SEPARATION OF SOLVENT IN RAFFINATE AND/OR BACK EXTRACTION LIQUID IN SOLVENT EXTRACTION METHOD

摘要

PURPOSE:To recover easily solvent in a high yield by washing the raffinate after extraction of the solvent with carbon tetrachloride. CONSTITUTION:The raffinate obtd. by subjecting an aq. soln. to be treated to an extraction treatment using TBP, etc. as a solvent is washed by CCl4. The solvent-contg. CCl4 is then separated from the raffinate and is distilled under an atmospheric pressure or reduced pressure whereby the solvent and the CCl4 are fractionated. The distillation residue obtd. after removal of CCl4 is further fed to a refining stage according to need where the residue is fractionated to pure CCl4 and a pure solvent. The solvent is thus quickly and efficiently recovered.