GB1220501A - Potassium and cesium recovery process - Google Patents

Abstract

1,220,501. Recovery of caesium and potassium values. AMERICAN METAL CLIMAX Inc. 10 Jan., 1968 [1 Feb., 1967], No. 1429/68. Heading C1A. Caesium and potassium values are recovered from aqueous solution by contacting said solutions with a substituted hexanitrodiphenylamine salt dissolved in an organic solvent which is immiscible with water. Specified salts are the Li, Na, Mg, Ca, Sr and/or Ba salts. The substituted 2,4,6,2<SP>1</SP>,4<SP>1</SP>,6<SP>1</SP>-hexanitrodiphenylamine is one in which at least two hydrogen atoms on one of the phenyl rings of the amine are substituted; the substituents being alkyl, chloroalkyl, alkoxy or chloroalkoxy groups containing 1 to 8 carbon atoms. Dimethoxypicrylamine and tetramethoxypicrylamine salts are preferred extractants. The solvents specified are nitrobenzene, chloronitrobenzene, nitroxylene, nitrotoluene and mixtures of these. Nitrobenzene is preferred as it enhances the selectivity of the extractant for Cs and K. During the extraction the extractant salt is converted into the K and/ or Cs salt of the substituted dipicrylamine. By contacting said Cs and/or K salt(s) with a mineral acid (e.g. HCl, HNO 3 ), an aqueous solution of Cs and/or K mineral acid salt is produced (e.g. CsCl, KNO 3 ), and a solution of the free amine in an organic solvent is produced. The free amine may be converted back to the extractant salt by contacting the free amine with lime or dolomite. Recovery of the extractant and organic solvent can be improved by removing these from the product stream by contacting it with a stream of toluene.