S300树脂对汽车失效催化剂浸出液中Pd(Ⅱ)的吸附行为

Selective recovery of Pd(Ⅱ)from leach liquors of spent automobile catalyst by S300

基于实验室合成的S300树脂对汽车失效催化剂浸出液中Pd^2+吸附过程进行研究,考察温度、溶液体系中HCl浓度、吸附时间等因素对Pd^2+在S300树脂上吸附行为的影响,并对Pd^2+在S300树脂中的动力学特性、交换等温线、复杂体系中的选择性以及解吸过程进行研究,根据表征结果分析在盐酸体系下S300树脂的吸附机理。结果表明:温度对Pd^2+吸附过程影响较小,溶液体系中的HCl浓度在0~1 mol/L范围内,S300树脂的平衡吸附量随HCl浓度升高而显著增加,平衡吸附时间约为30 min。S300树脂吸附过程符合准二级动力学模型与Langmuir等温模型,对汽车失效催化剂浸出液中Pd^2+的吸附分配系数DM=68.66,静态解吸过程中,解吸3 min后,Pd^2+解吸率达到98.79%。研究结果表明,溶液中Pd(Ⅱ)以[PdCl4]2−形式通过离子−偶极作用与S300树脂发生吸附反应。

A novel functional ion exchange resin,S300,was synthesized under laboratory conditions.The adsorption process of Pd(Ⅱ)from the leaching solution of spent automobile catalyst was investigated.Batch adsorption experiments were carried out to understand the effects of temperature,HCl concentration in the solution,and reaction time on the adsorption behavior of palladium.In addition,the kinetic characteristics,exchange isotherm,and selectivity towards Pd(Ⅱ)in the complex system of the adsorption process were investigated.XPS analysis was applied to study the adsorption mechanism in detail.The results show that temperature has little effect on the adsorption process.The equilibrium capacity of the S300 resin increases significantly as the increase of the concentration of HCl within the range of 0−1 mol/L.The equilibrium adsorption time is about 30 min.The kinetic analysis indicate that the pseudo-second-order kinetic model and the Langmuir isotherm model shows the best agreement with the experimental data.The distribution ratio of Pd(Ⅱ)is 68.66,showing very high selectivity of the S300 resin towards palladium.In the static desorption process,the desorption rate of Pd^2+reaches 98.79%after 3 min desorption.Furthermore,characterization results show that the adsorption of palladium is proceeded following the mechanism of ion-dipole action between[PdCl4]2−and the S300 resin.