Patent ID: 6458333
Filing Date: 2002-10-01
Classification: C01D

Abstract:
A process for recovering alkali metal fluorides and/or difluorides from waste mixtures containing alkali metal chlorides and/or alkali metal fluorides and/or difluorides and, optionally, organic compounds, comprising(a) subjecting a waste mixture comprising one or more alkali metal chlorides and/or one or more alkali metal fluorides and/or difluorides and, optionally, one or more organic compounds, to a thermal/oxidative pre-treatment or a combination of a thermal/oxidative pre-treatment and an extractive pre-treatment, wherein the thermal/oxidative pre-treatment is carried out by heating the waste mixture in the presence of air or elemental oxygen at a temperature of from 400 to 1110Â° C. for from 10 sec. to 5 hours (b) bringing the pre-treated mixture into contact with hydrogen fluoride, and (c) recovering the resultant alkali metal fluorides and/or difluorides.