The preparation of alumina from fly ash is the hot topic of resource comprehensive utilization of fly ash.At present, the reported from the comprehensive utilization technology are mainly alkaline,acid and alkali.Specific include:limestone calcination method,alkali roasting method, pre desilication alkali
lime roasting method,soda roasting method,ammonium sulfate roasting method,acid leaching,acid and alkali,etc.Some units also try the industrialization
of the production of alumina from fly ash, but die on the vine.This situation caused by two reasons,first,the metallurgical grade alumina price is not high, low
alumina content in the fly ash,high cost in the extraction process,less output,least profitable for investors,second is the process almost exist the problem of the
large amount of waste residue,against the principle of producing pollution,unable to solve the problem of impact on the environment.
Aiming at the shortage of existing comprehensive utilization technology of fly ash in China,to seek a pathway of low-cost,high-yield,non-polluting,can realize
the full elements in fly ash utilization of valuable components.Nanyang Oriental Application Chemical Research Institute set up the project and carried out the
research of fly ash utilization of new technology in 2013,after two years efforts,successfully developed by the preparation of fly ash high dispersibility
tire special white carbon black,nano-scale ultra thin white carbon black,cryolite,high purity alumina,new technology of high purity iron oxide,iron
oxide red industrial pigment.In February and April 2015,respectively through the test research and industria production validation.Practice shows that,the
developed process has a high level of comprehensive utilization of resources,products with high added value,low cost,remarkable benefit,complete
waste treatment,small impact on the environment,it’s a mature and reliable technology.In the process,product structure and product direction is a major
breakthrough in the comprehensive utilization technology of our country existing fly ash.For resources,China's fine fly ash,high added value utilization brings new
vitality.