Controlling the longwall coal mining process at a variable level of methane hazard

The systems for monitoring the mine atmosphere, especially in the longwall panels, have been used for many years. Thanks to their use, it was possible to reduce the number of hazardous events (accidents). Until now, the attention was paid primarily on securing the mine personnel as the most important aspect of the methane explosion hazard. Recent years show that the number of accidents in Poland decreased to several cases per year. Such an event can cause a risk of damage. In order to further reduce the number of hazardous events, the existing solutions will not be enough, so a new approach to monitoring and using the methane concentration prediction methods in longwall panels is necessary to be applied. The reasons for changes in methane hazard level at the coalmine longwall faces are discussed at the beginning. Then, the methods for controlling the longwall shearer's operation depending on methane hazard level are presented. Dangerous events caused by the sudden outflow of methane into the longwall panel were recalled. In the further part, an additional subsystem for monitoring the methane concentration in the longwall panel in the context of controlling the operation of the longwall shearer and the run-of-mine transportation in the longwall area is described. Finally, the importance of the new way of controlling the mining process and run-of-mine transportation for work safety and mining efficiency was emphasized.