Assessment of coal mine water in Moatize by static and leaching tests

Acid mine drainage (AMD) is one of the most serious environmental problems in mining worldwide. One of the largest unexploited coal basins in the world is located in Moatize. It contains about 23 billion metric tonnes of coal. The coal mining there is done in riparian sections of the Zambezi River basin, making it particularly vulnerable to pollution. Much of the coal waste is produced by a number of multinational mining companies operating in the area. Accordingly, it was of clear interest to investigate the possibility that AMD was being generated there. Coal waste and pit water were collected randomly from different piles and pits in two mines in Moatize. Both static and kinetic tests were performed. It was found that AMD could be generated in one of the two mines that were studied. The mine drainage obtained from both coal mines was found to be of neutral pH and to have a high content of sulfates, calcium, magnesium, and manganese