Effect of CO Partial Pressure on Extraction of Alumina from Coal Fly Ash During Carbothermal Reduction Process

Comprehensive utilization of coal fly ash is a promising industry with great environmental protection and resource recycling. Alumina extraction from coal fly ash usually produces a large amount of silicon-containing waste, which would have adverse effects on the environment. In order to reduce the production of silicon-containing slag, a new process of carbothermal reduction is proposed. Owing to the generation of CO in solid phase reaction, it is necessary to study the effect of CO partial pressure on the reaction. By changing argon gas flow rates, the effect of CO partial pressure on carbothermal reduction process is analyzed. Moreover, the experiments in vacuum furnace have been studied. The results show that the mullite phase in coal fly ash can be more easily decomposed with low CO partial pressure at the same reduction temperature. This paper provides a new sight for the industrial application of alumina extraction from coal fly ash.