The residues of salt lake brine from which potassium had been removed were used to extract Rb＋ and Cs＋ together with a sulphonated kerosene（SK） solution of 1.0 mol/L 4-tert-butyl-2-（α-methylbenzyl） phenol（t-BAMBP）. Rb＋ and Cs＋ were enriched and separated effectively by precipitating Mg2＋ before extraction and by scrubbing out K＋ and Na＋ repeatedly before stripping. The effects of the volume ratio of organic phase to aqueous extraction phase（O/A）, alkalinity of aqueous phase（c（OH）-）, interference from K＋ and Mg2＋, and ratio the volume of organic phase to aqueous scrubbing phase（O/A′） were investigated. The experimental brine was extracted optimally by 5-stage extraction with 1.0 mol/L t-BAMBP in SK, c（OH-）=1 mol/L, and O/A=1：1. The scrubbing yield of rubidium was only about 10.5% when the extraction solvent was washed 3 times with 1×10-4 mol/L Na OH at O/A′=1：0.5. After 5-stage countercurrent extraction, the final extraction yields of Rb＋ and Cs＋ reached 95.04% and 99.80%, respectively.
