Synthesis Of T-BAMBP And The Properties Of Solvent Extraction Of Rubidium And Cesium With Its By-products

.:4-tert-butyl-2-(a-methybenzyl)phenol(t-BAMBP) is the major extractant for Rubidium and Cesium. The synthesis of t-BAMBP catalyzed by mineral acid produces crude product with low yield of t-BAMBP, high costs and various kinds of by-products whose influence on solvent extraction are still unclear. t-BAMBP was synthesized using D001strong-acid cation exchange resin as catalyst for the first time in order to determine optimized conditions. The research highlight were the effects of four by-products:styrene dimer,2,6-di-tert-butyl-4-methylphenol,2,4-di-tert-butylphenol and2-benzylphenol on extraction.The optimal synthesis conditions for D001resin as catalyst were: reaction temperature of130℃, a catalyst dosage equal to0.5%of4-tert-butylphenol, a reagent molar ratio of1:1.5, and a reaction time of2.Oh. Under such conditions, the yield of t-BAMBP was54.90%and the selectivity of4-tert-butylphenol was81.48%. Resin could be reused twice with a yield above50%. The purified t-BAMBP extractant performed well in extracting Rubidium and Cesium from the mother liquor after precipitating Lithium.When changing the mass fraction of styrene dimer from0%to50%, there was no marked change in distribution ratio and separation coefficient, while the density and viscosity of the organic phase as well as the time for phase disengagement increased, which had a negative effect on solvent extraction by t-BAMBP. None of the three substituted phenol species showed synergism with t-BAMBP.2-benzylphenol was an effective and selective extractant for Cesium in various organic dilutes, while2,4-di-tert-butylphenol gave Cesium extraction only in nitrobenzene.2,6-di-tert-butyl-4-methylphenol showed barely no extraction in all tested dilutes. The effects of extracting time, concentration of extractant in organic phase and Cs+in aqueous phase, pH and temperature on the extraction of Cesium by2-benzylphenol and2,4-di-tert-butylphenol were investigated. To understand the nature of extraction of Cesium by2-benzylphenol, further studies gave a third-power dependence of distribution coefficient on its mole concentration and a first-power dependence on pH. The infrared spectrum indicated that2-benzylphenol existed in the form of hydrogen-bonded dimer rather than monomer in dimethylbenzene within a concentration range of0.1-1.0M. At298K, the reaction equilibrium constant K=140.64, AH=-62.94kJ/mol, AG=-12.25kJ/mol, AS=-170.1J/(K· mol) with1M of2-benzylphenol in organic phase and0.1M of OH" and0.01M of Cs+in aqueous phase. It was proposed that the principal species in the extraction of Cesium with2-benzylphenol should be [Cs(ROH)5]OR and the extraction reaction on alkaline conditions was as follows:...