High-efficiency enrichment process of uranium from amidoxime-functionalized fibers after treated by alkaline elution system
Developing an efficient uranium enrichment process for large-scale eluates from marine-tested fibers is crucial for filling the gap in the downstream of seawater uranium extraction. Alkaline elution of 10 kg real marine-tested fibers yielded 33 L of clear eluate after pretreatment, where uranium existed mainly as [UO 2 (CO 3 ) 2 ] 2− , [UO 2 (CO 3 ) 3 ] 4− , and [UO 2 (O 2 )(CO 3 ) 2 ] 4− species with a concentration of 11.98 mg/L, while magnesium concentration was up to 352.48 mg/L.MIP analysis selected D201 resin with more and larger pores, which showed better uranium adsorption due to a maximum electrostatic potential of 114.93 kcal/mol via simulation. 1 kg of D201 resin was used in a self-developed ion exchange equipment (maximum 100 L eluate per run) for concentration and purification. After 5 days of enrichment, 3 L of uranium concentrate was obtained, with uranium concentration increased to 121.48 mg/L and magnesium reduced to 14.9 mg/L. Ammonia water was added to the concentrate for precipitation, collecting 1112.45 mg of uranium product. The uranium precipitation rate was 99.27 %, and that of magnesium was only 31.1 %. The overall enrichment efficiency reached 93.13 % for uranium. ICP results showed the uranium mass fraction in the product was 33.1 %. TI-MS results indicated the U-235 abundance (≈0.72 %) was consistent with natural levels, and U-234 abundance (0.0064 %) was, slightly higher than natural, but still qualified it as natural uranium. This study provides an innovative enrichment process and theoretical support for efficient downstream uranium recovery in seawater uranium extraction.
危险品化学品经营许可证（带存储）