Materiały konferencyjne SEP 2023

In a two-stage mode (see Fig. 1, a), the HDI provides a reduction in the gas pressure in the seam and the initial velocity of gas emission from the control holes to almost zero. Thus, when opening the seam, there is no gas emission into the roadway atmosphere. The three-stage mode of the HDI (see Fig. 1, b) is used in the lower part of the strips worked out by the frontal units. This improves the manufacturability of the method, since the air jet (outgoing) from the bottom gangway face enters the fresh stream of longwall, and the size of the abutment pressure zone significantly exceeds the seam processing area when it is opened. Studies have found that with an increase in the coal hardness in the array, the intensity of crack formation increases, and the amount of extracted coal decreases. For example, when processing the seam m 3 - "Tovstyi" ( f = 1.5) in the conditions of the mine named by M.I. Kalinin PA "Artemvugilliy" 336 cycles of impact were performed at 4 boreholes. Less than 1% of destroyed coal was extracted from each borehole (the process of layer-by-layer destruction did not appear). At the same time, the control of the technological process with sound-catching equipment [8] showed that intensive crack formation processes occur in the rock massif (Fig. 3) [6]. a – development of acoustic emission during the seam opening ( k rec =5-10%), b – development of acoustic emission in the abutment pressure zone of the lower part of the lift ( k rec =1-4%) 1 – pressure release, 2 – continuous acoustic emission (CAE), А – signal amplitude, τ – signal duration, Ι - Ⅸ phase of CAE Figure 3. Fragments of the CAE development diagram during the HDI a - rozwój emisji akustycznej podczas udostępnienia pokładu ( К и =5-10%), b - rozwój emisji akustycznej w strefie wzmożonego ciśnienia górotworu dolnej części piętra ( К и =1-4%) 1 - obniżenie ciśnienia, 2 - ciągła emisja akustyczna (CEA), A - amplituda sygnału, τ - czas trwania sygnału, Ι - Ⅸ faza CEA. Rys. 3. Fragmenty wykresów rozwoju CEA podczas OHD