Radon Release Characteristics and Influence of Physical Parameters in Different Types of Coal

Radon is a gas associated with coal that is released during coal mining, storage, processing, transportation and utilization. Poor ventilation and small spaces can cause a sharp increase in the environmental radon concentration, increasing the potential radiation risk to miners. Coal radon emanation is related to the physical parameters of coal. In this study, a theoretical model of the radon exhalation of coal piles is established and the six main forms of radon gas generated by radium decay in coal are analyzed. It is determined that the main physical parameters affecting radon release are the radium nuclides, inorganic minerals, moisture, and pore structure. On this basis, the radon concentrations and physical parameters associated with different types of coal (lignite, long flame coal, weak caking coal, gas coal, coking coal, lean coal, and anthracite) in China’s coalfields are measured. The Gray correlation analysis method is then used to obtain the order of influence of coal physical parameters on radon release, i.e., radium concentration > total pore volume > moisture content > inorganic mineral content. The study results have important research significance and application value because they can be used to improve miners’ awareness of radon risks and provide fundamental data for coal-related enterprises to reduce radon pollution and formulate reasonable radon control measures.