常压氢还原盐酸介质中的铑之动力学

Kinetics of Reducing Rhodium with Normal Pressure Hydrogen in Hydrochloric Acid Solution

研究了常压下温度、搅拌强度、铑初始浓度、盐酸浓度、氯离子浓度等对氢还原铑反应速效的影响。结果表明，氢还原铑是一均相沉淀过程，与铑初始浓度有关，不受品种的影响。还原分二个阶段进行，但都受到传质过程的影响。还探讨了常压下用氢还原法从纯铑液中制取９９．９９％铑的可能性。

The reduction rate of rhodium with normal pressure hydroirroenincreases with the increase of temperature and stirring,and decreases withthe initial concentrations of Rh, HCl,and NaCl.The experimental resultsindicated that the reduction rate was not affected by the crystal nucleus,and the reduction was considered to bc a homogeneous precipitation.Thereduction mechanism consisted Of two stages,both are influenced by the masstransfer.The reduction rate in the first stage was controlled by the absorptionrate of H_2 in the solution, the apparent activation energy to be 11.2kJ/mol at20～60℃,the recuction rate in the second stage was determined by the diffusionof Rh in the liquid membranc,with the activation energy of 17.5kJ/mol.Anew method to obtain high purc rhodium powder from HCl solution wasproposed.