Geochemical and Mineralogical Specifics of Ekibastuz Coals’ Natural Radioactivity in Terms of Assessing Their Qualitative Characteristics and Radiological Safety

The modern development of the energy and metallurgy industries is accompanied by the increasing use of coal in the form of fuel and raw material. However, at the same time, urgent issues are arising concerning assessments of its radiological and environmental safety. Coal and ashes accumulate natural radionuclides (such as thorium, uranium, and potassium-40), and toxic and rare earth elements (REEs) that are capable of migrating into the environment during the processes of production, burning and ash disposal. Special attention has recently been paid to rare earth elements that are of economic value as critical metals for sophisticated technologies, but these can pose environmental risks. Their presence in coal is becoming an increasingly relevant issue for cross-disciplinary research, at the intersection of geochemistry, radioecology and the sustainable use of natural resources. Moreover, issues regarding the radiological safety of coal deposits and their derivative products are especially crucial for Kazakhstan, Russia, China and other countries with developed coal production industries. Studies demonstrate that ash and slag of thermal power plants can comprise increased concentrations of natural radionuclides that can accumulate in soil, water and the environment. Therefore, the study of rare earth, toxic and radioactive element contents in coal using nuclear analytical methods is of high practical and environmental significance, especially in terms of assessing radiation load on the environment, designing control measures and ash disposal, and the prospect of the selective extraction of REEs from the coals.