Novel red mud comprehensive utilization method

Abstract

The invention discloses a novel red mud comprehensive utilization method which includes the steps: a drying and crushing red mud, uniformly mixing the red mud with hydrochloric acid, performing boiling reaction for 1-3 hours under normal pressure and filtering mixture to obtain first filtrate and first filter residues; b adding calcium hydroxide solution into the first filtrate, adjusting the first filtrate to be neutral, then filtering the first filtrate to obtain aluminum hydroxide coarse residues and second filtrate, and concentrating and crystallizing the second filtrate to successively generate sodium chloride and calcium chloride; c washing the first filter residues to be neutral, adding sodium hydroxide solution, performing boiling reaction for 2-8 hours under the normal pressure, and performing filtering separation after reaction to obtain third filtrate and second filter residues; d adding sodium hydroxide solution into the third filtrate, adjusting the mole ratio of sodium oxide and silicon dioxide in mixed solution to be 1-3, transferring the mixed solution into a crystallizing pond and performing standing to obtain sodium metasilicate nonahydrate. The red mud is treated by acid and alkali to produce various products such as crude aluminum hydroxide, the sodium chloride, the calcium chloride and the sodium metasilicate nonahydrate, and the method is low in cost and less in energy consumption.

Description

technical field [0001] The invention relates to a new method for comprehensive utilization of red mud, which belongs to the field of comprehensive utilization of waste residues. Background technique [0002] Red mud is the waste residue discharged when the aluminum industry extracts alumina. According to statistics, the annual production of red mud in the world is about 70 million tons, and the annual production of red mud in my country is more than 30 million tons. A large amount of red mud cannot be fully and effectively utilized, and can only be stacked in a large area of ​​storage yard, which occupies a large amount of land and causes serious pollution to the environment. The production of a large amount of red mud has caused direct and indirect impacts on human production and life in many aspects. Therefore, it is imminent to reduce the output and harm of red mud to the greatest extent and realize multi-channel and large-scale resource utilization. [0003] The mineral...

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Problems solved by technology

But after all, the amount used is not high, and a large amount of red mud has not been effectively treated

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