γ irradiation effects on natural GMZ bentonite

• Published in: Physics and chemistry of minerals Vol. 52; no. 2; p. 21
• Main Authors: Liu, Wei, Liang, Dong, Yang, Zhongtian, Gao, Chao, Xie, Jingli
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2025; Springer Nature B.V
• Subjects: Adsorption; Bentonite; Beta rays; Chemical properties; Chemistry; Clay; Cobalt; Crystallography and Scattering Methods; Earth and Environmental Science; Earth Sciences; Gamma irradiation; Geochemistry; Geology; Infrared analysis; Infrared spectrometers; Irradiation; Mineral Resources; Mineralogy; Minerals; Mossbauer spectroscopy; Nuclear energy; Nuclear power plants; Original Paper; Physics; Point defects; Radiation; Radioactive wastes; Stainless steel; Swelling pressure; Thermal analysis; Waste management; X-ray diffraction; Bentonite; Reduction; Radiolysis gas; γ irradiation; Swelling pressure
• ISSN: 0342-1791; 1432-2021
• DOI: 10.1007/s00269-025-01322-y

To investigate the impact of γ irradiation on bentonite, the natural bentonite from GaoMiaoZi (GMZ), located in Inner Mongolia, China, and foreseen as an engineering barrier in geological disposal facilities, was selected as the subject of this study. The sample underwent exposure to a Co-60 source followed by comprehensive analysis utilizing various techniques, including mass spectrometer, swelling pressure testing system, X-ray diffraction, simultaneous thermal analysis, infrared spectrometer, and Mössbauer spectroscopy. The findings indicated that γ irradiation detrimentally altered the microstructure and reduced the structure trivalent iron of GMZ bentonite, leading to a decrease in swelling pressure, with a noticeable cumulative dose effect. Additionally, a negative exponential correlation was observed between the maximum swelling pressure and absorbed dose. The effect of γ irradiation significantly influenced the physical and chemical properties of GMZ bentonite.