Method for preparing and comprehensively utilizing aluminum oxide by pelletizing, chloridizing and electrolyzing bauxite

Abstract

The invention relates to a method for preparing and comprehensively utilizing aluminum oxide by pelletizing, chloridizing and electrolyzing bauxite. The method comprises the following steps: mixing bauxite, a carbon source and kaolin at a ratio; adding a binder and water, pelletizing and airing; chloridizing, separating and purifying, thereby obtaining anhydrous aluminum chloride, anhydrous ferric chloride, silicon tetrachloride, titanium tetrachloride, scandium chloride and gallium trichloride; converting anhydrous aluminum chloride and anhydrous ferric chloride into a corresponding chloride solution; controlling voltage and current density to electrolyze, thereby obtaining aluminum hydroxide, ferric hydroxide, hydrogen and chlorine; returning the chlorine to a chloridizing section; roasting aluminum hydroxide, thereby obtaining metallurgical/chemical aluminum oxide; roasting ferric hydroxide, thereby obtaining iron oxide red or other iron-containing products; purifying silicon tetrachloride; refining titanium tetrachloride, thereby obtaining a titanium sponge raw material; and enriching scandium chloride to serve as a scandium raw material. The method provided by the invention is low in cost, the raw materials are low-cost and are easily obtained, the complete chlorination is realized through pelletizing and chloridizing, the operation process is simple, the degree of automation is high, the product purity is high, and the raw materials, such as, chlorine and zinc, can be reused.

Description

Technical field: [0001] The invention belongs to the technical field of bauxite utilization, and in particular relates to a method for comprehensive utilization of bauxite balls by chlorination and electrolysis. Background technique: [0002] The vast majority of bauxite in my country (>95%) is diaspore type bauxite, and only the bauxite in some areas such as Hainan is gibbsite type, but it has not been used in industry so far. my country's bauxite is characterized by high aluminum, high silicon and low iron (a small number of exceptions), that is, high alumina content and high silicon oxide content, but relatively low aluminum silicon (mostly between 4-7), aluminum silicon High-quality bauxite resources with a ratio of more than 9 only account for 18.5% of the total reserves. The weighted average aluminum-silicon ratio of bauxite in more than 40 typical mining areas across the country is only about 6. Except for a few mining areas such as Guangxi, the iron oxide content...

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to provide a method for preparing alumina by chlorination and electrolysis of bauxite balls and its comprehensive utilization in view of the technical problems of long process, high energy consumption and inability to comprehensively utilize existing technologies. The purpose is to make bauxite into pellets through batching; the pellets can be chlorinated and separated to obtain anhydrous aluminum chloride, anhydrous ferric chloride, silicon tetrachloride, titanium tetrachloride, scandium chloride, chloride Gallium products; convert anhydrous aluminum chloride and ferric chloride into corresponding chloride solutions and directly electrolyze to obtain aluminum hydroxide, ferric hydroxide products, hydrogen products and chlorine gas; chlorine gas generated by electrolysis returns to the chlorination section; hydrogen oxidation Aluminum can be roasted to obtain metallurgical grade alumina or chemical alumina; ferric hydroxide can be calcined to obtain iron red or other iron-containing products; silicon tetrachloride can be further purified and reduced with high-purity zinc to prepare polysilicon, and the by-product zinc chloride can be electrolyzed Zinc and chlorine gas can be obtained, zinc cyclically reduces silicon tetrachloride, and chlorine gas returns to the chlorination section to realize the recycling of zinc and chlorine gas; titanium tetrachloride can be used as raw material for sponge titanium after being refined; scandium is enriched in chlorination slag, Can be used as scandium extraction raw material

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