高砷锑金矿湿法选择性浸出锑

Selective leaching of antimony from high-arsenic antimony-gold concentrate

针对高砷锑金矿利用难度大的问题,提出高砷锑金矿在碱性硫化钠体系选择性浸出锑的方案,考查各因素对锑浸出率的影响并确定了最优浸出条件,同时,查明了最优浸出条件下金和砷的浸出率。结果表明:硫化钠过量系数、氢氧化钠浓度和温度的升高均有利于提高锑的浸出率,过度延长反应时间会使部分溶解的锑氧化沉淀,提高搅拌速度可以强化硫化钠与高砷锑矿物之间的扩散过程,增大洗水比可以实现锑的完全脱除。在最优条件下,锑的浸出率达到99.0%以上,金和砷的浸出率分别为1.50%和0.06%,表明浸出过程中金和砷的溶解损失较小;浸出液静置后析出的沉淀物分子式为NaSbO。

Aiming at solving the problem of difficult utilization, a novel method for selective leaching of antimony from high-arsenic antimony-gold concentrate in alkaline sulfide solution was proposed. The effect of various factors on the leaching rates of antimony was investigated, and these leaching rates of gold and arsenic were also studied at the optimum conditions, The results show that the NaES excess coefficients, NaOH concentration and temperature increase are beneficial to promote the leaching rate of antimony. Antimony content in the leaching residue can be decreased with increasing the temperature. Antimony dissolved in the leaching solution will be oxidized and precipitated in the residue with excessive prolonging time. Increasing stirring speed can improve the diffusion between sodium sulfide and concentrate. Antimony will be removed completely by increasing washing water ratio. Under the optimum conditions, the leaching rate of antimony reaches more than 99.0%, and the leaching rates of gold and arsenic are 1.50% and 0.06%, respectively. It indicates that antimony can be removed efficiently from antimony-gold concentrate, meanwhile, the dissolved losses of gold and arsenic are negligible. A black deposit of NaSbO can be precipitated from leaching solution.