METHOD OF PROCESSING FLUOROCARBON-CONTAINING ALUMINIUM PRODUCTION WASTES Russian patent published in 2016 - IPC C22B7/00 

FIELD: technological processes; processing and recycling of wastes.

SUBSTANCE: invention relates to processing of fluorocarbon-containing wastes from production of aluminium by electrolysis of fused salts. Method includes high-temperature processing of wastes in presence of oxygen-containing gas to produce secondary raw material for aluminium production, processing of wastes is performed by gasification to obtain fuel of fluorine-containing synthetic gas and solid products of gasification. Content of carbon and carbon-containing substances in fluorocarbon-containing wastes is kept not less than 43 wt%. Fluorocarbon-containing aluminium production wastes used are waste carbon lining of electrolytic cells, ashes of burned anodes, dust of electrostatic precipitators, gas cleaning slurry, floatation tailings of coal froth electrolyte or a mixture of specified wastes in different combinations. Oxygen-containing gas used is a mixture of steam with air and/or oxygen. Processing of wastes can be performed by plasma arc gasification, including steam plasma, and obtained combustible fluorine-containing synthetic gas is used as a source of thermal energy in various technological processes of production of aluminium, in particular, for drying mixed cryolite, upon firing coke and anode units. Fluorine-containing compounds of synthesis gas or combustion products are caught at dry adsorption and/or wet absorption gas cleaning and returned to aluminium electrolysis, and solid products of gasification are processed into alumina or without processing are returned to aluminium electrolysis process.

EFFECT: reduced power consumption.

17 cl, 6 tbl, 1 dwg