Simulating underground mine fires for emergency planning

Abstract

The mining industry plays a vital role in the economy of South Africa, and continued growth depends on maintaining safe working conditions. Fires in underground mines are considered one of the most serious hazards as they pose a risk to lives and disrupt operations. The complexity of underground ventilation systems complicates fire management. Contaminants such as carbon monoxide can spread rapidly throughout the ventilation network, reaching distant areas and endangering worker safety. Effective planning and fire mitigation strategies are essential for maintaining safe working conditions and minimising incident impacts.

The existing literature mainly focuses on the localised effects of fires in mine ventilation systems but offers limited insight into the spread of fire-related contaminants throughout the ventilation network. There is also a lack of detailed assessments of indirect ventilation control strategies, such as pressure control and airflow partitioning, which can mitigate the effects of fires across interconnected mine areas.

This study developed a method to identify and evaluate ventilation control strategies to mitigate the effects of fire in underground mines. A risk assessment revealed that conveyor belts pose the greatest risk to the ventilation system. To address this issue, a simulation model was developed to represent the ventilation network of a twin-shaft gold mine located in South Africa. The model was calibrated using actual mine data and achieved a mean absolute error of less than 5%. Standardised design fire scenarios were applied to investigate the spread of temperature andcarbon monoxide. The study analysed the impact of airflow reversal, which can worsen the spread of contaminants and increase the risk to the health and safety of mineworkers.

The findings indicated that indirect ventilation control strategies, including pressure control, airflow partitioning, and smoke extraction, are crucial for mitigating the spread of contaminants. The study validated the effectiveness of the developed simulation model, highlighting its value as a proactive tool for fire mitigation and emergency response planning in underground mines.