Study on magma intrusion affected to coal properties of Daxing Mine

In order to study the magma intrusion in Daxing Mine of Tiefa Coalfield affected to the coal properties, seven coal samples with different distances to the igneous rock wall were selected. The vitrinite reflectance, proximate analysis, mercury injection test, adsorption constant, adsorption initial velocity and other experimen ts as well as determination were conducted on the samples. The following conclusions were obtained that the magma intrusion made the coal metamorphic degree incre ased. With the distances to the magma continuously decreased, the vitrinite reflectance would be steadily increased. Coal was transited from long flame coal to coking coal, meanwhile the ash content of the coal was seriously increased and the moisture content, volatile matter and fixed carbon were steadily reduced. With the distance to the magma was continuously reduced, the total pore volume, total specific surface area and porosity were firstly increased and then decreased, meanwhile the influe nces of the magma intrusion were mainly in the micro pore. With the distance to the igneous rock wall was reduced, the limit adsorption and emission initial velocity bot h were firstly increased and then rapidly decreased.