Study of acid mine drainage production potential in flotation tailings of Sarcheshmeh porphyry copper mine

摘要

Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. Water infiltrating through the metal sulfide minerals, effluents of mineral processing plants, and seepage from tailing dams becomes acidic, and this acidic nature of the solution allows the metals to be transported in their most soluble form. To predict, prevention and treatment of AMD, wastes, and tailing are subjected to series of evaluations that more include the following: mineralogical and textural evaluation studies, static tests that evaluate the balance between acid generation potential and acid neutralizing capacity and kinetic testing that involve site or laboratory tests which describe the weathering, relative potentials for acid production neutralization, sulfide mineral oxidation rates, potential for metal release, and the effectiveness of control techniques. Sarcheshmeh copper mine in Kerman, Iran, has the most important copper concentration plants in Iran. The plant processes more than 40,000 t of copper feeds and rejects about 39,000 t of tailings containing sulfide minerals such as pyrite. AMD is formed by the oxidation of metal sulfides, mainly pyrite and marcasite, which have been exposed to air and water during and following mining operations. With regard to AMD generation possibility, studies related to the AMD problem were carried out. These evaluations were included site geology study, mineralogical studies, paste pH and modified acid-base accounting (ABA) static tests, and modified humidity cell tests. According to the results, it was demonstrated that long dryness cycles in Kerman result to pyrite weathering and production of AMD.