锑矿废渣模拟酸雨淋溶重金属Sb、As、Hg淋溶释放规律

为了全面系统地研究锑矿废渣中重金属的淋溶释放规律,以湖南省冷水江锡矿山锑矿的锑矿废渣为研究对象,通过对锑矿废渣的消解试验与半动态淋溶试验,测定锑矿废渣与淋溶液中重金属的含量,分析锑矿废渣淋溶液中Sb、As、Hg淋溶释放规律。结果表明:锑矿废渣中重金属含量较高,除Pb以外,其余重金属均超《土壤环境质量农用地土壤风险管控标准》(GB 15618—2018)的风险筛选值(pH≤5.5),重金属含量均超湖南省土壤背景值;锑矿冶炼渣在模拟酸雨淋溶下重金属析出浓度在第2～3天达到峰值,锑矿废石与锑矿尾砂淋溶一天后就达到峰值,锑矿废渣重金属累计析出量均为锑矿冶炼渣>锑矿尾砂>锑矿废石;锑矿废渣重金属的累计淋出量与模拟酸雨累计淋出量之间呈二次函数关系。

Release law of Sb, As, and Hg in antimony mine wastes under simulated acid rain

This paper takes the antimony mine wastes from Xikuangshan (XKS) Antimony Mine in Lengshuijiang City, Hunan Province as the research object, and studies the leaching and releasing regularity of heavy metals from antimony mine wastes comprehensively and systematically. The content of heavy metals in antimony mine wastes and leaching solution was determined through the digestion test and semi-dynamic leaching test, and the release regularity of Sb, As and Hg in antimony mine wastes leaching solution was analyzed. The results show that the concentration of heavy metals in antimony smelting slags is relatively high. Except Pb, the concentration of heavy metals in all the three kinds of antimony mine wastes exceeds the risk screening value of Standard for Risk Control of Soil Pollution in Agricultural Land of Soil Environmental Quality(GB 15618-2018); the concentration of Sb, As and Hg in antimony mine wastes exceeds the standard background value of soil in Hunan Province.The leaching concentration of Sb, As and Hg in antimony smelting slags reached the maximum in 2-3 days of simulated acid rain leaching, and the leaching concentration of Sb, As and Hg in antimony ore waste rocks and antimony ore tailings reached the maximum on the first day of leaching, the antimony mine wastes from which the amount of heavy metals can be precipitated from the most to the least is in the following order:Antimony smelting slags > antimony ore tailings > antimony ore wastes. There is a quadratic function relationship between the cumulative leaching amount of heavy metals from antimony mine wastes and the cumulative leaching amount of simulated acid rain. The experimental results will provide some theoretical support for the prevention and control of soil-groundwater pollution by antimony mine wastes.