Coal spoil, a by-product of coal mining, consists of more than 30 weight percent alumina. A large number of coal spoils, 7,000 million tons at present, remained un-used in China and thus caused serious environmental problems. Increased worldwide demand for aluminum oxide is leading to a gradual global decline of high-grade bauxite. Many aluminum-producing countries have become increasingly interested in looking for an alternative to bauxite. This research investigated the recovery of Al from coal spoil systematically.
http://pubs.acs.org/doi/abs/10.1021/es801798u
