Acid neutralizing capacity minerals in Barani Pit PT Agincourt Resources Martabe, North Sumatera: alternative agent on neutralizing acid mine drainage

Acid Mine Drainage (AMD) is produced when sulfide-bearing material is exposed to oxygen and water. The mine may accelerate this natural reaction due to the wide and rapid exposure of sulfide minerals. Although economical ores are considered environmental pollutants, there are several elements that act as acid neutralizing capacity (ANC) mineral are associated with the ore, especially silicate minerals. Currently, PT Agincourt Resources Martabe has only relying on the use of carbonates mineral groups to handle the AMD issue. In fact, the geological condition in this area is formed of typically alumina-rich and alkaline minerals which are capable to neutralize the AMD as well. The aim of this study is to determine ANC minerals from the rock formations that has impact to neutralize the AMD in Barani Pit. The methods are geological field observation, mineral determination using spectral analysis, and assay analysis that provides data to sort the recommended ANC minerals. The ANC minerals from the rock formations and wastes within Barani Pit, other than calcite, are muscovite, illite, smectite, kaolinite, dickite and gypsum. The knowledge about these alternative ANC minerals might give contribution to reduce and solve the risk of acid mine drainage polluting the environment