Effect of magmatic intrusion activity on coal bed and quality in Liujiang Basin

In order to find out the influence of magmatic intrusion on the continuity and stability of coal seam, coal and rock characteristics and coal quality, etc. in Liujiang Basin,and provide support for deep resource exploration and coal development and utilization in the basin, this paper was based on the data of ground investigation, drilling, logging, coal petrology and coal quality testing, analyzed the characteristics of coal seam, coal petrology and coal quality in magmatic intrusion area, and several models of magmatic intrusion into coal seam, and summarized the physical and chemical properties of coal under different magma intrusion modes. The study results show that the intrusion of magma into coal seams in the basin can be roughly divided into four modes, and the degree of damage to coal seam and coal quality is different; Coal seams affected by magmatic intrusion have coal-rock zoning characteristics in the longitudinal direction. These can be divided into normal coal, coal charcoal mixed zone and natural coke. Magma intrusion increases ash content, the fixed carbon content decreases, the calorific value decreases, the thermal stability and the selectivity deteriorate, and the degree of influence increases as the distance between the coal seam and the intrusive rock decreases.