|
|
Rajaram, V. (2001). Methodology for estimating the costs of treatment of mine drainage. Proceedings of the Seventeenth International Mining Congress and Exhibition of Turkey, , 191–201.
Abstract: Tetra Tech developed worksheets for the U.S. Department of the Interior, Office of Surface Mining (OSM) to allow a consistent, accurate, and rapid method of estimating the costs of long-term treatment of mine drainage at coal mines, in accordance with the Surface Mining Control and Reclamation Act (SMCRA) of 1977. This paper describes the rationale for the worksheets and how they can be used to calculate costs for site-specific conditions. Decision trees for selection of alternative treatments for acidic or alkaline mine drainage are presented.
|
|
|
|
Swayze, G. A. (2000). Imaging spectroscopy: A new screening tool for mapping acidic mine waste. ICARD 2000, Vols I and II, Proceedings, , 1531–+.
Abstract: Imaging spectroscopy is a relatively new remote sensing tool that provides a rapid method to screen entire mining districts for potential sources of surface acid drainage. An imaging spectrometer known as the Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS) measures light reflected from the surface in 224 spectral channels from 0.4 – 2.5 mum. Spectral data from this instrument were used to evaluate mine waste at the California Gulch Superfund Site near Leadville, Colorado. Here, the process of pyrite oxidation at the surface produces acidic water that is gradually neutralized as it drains away from mine waste, depositing a central jarosite zone surrounded by a jarosite + goethite zone, in turn surrounded by a goethite zone with a discontinuous hematite rim zone. Leaching tests show that pH is most acidic in the jarosite and jarosite+goethite zones and is near-neutral in the goethite zone. Measurements indicate that metals leach from minerals and amorphous materials in the jarosite + goethite and jarosite zones at concentrations 10 – 50 times higher than from goethite zone minerals. Goethite zones that fully encircle mine waste may indicate some attenuation of leachate metals and thus reduced metal loading to streams. The potential for impact by acidic drainage is highest where streams intersect the jarosite and jarosite + goethite zones. In these areas, metal-rich acidic surface runoff may flow directly into streams. The U.S. Environmental Protection Agency estimates (U.S. EPA, 1998) that mineral maps made from AVIRIS data at Leadville have accelerated remediation efforts by two years and saved over $2 million in cleanup costs.
|
|
|
|
Campbell, A. (2000). Mitigation of acid rock drainage at the Summitville Mine Superfund Site, Colorado, USA. ICARD 2000, Vols I and II, Proceedings, , 1243–1250.
Abstract: Numerous techniques for treating, controlling, and preventing acid rock drainage have been applied at the Summitville Mine Superfund Site. Challenging aspects of the remote mine site include the wide-spread occurrence of acid-generating soils and rocks, extensive surface and underground mine workings, and a cold and wet climate. Water treatment was an immediate necessity when the Government took control of the abandoned site in December of 1992. Subsequent reclamation activities have emphasized prevention and control of ARD to minimize future water treatment requirements. A combination of conventional, innovative, and experimental methods are being applied to successfully mitigate ARD at Summitville.
|
|
|
|
McGregor, R. (2000). The use of an in-situ porous reactive wall to remediate a heavy metal plume. ICARD 2000, Vols I and II, Proceedings, , 1227–1232.
Abstract: The oxidation of sulfide minerals at an ore transfer location in Western Canada has resulted in widespread contamination of underlying soil and groundwater. The oxidation of sulfide minerals has released sulfate [SO4] and heavy metals including cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], and zinc [Zn] into the groundwater. A compost-based sulfate-reducing reactive wall was installed in the path of the plume in an attempt to reduce the potential impact of the heavy metals on a down-gradient marine inlet. Monitoring of the reactive wall over a 21-month period has shown that Cu concentrations decrease from over 4000 mug/L to less than 5 mug/L. Cadmium, Ni, Pb, and Zn concentrations also show similar decreases with treated concentrations generally being observed near or below detection limits.
|
|
|
|
Aube, B. C. (2000). Molybdenum treatment at Brenda Mines. ICARD 2000, Vols I and II, Proceedings, , 1113–1119.
Abstract: Brenda Mines, located 22 km Northwest of Peachland in British Columbia, Canada was an open pit copper-molybdenum mine which closed in 1990 after 20 years of operation. The primary concern in Brenda's tailings and waste rock drainage is molybdenum at a concentration of approximately 3 mg/L.. The mine drainage is alkaline and contains little or none of the typically problematic heavy metals. Given that the waters downstream are used for municipal water supply and some irrigation, a discharge limit of 0.25 mg/L molybdenum was imposed with specific water quality guidelines in the receiving creek. A. review of all existing and potential molybdenum removal methods was undertaken prior to mine closure. The chosen process is a two-step iron co-precipitation with clarification and sand filtration at a slightly acidic pH. A 4,000 usgpm (912 m(3)/h) treatment plant was constructed and commissioned in 1998, at a cost of $10.5M. The successful removal of molybdenum from the drainage water is explained with details on some design innovations and operational challenges encountered during plant start-up. Investigated sludge disposal options are discussed although the long term disposal scenario has not yet been finalised.
|
|
