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CLEAN TAILING RECLAMATION: TAILING REPROCESSING FOR SULFIDE REMOVAL AND VEGETATION ESTABLISHMENT

This problem is further exacerbated by the presence of pyrite which oxidizes upon exposure to the atmosphere resulting in acid generation. Since pyrite was not recovered as a mineral of economic value during mining, it was disposed of in waste piles and tailing ponds which are now a source of acid generation and release of metals to the environment.

Tailing cleaning, or sulfide mineral recovery through reprocessing, was evaluated as an innovative reclamation technology. Tailing materials, from both operational and abandoned mines, were collected and evaluated to determine the feasibility of sulfide mineral recovery. Successful mineral separation was performed resulting in a low-volume metal sulfide concentrate and a high-volume cleaned silicate media.

Total and water soluble metal concentrations were decreased in the cleaned tailing material and elevated in the sulfide concentrate compared to the original tailing chemistry. Vegetation establishment in the cleaned media relative to growth in topsoil and lime amended tailings was measured and favorably demonstrates the potential for plant establishment and cost savings in contrast to conventional reclamation methods. A field demonstration of the technology is planned for the summer of 1997.

Key words: tailings, reclamation, heavy metals, recovery