Process for removing impurities in production of dry-method aluminum fluoride

Abstract

The invention provides a process for removing impurities in production of dry-method aluminum fluoride and belongs to the field of chemical engineering. A purifying system is used in the process; the purifying system comprises a gas inlet tube, a gas outlet tube, a purifying tower, a dust collecting device and a back-blowing device, wherein anhydrous hydrogen fluoride gas carrying a large amount of dust particles is generated by the reaction of fluorite and sulfuric acid in an acid making furnace and then enters the purifying tower through the gas inlet tube; the gas is filtered by film materials in the purifying tower and discharged by the gas outlet tube; and finally, the gas enters a fluidized bed to react with aluminum hydroxide to form the dry-method aluminum fluoride product, and in the impurity removing process, the product is blow-washed once every one to two hours by the back-blowing device, and the dust particles blown down are collected by the dust collecting device and then discharged from the bottom part of the purifying tower. The process has the advantages of low production cost, easy technological parameter control, convenient procedure operation, safety and environmental protection, industrialized continuous production and the like; and after the product of the dry-method aluminum fluoride undergoes the impurity removing process, the quality of the product of the dry-method aluminum fluoride meets all first-grade product indexes specified in national standards.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to an impurity removal process in dry aluminum fluoride production. Background technique [0002] As one of the important inorganic fluoride products, dry-process aluminum fluoride is mainly used in the aluminum smelting industry and is one of the main fluoride salt solvents for electrolytic aluminum production. In the prior art, the main production process of dry-process aluminum fluoride is as follows: first, fluorite and sulfuric acid are used to react in an acid furnace to produce hydrogen fluoride gas containing a large amount of dust, and then purified by sulfuric acid and then enter the fluidized bed and The dry dehydrated aluminum hydroxide is reacted to obtain the dry aluminum fluoride product. Due to the simple dry process and high reaction efficiency, this process has become the main development direction of aluminum fluoride production in my coun...

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Problems solved by technology

However, this method has the disadvantages of high energy consumption, easy to cause environmental pollution, and only one kind of silicon-containing dust particles can be removed.

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