"Tailings Dams hold millions of tonnes of dangerous metals and sometimes lead to severe damage to farms in nearby areas. Government accorss mining regions have passed the surface mining control and reclamation acts thus mine operators are required to meet environmental land reclamation performance standards established . Operators must also meet water quality standards.
Overview of Chemicals Available to Treat Acid Mine Drainage
The chemical choice depends on both technical and economic factors. Technical factors include acidity levels, flow, the types and concentrations of metals in the water, the rate and degree of chemical treatment needed, and the desired final water quality. The economic factors include prices of reagents, labor, machinery and equipment, the number of years that treatment will be needed, the interest rate, and risk factors.
Coagulants and flocculants are also used in water treatment where retention time in sedimentation ponds is insufficient for metal precipitation."