China Nonferrous Metallurgy

China’s bauxite is highly dependent on foreign countries. Due to fly ash as an aluminum-rich product, how to recycle aluminum from fly ash is one of the hotspots in the aluminum and coal chemical industry. The development of aluminum extraction technology from fly ash is of great significance for improving the environment and realizing the optimal allocation of resources. The physical and chemical properties of fly ash from different places (Inner Mongolia, Shanxi, Anhui and Beijing) were analyzed, the technical progress of extracting alumina from fly ash was introduced, and the technological processes, principles and shortcomings of alkali method (alkali sintering method and alkali dissolution method), acid method (sulfuric acid leaching method, hydrochloric acid leaching method and ammonium bisulfate method), acid-alkali combination method and other methods (carbothermal reduction method, microwave assisted dissolution method and biological leaching method) were systematically summarized. The industrial production progress of aluminum oxide extraction from fly ash by some enterprises in China was investigated, and suggestions were put forward to develop more economical and efficient processes and further realize resource utilization of aluminum tailings and extraction of other valuable metals.