摘要：This work shows the extraction of cesium (Cs^+) and rubidium (Rb^+) from salt lake brine containing potassium (K^+) and magnesium (Mg^2+). The results show that 4-tert-butyl-2-(α-methylbenzyl) phenol ( t -BAMBP) diluted in sulfonated kerosene (SK) has an excellent extraction effect. Infrared spectroscopic studies indicate that polymerize to form the dimer in the t -BAMBP when Cs^+ or Rb^+ were extracted. The effects of K^+, Mg^2+, t -BAMBP concentration, the volume ratio of organic phase to aqueous phase (O/A) and the alkalinity (pH) of aqueous phase were investigated. The K^+ and Mg^2+ should be eliminated through precipitating before the extraction and separation of Cs^+ and Rb^+.The optimum extraction conditions of the experimental brine were as follows: 0.8 mol/L t -BAMBP diluted in SK, pH≥13, a phase ratio of 1:1, and an extraction contact time of 2 min at room temperature. The optimal extraction yields of Cs^+ and Rb^+ were as high as 100% and 85.8%, in addition, 8.76% of K^+ was co-extracted. Further work would increase the extraction yield and selectivity of Rb^+ and realize the efficient separation of Cs^+ and Rb^+ from brine.