SE379994

1332968 Hydrogen fluoride recovery IMPERIAL CHEMICAL INDUSTRIES Ltd 16 Feb 1972 [8 March 1971] 6269/71 Heading C1A Hydrogen fluoride is recovered from a gaseous mixture by passing the gaseous mixture through a mixture of an alkali metal fluoride (e.g. sodium fluoride) and an inert liquid (e.g. high boiling point aromatic compounds, esters, polyglycols, long chain carboxylic acids, mineral oils or mixtures thereof) at a temperature at which the hydrogen fluoride is absorbed and thereafter heating the so formed mixture to a temperature sufficient to liberate hydrogen fluoride. The alkali metal fluoride may comprise 1 to 50% by weight of the mixture with the liquid. The latter is preferably substantially immiscible in water and preferably does not appreciably dissolve the alkali metal fluoride.