碳酸盐岩地区铅锌矿山水系中铅、锌、铜的迁移及其硫同位素示踪  

THE MIGRATION OF LEAD, ZINC AND COPPER IN Pb-Zn MINING WASTE WATERS AND SULFUR ISOTOPE AS A TRACER

作　　者：张国平[1] 刘丛强[1] 杨元根[1] 吴攀[1] 

机构地区：[1]中国科学院地球化学研究所,贵州贵阳550002

出　　处：《矿物学报》2002年第3期249-254,共6页Acta Mineralogica Sinica

基　　金：中国科学院知识创新工程项目 (KZCX2 10 5 )

摘　　要：铅锌矿的开采使含有铅锌等有害物质的尾矿暴露于地表 ,这些有害物质通过风化淋滤进入地表水 ,并影响下游水系 ,但碳酸盐岩对重金属的迁移有抑制作用。本文对典型的碳酸盐岩地区———贵州省杉树林铅锌矿下游的河水和沉积物进行了研究 ,发现水中重金属只是在尾矿堆附近的水体含量高 ,随着离矿山的距离增大 ,含量迅速降低。沉积物铅锌含量在所研究河段一直很高。硫同位素研究表明 ,沉积物硫主要来源于尾矿中硫化物 ,到下游则有其他硫源 (如土壤硫、支流悬浮物硫 )的加入。本区大气降水及泉水的 (3 4 S都较低 ,分别为 -3 .83‰和 +5 .5 0‰ ,而干流水的 (3 4 S一直保持在 +1 0‰左右 ,不受矿山影响的支流水 (3 4 S也高至 +9.76‰。这说明水中硫不仅来源于矿山物质 ,还可能来源于石膏盐层。本区沉积物的重金属含量、硫含量和硫同位素值对矿山物质的影响有很好的指示作用 ;而本区水中重金属含量由于受到吸附作用的影响 ,水的硫含量及同位素值由于受到煤及石膏盐层的影响 ,可能不适合用来示踪矿山物质的影响。The exploitation of mines generated mine tailings, which were piled on the ground and exposed to atmospheric conditions. The mine tailings can be a long term source of contamination. Previous studies showed that the migration of heavy metals can be mitigated by carbonate rocks, so in this research, we investigated heavy metal and sulfur isotope characteristics of the downstream river by the Shanshulin Pb Zn mine, which is located in Guizhou Province, a typical carbonate area in the world. The result shows that heavy metals in water decrease more quickly than in sediments. In contrast, sediments 30 km downstream still have high Pb and Zn contents. Sulfur characteristics indicate that in sediments close to the pile sulfur is mainly from mine tailings, whereas in sediments downstream it is also from other sources like soil and suspended matter in tributaries. Rain water and spring water do not have high δ 34 S values (only -3.83‰ and +5 50‰ , respectively). However, water of the main stem has a high δ 34 S value around +10‰, and a tributary also has a similar δ 34 S value of +9.76‰. It seems that gypsum layer (δ 34 S = +20‰) in this area is also a source of sulfur in water and contributes to the high δ 34 S values of water. In conclusion, the environmental impact of mine tailings can be indicated by heavy metal and sulfur contents and sulfur isotopes of sediments. Whereas, heavy metal and sulfur contents or sulfur isotopes of water are possibly not good indicators for mine impact due to mitigation of carbonate rocks, sorption of heavy metals, as well as interference of gypsum layers.

关 键 词：碳酸盐岩 重金属 硫同位素 铅锌矿床 淋滤作用 迁移 吸附作用 

分 类 号：P618.42[天文地球—矿床学] P618.43[天文地球—地质学]