Method and system for preparing high-whiteness and high-purity aluminum hydroxide from high-silicon bauxite

Abstract

The invention relates to a method and system for preparing high-whiteness and high-purity aluminum hydroxide from high-silicon bauxite, and the preparation method comprises the following steps: firstly, taking a raw material crushed to process control fineness as a pre-powder material, carrying out raw material preparation and blank forming on the pre-powder material to obtain a blank, sintering the blank to obtain clinker, carrying out clinker dissolution on the clinker to obtain slurry, and carrying out drying on the slurry to obtain the high-whiteness and high-purity aluminum hydroxide. Carrying out slurry desilication, carbon component reaction, hydrogen-aluminum separation and drying on the slurry to prepare high-whiteness and high-purity aluminum hydroxide; wherein the raw materials comprise high-silicon bauxite, coal gangue, calcium-containing solid waste, pulverized coal and sodium carbonate; blank sintering refers to temperature programming roasting of the blank, and the roasting temperature ranges from 800 DEG C to 1100 DEG C. According to the method, the high-silicon bauxite, the solid wastes such as the coal gangue and the carbide slag, the pulverized coal and the sodium carbonate are crushed into materials with the same fineness, the high-whiteness and high-purity aluminum hydroxide can be obtained through alkali-method blank sintering, the recovery rate of aluminum in the solid wastes is about 85%, and low-cost resource development and utilization of the high-silicon bauxite are achieved.

Description

technical field [0001] The invention belongs to the technical field of resource development and utilization, and in particular relates to a method and system for preparing high-white and high-purity aluminum hydroxide from high-silicon bauxite. Background technique [0002] At present, the methods for extracting alumina from aluminum-containing mineral raw materials basically use bauxite as raw material, mainly including Bayer method, soda lime sintering method and mixed method. The Bayer method requires that the aluminum-silicon ratio in bauxite raw materials be greater than 9, which is only suitable for the development of gibbsite-type bauxite and boehmite-type bauxite with low silicon content. In my country's bauxite resources, high-alumina bauxite with an aluminum-silicon ratio greater than 9 only accounts for 18.6%, and most of them belong to high-silicon bauxite with an aluminum-silicon ratio of less than 7 or even less than 3. The soda lime sintering method requires ...

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Problems solved by technology

At present, the development and utilization of high-silicon bauxite resources in China is mainly to prepare white carbon black through pre-desilication process or to prepare refractory materials through high-temperature calcination process. However, these utilization methods are affected by factors such as low economic value of products and high energy consumption in the production process. impact, leading to restrictions on the development and utilization of high-silicon bauxite resources

[0003] Patent CN200910026426 uses high-silicon and low-aluminum mineral raw materials to produce aluminum hydroxide and cement process method, and proposes a process for preparing aluminum hydroxide by using high-silicon and low-aluminum minerals. , to realize the extraction of alumina from high-silicon and low-aluminum mineral raw materials, but the process is complicated, the energy consumption is high, and the production process produces more tailings, and the raw material powder-soda ash mixture powder is heated for soda ash fusion to obtain molten clinker , the rapid water quenching operation at high temperature is demanding, and there is a big safety risk

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