Adsorption Properties of a Polyamine Special Ion Exchange Resin for Removing Molybdenum from Ammonium Tungstate Solutions

Abstract

A polyamine special ion exchange resin was used to adsorb Mo from ammonium tungstate solutions. The effects of adsorption time, S2− concentration, adsorption temperature, CO32− concentration, mass ratio of WO3 to Mo, and Mo concentration on the Mo and WO3 adsorption capacities were investigated. Energy dispersive spectrometer plane scans were used to study the distributions of Mo, W, S, and Na on the loaded polyamine special ion exchange resin and the desorbed polyamine special ion exchange resin. The results showed that the polyamine special ion exchange resin performed well during adsorption and desorption. Under the optimum conditions for the static adsorption experiments, the adsorption capacities for Mo and WO3 were 99.29 mg/mL and 31.97 mg/mL, respectively, and the desorption rates for Mo and WO3 were 99.35% and 99.43%, respectively. Adsorption and desorption of molybdenum and tungsten on the polyamine special ion exchange resin were investigated by dynamic adsorption experiments with an ammonium tungstate solution containing 125.0 g/L WO3, 12.50 g/L Mo, 15.65 g/L S2−, and 0 g/L CO32−. The adsorption capacities for Mo and WO3 were 53.48 mg/mL and 9.79 mg/mL, and the adsorption rates for Mo and WO3 were 99.05% and 1.81%, respectively. The loaded polyamine special resin was desorbed with a 45 g/L sodium hydroxide solution, and the dynamic desorption rates for Mo and WO3 were 99.02% and 99.29%, respectively.