Laboratory scale experiments were employed to investigate the feasibility of coal mine drainage neutralization treatment with the formation of magnetite and other high density/low volume sludges. Where applicable, the effects of bacterial catalysis on ferrous iron oxidation were incorporated into the the investigations. Major process types studied included magnetite formation, and high density sludge from lime treatment of acid mine drainage. Both acidic iron solutions and synthetic acid mine drainage were studied, primarily in batch process reaction systems, both with and without sludge recycle. Emphasis was placed on development of a basic understanding of the results observed, and interpretations draw heavily on both experimental results and an incisive literature review.