Improvements in or relating to the separation of bromine or iodine from solutions containing the same

Bromine or iodine is extracted from a solution thereof by contact with an anion exchange polystyrene resin in halide form, the halogen of the halide being the same as or stronger than the halogen being extracted. The resin may be a quaternary ammonium polystyrene. The resin may be regenerated by washing with an organic solvent for the halogen, e.g. alcohol or acetone, or with a solution of a compound reactive to the halogen, e.g. a solution of aniline or styrene in alcohol, of ethylene in ethylene dibromide, or an aqueous solution of sodium bisulphite or thiosulphate. The solution treated may be a 48% aqueous hydrogen bromide solution containing free bromine, a 30% aqueous hydrogen iodide solution containing free iodine, or sea water which has been acidified with sulphuric acid to produce a pH of 3,5 and then treated with chlorine to liberate free bromine.ALSO:Bromine or iodine is extracted from a solution thereof by contact with an anion exchange polystyrene resin in halide form, the halogen of the halide being the same as or stronger than the halogen being extracted. The resin may be a quaternary ammonium polystyrene. The resin may be regenerated by washing with a solution of a compound reactive to the halogen, e.g. a solution of aniline or styrene in alcohol or of ethylene in ethylene dibromide, when halogenation of the double bond takes place. The solution treated may be a 48% aqueous hydrogen bromide solution containing free bromine, a 30% aqueous hydrogen iodide solution containing free iodine, or sea water which has been acidified with sulphuric acid to produce a pH of 3.5 and then treated with chlorine to liberate free bromine.