某低品位金矿综合回收试验研究

Experimental study on comprehensive recovery of a low grade gold ore

以某低品位金矿作为研究对象,根据原矿MLA工艺矿物学分析,初步确定试验采用原矿混合浮选-精矿氰化浸金-浸渣浮铅的联合工艺流程。原矿经一粗两扫两精的混合浮选流程,得到Au品位16.36g/t、回收率78.44%;Pb品位7.21%、回收率84.12%的混合精矿;再对混合精矿进行氰化浸金,为考察NaCN用量、CaO用量、浸出时间对金浸出率的影响,进行单因素试验,并利用响应曲面法优化浸出条件。结果表明,响应曲面法优化金浸出率模型p值小于0.05,响应曲面法优化得到的最佳浸出条件为:CaO用量为3093.03g/t;NaCN用量为2317.91g/t;浸出时间为33.49h,在此条件下模型预测金浸出率为90.49%。经过试验验证,得到金浸出率为89.91%,试验结果与响应曲面法优化结果基本一致;浸渣经过一粗一扫两精的浮选试验,最终得到Pb品位50.41%、作业回收率51.11%;Au品位8.56g/t、作业回收率38.87%的铅精矿。此联合工艺流程得到了不错的选矿指标,实现了资源的综合利用。

According to the MLA analysis of a low grade gold mineral,the combined process flow of mixed flotation of raw ore,cyanide leaching of gold from concentrate and lead flotation from leaching residue was preliminarily determined.A mixed concentrate with Au grade of 16.36 g/t and recovery of 78.44%and Pb grade of 7.21%and recovery of 84.12%was obtained by the mixed flotation process of one roughing,two scavenging and two refining.Then,the mixed concentrate was cyanidated.In order to investigate the effects of NaCN dosage,CaO dosage and leaching time on gold leaching rate,the single factor experiment was carried out,and the leaching conditions were optimized by response surface methodology.The results showed that the pvalue of response surface methodology was less than 0.05,and the optimal leaching conditions were as follows:CaO dosage was 3093.03 g/t,NaCN dosage was 2317.91 g/t,and leaching time was 33.49 h.Under these conditions,the model predicted gold leaching rate was 90.49%.After experimental verification,the gold leaching rate is 89.91%,and the experimental results are basically consistent with the optimization results of response surface methodology.After the flotation experiment of one roughing,one scavenging and two refining,the final lead concentrate with Pb grade of 50.41%and recovery of 51.11%as well as Au grade of 8.56 g/t and recovery of 38.87%was obtained.Good beneficiation indexes are obtained by this combined process,and comprehensive utilization of resources is realized.