Mo extraction from acid leaching solution containing molybdenum by ion exchange method

Molybdenum was extracted selectively from molybdenum-containing acid leaching solution that was obtained by oxidation acid leaching superalloy scrap with Mo concentration of 0.67 g·L-1 by the mean of ion exchange. The molybdenum was adsorbed from acid leaching solution containing molybdenum by D296 resin after adjusting pH of acid leaching solution containing molybdenum with sodium carbonate solution, followed by desorption of Mo from D296 loaded resin with mixed solution of ammonia and ammonium chloride. Then white crystal of ammonium molybdate was obtained from the ammonium molybdate solution by cooling and crystallizing after evaporative concentrating, which recycled molybdenum effectively. The experimental results showed that D296 strong base anion exchange resin was selected as the adsorbent resin of Mo using the method of static adsorption. The optimum adsorption parameters were proposed as following: the resin-bed volume of 10 ml, the reaction temperature of 25℃, the stock solution pH of 2, the adsorption flow rate of 45 ml·h-1. With the optimum parameters mentioned above, molybdenum adsorbing rate reached 98.45%. The saturation adsorption capacity of D296 resin was 50 mg·g-1 measured by Mo adsorption curve. When ammonia concentration was 5%, ammonium chloride concentration was 30 g·L-1, the resin-bed volume was 10 ml, the amount of mixed solution of ammonia and ammonium chloride was 80 ml and the desorption flow rate was 10 ml·h-1, the Mo concentration of the desorbed solution was 3.282 g·L-1 and molybdenum desorbing rate reached 99.52%. When Mo concentration was more than 60 g·L-1, the ammonium molybdate white crystals could be obtained from the ammonium molybdate solution by cooling to room temperature and crystallizing more than 12 h. The purity of the ammonium molybdate reached 97.95%. © 2015, Editorial Office of Chinese Journal of Rare Metals. All right reserved.