation tank achieves favorable pretreatment results, the oxidation rate of is more than 60% and meets the industrial requirementsContinuous expansion of bacterial oxidation pretreatment and cyanide leaching shows: after 168 hours’ continuous bacterial oxidation, the final arsenic removal rate, desulfurization degree and weight loss rate of gold concentrate with 10% pulp density reach 96.61%,90.65% and 83.48%, respectively. The gold leaching efficienc of oxidation residue reach 97.93%, it improves 39.84% compared with the previous bacterial oxidation, It proves that continuous bacterial oxidation achieves favorable pretreatment results.The study on bacterial oxidation of stibnite ore indicates that:the oxidation products of stibnite are Sb2(SO4)3 and Sb2(SO4)5. Sb3+ and Sb5+ are easily hydrolyzed under this system, the hydrolysis product (SbO)2SO4 and (SbO2)2SO4 are produced as amorphous compounds.