Aerological risk management in preparation mining of coal mines

Objective. The purpose of the research is to assess the indicators of aerological risk in the development workings of highly gas-rich coal mines. Introduction. The results of a retrospective analysis are presented, substantiating that the vast majority of explosions of dust-methane-air mixtures occur in development workings, and 63.8% of their gassing with methane to explosive concentrations is associated with ventilation disorders. Methodology. The assessment of aerological risk consists in the calculation of some indicators that reflect the measure of danger, in which an accident may occur, caused by the excess of the values of the mine atmosphere parameters in comparison with the normative ones. Indicators of the main hazards and vulnerability of ventilation schemes and methods make up the general structure of risk in development workings. Results. The methodological bases for assessing and forecasting the aerological risk of accidents in development workings are presented. A formula for calculating the predictive indicator of aerological risk is given. In accordance with the methodology, it is possible to quantify the reduction in the level of aerological risk when managing outgassing with the help of degassing. Discussion. Calculations have shown that the schemes and methods of ventilation of dead-end workings, in which there is a large degree of influence of the activity of mixing gases in the bottomhole zone and a small degree of influence of the exhaust gas zone on ventilation, are the most effective, with a normal level of safety. The values of the predicted upper-air risk indicator reach unity for the schemes and methods of ventilation of dead-end workings with a low degree of gas mixing activity in the bottomhole zone and a high degree of influence of the exhaust gas zone on ventilation, which indicates an extremely high level of explosiveness. Conclusions. Application of the developed methodology allows not only forecasting aerological risks during design, but also justification of aerological safety.