Uranium sorption from radioactive waste of uranium ore processing at Pridneprovsk Chemical Plant

Abstract

Abstract. The research results were generalized regarding the possibility of uranium sorption from radioactive waste accumulated at Production Association “Pridneprovsky Chemical Plant” (PA PCP). The conceptual possibility was illustrated for sorption leaching of uranium from pulps produced by acidic leaching of radioactive waste dumped at Zapadnoye (Western) tailing impoundment using AMP anionite contained benzyl pyridinium functional groups (manufactured by Smoly State Enterprise). Uranium recovery was 70 % to 80 % during waste acidic leaching with the mixture of 15 % sulphuric and 1.5 % nitric acids. Application of sorption leaching allowed the recovery increase up to 15 %. Uranium recovery was assessed from upper ground and underground water of Centralny Yar tailing site using AM-p-2 strong base macroporous anionite (produced by Smoly SP) based on styrene-divinyl benzene copolymer with 2-hydroxyethyl-dimethylammonium functional groups. This tailing impoundment features acidic reaction of radioactive water since the pulp was almost not neutralized after ore processing. It poses an environmental hazard due to active uranium leaching from the tailing impoundment body and its ability to migrate into groundwater. It was found that the distribution factor may attain ~2 000 for uranium concentration 7 mg/l in interstitial water and 4 mg/l in underground water. Assessment results were given regarding uranium recovery from radioactively contaminated water accumulated in the basement of building No. 103 using phosphate cationite based on modified plant material. The building is extremely contaminated and of top-priority for treatment and further dismantling. Sorbent capacity by uranium achieved in static mode was ~20 mg/g with distribution factor ~4 800. The results obtained may be proposed as the reasoning for the method and technology intended to decontaminate polluted water before it would be pumped from underground rooms of building No. 103. The research performed has shown that application of sorption materials is the most expedient and promising method for selective uranium recovery when solving the problems of tailing site remediation and handling radioactive waste of the former Pridneprovsky Chemical Plant.