Mining Publication: Validation of the Ventgraph Program for Use in Metal/Non-metal Mines
The mine ventilation program Ventgraph has been utilized and validated extensively in coal mines in Europe, Australia, and the United States. Ventgraph is used for studying coal mine fires, fighting fires with inert gases, spontaneous combustion, and mine emergency exercises. However, it has been used to a much lesser extent in metal/non-metal (M/NM) mines. Its application to hardrock mining methods would be beneficial for studying M/NM ventilation effects, mine evacuation training, risk analysis of potential mine ventilation changes, airborne contaminants, recirculation, and mine fires. In order to determine its applicability to M/NM mine fire modelling, Ventgraph was utilized to simulate the 1972 Sunshine Mine fire, where 91 miners perished. The Sunshine Mine was selected due to its deep, complex ventilation system, involving ventilation thermal effects and recirculation not normally found in single-level coal mines. Information sources such as the United States Bureau of Mines (USBM) accident reports, ventilation surveys, books, and publications were examined to recreate the pre-fire Sunshine Mine ventilation system. Next, Ventgraph’s network and fire simulation were run using assumptions from a USBM contract report to re-create the early stages of the mine fire and contaminant flow. Options to better control the ventilation system, evacuation, and early mine rescue attempts were tested. Calibration of Ventgraph’s fire simulation module to known events of the fire showed close correlation to contaminant levels observed and real-time movement of fire combustion products through the mine. This study’s conclusions validate the use of Ventgraph in a deep M/NM mine fire and illustrate its use as a valuable tool in mine ventilation, fire, and evacuation planning.