METHOD OF SEPARATION OF THE FLUOHYDROGEN FROM THE WASTE GASES AT THE ALUMINIUM ELECTROLYSIS BYTHE DRY ADSORPTION OF THE ALUMINIUM OXIDE BY THE COMPLETE SEPARATION OF INJURIOUS COMPOUNDS

摘要

Hydrogen-fluoride-containing gases from the electrolytic production of aluminum are subjected to electrostatic precipitation to remove dust particles containing substances which are deleterious to aluminum production before the gases are treated in an expanded bed with alumina on which the hydrogen fluoride is adsorbed. Following the dry adsorption in the expanded bed, the gases entraining the adsorbent particles are subjected to electrostatic precipitation in which the particles are separated from the gas thus freed from hydrogen fluoride. The particles are recycled to the electrolytic aluminum production apparatus, the particles being free from the deleterious substances which have previously been removed.