Study on the destruction process of cationic exchange resins treated by Li2CO3-Na2CO3-K2CO3 molten salt

With the continuous development of the nuclear industry, there is an urgent need to find a method that can safely and efficiently dispose of spent resins. Molten salt oxidation (MSO) is a promising waste treatment technology . In this paper, the newly shipped resins were used to simulate the actual spent ion exchange resins . The destruction of the resins is mainly divided into three stages. The addition of oxygen can increase the activation energy ( E ) required for the reaction. Some solid residues which were proved to be amorphous carbon materials generated after MSO. In the high-resolution XPS spectra of C 1s, the C-S bond disappeared after MSO at 400 ℃ for 2 h proved the destruction of the sulfonic acid groups. The core-level scan XPS spectra of S 2p illustrated that sulfur and sulfonyl bridges were formed after sulfonic acid groups were destroyed. The infrared spectrum also showed that the sulfonic acid groups were destroyed at 400 ℃ to form sulfonyl structure, but sulfur bridges were not found due to its small IR absorptions. In this paper, the ternary eutectic Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 , can be operated efficiently at a relatively low temperature. The generated sulfur dioxide is captured by the carbonate to form sulfate. These merits make MSO become a promising and environmentally friendly approach for the treatment of sulfur-containing organic waste.