|
Kuyucak, N. (2002). Acid mine drainage prevention and control options. CIM Bull., 95(1060), 96–102.
Abstract: Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. It occurs as a result of natural oxidation of sulphide minerals contained in mining wastes at operating and closed/decommissioned mine sites. AMD may adversely impact the surface water and groundwater quality and land use due to its typical low pH, high acidity and elevated concentrations of metals and sulphate content. Once it develops at a mine, its control can be difficult and expensive. If generation of AMD cannot be prevented, it must be collected and treated. Treatment of AMD usually costs more than control of AMD and may be required for many years after mining activities have ceased. Therefore, application of appropriate control methods to the site at the early stage of the mining would be beneficial. Although prevention of AMD is the most desirable option, a cost-effective prevention method is not yet available. The most effective method of control is to minimize penetration of air and water through the waste pile using a cover, either wet (water) or dry (soil), which is placed over the waste pile. Despite their high cost, these covers cannot always completely stop the oxidation process and generation of AMD. Application of more than one option might be required. Early diagnosis of the problem, identification of appropriate prevention/control measures and implementation of these methods to the site would reduce the potential risk of AMD generation. AMD prevention/control measures broadly include use of covers, control of the source, migration of AMD, and treatment. This paper provides an overview of AMD prevention and control options applicable for developing, operating and decommissioned mines.
|
|
|
Zinck, J. M., & Aube, B. C. (2000). Optimization of lime treatment processes. CIM Bull., 93(1043), 98–105.
Abstract: Lime neutralization technology is widely used in Canada for the treatment of acid mine drainage and other acidic effluents. In many locations, improvements to the lime neutralization process are necessary to achieve a maximum level of sludge densification and stability. Conventional lime neutralization technology effectively removes dissolved metals to below regulated limits. However, the metal hydroxide and gypsum sludge generated is voluminous and often contains less than 5% solids. Despite recent improvements in the lime neutralization technology, each year, more than 6 700 000 m3 of sludge are generated by treatment facilities operated by the Canadian mining industry. Because lime neutralization is still seen as the best available approach for some sites, sludge production and stability are expected to remain as issues in the near future. Several treatment parameters significantly impact operating costs, effluent quality, sludge production and the geochemical stability of the sludge. Studies conducted both at CANMET and NTC have shown that through minor modifications to the treatment process, plant operators can experience a reduction in operating costs, volume of sludge generated, metal release to the environment and liability. This paper discusses how modifications in plant operation and design can reduce treatment costs and liability associated with lime treatment.
|
|
|
Sanders, F., Rahe, J., Pastor, D., & Anderson, R. (1999). Wetlands treat mine runoff. Civil Engineering, 69(1), 53–55.
Abstract: In the late 1890s, silver, lead and zinc deposits were discovered along the headwaters of the Blackfoot River, northeast of Missoula, Mont. Settlers began mining the metals in earnest, and eventually the mines became known as the Upper Blackfoot Mining Complex (UBMC). Many of the mines were operated long enough to supply metals for World War II weaponry, but after the war the mines were abandoned, and by the 1960s, their orange-tainted runoff began to concern both passersby and state officials. In 1991, the state contacted the current owners of several of those mines-including the Mike Horse and the Anaconda-to negotiate a voluntary cleanup. The American Smelting and Refining Co. (ASARCO) and the Atlantic Richfield Co. (ARCO) agreed to remediate the sites' metal-enriched, moderately to severely acidic drainage, which was discharging into the upper Blackfoot River. As part of effort to reclaim the Mike Horse and Anaconda mines, engineers with McCulley, Frick and Gilman Inc. (MFG), Boulder, Colo., developed an integrated, passive wetland treatment system that will take several years to reach full treatment capacity in the high-elevation environment, but will last for decades. (Constructed and restored wetlands have also been part of the remediation of other UBMC mines, such as the Carbonate and Paymaster mines.) The Mike Horse and Anaconda system, designed to meet National Pollutant Discharge Elimination Systems (NPDES) restrictions, concentrates primarily on zinc and iron and, to a lesser extent, on copper, lead and other metals.
|
|
|
Wingenfelder, U., Hansen, C., Furrer, G., & Schulin, R. (2005). Removal of heavy metals from mine waters by natural zeolites. Environ Sci Technol, ES & T, 39(12), 4606–4613.
|
|
|
Banks, D., Younger, P. L., Arnesen, R. - T., Iversen, E. R., & Banks, S. B. (1997). Mine-water chemistry: The good, the bad and the ugly. Environ. Geol., 32(3), 157–174.
Abstract: Contaminative mine drainage waters have become one of the major hydrogeological and geochemical problems arising from mankind's intrusion into the geosphere. Mine drainage waters in Scandinavia and the United Kingdom are of three main types: (1) saline formation waters; (2) acidic, heavy-metal-containing, sulphate waters derived from pyrite oxidation, and (3) alkaline, hydrogen-sulphide-containing, heavy-metal-poor waters resulting from buffering reactions and/or sulphate reduction. Mine waters are not merely to be perceived as problems, they can be regarded as industrial or drinking water sources and have been used for sewage treatment, tanning and industrial metals extraction. Mine-water problems may be addressed by isolating the contaminant source, by suppressing the reactions releasing contaminants, or by active or passive water treatment. Innovative treatment techniques such as galvanic suppression, application of bactericides, neutralising or reducing agents (pulverised fly ash-based grouts, cattle manure, whey, brewers' yeast) require further research.
|
|