The Experimental Studies On Thermophilic Bacteria Pretreating-Cyanide Leaching Complex Refractory Gold Ore

The gold leaching rate of the high-sulfur high-iron gold concentrate from a business is low,the economic and technical indicators are irrational,so the gold concentrate is complex refractory gold ore.This study used thermophilic bacteria oxidate pretreating and cyanide leaching high-sulfur high-iron gold concentrate in different fineness:sample 1(<38?m,73%),sample 2(<38 ?m,86%),sample 3(<38 ?m,98%)to determine the best conditions of pretreating and leaching the gold concentrate and provide theoretical guidance for the actual producers,and ultimately get the following conclusions:The bacterial oxidation test in the single bacterial reaction groove showed that:the weighllessness rate of ore was 50.30%,the oxidation rate of As,Fe and S were 96.65%,86.08%and 78.82%respectively,the enrichment rate of Au and Ag were 58.15 g·t-1 and 40.45 g·t-1.The continuous bacterial oxidation in bacterial reaction groove showed that:bacterial oxidation can greatly improve the oxidation rate of As,Fe,S and the enrichment rate of Au,Ag;In the bacterial oxidation slag of sample 1,sample 2 and sample 3,the enrichment ratio of Au were 1.91,2.08 and 2.03 respectively,and the enrichment ratio of Ag were 2.00,2.06 and 2.05;The oxidation effectt of sample 2 was the best,the oxidation rate of As,Fe,S were 96.44%,90.03%and 72.80%respectively.The grinding tests showed that:the leaching rate of gold in the original gold concentrate(sample 1)was 59.86%,the leaching rate of glod in sample 2 which was ground for 5-minute was 68.17%,the leaching rate of glod in sample 3 which was ground for 10-minute was 69.20%.The gold extraction tests of oxidation slag from single groove showed that:after the one-stp leaching of bacterial oxidation slag,the leaching rates of gold and silver increased significantly,and they were 95.2%and 65.6%respectively.Compared with the direct extracting gold and silver,the leaching rates were increased by 35.34%and 41.22%.The cyanide leaching curve showed that,after cyanide leaching for 24 hours,the leaching rate of gold could be as high as 93.2%,the leaching efficiency was very significantly.The gold extraction tests of the continuous bacterial oxidation slag showed that:after the one-step leaching of continuous bacterial oxidation slag,the leaching rates of gold and silver increased significantly,and they were 96.51%and 71.36%respectively.Compared with the direct extracting gold and silver,the leaching rates were increased by 36.65%and 46.98%.