Improving the ventilation of deep-level gold mines by simulating inactive sections

Abstract

The South African deep-level gold mining industry has experienced several challenges in ensuring profitability. These challenges can be mainly attributed to increasing operational costs as mines continue to reach new depths. Cooling systems comprise a large portion of operational expenses. It is, therefore, essential that the ventilation system, which serves as the primary form of cooling, operates effectively by reducing wastage. In deep-level mines, the ventilation systems are extensive and, in some cases, incorporate decommissioned areas. These areas are often difficult to access since little maintenance is conducted on structural support. This leads to a unique challenge when attempting to evaluate such systems to ensure key ventilation system performance indicators are achieved. An alternative approach to evaluating such systems is therefore required. The methodology developed in this study uses thermohydraulic simulation software to accurately model a mine's ventilation network and develop a reconditioning plan. This methodology was applied to a deep-level gold mine in South Africa and led to the development of a comprehensive sealing strategy. The implementation of this strategy resulted in an airflow increase of a measurable 35 m³/s through the mine working areas. The increase in system resistance resulted in an increase in static pressure of the main surface fans. The increase in static pressure is associated with improved air utilisation and makes continuous mining operations possible. The case study results indicated that the use of simulation software could be used to evaluate and optimise the ventilation of inactive areas accurate to within 10% error. Despite the approach being applied to a deep-level gold mine, it can also be used to address inefficiencies in other mining configurations as well.