The closure of deep mines, featuring multi level seam extraction, lasts many years. During this time period, the ventilation system must ensure adequate working conditions, and ensure the safety and stability of fan operation in gas and fire hazards conditions. The analysis of air flows and methane inflows during the progress of mining mine excavations closure, is the primary object of the article. Execution of such analysis requires knowledge of the mining mine excavations’ closure schedule, the structure of the ventilation system under consideration, the values of the parameters describing the air flows delivered to the mine excavations, and the current characteristics of operating fans and predicted methane exhalation. A computer database, currently being updated by a mine ventilation department for the VentGraph-Plus computer software, has been used simulate the various ventilation scenarios experienced, during the final stage of closure, including the shutdown of the main fans and the backfilling of shafts. The results of case study, containing 2 variants of simulated examples, are presented in the form of diagrams of methane concentration changes in time at characteristic places of the mine. The completed simulations of ventilation processes during the closure of mine excavations and transfer of inflowing methane, indicate useful possibilities of the computational tool used.

In recent decades, two different approaches to mine ventilation control have been developed: ventilation on demand (VOD) and automatic ventilation control (AVC) systems. The latter was primarily developed in Russia and the CIS countries. This paper presents a comparative analysis of these two approaches; it was concluded that the approaches have much in common. The only significant difference between them is the optimal control algorithm used in automatic ventilation control systems. The paper describes in greater detail the algorithm for optimal control of ventilation devices that was developed at the scientific school of the Perm Mining Institute with the direct participation of the authors. One feature of the algorithm is that the search for optimal airflow distribution in the mine is performed by the system in a fully automated mode. The algorithm does not require information about the actual topology of the mine and target airflows for the fans. It can be easily programmed into microcontrollers of main fans and ventilation doors. Based on this algorithm, an automated ventilation control system was developed, which minimizes energy consumption through three strategies: automated search for optimal air distribution, dynamic air distribution control depending on the type of shift, and controlled air recirculation systems. Two examples of the implementation of an automated ventilation control system in potash mines in Belarus are presented. A significant reduction in the energy consumption for main fans’ operation obtained for both potash mines.