The elimination of electrical power limitations in the production section of a South African coal mine to facilitate additional production improvements

Abstract

Sasol Mining embarked on a renewal process during the beginning of 1998. The objective of this renewal process was based on a very clear case for change - Sasol Mining had to improve on its profitability as a coal mining company. The renewal process focussed on the following drivers: Q - The quality of coal delivered to the synthetic fuels plant (Sasol Synfuels) has to improve with respect to contamination. C - Production cost of coal/tonne must be contained, with an annual escalation of 1% less than the Producer Price Index (PPI). D - Delivery (tonne/continuous miner/shift) must improve. S - The health and safety of the operations has to be improved substantially, e.g. dust in ventilated areas. M - Morale of employees has to be raised substantially. Referring to the above and specifically to `Delivery`, there was a potential threat that some of the underground (in-section) electrical equipment and infrastructure may be stressed beyond their design capacity and limits. A typical example was the question: Will the electric cutter motors on the continuous miner be able to cut continuously at the increased rate? This study proactively investigated the matter and analysed the effect of the increased demand on certain equipment and infrastructure of the electrical in-section systems. The objective was to determine the production capacities (tonne/continuous miner/shift) that can be sustained by utilising present mining equipment and cables. The power consumption of all the equipment in a standard section was measured to determine the present production capacity of various items of mining equipment used in a production section. The data was then evaluated to determine the limitations in the production section. These results will assist Sasol Mining to determine the focus for upgrading different items of production equipment, taking into account the production potential of the insection production equipment.