富镉铅锌矿山的环境影响——以贵州都匀牛角塘矿床为例

矿床的开采和选冶,常常将其中重金属有毒元素释放到环境中,铅锌矿造成的环境污染尤为严重。贵州都匀牛角塘矿床是国内外少见的富镉锌矿床,其中镉高度富集。本文通过对通过对矿区水、土壤及植物的分析和调查,发现其中镉和锌均已远远超过国家标准,矿区周围环境已受到严重污染。研究表明矿床的表生风化作用是镉等重金属释放的主要途径之一,更重要的是矿山的采矿和选矿更加剧了其释放量,虽在目前人群中没有明显中毒现象,可能是由于矿床开采时间较短,Cd等重金属元素在人体中积累不多所致。但矿山环境污染是污染元素长期积累造成的结果,即使在矿山关闭十年、上百年甚至上千年时间内,矿山尾矿淋滤液对环境生态的影响依然存在。因此,在矿山开发过程中必须注意矿床中有用元素的综合利用和重视环境保护,防患于未然。特别是对这类富含有毒污染元素的金属矿山的开采更应如此。

THE ENVIRONMENTAL IMPACT OF CADMIUM-RICH PB-ZN DEPOSIT FOR THE EXAMPLE OF NIUJIAOTANG CD RICH ZNIC DEPOSIT, DUYUN, GUIZHOU, CHINA

Heavy metal toxic elements were usually released to circumferential environment during the activities of exploitation, ore cleaning mine and smelting in mine, especially for Pb-Zn mine. The content of Cadmium is abnormally high in Niujiaotang Cadmium-rich zinc deposit, Dunyun, Guizhou province, China, which is infrequent in world. By study on water, soil and plants in ore area, in which the content of Cd and Zn are greatly high than Chinese standard, it shows that circumferential environment in ore area has been polluting. It was proved that supergene weathering is one of main ways of releasing heavy metal toxic elements of Cd et al. , and it is more important that exploitation, ore cleaning mine and smelting of mine aggravate their released amount of heavy metals. Though there are not evident poisoning symptom in human, this is probably results from that time of mining is too short leading in accumulation of heavy metals is less body. However, the mine environment is a long-time problem. Even though mine was closed for ten years, several hundred years, even thousand years, it is still exist that solutions which come form tail ore weathering-leaching , impact environment. Therefore, in process of mine development, it should be attached importance to the synthetic utilization of elements and environmental protection in order to early prevent pollution, especially for those toxic elements-rich metal deposits.