Immobilization of TRPO waste by Na2O-B2O3-SiO2 matrix: Effects of Nd-containing crystals

This study used a ternary Na2O-B2O3-SiO2 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 Na2O-B2O3-SiO2 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 NdBO3 and Na3Nd(BO3)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 NdBO3 and Na3Nd(BO3)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-1cm-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. [Display omitted]