钼矿尾矿铜铅重金属离子溶出规律研究

为了评估钼矿尾矿的环境危害,通过105 d连续静态浸泡试验,定期监测钼矿尾矿浸泡液的pH值及其铜铅重金属离子浓度,研究了尾矿的离子溶出规律.结果表明,尾矿对酸性溶液有很强的中和能力,可将pH=3.5～6的酸性溶液在8 d内中和到pH=7的中性状态,并维持不变.液固比为1:10的浸泡液中Cu~(2+)和Pb~(2+)的浓度都在25 d内达到最大值(分别为29.52和9.40μg/L),此后浓度下降,并发生震荡,但Cu~(2+)和Pb~(2+)的浓度随时间的变化趋势不同.浸泡液中Cu~(2+)和Pb~(2+)的平均浓度分别为19.37和4.29μg/L,尾矿中Cu和Pb的平均溶出率分别为0.097%和0.043%.钼矿尾矿可在中性条件下长期释放Cu~(2+)和Pb~(2+),且Cu比Pb更容易溶出.

Release of Heavy Metal Ion Copper and Lead of Molybdenum Mine Tailings

To evaluate and predict the environmental hazard from molybdenum mine tailings, the law of ion release of molybdenum mine tailings was investigated by continuous static soa-king experiments for 105 days and periodically monitoring the pH values and ionic concentra-tions of copper and lead in the soaking solutions. The molybdenum mine tailings shows strong ability to neutralize the acidic solutions of pH values of 3.5-6 to neutral state and then to maintain this state. In the case of mass ratio of solid/liquid of 1:10, the monitored ionic con-centrations of copper and lead in static soaking solutions reach their maximum values (i. e. 29.52 and 9.40 μg/L) within 25 days, and then they decline and keep oscillating with different variation trends for Cu~(2+) and Pb~(2+). The mean ionic concentrations of copper and lead are 19.37 and 4.29 μg/L, respectively. The released mass rates of copper and lead are 0. 097% and 0. 043%, respectively. Under neutral conditions the molybdenum mine tailings will release Cu~(2+) and Pb~(2+) in long term and copper is easier to release out of the tailings than lead.