某生物氧化氰化尾矿回收金试验研究

Experimental research on the recovery of gold from biologically oxidized cyanide tailings

某生物氧化氰化尾矿中金与硫的关系密切,金主要以硫化物包裹金形式存在,黄铁矿粒度微细,直接浮选或再磨分选效果差。试验采用再磨—预处理—浮选工艺回收氰化尾矿中金,并对试验条件进行了优化。结果表明:硫酸和碳酸钠预处理能够有效去除黄铁矿表面的亲水膜,分解残余氰化物,缓冲矿浆pH,活化黄铁矿,分散微细矿泥;闭路试验获得的金精矿中金、硫品位分别为10.14 g/t、43.67%,回收率分别为93.41%、99.67%,实现了金的高效回收。

The gold and sulfur in certain biologically oxidized cyanide tailings are closely related.The gold mainly takes the form of sulfide-included gold.The pyrite grain size is microfine,making direct flotation or regrinding separation less effective.The experiment recovers the gold from cyanide tailings by using regrinding-pretreatment-flotation process.The experimental conditions are optimized.The results show that sulfuric acid and sodium carbonate pretreatment can effectively remove the hydrophilic film from pyrite surface,dissolve the residual cyanide,buffer slurry pH,activate pyrite,and disperse microfine ore slime;the gold and sulfur grades in the gold concentrate obtained in the closed circuit test are 10.14 g/t and 43.67%respectively,the recovery rates are 93.41%and 99.67%respectively,achieving the goal of efficiently recovering gold and sulfur.