China Nonferrous Metallurgy

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 PdCl₃[SC(NH₂)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 10mg, temperature of 25℃, desorption time of 60min, desorption agent (10mol·L ^-1 hydrochloric acid and 06mol·L ^-1 thiourea) of 20mL, the maximum desorption rate of palladium was 9626%. The results showed that the optimal regeneration times of adsorbent was 4.