نوع مقاله : مقاله پژوهشی
نویسندگان
پژوهشکده چرخه سوخت هستهای، پژوهشگاه علوم و فنون هستهای، سازمان انرژی اتمی ایران، صندوق پستی: 8486-11365، تهران- ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
Liquid-liquid extraction is one of the most common methods for purifying thorium from multicomponent aqueous solutions. In this study, the ability of different organic solvents, such as tributyl phosphate (TBP), di-2-ethylhexyl phosphoric acid (DEHPA), and di(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), to separate thorium from a multicomponent aqueous nitrate solution containing uranium, vanadium, and iron elements was investigated. The experimental results showed that the extraction efficiency of elements for tributyl phosphate and di-2-ethylhexyl phosphoric acid is uranium > thorium > iron > vanadium, and for Cyanex 272 is thorium > uranium > vanadium > iron, respectively. Additionally, the separation factor of thorium compared to uranium, vanadium, and iron by Cyanex 272 was calculated as 63.4, 384.4, and 615.6, respectively. The investigation of various process parameters on the solvent extraction process revealed that at a contact time of 15 minutes, a pH of the aqueous phase equal to 0.5, a ratio of aqueous to organic phase equal to 1, and a concentration of Cyanex 272 equal to 0.1 M, the highest percentage of thorium extraction is achieved, with extraction efficiencies of thorium, uranium, vanadium, and iron at 98.6%, 37.8%, 10.6%, and 11.1%, respectively. Furthermore, different mineral acids, including nitric acid, sulfuric acid, and hydrochloric acid solutions, were evaluated for the stripping process from the loaded organic phase. The results demonstrated that utilizing a 4 M sulfuric acid solution could achieve thorium stripping efficiency above 91% from the loaded organic phase.
کلیدواژهها English