Adsorption of rhenium and rhodium in nitric acid solution by Amberlite XAD-4 impregnated with Aliquat 336

摘要

An Extractant Impregnated Resin (EIR) was prepared by impregnation of Aliquat 336 into Amberlite XAD-4 for tentative separation of rhenium from rhodium in nitric acid solution. An optimum loading ratio of the XAD-4 resin for Aliquat 336 was found to be about 0.4 (g Aliquat 336/g resin). The prepared EIR showed high preference for rhenium over rhodium and adsorption isotherms for rhenium were described well by Langmuir equation in both the single and multi-component systems. Maximum adsorption capacities obtained by modeling the isotherms of rhenium were 2.01 and 1.97 meq/g for the single and the multi-component systems, respectively. On the other hand, only little adsorption of rhodium ions was observed. The homogeneous model fitted the kinetic data quite well and the obtained effective diffusivities of rhenium and rhodium ions were on the order of 10~(-7) and 10~(-6) cm~2 min~(-1), respectively.