Control of technological processes and reduction of gas dynamic hazard on the basis of using the acoustic afteraction

Abstract

The objective of the work was to develop new methods for controlling technological processes during driving development headings and mining coal in stope faces. Accidents happened while performing of underground mining operations are often caused by the so-called “human factor”: miners do not always accurately follow the safety regulations, namely, the roadways are not supported in due time, the gas-drainage boreholes are drilled to the wrong depth, duration of the fluid injection at hydraulic loosening is cut, etc. In real conditions, it is difficult to control all the technological processes occurred underground. Therefore, the purpose of the study was to develop recommendations for controlling technological processes in the mines in order to reduce the risks of gas-dynamic phenomenon occurrence. In this work, the authors present further development of the most rational known approach to the control of technological processes consisted in assessing of gas-dynamic hazard by the method of seismoacoustic aftereffect. The nature of changes in acoustic activity depending on the type of winning operations was analyzed. The clearer differentiated assessment of the stress-strain state of the coal seam face area was obtained. The study of the acoustic aftereffect during the mining of a coal seam by different technological methods made it possible to assess the technology of winning operations from the point of view of ensuring safe working conditions. The block diagram was built, on the basis of which an algorithm of performing operational control of technological processes in development headings and stope faces was developed, including operations in prone-to-outburst seams. The basic requirements for the correction of existing software for the classification and recognition of technological processes by their acoustic aftereffect (trace) in the records of the predicting systems carried out during mining operations in the mine were formulated. These recommendations for the control of technological processes were proposed the Pokrovskoe Mine for implementation. The proposed recommendations improve accuracy of the forecasting of gas-dynamic hazards during mining operations, make it possible to control technological processes as well as simplify the investigation procedure for establish the causes of a critical situation in the case of an accident. The implementation of the recommendations will also make it possible to assess a gas-dynamic hazard during stoppages for repair and other auxiliary work, to predict geological disturbances ahead of the moving face, to determine the size of the unloading zone of the bottom area of the coal seam, and to assess the effectiveness of measures to prevent gas-dynamic phenomena. Keywords: acoustic aftereffect, technological processes, gas-dynamic phenomenon, safety of mining operations.