Since 1991 and continuing into the present, SRK’s mine ventilation team, formerly Mine Ventilation Services Inc., has been involved with the development of the ventilation system at the West Elk Mine. As the mine has been developed in the F Seam, down to the B Seam, and back up into the E Seam SRK engineers have surveyed, tested, evaluated, and provided planning services to the mine.
Full ventilation (pressure/quantity) surveys have been performed periodically to provide an accurate, updated ventilation model that can be used for planning air changes required for developments into the different seams and mining areas. One area that has been identified by the ventilation surveys as a continuing issue is the gradual increase in the resistance of the exhaust airways due to the deep accumulation of rock dust and its effect on the future ventilation of the deeper panels in the E Seam has been identified. The models have been directly used for daily planning and in support of the longwall move sequencing.
One of the more interesting studies developed for this operation includes assisting in the transition from a full exhaust system (F Seam and B Seam) to a partial push/pull ventilation system so that a remote exhaust shaft could be utilized.
One aspect that separates coal mine ventilation systems from metal mine ventilation systems is the significant quantity of leakage encountered. As the mine has developed, different types of bulkhead construction have been encountered which has provided different leakage factors. Fan placement and airway grouping also effects the leakage rates. The ventilation models help to both increase efficiency, minimize leakage, and allow the site ventilation engineer to preview the potential results of ventilation changes and the development into new areas. The required modifications to the ventilation system and system infrastructure can be rapidly evaluated and plans for the successful ventilation of the new area developed.
At the West Elk Mine the ventilation models have been useful in minimizing pressure differentials in the system and in identifying overall system constrictions. Ventilation modeling is an appropriate tool to use when developing a ventilation plan, but the key is to develop the plans based on an accurate ventilation model. The best way to achieve a high level of accuracy is to develop the base model upon the results of a full pressure/quantity survey. Periodic ventilation surveys are a very good way to observe changes in the system over time.
