磷钨酸铵复合材料对铷铯吸附性能的研究

针对卤水中铷、铯富集困难的问题,以磷钨酸铵为原料,通过与焦磷酸钛复合制备了一种新型吸附材料——磷钨酸铵-焦磷酸钛复合材料,用于吸附铷、铯离子。研究了复合材料对铷、铯离子的吸附过程热力学、动力学性能。动力学和热力学研究发现,准二级动力学方程和Freundlich吸附等温方程能较好地拟合吸附过程,相关性良好;热力学研究发现,ΔG ⁰、ΔH ⁰、ΔS ⁰均小于零,铷、铯在复合吸附剂上的吸附是自发进行的,复合吸附剂吸附铷、铯均为放热反应,升高温度不利于吸附的进行,吸附过程中固液界面的混乱度减小,是熵减过程。

Study on adsorption properties of ammonium phosphate tungsten composites on rubidium and cesium

In order to solve the problem of rubidium and cesium enrichment in brine,a new adsorbent material,ammonium phosphotungstate-titanium pyrophosphate composite,was used for adsorbing rubidium ions and cesium ions,the new adsorbent material was prepared by ammonium phosphotungstate compounded with titanium pyrophosphate.The thermodynamics and kinetics of the adsorption process of rubidium and cesium ions on composites were studied.It found that the quasi-second-order kinetic equation and the Freundlich adsorption isotherm equation can fit the adsorption process well and the correlation was good through the kinetics and the thermodynamic study.It also found that ΔG ⁰、ΔH ⁰、ΔS ⁰ were all less than zero and the adsorption of rubidium and cesium on the composite adsorbent was spontaneously carried out.The adsorption of ruthenium and osmium by the composite adsorbent was an exothermic reaction.The increase of temperature was not conducive to the adsorption,and the chaos of the solid-liquid interface was reduced during the adsorption process,which was an entropy reduction process.