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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.
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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.
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Reisinger, R. W., & Gusek, J. (1999). Mitigation of water contamination at the historic Ferris-Haggarty Mine, Wyoming. Min. Eng., 51(8), 49–53.
Abstract: An historic underground copper mine in Wyoming is discharging neutral but copper-laden water into a pristine creek. The EPA-deferred site qualifies for reclamation by the Wyoming Abandoned Mine Land (AML) program. The cleanup goal is to restore the discharge so that the creek can eventually support a trout fishery. Hydrological and geochemical investigations underground have suggested two sources of mine water: one clean and the other containing copper. Results of bench- and pilot-scale tests support the viability of using low-cost passive treatment techniques to reduce copper concentrations in the near-freezing mine discharge.
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Wolkersdorfer, C. (2002). Mine water tracing. Geological Society Special Publication, -(198), 47–60.
Abstract: This paper describes how tracer tests can be used in flooded underground mines to evaluate the hydrodynamic conditions or reliability of dams. Mine water tracer tests are conducted in order to evaluate the flow paths of seepage water, connections from the surface to the mine, and to support remediation plans for abandoned and flooded underground mines. There are only a few descriptions of successful tracer tests in the literature, and experience with mine water tracing is limited. Potential tracers are restricted due to the complicated chemical composition or low pH mine waters. A new injection and sampling method ('LydiA'-technique) overcomes some of the problems in mine water tracing. A successful tracer test from the Harz Mountains in Germany with Lycopodium clavatum, microspheres and sodium chloride is described, and the results of 29 mine water tracer tests indicate mean flow velocities of between 0.3 and 1.7 m min-1.
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Hulshof, A. H. M., Blowes, D. W., & Douglas Gould, W. (2006). Evaluation of in situ layers for treatment of acid mine drainage: A field comparison. Water Res, 40(9), 1816–1826.
Abstract: Reactive treatment layers, containing labile organic carbon, were evaluated to determine their ability to promote sulfate reduction and metal sulfide precipitation within a tailings impoundment, thereby treating tailings effluent prior to discharge. Organic carbon materials, including woodchips and pulp waste, were mixed with the upper meter of tailings in two separate test cells, a third control cell contained only tailings. In the woodchip cell sulfate reduction rates were 500 mg L-1 a-1, (5.2 mmol L-1 a-1) this was coupled with the gradual removal of 350 mg L-1 Zn (5.4 mmol L-1). Decreased δ13CDIC values from -3‰ to as low as -12‰ indicated that sulfate reduction was coupled with organic carbon oxidation. In the pulp waste cell the most dramatic change was observed near the interface between the pulp waste amended tailings and the underlying undisturbed tailings. Sulfate reduction rates were 5000 mg L-1 a-1 (52 mmol L-1 a-1), Fe concentrations decreased by 80–99.5% (148 mmol L-1) and Zn was consistently <5 mg L-1. Rates of sulfate reduction and metal removal decreased as the pore water migrated upward into the shallower tailings. Increased rates of sulfate reduction in the pulp waste cell were consistent with decreased δ13CDIC values, to as low as -22‰, and increased populations of sulfate reducing bacteria. Lower concentrations of the nutrients, phosphorus, organic carbon and nitrogen in the woodchip material contribute to the lower sulfate reduction rates observed in the woodchip cell.
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