Alkali-type dissolving method of carbon powder in electrolytic aluminum scraps

Abstract

The invention discloses an alkali-type dissolving method of carbon powder in electrolytic aluminum scraps, characterized by comprising the following steps: crushing electrolytic aluminum scraps in a wet type, floating and magnetically separating to remove iron and silicon and obtain carbon powder A; putting the carbon powder A in an alkali solution to dissolve; dissolving fluoride in the carbon powder A; and then, adding carbon dioxide to separate out cryolite B. The invention adopts the technical scheme that the theory that fluoride has a certain solubility in caustic soda is utilized to design an alkali-method process, i.e. carbon powder primarily separated at normal pressure is dissolved in an alkali type, and CO2 generated in the product-drying process is utilized to carbonize so as to separate out the cryolite. Tested by the proposer to the product, high-purity cryolite achieving the national standard can be obtained. Iron and silicon in the carbon powder can be eliminated by the secondary floatation of the carbon powder because the fluoride carrier is damaged, and the processed carbon powder (with 1-2 percent of ash content) can reach a high-purity carbon powder level.

Description

technical field [0001] The invention relates to an alkaline dissolution method of carbon powder in electrolytic aluminum waste, belonging to the technical field of electrolytic aluminum waste recovery. Background technique [0002] Electrolytic aluminum waste includes: alumina dirt and pallet materials mainly composed of fluorine-containing alumina; fire eye carbon slag mainly composed of fluoride salts; anode ash and cathode blocks mainly composed of carbon-containing materials, due to electrolytic aluminum waste The complex components make it very difficult to separate, purify, and synthesize waste materials; for a long time, traditional aluminum industry giants such as the United States, Japan, and Germany, as well as large domestic state-owned aluminum factories such as Guizhou, Xining, Fushun, etc., have all dealt with electrolytic aluminum waste A lot of research has been carried out, but due to the inability to break through the relevant technical bottlenecks, an effe...

AI Technical Summary

Problems solved by technology

However, the separated carbon powder mainly contains iron, silicon, 6%-12% cryolite (Na 3 AlF 6 ), iron and silicon must be removed as harmful impurities, cryolite (Na 3 AlF 6 ) is a reusable product. If it cannot be separated and purified, it cannot meet the requirements of industrial applications. It can only be sold as a general combustion aid, and its market value is very low.