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Beck, P. (2003). CL:AIRE – Providing support for remediation research. Land Contam. Reclam., 11(2), 99–104.
Abstract: CL:AIRE (Contaminated Land: Applications in Real Environments) is a public-private partnership which was established in 1999 to encourage the demonstration of remediation research and technologies on contaminated sites throughout the UK. Project proposals are submitted to CL:AIRE and reviewed and approved by the CL:AIRE Technology & Research Group. CL:AIRE provides independent verification of its projects and plays a crucial role in the dissemination of project information. During the course of the project, progress is reported through the newsletter, CL:AIRE view, which is mailed free of charge to a database of more than 4500 stakeholders with an interest in contaminated land. Progress is also tracked on the CL:AIRE website at www.claire.co.uk. On completion of the project, a project report is published and a one page summary fact sheet is prepared. The fact sheet is distributed to our database subscribers and posted on the website. The project is also presented at the CL:AIRE Annual Project Conference. In addition, aspects of the research which have practical application will be published as CL:AIRE Research Bulletins. Acid mine waters discharging from abandoned mines represent a significant environmental problem in many parts of the UK. Considerable research has been carried out to understand the geochemical process involved, and the knowledge has been used to manage groundwater discharge through physical/chemical treatment and constructed wetlands. CL:AIRE supports the development of a national site for wetland research managed by the University of Newcastle and will encourage collaborative research projects to be submitted through CL:AIRE. CL:AIRE is currently supporting two projects which demonstrate remediation of acid mine drainage and is disseminating the results of this and other research to improve confidence in the use of these techniques.
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Becker, G., Wade, S., Riggins, J. D., Cullen, T. B., Venn, C., & Hallen, C. P. (2005). Effect of Bast Mine treatment discharge on Big Mine Run AMD and Mahanoy Creek in the Western Middle Anthracite Field of Pennsylvania.
Abstract: The Bast Mine (reopened in 2001) and Big Mine are two anthracite coal mines near Ashland, PA, that were abandoned in the 1930's and that are now causing drastic and opposite effects on the water quality of the streams originating from them. To quantify these effects, multiple samples were taken at 5 different sites: 3 along Big Mine Run and 2 from Mahanoy Creek (1 upstream and 1 downstream of the confluence with Big Mine Run). At each site, one set of the samples was treated with nitric acid for metals survey, one set was acidified with sulfuric acid for nitrate preservation, one set was filtered for sulfate and phosphate tests, and one set was unaltered. Measurements of pH, TDS, dissolved oxygen, and temperature were made in the field. Alkalinity, acidity, hardness, nitrates, orthophosphates and sulfates were analyzed using Hach procedures. Selected metals (Fe, Ni, Mg, Ca, Cu, Zn, Hg, Pb) were analyzed utilizing flame atomic absorption spectroscopy. Drainage from the Bast Mine is actively treated with hydrated lime before the water is piped down to Big Mine Run. pH and alkalinity values were much higher at the outflow compared to those in the water with which it merged. The two waters could be visibly distinguished some distance downstream. pH values decreased, sulfate and dissolved iron increased and alkalinity was reduced to zero until the confluence with Mahanoy Creek. The high alkalinity, turbidity, TDS and calcium values in Mahanoy Creek were somewhat reduced downstream of the confluence with the much lower discharge Big Mine Run.
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Beers, W. F., Ciolkosz, E. J., & Kardos, L. T. (1974). Soil as a medium for the renovation of acid mine drainage water.
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Benner, S. G., Blowes, D. W., & Ptacek, C. J. (1997). A full-scale porous reactive wall for prevention of acid mine drainage. Ground Water Monitoring and Remediation, 17(4), 99–107.
Abstract: The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problem is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. Comparing water entering the wall to treated water existing the wall, sulfate concentrations decrease from 2400 to 4600 mg/L to 200 to 3600 mg/L; Fe concentration decrease from 250 to 1300 mg/L to 1.0 to 40 mg/L, pH increases from 5.8 to 7.0; and alkalinity (as CaCO<inf>3</inf>) increases from 0 to 50 mg/L to 600 to 2000 mg/L. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years.
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Benzaazoua, M., & Bussiere, B. (1999). Desulphurization of tailings with low neutralizing potential; kinetic study and flotation modeling. In D. Goldsack, N. Belzile, P. Yearwood, & G. Hall (Eds.), Sudbury '99; Mining and the environment II; conference proceedings.
Abstract: Environmental desulphurization is an attractive alternative for acid generating tailings management as demonstrated during the last few years. In fact, such process placed at the end of the primary treatment circuit allows to reduce greatly the amount of problematic tailings by concentrating the sulphidic fraction. Moreover, the desulphurized tailings (non-acid generating) have the geotechnical and environmental properties for being used as fine material in a cover with capillary barrier effects. To produce desulphurized tailings, non selective froth flotation is the most adapted method as shown in many previous works. Desulphurization level is fixed by tailings sulphur content (or sulphide content) and neutralization potential NP. The final residue should have enough NP to compensate for his acid generating potential AP. In this paper, the authors present the results of laboratory tests conducted in Denver cells for studying the sulphide flotation kinetics of four mine tailings which are characterized by a weak neutralization potential (under 37 kg CaCO (sub 3) /t). Tailings 1, 2, 3 and 4 contain respectively 5.27, 10, 4.25 and 16.9 sulphur Wt. %. Tailings 1 and 2 are cyanide free and are well floated at pH around 11 by using amyl xanthate as collector. Collector dosage was optimized for these tailings and the results show that Tailing 2 need more collector. However, Tailings 3 and 4, which come from a gold cyanidation process, could not provide good sulphide recovery with xanthate collector because of the pyrite depression. To overcome this problem, amine acetate was used successfully but induces important entrainment. The consumption of this collector was also optimized. The results of kinetic tests and collector dosage were combined and modeled to establish relationships which allow to estimate the desulphurization performances.
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