Method for firing Bayer process alkali red mud with dry method

Abstract

The invention provides a method for firing Bayer process alkali red mud with a dry method.The method includes the following steps that alkali red mud, limestone powder, bauxite powder and sodium carbonate are prepared and fully mixed, the mixture is dried and enters a rotary kiln to be sintered, and then the mixture is levigated; regulation liquor is added into the levigated clinker powder for digestion, slag obtained after digestion is subjected to sufficient back washing 5-7 times, and then the slag is stacked; a solution obtained after digestion of the clinker powder and sodium aluminate crystals are mixed, desilicication is carried out after dissolution, aluminum hydroxide seed crystals are added into a solution obtained after desilicication for seed decomposition, and seed decomposition mother liquor is subjected to evaporation and salt elimination in two steps.For solving the problem that a large amount of alkali red mud is difficult to dispose, the alkali red mud dry method firing technology is proposed based on a traditional aluminum oxide sintering method; the whole seed decomposition technology is adopted, the technological process of the sintering method is shortened by 2 / 3 or above, the seed decomposition rate is increased to 90% or above through comprehensive calculation, operation difficulty is lowered, equipment and personnel input is reduced, and energy consumption is reduced.

Description

technical field [0001] The invention belongs to the field of industrial waste treatment, and in particular relates to a dry burning method of alkali red mud. Background technique [0002] The aluminum industry is the basic industry of our country, and the demand for bauxite in economic construction is very large, and most of our country is medium and low-grade bauxite. At present, more than 99% of my country's alumina production is produced by the Bayer process. With the declining trend of bauxite supply grade, the amount of alumina and sodium oxide abandoned in the red mud of the Bayer process is also increasing, resulting in Great waste of resources. On the other hand, because the quality of domestic bauxite is getting worse and higher, the price is getting higher and higher, and the cost of the Bayer process is also rising. In recent years, some enterprises have to import a large amount of bauxite from abroad. The foreign dependence of my country's bauxite aluminum resour...

AI Technical Summary

Problems solved by technology

[0003] Although over the years, some scientific research institutes and enterprises in our country have developed technologies such as series method and mixed method to utilize alkali red mud and improve the recovery rate of alumina and sodium oxide, but these two methods need to use the traditional sintering method. Wet sintering, which causes a series of problems such as complex and huge production system, increased infrastructure investment, high energy consumption, difficulty in control, poor product quality, etc., and the economy is not good, so it is gradually reduced or stopped.

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