Abstract
The aim of the research is to investigate factors that optimize the Overall Equipment Effectiveness (OEE) of an underground Bord and Pillar coal mine that has limited coal reserves and unfavorable geological conditions. OEE is a Total Productive Maintenance (TPM) tool that was first introduced by Nakajima. It is used to identify and quantify losses in a manufacturing system by taking into account the six big production losses and grouping them into 3 efficiency baskets known as downtime losses, speed losses and quality losses. The OEE equation is a function of Availability x Performance Rate x Quality, with the key OEE measure applications being for benchmarking purposes, improving performance of individual equipment and that of pieces of equipment functioning as a single manufacturing line or batch process. The research focusses on OEE improvement of a Bord and Pillar mining operation that consists of 10 Continuous Miner (CM) sections, mining both the higher seam and lower seam coal operations. The equipment-suit functions as a batch process and consists of the CM, Shuttle Cars, Feeder Breaker, Conveyor Belts and Roof Bolter. The equipment-suit in use, has to be adequately allocated for correct mining application in order to ensure optimal mining operation with considerations of constrained reserves and poor geological conditions. Three elements making up the OEE equation (Availability, Performance Rate and Quality), are all under review to establish factors that influence the OEE value in a Bord and Pillar mining operation. Availability is a combination of Equipment Availability (EqA) and Use of Equipment Availability (UEA). The EqA is primarily a function of unplanned engineering and operational downtime events such as electrical/ mechanical downtimes, cable damages, changing picks and sleeves on CM cutter head. UEA is driven by production and consequential delays such as conveyor belt downtimes, excessive number of belt extensions/ section moves and roof support due to geological conditions. The average OEE figures for this Bord and Pillar operation are in the region of 45%. The planned qualities and de-rated productivity rate percentages are high with average figures of 85% and 103% respectively. The results demonstrate that Availability is at an average of 52% and presents an area of opportunity for overall OEE improvement. Geological mining conditions inherently contain mining inefficiencies that lead to a loss of direct operating hours (DOH), which effectively affects the availability component of OEE...
M.Phil. (Engineering Management)