Department of Chemical Engineering and Geosciences, Luleå University of Technology, Luleå, Sweden.
Sci Total Environ. 2010 Feb 15;408(6):1386-92. doi: 10.1016/j.scitotenv.2009.11.005. Epub 2009 Nov 24.
Tailings containing pyrrhotite were deposited in an impoundment at a copper mine at Laver, Northern Sweden, which operated between 1936 and 1946. Since then the oxidation of sulphides has acidified recipient water courses and contaminated them with metals. Measurements from surface water sampled in 1993, 2001 and 2004-05 from a brook into which the tailing impoundment drains indicate that the amounts of sulphide-associated elements such as Cu, S and Zn released into the brook have decreased over time, while pH has increased. The mass transport of S in the brook during 1993 and 2001 corresponded well with the amount of S estimated to be released from the tailings by oxidation. Secondary precipitates such as covellite and gypsum, which can trap sulphur, were shown in earlier studies to be present in only low amounts. The annual release of elements from the tailings was estimated from the volume of tailings assumed to oxidise each year, which depends on movement of the oxidation front with time. The results indicate that the oxidation rate in the tailings has decreased over time, which may be due to the increased distance over which oxygen needs to diffuse to reach unoxidised sulphide grains, or their cores, in the tailings.
在瑞典北部拉弗的一座铜矿，曾于 1936 年至 1946 年期间开采含有磁黄铁矿的尾矿，并将其堆积在一个堤坝中。自那时起，硫化物的氧化作用使受纳水体酸化，并使其中金属元素含量超标。1993 年、2001 年和 2004-05 年期间，对一条从尾矿坝排水的小溪进行了地表水采样测量，结果表明，随着时间的推移，小溪中释放到溪流中的与硫化物相关的元素（如铜、硫和锌）的数量有所减少，而 pH 值有所增加。1993 年和 2001 年小溪中的硫质量迁移与估计的由尾矿氧化释放的硫量非常吻合。早期研究表明，次生沉淀（如蓝铜矿和石膏）的含量较低，这些沉淀可以捕获硫。尾矿中元素的年排放量是根据每年假定氧化的尾矿体积来估算的，这取决于氧化前沿随时间的推移而移动。结果表明，尾矿中的氧化速率随时间的推移而降低，这可能是由于氧气需要扩散到尾矿中未氧化的硫化物颗粒或其核心的距离增加所致。
