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Jage, C. R., & Zipper, C. E. (2000). Acid-mine drainage treatment using successive alkalinity-producing systems. Powell River Project research and education program reports.
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Eger, P., Melchert, G., & Wagner, J. (2000). Using passive treatment systems for mine closure – A good approach or a risky alternative? Min. Eng., 52(9), 78–83.
Abstract: In 1991, LTV Steel Mining decided to close an open-pit taconite mine in northeastern Minnesota using a passive-treatment approach consisting of limiting infiltration into the stockpiles and wetland treatment to remove metals. More than 50 Mt (55 million st) of sulfide-containing waste had been stockpiled adjacent to the mine during its 30 years of operation. Drainage from the stockpiles contained elevated levels of copper, nickel, cobalt and zinc. Nickel is the major trace metal in the drainages. Before the closure, the annual median concentrations ranged from 1.5 to 50 mg/L. Copper, cobalt and zinc are also present but they are generally less than 5% of the nickel values. Median pH levels range from 5 to 7.5, but most of the stockpile drainages have pH levels greater than 6.5. Based on the chemical composition of each stockpile, a cover material was selected. The higher the potential that a stockpile had to produce acid drainage, the lower the permeability of the capping material required. Covers ranged from overburden soil removed at the mine to a flexible plastic liner. Predictions of the reduction in infiltration ranged from 40% for the native soil to more than 90% for the plastic liner. Five constructed wetlands have been installed since 1992. They have removed 60% to 90% of the nickel in the drainages. Total capital costs for all the infiltration reduction and wetlands exceeded $6.5 million, but maintenance costs are less than 1% of those for an active treatment plant. Because mine-drainage problems can continue for more than 100 years, the lower annual operating costs should pay for the construction of the wetland-treatment systems within seven years.
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Carlson, L., & Kumpulainen, S. (2001). Retention of harmful elements by ochreous precipitates of iron. Tutkimusraportti Geologian Tutkimuskeskus, -(154), 30–33.
Abstract: The capability of soil fines to fix harmful elements, e.g. heavy metals and arsenic, depends on specific surface area and other characteristics, such as surface charge. In the pH-range typical of natural waters (pH 5,5-7,5), the surfaces of fine-grained silicate particles and manganese oxides are negatively charged; consequently cations, such as heavy metals, fix effectively to them. The iron oxide surfaces are usually positively charged and typically fix anions, such as sulphate and arsenate. Retention of anions is especially extensive to precipitates formed from acid mine drainage (pH 2,5-5,0). For example, precipitates found at Paroistenjarvi mine, Finland, contain more than 70 g/kg of arsenic (dry matter). Adsorbed anions, e.g. sulphate, enhance the capacity of precipitate to fix heavy metal cations in low-pH environments.
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Burnett, M., Skousen, J. G., Skousen, J. G., & Ziemkiewicz, P. F. (1996). Injection of limestone into underground mines for AMD control. In Acid mine drainage control and treatment. Morgantown: West Virginia University and the National Mine Land Reclamation Center.
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Brown, M., Barley, B., & Wood, H. (2002). Minewater treatment; technology, application and policy. London: IWA Publishing.
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