Yang Li,Fen Luo,Jiahong Wang,Yu Gao,Gangchuan Ji,Xirui Lu
This study used a ternary Na 2 O-B 2 O 3 -SiO 2 matrix to simulate the immobilization of complex TRPO waste. The study investigated the relationship between the solidified bodies with different TRPO waste contents and their solid solubility, FT-IR, Vickers hardness, and density. The study found that the maximum amount of TRPO waste that can be immobilized in the Na 2 O-B 2 O 3 -SiO 2 matrix was 20 wt .%. When the TRPO waste content ranged from 5-15 wt .%, it was primarily immobilized in the glassy phase. When the TRPO waste content exceeded 20 wt .%, the crystalline phases NdBO 3 and Na 3 Nd(BO 3 ) 2 , which contain the main waste element Nd appeared. Samples containing 20 wt .% TRPO waste resulted in leaching of 10 -6 g·m -2 ·d -1 . The presence of NdBO 3 and Na 3 Nd(BO 3 ) 2 crystals resulted in a decrease in the Vickers hardness and density of the samples. The highest values for Vickers hardness and density were 6.77 GPa and 2.7 g -1 cm -3 , respectively. The borosilicate matrix utilized in this study has proven to be an effective immobilization of complex TRPO wastes and holds promise as a treatment matrix for TRPO wastes.
Summary As a rapid sintering method, spark plasma sintering (SPS) process has been widely applied to immobilize nuclear waste. In this work, trialkyl phosphine oxides (TRPO) were immobilized by the mixture of Gd 2 O 3 and ZrO 2 with SPS proceedings at 1650°C in 3 minutes. X-ray diffraction results present that the solid solubility is 10 to 20 wt% and all the sintered samples show a fluorite structure. Raman spectroscopy results show that the order degree of structure decreases as waste content increases. The lattice parameters decrease with the increasing doped waste content indicating the success of waste immobilization. Densities decrease for the sample with higher waste content which mainly caused by the existence of pores. Scanning electron microscope-energy dispersive X-ray spectroscopy and backscattered electron results perform the microstructure of the sintered sample. Furthermore, the leaching test shows that the sample has a considerable chemical stability. This study confirmed the possibility of rapid consolidation of Gd 2 Zr 2 O 7 bulk, dense ceramic with up to 10 ~ 20 wt% of immobilized TRPO waste. Highlights Multi-nuclides waste was rapidly immobilized by Gd 2 Zr 2 O 7 via SPS process. Phase transition happened with enhanced doping content. Density results decreased with the higher waste content. The order degree of structure decreased as waste content increased. The sintered matrix represented considerable chemical stability.
危险品化学品经营许可证（带存储）