【摘要】 暴露于氧化环境的废矿尾矿等含硫化物的固体废弃物,在风化作用下产生的酸性矿山废水是导致矿山周边生态环境污染的主要原因。目前国内外研究工作主要集中在富氧环境下尾矿的重金属释放迁移行为,较少有研究关注到缺氧环境下含硫化物尾矿的环境行为及潜在的金属污染风险。设计了黄铁矿尾矿的水封淋滤装置,研究缺氧状态下不同深度淋滤液电导率、溶解氧、氧化还原电位、p H的变化规律以及铊(Tl)等金属的释放能力。结果表明:水封处理方法能使体系处于缺氧环境,并抑制了黄铁矿尾矿氧化产生酸性排放,维持体系处于中性的还原状态;水封条件下不同金属的释放迁移行为出现两种相反的趋势,即尾矿中Tl、Pb、Cr、Al、Fe等金属的迁移活性被有效抑制,其释放量随溶解氧降低而减少;而Mn、As、Ni、Cu、Rb、Sr等金属的迁移活性随溶解氧的降低而增强,其中Mn、As等变价金属的迁移活性与释放浓度增加更明显;重金属Ni、Cu、Rb、Sr等非变价金属因铁锰氧化物的还原被大量释放到水环境中。综上,利用水封法处置尾矿能有效控制含硫化物的尾矿氧化产酸,抑制部分金属的释放,但不能抑制变价金属及以氧化物形式存在的金属的释放。更多还原

【Abstract】 Solid waste, such as sulfide tailings, is exposed to oxidizing environment. And the acid mine wastewater generated by solid waste in the weathering is the main cause for the surrounding mining ecological environment pollution. Current domestic and foreign research work has mainly focused on the release of heavy metals in the oxidation environment. The release of heavy metals in the anoxic environment, however, is less paid attention to the environmental behavior of sulfide tailings and the potential risk of metal pollution. A water seal device of pyrite tailings leaching is designed in this work to investigate the variation of anoxic condition in different depth of leachate conductivity, dissolved oxygen, redox potential, p H and the release ability of metal such as thallium(Tl). Our results show that this method can make the water treatment system in a hypoxic environment, and inhibit the oxidation of pyrite tailings to produce acid emissions, so that the system of the reduction state in neutral is maintained. The migration behavior of different metals under the condition of water seal has opposite trend, namely, the migration activity of Tl, Pb, Cr, Al, Fe in the tailings is suppressed effectively, and reduce its emissions with the reduction of dissolved oxygen. The migration activity of Mn, As, Ni, Cu, Rb, and Sr is increased with decrease of dissolved oxygen, while, the migration activity of Mn and As is increased more obviously with the increasing of the release concentration. Heavy metals of Cu, Rb, Ni, Sr are released into the aquatic environment due to reduction of iron and manganese oxides. To sum up, the water seal method can effectively control the disposal of tailings containing sulfide to produce acid oxidation, so that to inhibit the release of metals. But it could not inhibit the release of transition metals or the metal in the form of metal oxides.更多还原