In mine workings between air and rock massif, beaten coal, as well as settled dust there is a mass and heat exchange. In the cold season, when air is supplied to the mine without heating and humidification, the process of mass exchange is directed from rocks to air. The amount of moisture released into the atmosphere depends on the moisture content of coal, dust and host rocks, the degree of grinding of coal or rocks, the speed of air movement, its humidity and other factors ...