An integrated ventilation and cooling strategy for mechanised deep-level mining

Abstract

Planning of mine ventilation and cooling ensures acceptable environmental conditions underground. To this end, simulation-based planning tools are used for their advantages over calculation-based planning techniques. Various studies and literature on mine ventilation planning exist but tend to neglect certain heat sources, life-of-mine planning considerations, and continuous monitoring. Deep-level mining operations have an increased need for temperature control while pollutant emissions decline with the application of improved technologies. By analysing literature on mine planning strategies, a generic methodology was proposed in this study with a focus on the simulation of life-of-mine models, temperature and pollutant control, integration with existing planning structures, and continuous monitoring. Surveys and plans for the mining environment were used to construct the baseline and future models, which were verified by calculations and audit values. Required airflows and temperatures were calculated from regulation and used to analyse future model results, alongside mine management. Solutions to identified issues were proposed, evaluated, and implemented alongside future model updates. In the case study, an additional 6.5-MW surface cooling plant was constructed to address the cooling shortfall identified. Post-construction surveys of the mining environment revealed a model error of 36.6% for airflow, 16.5% for wet- and 17.8% for dry-bulb temperatures. The errors were subsequently reduced to 12.2%, 5.4% and 5.5% respectively after implementing updates related to deviations from the plan. The errors were deemed acceptable in the light of measurement limitations and the proposed methodology was successfully used to predict the ventilation and cooling infrastructure requirements and impact thereof on one mechanised deep-level mine, while improving on the inherent errors related to non-continuous planning strategies.