硫代硫酸盐浸金液中金回收的研究进展

为开发简单高效的Au(S2O3)23-回收技术,进而推进环境友好型硫代硫酸盐提金技术的大规模工业化应用,实现金的绿色无氰化提取,详细评述了置换沉淀法、吸附法、溶剂萃取法和电解沉积法等几种硫代硫酸盐浸出液中Au(S2O3)23-回收的主要方法,并就各方法的优缺点及存在问题进行了归纳总结。传统活性炭及介孔硅吸附剂对Au(S2O3)23-的亲和力弱,改性处理虽可在一定程度上提高其对Au(S2O3)23-的吸附能力,但处理工艺复杂、成本较高;树脂法可较好地富集浸出液中的Au(S2O3)23-,但该方法存在金络合离子洗脱困难,树脂价格昂贵、易中毒粉化等缺点。溶剂萃取法适用于高浓度浸金液,且该方法对pH等溶液环境要求较高,工艺复杂,成本高。置换沉淀法和电解沉积法可直接获得金单质,但这两种方法对浸出液中Au(S2O3)23-浓度有一定要求,且多组分浸出液中其他金属的共沉淀严重影响了金产品纯度。在上述回收方法中,吸附法因成本低廉、操作简单、吸附剂可循环使用等优点,最具工业应用前景,但现有吸附剂无法有效回收硫代硫酸盐浸出液中的Au(S2O3)23-,因此,开发新型高效的Au(S2O3)23-吸附剂,突破硫代硫酸盐浸金液中金络合离子难以回收的技术瓶颈,是未来硫代硫酸盐提金技术的主要发展方向。

Effect of mechanical activation on thiosulfate leaching of gold from complex sulfide concentrate

The use of mechanical activation to enhance gold recovery from a CuPbZn complex sulfide concentrate was investigated. The effects of milling time, ball size, sample to ball ratio and milling speed on thiosulfate leaching were studied. Under optimum conditions of milling time 1 h, ball size 20 mm, sample to ball ratio 1/15 and mill speed 600 r/min, nearly 78% of sample is amorphized, particle size decreases from d100=30 μm to d100=8 μm, specific surface area increases from 1.3 m2/g to 4.6 m2/g and gold recovery enhances from 17.4 % in non-activated sample to 73.26 %.