Reducing Oxidation of Pyrite Through Selective Reclamation Practices.
Erickson PM; Kleinmann RLP; Campion PSA
Reclamation efforts concentrating on establishing vegetation frequently fail to control discharge of acid mine water from surface mines and coal refuse areas. A proposed method of combining control of acid drainage and establishment of vegetation is to use the plant- soil zone to produce a low-oxygen environment in the underlying pyritic material. Oxygen consumption by plant roots, soil biota and organic material decay, and oxygen diffusion barriers formed by fine- grained material provide potential means of limiting the oxygen available for pyrite oxidation. Detailed studies of field relationships among pyrite oxidation, reclamation treatments, and subsurface oxygen profiles were conducted at an experimental refuse area and an abandoned surface mine. Preliminary results from unreclaimed refuse areas indicated that significant oxygen concentrations were limited to the uppermost meter of material. A shallow, near-surface oxygenated zone was also found at the experimental refuse area in plots subjected to various reclamation treatments. Soil moisture sample ph values from the plots were generally consistent with pyrite oxidation being limited to the oxygenated zone. The effects of 13 reclamation treatments on subsurface oxygen and water quality profiles were investigated.
1982 Symp. on Surface Min. Hyd., Sediment. and Reclam., Lexington, Kentucky, Dec. 5-10, 1982, pp.97-102