The Study Of Enrichment Separation And Solvent Extraction Of Cesium

As a chemically reactive alkali metal,cesium is mainly stored in cesium garnet,cesium silication,lithium mica,gas field water,geothermal water and salt lake brine,which is widely used in many fields such as catalysis,photoelectric,magnetic fluid power generation and medicine because its excellent photoelectric properties.The main separation methods of cesium are fractional crystallization,precipitation,sulfuric acid leaching,ion exchange and solvent extraction,and the most suitable for the separation of cesium in liquid ore is the solvent extraction method.It's hard to separation the cesium form gas field water,geothermal water and brine because the concentration of cesium is very low and many associated metal ion such as potassium,sodium,magnesium and rubidium have serious impact on extraction.It is impossible to extract cesium from most liquid ores for industrial production because of these reasons.Therefore,it's important to establish a simple,quick,selective and expediently efficient separation method for cesium.In this paper,the effect of extraction of cesium by t-BAMBP(4-tert-butyl-2-(?-methylbenzyl)phenol)/sulfonated kerosene was investigated,and the kinetics of extraction was study.Cs(I)ion-imprinted polymers which was using Cs(I)ions as functional template monomers was prepared.The contents of the paper as follows:1.The effect of t-BAMBP/sulfonated kerosene system on the extraction of trace cesium in solution by solvent extraction method was studied.The study had mainly inspected the extracting agent concentration,O/A(the ratio of water phase extraction solvent oil solution phase),alkalinity,extraction time,the strength of oscillation,extraction temperature,stripping acid concentration and stripping time.The orthogonal experiment found that the best condition was:c(t-BAMBP)=1.5 mol/L,O/A=0.5:1,1.0 mol/L NaOH,200 r/min,0?,c(HCl)=0.1 mol/L,2 min(extraction time)and 3 min(stripping time).2.The kinetics of the extraction to cesium in liquid phase used t-BAMBP/sulfonated kerosene system was studied by using single droplet device.The effect of the area ratio S,the cesium ion concentration in liquid phase and the concentration of extraction solvent on reaction rate R were investigated.The reaction series of cesium ion concentration and t-BAMBP concentration was calculated,and the kinetic equation of extraction reaction was established.3.Cs(I)ion as the functional template prepared to prepare the Cs(I)ion-imprinted polymer by the surface ion imprinting technique.The adsorbents were characterized by FT-IR,SEM,thermogravimetric analysis and nitrogen adsorption surface area detector.The adsorption and enrichment properties of Cs(I)were investigated in detail by Cs(I)imprinted polymer and non-imprinted polymer.The results showed that Cs(I)ion-imprinted polymer can adsorb Cs(I)at pH 6,and achieve adsorption equilibrium at 60 min and has good repeatability.The maximum adsorption capacity is 38.46 mg/g,which is significantly higher than that of non-imprinted polymer's adsorption capacity of 13.20 mg/g.The kinetics of adsorption conforms to the quasi-second-order kinetics model,and the adsorption isotherm conforms to the Langmuir model.The value of relative choice factor?_r to Cs(I)ion imprinted polymer for Cs~+/Li~+,Cs~+/Na~+,Cs~+/K~+,Cs~+/Rb~+are 28.2,34.8,30.2,38.0,which is much higher than 1.It's suggested that the Cs(I)ion-imprinted polymer has better selection and identification than non-imprinted polymers.It was found that recovery of Cs(I)-IIP to Cs(I)was still not less than 96%after 10adsorption and desorption cycles,indicating that the good regeneration behavior of the adsorbent material and can be reused.The Ion imprinted polymer of Cs(I)were used in the adsorption of cesium ions in salt lake brine,and its adsorption performance about cesium ions can reach at 4.92 mg/g,the adsorption efficiency is75.23%,the material has wide application foreground.It was found that the detection limit of Cs(I)was 0.06 mg/L by this Cs(I)ion-imprinted polymer,which can be applied to the determination of trace Cs(I)in synthetic salt lake brine samples.