Optimal use of mobile cooling units in a deep-level gold mine

Abstract The South African gold mining sector remains a significant contributor to the country’s economy. Facing several challenges that hinder the realisation of South Africa’s full mineral potential, the sector’s sustainability and profitability can be enhanced through implementing operational improvement measures. Mobile cooling units (MCUs) were identified as a potential focus area for operational improvement. MCUs are used as tertiary or in-stope cooling in hot underground workings. In this paper, a method was presented to characterise the performance of existing MCUs based on three key performance indicators (KPIs), namely, the wet-bulb temperature ratio (WTR), efficiency and position. Optimisation strategies were then elected and implemented based on these KPIs. The implementation of this method in a South African gold mine attained a reduction in pumped water volumes, reduced operating costs through electricity cost savings and improvements in underground ventilation air temperatures.