氨基改性苯乙烯树脂的合成及其对铼的吸附

Preparation of amino modified styrene-divinylbenzene resin and its adsorption of rhenium

离子交换法因适于低浓度物质的分离富集而被广泛应用于湿法冶金行业,新型高效吸附材料的合成与应用成为该领域的发展趋势。针对铀矿中伴生铼这一稀缺资源需要同步回收的现状,根据新近研发的氨基改性苯乙烯阴离子交换树脂(LSC-Re),通过静态和动态吸附解吸试验,系统考察了溶液酸度、初始浓度、吸附时间、吸附温度等因素对吸附性能的影响,结果表明:在室温(25℃)下,铼溶液初始浓度为100 mg·L-1,该树脂6 h达到吸附平衡,酸度对该树脂吸附铼的影响不大,树脂在pH=1.5时铀铼分离效果最佳,分离系数可达到41.68;树脂的饱和吸附容量达到129.3 mg·g-1;从热力学和动力学角度分析,吸附过程符合Langmuir吸附等温模型和准二级动力学模型,且吸附是自发的吸热过程。动态吸附解吸试验中,控制溶液流速0.5 ml·min-1,动态饱和吸附容量达到76.17 g·L-1,饱穿比为2.35,用1 mol·L-1氨水进行解吸铼效果较好,8个树脂床体积可将其解吸完全,由此可见富集倍数接近70倍,具有良好的工业应用前景。

The ion exchange method is widely used in the hydrometallurgical industry because it is suitable for the separation and enrichment of low-concentration substances.The synthesis and application of new high-efficiency adsorption materials have become the development trend in this field.In view of the current situation that the associated scarce rhenium minerals in uranium mine need to recover synchronously,the preparation of amino modified styrene-divinylbenzene resin(LSC-Re)was used to recover rhenium in this work.The effect of aqueous acidity,initial concentration,adsorption time and adsorption temperature on the adsorption performance were systematically investigated by static and dynamic adsorption desorption experiments.The results show that 6 h is sufficient up to equilibrium for the LSC-Re anion exchange resin at room temperature,and the acidity has little effect on the adsorption.The LSC-Re anion exchange resin exhibited higher affinity toward Re(Ⅳ)than U(Ⅵ)at pH 1.5,the maximum value of separation factorβRe(Ⅳ)/U(Ⅵ)is 41.68.The saturated adsorption capacity of resins could reach 129.3 mg·g-1 at present conditions.The adsorption mechanism is in accordance with Langmuir adsorption isotherm model and quasi-second-order kinetic model,and the adsorption process is a spontaneous endothermic from the perspective of thermodynamics and kinetics.The dynamic saturated adsorption capacity could reach 76.17 g·L-1 and the saturation ratio could reach 2.35 by controlling the solution flow rate to 0.5 ml·min-1 in the dynamic adsorption experiment.The 8 resin bed volumes can be desorbed completely by 1 mol·L-1 NH3·H2O,the enrichment factor is close to 70 times,which means that the LSC-Re anion exchange resin has good industrial application prospects in recovery Re(Ⅳ).