Low-Temperature Thermomechanical Consolidation of Aluminosilicate Sorbents Impregnated with Model Oil-Containing Radioactive Waste.

This paper investigates the possibility of pressure-assisted thermomechanical consolidation and thermal treatment without applied pressure during the low-temperature consolidation of oil-saturated aluminosilicate sorbents for their subsequent application in the conditioning of liquid oil-containing radioactive waste (RAW). The Premium and Absorbent sorbents saturated with transformer oil not containing radionuclides were used as model RAW systems. It was established that pressure-assisted thermomechanical consolidation leads to the formation of a denser structure and a reduction in hydrocarbon-phase losses compared with thermal treatment without applied pressure. For Premium, mass losses decreased from 0.74 to 0.35 g (by 53%), and for Absorbent, from 0.75 to 0.47 g (by 37%), and the consolidated samples were characterized by a more homogeneous microstructure and increased resistance to exudation. It was established that the efficiency of hydrocarbon-phase retention is determined by both the treatment conditions and the mineral composition of the sorbent. The obtained results indicate the prospects of low-temperature pressure-assisted thermomechanical consolidation at a temperature of 150 °C, a pressure of 1.5 MPa, and a holding time of 20 s for the conditioning of oil-containing RAW without the use of additional binding components.