关键词: 粉煤灰;氧化铝;二氧化硅;烧结;浸出

Abstract: Extracting alumina from fly ash can reduce the risk of environmental pollution , meanwhile it conform to the requirements of the country the development of circular economy .As an industrial solid waste fly ash also contains a large amount of aluminum resources , and the extraction of alumina from fly ash has attracted people's attention.The technical progresses of extracting alumina from fly ash were reviewed.According to the difference of treatment methods , the alumina extraction technologies can be divided into sintering and direct wet leaching processes .A lot of researches on sintering methods have been carried out , among which the three most important sintering methods are limestone sintering , alkali lime sintering and soda sintering , but most of them are only suitable for laboratory .There is great potential for wet acid leaching of fly ash .Hydrochloric acid leaching method has been successfully used in industry , but more research is needed in leaching process .Wet alkaline leaching of fly ash has not been applied and few laboratory studies have been conducted .Therefore , wet acid leaching of fly ash is an important research direction in the future .

Key words: fly ash;alumina;silicon dioxide;sintering;extraction