Synthesis of n,n'-dimethyl-3-oxa-glutaramic acid and its application in the simplification of trpo process

A novel ligand, N,N'-Dimethyl-3-Oxa-Glutaramic Acid (DOGA), which consists of CHON, was synthesized. The extraction distribution ratios of transuranium(TRU) elements, including Np(IV), Pu(IV), Am(III) and fission products such as Ln, Fe and Zr with 30% TRPO-kerosene from HNO3 solution containing DOGA were measured. Results showe that DOGA has strong complex ability to transuranium and Ln(III) at lower nitric acid concentration; With the addition of DOGA in aqueous phase, the distribution ratio of the TRU and Ln with TRPO was decreased dramatically. DOGA was employed as a stripping reagent for TRU in TRPO process, to replace 5.5 M HNO3 stripping of Am(III)+ Ln(III) and 0.6 M oxalic acid solution stripping for Pu(IV) and Np(IV). Results show that the TRU extracted to TRPO from simulated high level liquid waste can be completely recovered. With the new stripping reagent, the TRPO process becomes simpler and more compact. Based on the experiments results, a flowsheet of simplified TRPO process was proposed.