氰化尾渣碱法水热浸出脱石英试验

Research on Desilicication of Cyanide Tailings via Alkaline Hydrothermal Process

湖南某黄金冶炼厂的氰化尾渣含金5 g/t以上,其中的主要物相为赤铁矿、石英、白云母,石英包裹黄铁矿与金的共伴生体是导致金不能充分与氰化药剂接触的重要原因。为解决此问题,进行了氰化尾渣碱法水热浸出脱石英工艺条件研究。结果表明,氢氧化钠浓度为25%,体积质量比为2 L/kg,浸出温度为160℃,搅拌速度为400r/min,浸出时间为3 h情况下的脱石英率为57.6%。经过该工艺脱石英,金的浸出率可由4.7%提高到38.4%。

Cyanide tailings from a gold smelter in Hunan contains more than 5 g/t of gold,and its main phase is hematite, quartz and muscovite. The intergrowth of quartz with inclusion of pyrite and gold is the important reason that gold can not fully contact with cyanide. In order to solve this problem, the conditioning tests of alkaline hydrothermal leaching for desilication of cyanide tailings are carried out. The results show that under the concentration of sodium hydroxide 25% , the volume mass ratio 2 L/kg,the leaching temperature at 160 ℃ ,the stirring speed 400 r/min, and the leaching time for 3 h ,the desilica- tion rate reached 57.6%. Through the process of desilication,the leaching rate of gold is increased from 4.7% to 38. 4%.