On the relationship between gas emission from undermined coal-bearing stratum and the intensity of coal seam mining

Abstract

A theoretical scheme of gas release from the coalbed under production by treatment workings has been developed. The sizes of zones of different intensity of gas release from the working thickness are set according to the characteristic points of muld shift of the earth's surface. Total amount of releasing gas is determined by the area of the developed space, over which there is an intensive movement of the mined coal. The formation of this area is associated with the development of cleaning operations within the boundaries of the excavation site and the speed of movement of the treatment face. During the development of the theoretical scheme, several assumptions were made, the validity of which was verified on the basis of experimental data obtained in the conditions of four mines at fifteen excavation sites. Coal seams with coals of grades G and A were worked out by them at a depth of 300-1195 m, the capacity of coal seams was 0.90-2.20 m, cleaning works were carried out at a depth of 300-1195 m, the length of the lavas was in the range of 74÷270 m. The monthly movement of the treatment faces and the amount of gas released during this period were taken into account for each excavation site. It is established that the relative gas release per unit area of the developed space remains a fairly constant value for some mining and geological conditions, if the total amount of gas is attributed to the area that determines the active movement of rocks over a moving treatment face. This allows you to use the previously obtained results of determining the categorical danger of mines by relative gas release per ton of coal production in terms of improving the forecast of gas release from the coalbed under production more efficiently.

Development of methods and software algorithms for state forecast of the ultimate stressed rock massif

“…As a consequence of the massif dangerous manifestations, there is an increase of methane emissions, an increase of the mixture radioactivity, dust content, pressure and speed of the outgoing air jet, acoustic vibrations, electromagnetic radiation, etc. [1][2][3][4][5][6][7]. Existing methods for assessing of the coal-rock massif hazardous state in mining are based on the analysis of the main informative parameters that determine the gasdynamic phenomena: the magnitude and structure of the rock pressure, the output of the gas contained in the coal, the physical and mechanical properties and the state of the coal-rock massif.…”