The applicability of selected lean manufacturing tools in a coal beneficiation plant

Abstract

The main objectives of this study were to investigate if lean manufacturing tools were applicable in a coal beneficiation plant and to apply these tools in an effort to optimise the plant processes. This study was conducted at XYZ coal beneficiation plant situated in the Mpumalanga province. The volatility of mining commodity prices like coal prices poses a threat to the profitability of mining companies. Since mining companies have no control over the coal price; they need to keep their unit costs low to widen their profit margins. Lean manufacturing is one approach that could be utilised to improve productivity, eliminate waste and improve unit costs. A literature study was conducted to understand the Lean concepts, to analyse theory as well as to investigate similar studies on the topic. The theory was also analysed together with the practical processes to understand how theory can be applied to a coal beneficiation plant in practice. The current state Value Stream Mapping (VSM) was drawn to uncover the type and amount of wastes and inefficiencies in the plant so as to identify opportunities for improvement. The study identified wastes of motion, inventory, inappropriate processing as well as other process inefficiencies. Subsequent to this, projects were initiated to optimise the processes. The projects were carried out through the application of such lean tools as Six Sigma, flexible plants, flexible processes, 5S's of good housekeeping, standard work and quality at the source which all proved to yield positive results for XYZ plant. The selected lean manufacturing tools were conclusively found to be applicable to the XYZ coal beneficiation plant; whilst some tools were not applied either because they were less applicable or have already been applied by the organisation. The study also presented opportunities for longer term projects which the organisation could pursue further for future optimisation as well as recommendations for the organisation and for future research.