Synthesis of kryocide ionic liquid

Abstract

The invention provides cryolite ionic liquid with hydrofluoaluminic acid radical (AlF6 or AlF4) as anion, which is synthesized by dry or wet method and using aluminum hydroxide, aluminum fluoride, hydrogen fluoride, halogen as well as halogen ionic liquid as raw materials; wherein, in the dry method, anhydrous aluminum fluoride as well as villaumite ionic liquid are prepared firstly, and then the anhydrous aluminum fluoride is reacted with villaumite or villaumite ionic liquid to prepare the cryolite ionic liquid; in the wet method, aluminum hydroxide serosity or aluminum fluoride trihydrate is reacted with hydrofluoric acid to prepare hydrofluoaluminic acid firstly, and then the hydrofluoaluminic acid performs replacement reaction with halogen or halogen ionic liquid to generate the cryolite ionic liquid. The cryolite ionic liquid has excellent electric conductivity, thermal stability and electrochemical stability, has certain solubility towards aluminum oxide, and provides material basis for low temperature electrolytic aluminum research and production with aluminum oxide as the raw material.

Description

technical field [0001] The invention relates to the synthesis of a cryolite ionic liquid applicable to low-temperature electrolytic aluminum in the field of chemical, chemical and metallurgy. Background of the invention [0002] The production of primary aluminum in the modern aluminum industry still uses the Hall-Héroult method invented in the late 19th century, that is, the cryolite-alumina method. This method has been very mature after more than 100 years of development, but the energy consumption per ton of aluminum is still as high as 13,000 kWh, and the energy utilization rate is less than 50%. The reason why the energy utilization rate is generally not high is that the heat loss in the aluminum electrolysis process is unavoidable at high temperature (920-950°C). Therefore, an important method of saving energy and reducing consumption in the electrolytic aluminum industry is to reduce the electrolysis temperature. Scholars at home and abroad have proposed many improv...

AI Technical Summary

Problems solved by technology

There is also a low-temperature electrolytic aluminum method using aluminum trichloride as raw material and chloroaluminate-type ionic liquid as electrolyte. Although this method can greatly reduce the temperature of electrolytic aluminum to about 100 ° C, the expensive anhydrous trichloride Aluminum production costs make the process much less likely to be industrialized

At present, the ionic liquid low-temperature electrolytic aluminum system directly using alumina as raw material has not been reported in the literature