Dry-process firing method of bauxite with low aluminum-silicon ratio

Abstract

The invention provides a dry-process firing method of bauxite with low aluminum-silicon ratio. The method comprises the following steps: dosing and mixing the limestone powder, bauxite powder, sodium carbonate and evaporation-return recycled alkaline solution; sintering in a rotary kiln; cooling the sintered clinker and levigating; adding adjustment liquid into the clinker powder for dissolving out; performing reverse sufficient washing of the slag dissolved out of the clinker powder for 5-7 times, wherein the washing liquid is used as adjustment liquid while the slag is piled; mixing the solution dissolved out of the clinker powder with sodium aluminate crystal for dissolution, and desiliconizing; performing seed decomposition; and performing evaporation and salt elimination of the seed mother liquor by two steps. In the method provided by the invention, for the bauxite with low aluminum-silicon ratio, the sintering raw material is combined with appropriate limestone and sodium carbonate so that the sintered clinker powder can be effectively leached; the dry-process firing conditions are controlled so that the technological process of the sintering process is shortened by over one third, the seed composition rate is improved by 90% or over, and the total recovery rate of aluminum oxide is 90% or over.

Description

technical field [0001] The invention belongs to the field of preparing alumina from aluminum-containing ore, and in particular relates to a dry firing method for bauxite. 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 al...

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 parallel method and mixed method to utilize bauxite 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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