High Value-added Utilization of Coal-Related Solid Wastes

Dr. Li Hui Quan, a researcher at Chongqing University recently presented at the recent Coal Ash Asia conference in Beijing, China from July 21-24, 2017. The following is the fully translated abstract of their research. For more information, or to contact this researcher please contact the team at Asian Coal Ash Association.

Thermal power generation is an important component of Chinese energy. Shanxi and Inner Mongolia are regarded as the most important energy bases of China. Large amounts of coal gangue, fly ash, desulfurization gypsum and waste denitration catalyst emerge during the processes of coal mining and coal to electricity conversions. This causes terrible environmental problems due to the low waste utilization ratio. Many metal elements such as Al, Li and Ga, enrich coal-related solid wastes. Our team proposes a theoretical system of the mild separation of active components, the coordinated control of mineral structure and the step by step extraction of associated elements.

We found key technologies of the mild activation by proton acid and deep desilication of silicon, the extraction of alumina by sub-molten salt, the selective adsorption and separation of rare metals, and the directional conversion of silicon resources. The technical system of utilizing alumina & silicon, the step by step extraction of associated elements and the clean recycling & carrier generation of waste denitration catalyst are established. A 3000 tons / annual experimental production line of Al-Si composite from high-alumina fly ash by deep desilication process has been built. The Al-Si composite can replace 80 Bauxite sinter. The establishment of this technical system should be standard practice for the new recycling economy pattern of energy output; low emissions and material preparation, forming green, intelligent and cyclic factories with high resources and ecology amalgamation.