Тип публикации: статья из журнала
Год издания: 2026
Идентификатор DOI: 10.1016/j.jenvman.2026.128626
Ключевые слова: spark plasma sintering, coal fly ash, dispersed microspheres, Mineral-Like Ceramics, Cs-kalsilite, pollucite, Geological disposal
Аннотация: The novel approach to high-tech application of CFA particulate matter (PM, dispersed microspheres) generated at coal-burning thermal power plants was highlighted as a resource-saving and energy-efficient method to solidify 135,137Cs-bearing radioactive waste in mineral-like ceramics based on feldspathoid phases suitable for disposaПоказать полностьюl in igneous rocks. The specific novelty of using dispersed microspheres lies in their size (<10 μm), which is a key technological variable in ceramic production. The combination of fine particle sizing with required composition (SiO2/Al2O3 = 1.2−3.5) was a prerequisite for PM involvement in 135,137Cs ceramization. To fabricate initial precursors, two microsphere fractions (PM2.5 and PM10) having close SiO2/Al2O3 ratios (2.2 and 2.7) but different size distributions (dmax of 2.5 and 9.9 μm) were isolated from CFA by applying aerodynamic and magnetic classifications. The Cs-bearing aluminosilicate precursors (Cs-PM2.5 and Cs-PM10) were prepared by impregnation of the microspheres with CsNO3 solution followed by drying and calcination at 800 °C. To fabricate ceramics, the Cs-PM blends were consolidated by the spar plasma sintering (SPS) at 700, 800 and 900 °C and pressure of 30 MPa. The PXRD, SEM-EDS analyses, measurements of density and Vickers microhardness, evaluation of the cesium leaching rate were performed to characterize the resulted ceramic materials. As established, the SPS fabricated ceramics for both precursors is the high-density (2.7−2.9 g/cm3) material composed of pollucite and Cs-kalsilite phases. Its hydrolytical stability is confirmed by the low cesium leaching rates (R ∼ 10−5−10−6 g/cm2⋅day), which meets the requirements of GOST R 50,926–96 and NP-019-2000 standards for solidified high-level waste.
Журнал: Journal of Environmental Management
Выпуск журнала: Т.399
Номера страниц: 128626
ISSN журнала: 03014797
Издатель: Academic Press