Method for producing metal aluminium by high-alumina fly ash chlorination electrolysis

Abstract

The invention discloses a method for producing metal aluminium by high-alumina fly ash chlorination electrolysis, which comprises the following process steps: firstly, magnetic separation of fly ash to remove iron; secondly, fluidizing chlorination, that is, mixing high-alumina fly ash and oil coke powder, adding the mixture into a fluidizing chlorination furnace, introducing chlorine into the furnace to allow the alumina in the fly ash to react completely so as to obtain aluminium chloride double molecular flue gas; thirdly, processing and purification of the aluminium chloride flue gas, that is, purifying the aluminium chloride flue gas by a filter, cooling the purified aluminium chloride flue gas in a condenser to condense other chloride impurities, discharging the impurities out of the flow in a form of ash, continuing cooling the flue gas in a trap to obtain raw anhydrous aluminum chloride crystals, performing impurity removal and sublimation purification of the raw anhydrous aluminum chloride crystals by an aluminium chloride sublimation purification furnace; fourthly, molten salt electrolysis, that is, adding the anhydrous aluminum chloride into an aluminium chloride electrolytic tank, performing electrolysis to obtain aluminium liquid, casting the obtained aluminium liquid to prepare aluminum ingots. The process of the invention is used for processing high-alumina fly ash to obtain aluminum ingots, and fly ash is utilized reasonably.

Description

technical field [0001] The invention relates to a method for producing metal aluminum by chlorination and electrolysis of high-alumina fly ash. Background technique [0002] At present, the electrolytic aluminum industry in the world mainly uses alumina as raw material, and alumina (Al 2 o 3 ) and cryolite (3NaF·AlF 3 ) at a high temperature of more than 900 ° C to form a molten electrolyte to form a basic electrolyte component, which is electrolyzed in an electrolytic cell to obtain metal aluminum. [0003] Alumina production mainly uses bauxite as raw material and is produced by the Bayer process. Alumina has many uses, but most of it (more than 90%) is used as raw material for electrolytic aluminum plants to produce metal aluminum. [0004] my country is the world's largest producer of alumina and metallic aluminum. The output of alumina and electrolytic aluminum accounts for about 40% of the world's total output. However, my country's bauxite resources are poor, and t...

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Problems solved by technology

[0013] The technical problem to be solved by the present invention is to provide a method for producing metal aluminum by chlorination and electrolysis of high-aluminum fly ash, which can completely improve the existing production process of alumina and electrolytic aluminum, and simplify the process of producing aluminum from fly ash process, reduce engineering investment and production costs, and enable enterprises to have better economic benefits, so as to overcome the existing technologies such as huge lime dosage, large amount of red mud, low concentration of sodium aluminate solution, high production energy consumption, or solution It is difficult to remove iron and impurities, and the requirements for corrosion resistance of equipment and materials are high.

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