High Concentration Of Sodium Tungstate Solution Ion Exchange Kinetics

The kinetics of ion-exchange process between 201×7 (Cl^- form) strong basic anion-exchange resin and strong concentration WO₄^2- was studied by Batch reactor method in this research. The ion-exchange adsorption isotherms in different conditions were determined and Double Driving-Force Model was applied to describe the kinetics of ion-exchange process. The results indicated that the ion-exchange rate was not affected by the concentration of WO₄^2- and the stirring rate; however it was increased with the increasing of the reaction temperature and the reducing of the bead radius and varied inversely with square of the bead radius. The ion-exchange process was controlled by the grain diffusion. The apparent activation energy of reaction was decreased with the increasing of the concentration of WO₄^2-.The effect of the concentration of Cl^- on the ion-exchange process was also studied in this paper. The results showed that the kinetical rule of the ion-exchange reaction was not changed, the ion-exchange process was still controlled by the grain diffusion, and the concentration of Cl^- has little effect on the apparent activation energy of reaction if the total concentration of ion in the solution kept invariableness. The exchange capacity and the adsorption rate of the resin to WO₄^2- were decreased with the increasing of the concentration of Cl^-.