A Review on Characteristics and Alumina Extraction of Coal Gangue in China

Coal gangue is a solid waste produced in the process of coal production and processing, with a large accumulation. Under the background of national dual-carbon strategy, the comprehensive utilization of coal gangue attracts worldwide attention. The characteristics of the resources, composition and aluminum-containing components of gangue in China were analyzed. Furthermore, the technological progress of extracting alumina from coal gangue was summarized including the principle, technological process, and industrialization process of acid and alkali extraction of alumina, and the key problems constraining its industrialization were pointed out. It was proposed to accelerate the research and improve the environmental protection and efficient alumina extraction technology from coal gangue to promote the high-value utilization of coal gangue.