关键词: 粉煤灰, 氧化铝, 铝土矿, 综合利用

Abstract: Coal fly ash，an industrial byproduct，is from coal combustion in fuel electric plant.It is the main source of solid waste.Meanwhile，it is a potential substitute for monohydrallite due to its high aluminum content.Extracting alumina from coal fly ash can reduce the pollution of the environmental caused by coal fly ash and relieve the shortage of monohydrallite resources.The necessity of extracting alumina from coal fly ash has been proven by summarizing the properties and danger of coal fly ash，status of bauxite resources，and utilization status of coal fly ash.Some extraction methods including limestone sintering method，ammonium sulfate sintering method，one-step acid digestion method as well as the merits and defects of their technology process and production condition were discussed specifically.The prospects for recovery of alumina from coal fly ash and correlated recommendations were also presented for the further study on comprehensive utilization of coal fly ash.

Key words: coal fly ash, alumina, monohydrallite, comprehensive utilization