盐酸硫脲从负载钯吸附剂中分离钯

Separation of palladium from palladium-loaded adsorbent with thiourea hydrochloride

本研究采用盐酸和硫脲从负载钯吸附剂中分离钯,通过对反应进行热力学分析探明含钯产物的化学形态及其分布特征,揭示解吸过程机理;利用动力学模型分析解吸行为;通过试验考察时间、盐酸浓度、硫脲浓度和解吸剂体积对分离效果的影响及再生次数对吸附剂再生性能的影响。热力学分析结果表明,解吸时负载钯吸附剂中的PdCl_(4)^(2-)与Cl^(-)发生离子交换后再与硫脲配合,含钯产物以PdCl_(3)[SC(NH_(2))_(2)]^(-)形态存在;解吸动力学分析表明,准二级动力学模型是最优模型;试验表明,在负载钯吸附剂10 mg、温度25℃、解吸时间60 min、解吸剂(1.0 mol·L^(-1)盐酸和0.6 mol·L^(-1)硫脲)20 mL的条件下,钯的最大解吸率为96.26%;吸附剂再生性结果表明,最佳的再生次数为4。

In this study,hydrochloric acid and thiourea were used to separate palladium from palladium adsorbent.Based on thermodynamic analysis of the reaction,the chemical morphology and distribution characteristics of palladium products were explored,and the mechanism of desorption process was revealed.Meanwhile,the effects of time,concentration of hydrochloric acid,concentration of thiourea and volume of desorption agent on the separation effect and the effects of regeneration times on the regeneration performance of the adsorbent were investigated.The results show that the palladium-containing products exist as PdCl_(3)[SC(NH_(2))_(2)]^(-)after ion exchange with Cl^(-)and thioureas in the palladium-loaded adsorbent.The quasi-second-order kinetic model is the best model for desorption kinetics.Under the conditions that the palladium-loaded adsorbent of 10 mg,temperature of 25℃,desorption time of 60 min,desorption agent(1.0 mol·L^(-1) hydrochloric acid and 0.6 mol·L^(-1) thiourea)of 20 mL,the maximum desorption rate of palladium was 96.26%.The results showed that the optimal regeneration times of adsorbent was 4.