Study on Cement Solidification of Fenton Oxidation slurry of Spent Ion-exchange Resin

摘要: The operation of nuclear power plants generated radioactive spent ionexchange resin, and Fenton oxidation technology have attracted growing attention for the treatment of spent resin. As this technology gain wider application, the stabilization of the Fenton oxidation effluent becomes increasingly important, cement solidification remains the preferred immobilization method for low-and intermediate-level radioactive wastes in many countries.Focusing on the cement solidification of Fenton oxidation effluent, this study performed component analysis on both the raw effluent and the slurry after evaporation concentration and pH condition. Orthogonal screening tests and formulation ratio optimization were conducted on the Evaporated and Conditioned Slurry. The influencing factors and hydration mechanisms were systematically investigated, leading to the determination of the optimal formulation, which was then validated through cold-test performance characterization and hot-test verification.Results show that silica fume exerts a significant influence on the compressive strength development, whereas sodium silicate exhibits a relatively minor effect. With increasing hydration age, the influence of cement proportion on strength growth becomes markedly more pronounced, and hydration products continue to form substantially up to 120 days. The optimal mass ratio of Evaporated and Conditioned Slurry: cement: superplasticizer: sodium silicate: silica fume was determined as 1.0:1.0:0.01:0.01:0.20. The resulting solidified waste form meets all requirements of the Chinese standard GB 14569.1-2011. Hot-test validation further confirmed that the optimized formulation is applicable to the Fenton oxidation slurry derived from radioactive spent resins, achieving a volume reduction ratio of 1.59 from spent resin to the final cement solidified form.