Assessment of underground mine production efficiency at Morupule coal mine

Abstract

Mining productivity is a measure of the effectiveness of mining resource inputs computed as a ratio of production output per input resources. Factors affecting productivity can be grouped as a combination of technical and economic factors. The ratio of the production outputs to inputs in a mine determines the mine’s productivity. The greater the output produced at optimum cost, the more efficient is the functional mine system. In this study, the factors affecting mine production efficiency at Morupule Coal Mine (MCM) were assessed using statistical analysis methods as the mine has varying daily production levels that are mostly below set threshold targets. Also, production shift variances were assessed and the causes of productivity variances were classified according to scale of impact. The results show wide variances in the production outputs between morning, afternoon and night shifts; the equipment availabilities for continuous miners (CMs) ranged from 79.5% to 92.2% and those for shuttle cars varied from 84.0% to 92.0%. The average engineering availabilities for CMs and shuttle cars were generally higher than their set threshold targets but they are the lowest performing equipment’s. The regression models show a high goodness of fit between the parameters and mine production showing that there is a strong correlation between them. It is recommended that the CMs should be frequently examined to be within their equipment reliability period and the duration of the mean time to repair of shuttle cars should be improved to ensure they are serviced within the maintenance service threshold targets.