湘中桃江锰矿废矿堆环境地球化学分析

对湘中桃江锰矿废矿堆的废石进行了主量元素、稀土元素、微量元素和重金属元素的地球化学分析。野外观察及分析结果表明:组成废矿堆的岩石主要是赋矿围岩中奥陶统黑色页岩和原生碳酸锰矿石。这些废石富含Cu、Pb、Zn、Cr、Tl、Sb、U等重金属元素。废石暴露地表而遭受风化分解,导致Sc、V、Cr、U、Cd、Th等重金属元素淋滤释出,在废石样品中均表现出不同程度的迁移特征,且以V、Cd、U的迁移性最为强烈。此外,黑色页岩中Ni、Cu、Zn、Pb、Tl、Sb也明显发生淋失。这些重金属元素如Cd、Tl等毒性极强,进入矿区周围不断积聚,便可能对环境造成严重的影响。故对区内分布的废矿堆作为重金属污染源应高度重视。

Environmental geochemistry of the waste rock dump in the Taojiang manganese deposit, Hunan, China

Major element, rare-earth element (REE), trace element and heavy metal geochemical analyses were performed on the waste rock dump of the Taojiang manganese deposit. Field observations and analysis indicate that the main materials of the waste rock dump are the host rock Middle Ordovician black shale and primary carbonate manganese ore. The waste rocks contain heavy metals such as Cu, Pb, Zn, Cr, Tl, Sb and U. They are subaerially exposed to weathering and disintegration, resulting in leaching and removal of Sc, V, Cr, U, Cd, Th and other heavy metallic elements. These elements show the features of migration to different degrees and, among these, V, Cd and U show the strongest mobility. Additionally, it is evident that Ni, Cu, Zn, Pb, Tl and Sb in black shale are also leached. These heavy metallic elements, such as Cd and Tl, have very strong toxicity. When they enter the mining area and are accumulated continuously, they can exert serious influence on the environment. So great attention should be paid to the waste rock dumps as the pollution sources of heavy metals distributed in the area.