SIMULATION OF THERMAL CONDITION OF UNDERGROUND GOLD MINE THROUGH VENTILATION AIR QUANTITY CONTROL USING ANALYTICAL AND NUMERICAL METHODS

• Main Author: Zaka Waly, Fadli
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86286
• Institution: Institut Teknologi Bandung

One of the main problems faced by underground mines is suboptimal thermal conditions on the working surface. This thermal problem is caused by the influence of artificial heat sources such as equipment and workers, or natural ones such as auto-compression, air temperature on the surface, and heat from rock strata. Underground mines in Indonesia, although on average included in the shallow category, because they are crossed by the equator, the average air temperature is 27°C, which is quite high before the influence of heat sources. Heat control in shallow underground mines can be done by increasing air flow with fan selection, preventing recirculation, and improving the overall ventilation network. However, the thing that is of concern in optimizing thermal conditions in underground mine ventilation systems based on quantity is the level of energy consumption. Underground mine ventilation systems can consume 40-50% of the total energy supplied to the mine. This fact is a challenge for experts and researchers so that the energy supply for the ventilation system can be used as efficiently as possible. In this study, there are two main criteria that are considered in designing the overall and local ventilation system, namely the aspect of fulfilling air needs (safety aspect) and saving fan power (economic aspect). This is done using numerical analysis where Ventsim 6.0 is used for the overall ventilation analysis and computational fluid dynamics for local ventilation. The system analyzed is the underground gold mine ventilation system of Area C PT XYZ. The overall ventilation simulation results show optimal thermal conditions using the main fan power of 110 kW with a WBGT value in the most extreme heat conditions ranging from 27.6°C to 30.4°C or an effective temperature of 26.7°C to 30.6°C. The local ventilation study provides a recommendation for a discharge ratio on the ramp and work front of 1.4: 1 to anticipate heat increases due to recirculation. Then, with consideration of anticipating air recirculation, the optimization design in hot conditions for other activities achieved savings of 41.94% for surveying activities while other activities such as drilling, charging, scaling, and/or supporting were 33.73%.