Dealkalization method of fly ash Al-extraction residues

Abstract

The invention discloses a dealkalization method of fly ash Al-extraction residues, comprising the following steps of: (1) adding water into the Al-extraction residues with stirring to prepare an Al-extraction residue slurry; (2) slowly adding calcium carbide slag into the Al-extraction residue slurry with stirring for a dealkalization reaction; (3) filtering the Al-extraction residue slurry which has undergone the dealkalization reaction, followed by washing to obtain the dealkalized Al-extraction residues. The invention is suitable for dealkalization of the Al-extraction residues by the fly ash alkali lime sintering method. After the dealkalization processing, the content of sodium oxide in the Al-extraction residues by the fly ash alkali lime sintering method is reduced from 1.3-2.0% to 0.4-0.6%, which can satisfy the requirement of mixing material addition material and cement clinker raw materials on the alkali content in the building material industry. The method provided by the invention has advantages of simple process, low energy consumption, less material consumption amount and low treatment cost, and is suitable for industrial popularization.

Description

technical field [0001] The invention relates to a comprehensive utilization technology of industrial solid waste, in particular to a dealkalization method of fly ash aluminum extraction residue Background technique [0002] With the increasing shortage of bauxite resources in our country, the use of fly ash, coal gangue and other industrial solid wastes to extract alumina has attracted more and more attention. For example, the Late Paleozoic coal seams and gangue in the Ordos Basin are rich in boehmite and kaolinite and other minerals, and the alumina content in the fly ash produced after combustion is as high as about 50%, which is comparable to that in medium-grade bauxite. The content is equivalent, and it is a very valuable raw material for alumina production. According to statistics, the potential reserves of high-aluminum fly ash in the central and western regions of Inner Mongolia are as high as 15 billion tons. With the increasing shortage of bauxite resources in o...

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Problems solved by technology

Although the treatment methods of the above two patents are relatively simple and the cost is relatively low, after the two methods are processed, the R in the red mud of the former 2 O (R stands for alkali metal elements, mainly Na and K) content is still as high as 0.9-1.1%, the latter is higher, which cannot meet the technical requirements of the building materials industry for alkali content

[0006] Although the chemical properties and composition of the aluminum extraction residue from fly ash soda-lime sintering are similar to those of red mud, its phase composition and the occurrence state of alkali metal elements are still quite different from those of pure red mud. There should also be some differences in the alkali mechanism and process methods. At present, there is no report on the dealkalization of similar aluminum extraction residues.

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