Study On Preparation And Properties Of Cesium Ion Sieve

Cesium is a very active metal and has a wide range of applications in various technical fields.There are many inland salt lakes in China.Extracting cesium from salt lake brine has broad prospects for development.Among many cesium separation methods,ion sieve adsorbent method has become the most promising method because of its simple device and good selectivity.The cesium ion sieve precursors were synthesized by five methods:zeolite modification,high temperature solid-state method,sol-gel method,solvothermal method and template method respectively.The composition and surface appearance of cesium ion sieve precursors were characterized by X-ray diffractometer and scanning electron microscope,and their characterization results were compared.Solvothermal orthogonal test showed that the optimum synthesis conditions were solvent heat treatment temperature 120?and calcination temperature 800?and the molar ratio of titanium to cesium was 2.5.The XRD results were basically consistent with the standard peak of Cs₂Ti₆O₁₃.SEM results showed that the monomer was a thin sheet with a thickness of about 30 nm.The peak value of the precursor of cesium ion sieve prepared by sol-gel method is basically consistent with the standard peak at calcination temperature with 900?and and cesium titanium ratio with 1:1.3.SEM results showed that the pore structure was complete and compact,and the structure was scaly.The precursor of ionic sieve was obtained by template method under the conditions of 82nm template size,1:1.5 Cesium-Titanium molar ratio and 800 C calcination temperature.The XRD pattern matched the standard peak best.SEM results showed that the monomer was prismatic and formed a three-dimensional space structure through the accumulation of monomers.The effect of acid modified concentration on the extraction rate of cesium ion was studied by four methods:the acid modification experiment of zeolite precursor,sol-gel method,solvothermal method and template method.The optimum operating conditions for preparing Cesium-Titanium composite oxides by template method were obtained by orthogonal experiment:the particle size of PMMA template was 82 nm,the molar ratio of Cesium to Titanium was 1:3,the calcination temperature was 800?,the acid modification concentration was 0.2 mol/L,and the leaching rate of Cesium ion was41.40%.The saturated exchange capacity of ion sieves prepared by zeolite modification method and template method was measured,and the influence trend of various influencing factors on saturated exchange capacity was explored.The optimum conditions of ion adsorption reaction were obtained by orthogonal test:pH was 10,concentration of Cs⁺was 0.2 mol/L and temperature was 25?.The degree of influence from large to small is pH value,Cs⁺concentration and temperature.