Abstract
Coal production operations remain and continue to remain at the center of South African electricity generation mostly utilized by Eskom and other smelters across the globe. Coal production industries depend profoundly on large, advanced, and heavy earthmoving equipment to extract and transport coal. Mining haul trucks and hydraulic excavators are one of the main earthmoving equipment that is used in surface coal mining industries and their performances are extremely codependent. Thus, the current research study attempts to systematically appraise the field of reliability engineering and surface coal mining equipment failures, through analysis and evaluation of collected coal mining equipment maintenance data, and ultimately develop a reliability improvement program based on the analysis of the collected data.
The research study appraises various kinds of literature on mining equipment reliability engineering and analysis couple maintainability analysis. Thus, for proper equipment maintenance and reliability data analysis, three (3) coal surface mines situated in Mpumalanga (Emalahleni) are selected for evaluation. Six (6) hydraulic excavators from each of the selected mines and six (6) haul trucks from each of the selected mines are also selected for analysis. Thus, the data is collected from the operation of the above-mentioned equipment (hydraulic excavators and haul trucks) between the period of January 2019 to December 2020 (24 months). Various statistical and reliability analysis approaches such as Mean Time Between Failures (MTBF), equipment reliability trends, Normal Distribution, K-S Tests, Failure Rate Function (𝜆), and equipment acute and chronic failures have been demonstrated within the current research to eradicate or reduce factors contributing to low-reliability values.
Furthermore, the research study has successfully demonstrated that five (5) out of the selected 36 pieces of equipment have not met the required reliability targets for a period of 24 months. The 5 types of equipment are one (1) excavator and one (1) truck from surface coal mine 1, one (1) truck and one (1) excavator from mine 2 and finally one (1) excavator from mine 3. The factors that have contributed to low-reliability values on the five (5) equipment have been identified through acute and chronic failure analysis. Additionally, the reliability improvement plans to reduce or eradicate identified factors have been completely demonstrated.