OXIDATION OF PYRITE IN ALKALINE ENVIRONMENTS

摘要

Acid mine drainage (AMD) is a severe environmental pollution problem commonly related to sulfide-containing ore mining operations, such as pyrite oxidation in coal wastes and ore tailings. The need to prevent AMD formation has triggered numerous investigations into the mechanisms of pyrite oxidation and prevention; remediation often involves the addition of alkaline reagents. The faster pyrite oxidation rates found in carbonate systems in comparison with other alkaline systems have been reported by many groups, including ours. This effect may be due to the ability of the carbonate ion to form metastable complexes with ferric and ferrous ions in neutral-alkaline region. The formation of these complexes is discussed with the help of techniques, such as X-ray diffraction, diffuse reflectance spectroscopy and stability Eh-pH diagrams.