A method of extracting aluminum oxide from fly ash

Abstract

The invention relates to a method of extracting aluminum oxide from coal ash and particularly relates to an integrated method for extracting aluminum oxide from a large quantity of coal ash discharged by an industrial solid waste coal-fired power plant and co-producing ultra clear glass and a calcium magnesium silicate material serving as a fireproof insulating material. The successfully developed method can thoroughly solve the problem that an ash storage field of the power plant occupies a large area and coal ash causes pollution, so that the comprehensive utilization ratio of coal ash is improved. The problem of resource shortage of bauxite is solved, so that safe supply of aluminum sources is effectively increased. The method solves the problems that extraction of aluminum from coal ash is high in cost, single type of product is generated, and secondary pollution is caused. The method solves the problem of rare raw materials for ultra clear glass production, so that the production cost of the ultra clear glass is greatly lowered.

Description

technical field [0001] This application relates to a method of extracting alumina from fly ash. In particular, it relates to an integrated method for extracting alumina from fly ash discharged from bulk industrial solid waste coal-fired power plants, and co-producing ultra-clear glass and magnesium-calcium silicate materials as refractory and thermal insulation materials. Background technique [0002] In China, fly ash is mainly high-aluminum fly ash, which is the main solid waste discharged from coal-fired power plants. The main oxide composition of fly ash is: SiO 2 、Al 2 o 3 , FeO, Fe 2 o 3 , CaO, TiO 2 etc., and associated impurity elements such as vanadium, lead, gallium, germanium, etc. Among them, more than 90% of the aluminum exists in the mullite-corundum crystal phase in the form of alumina and aluminosilicate, and the silicon oxide content is about 40%. [0003] At present, the methods for extracting alumina from fly ash mainly include acid and alkali proc...

AI Technical Summary

Problems solved by technology

Since the sintering method needs to add a large amount of lime to react at high temperature (>1150°C), the energy consumption is high, and the tailings are produced in a huge amount, causing serious secondary pollution problems

[0006] At present, the main purpose is to extract alumina from fly ash. The production process not only consumes a lot of energy, but also causes waste of resources of valuable elements in fly ash, causing secondary pollution problems.

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