Synthesis Of T-BAMBP And Its Extraction Property Of Rubidium And Cesium From The Qinghai Salt Lake

There is few studies found in reports on extracting trace cesium and rubidium ions from the actual salt lake brine which contain high concentration of impurity ions (such as K+, Na+Mg2+and so on) at present, and it’s still an unresolved worldwide problem to separate and purify such Rb+and Cs+economically and feasibly from the brine.The preparation of t-BAMBP (4-tert-butyl-2-(a-methylbenzyl)phenol) was studied in detail in this paper, and the t-BAMBP extraction capability of trace cesium and rubidium from Qinghai salt lake was also studied. The catalytic synthesis process of t-BAMBP was studied first. Concentrated phosphoric acid is used as catalyst, the optimal synthesis parameters were obtained by single factor experiments. The optimal synthesis conditions are as follows:the mole ratio of catalyst and tert-butyl phenol being0.75:1, the reaction temperature150℃, reaction time150min, and reactant ratio1:1.8. In such conditions, the percent conversion of tert-butyl phenol is81.29%, the selectivity of t-BAMBP62.65%, and the yield50.93%.Then the synthetic products were separated and purified by distillation and precise rectification, characterized by IR and1H NMR. The purity of t-BAMBP is higher than98%, and the yield is about85%. The reaction mechanism of t-BAMBP was also studied.t-BAMBP in sulphonated kerosene solution was used as extraction solvent to extract and separate rubidium and cesium ions from the tail liquid of potassium fertilizer process and the brine from sodium pool which obtained from CITIC Guoan Group Company, also from the desorption solution which ammonium molybdate phosphorus column treated with NH4Cl. The optimum extraction conditions are as follows:extraction with a1mol/L solution of t-BAMBP in sulphonated kerosene solution, the phase ratio (O/A)=1:1, COH-=0.5mol/L, oscillated in20℃heated box for10min. The maximum extraction ratio of rubidium (ERb+) in original brine reaches83.6%, separation factor (β)84.6%. After extraction, followed by scrubbing of organic phase with a1×10-4mol/L solution of NaOH, the phase ratio (O/A1)=1:0.5, the elution ratio of Rb+is10.5%.According to this process, the final purity of rubidium chloride reaches91.20%and the single recovery rate is51.25%after5-stage counter-current extraction of the desorption solution which ammonium molybdate phosphorus column treated with NH4Cl, following by three-stage alkali scrabbing and two-stage stripping. The optimal process is suggested finally, which provides a feasible project for industrial extraction of cesium and rubidium ions from the salt lake brine.