Solid-Phase Speciation of Copper in Mine Wastes

Bulletin of the Korean chemical society

Jaebong Jeong¹ 

关键词: Lake Superior;    Copper;    Solid-phase speciation;    Mine tailings;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Ecosystems in the Keweenaw Peninsula region of Lake Superior, USA, were disturbed by over 500 milliontons of copper-rich mine tailings during the period 1850-1968. Metals leaching from these mine residues havehad dramatic effects on the ecosystems. Vast acreages of exposed tailings that are over 100 years old remainunvegetated because of the combination of metal toxicity, absence of nutrients, and temperature and waterstress. Therefore, it is important to characterize and fractionate solid copper phases for assessing labile formsof copper in soils and sediments contaminated by the mining wastes. X-ray diffraction analyses indicate thatcalcite, quartz, hematite, orthoclase, and sanidine minerals are present as major minerals, whereas cuprite,tenorite, malachite, and chalcopyrite might be present as copper minerals in the mining wastes. Sequential extraction technique revealed that carbonate and oxide fractions were the largest pools of copper (ca. 50-80%)in lakeshore and wetland stamp sands whereas the organic matter fraction was the largest reservoir (ca. 32%) in the lake sediments. The concentrations of iron and copper were inversely correlated in the oxide fraction suggesting that copper may occur as a surface coating on iron oxides. As particle size and water contents decrease, the percent of the copper bound to the labile carbonate fraction increases.

【 授权许可】

Unknown