Thermal degradation of spent cation exchange resin with fixatives or metal ion catalysts: Insights from experiments, thermodynamics and kinetics

The treatment of spent ion exchange resins (CERs) has become a major concern with the development of nuclear industry. The migration and transformation mechanism of Cs in CERs in both pyrolysis and gasification were evaluated based on chemical equilibrium and experimental analysis. The pyrolysis and gasification temperatures should be limited below 813.15 K and 873.15 K, respectively, but after adding the fixatives, ZrO 2 or Nb 2 O 5 , the temperatures could be extended to 873.15 K, 1233.15 K (ZrO 2 ) or 1153.15 K (Nb 2 O 5 ). The kinetic and thermodynamic characteristics of CERs with metal ion catalysts in the gasification were evaluated based on thermogravimetric analysis. In 10 % O 2 /90 % N 2 , Fe 2+ and Mn 2+ metal nuclides would urge the decomposition of functional groups and polymer matrices, since they could promote the reaction in the second stage and the advance of the third stage. This study could provide basic data for the thermal treatment of CERs.