Alumina carbon mother liquid processing method

Abstract

The invention provides an alumina carbon mother liquid processing method, which relates to an alumina production process by a serial connection method or a sintering method. The invention is characterized in that the process comprises the following steps: (1) introducing carbon dioxide gas into the alumina carbon mother liquid so that all remained alumina can be separated out after the alumina carbon mother liquid is carbonated, and continuously introducing the carbon dioxide for converting the sodium carbonate in the carbon mother liquid into sodium bicarbonate; (2) adding the sodium carbonate into the over carbonated sodium bicarbonate solution so that the separation rate of the sodium bicarbonate reaches more than 90 percent; and (3) separating slurry after the separation of the sodium bicarbonate to obtain a mixture of the sodium bicarbonate, the aluminum hydroxide and the dawsonite with the attached water weight lower than 6 percent to be used for preparing raw material slurry. In the method of the invention, the carbon evaporation mother liquid with 220g / l sodium carbonate is converted into sodium bicarbonate crystals with the moisture content lower than 6 percent, the evaporation energy consumption is saved, in addition, the raw material moisture is reduced by 20 percent, and the energy consumption of the raw material sintering can be reduced by 40 percent.

Description

technical field [0001] The invention relates to a method for treating alumina carbon fraction mother liquor, which relates to a method for preparing raw slurry by crystallizing sodium carbonate from carbon fraction mother liquor in the production process of alumina by series method or sintering method. Background technique [0002] The series method and sintering method are effective processes for processing low-grade bauxite, but the high energy consumption of the sintering process limits its application and promotion. In order to greatly reduce the energy consumption of clinker sintering, alumina scientists have The development of preheating and drying technology outside the raw pulp kiln has been carried out, but because the alkali red mud slurry and carbon content mother liquor for preparing the raw pulp bring in a lot of water, reaching about 40%, this technology is also difficult to realize. If the sodium carbonate in the carbon separation mother liquor is crystallized...

AI Technical Summary

Problems solved by technology

[0002] The series method and sintering method are effective processes for processing low-grade bauxite, but the high energy consumption of the sintering process limits its application and promotion. In order to greatly reduce the energy consumption of clinker sintering, alumina scientists have The development of preheating and drying technology outside the raw pulp kiln has been carried out, but because the alkali red mud slurry and carbon content mother liquor in the preparation of raw pulp bring in a lot of water, reaching about 40%, it is difficult to realize this technology