Engineering & Mining Journal

JUN 2013

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 86 of 171

MAINTENANCE were estimated to yield a 16-fold reduction in particle contamination inside the engine, resulting in a projected three-fold extension of engine life. After 931 hours with the new filtration system, oil analysis was conducted and indicated that ISO cleanliness levels had been reduced from ISO 22/21/18 (c) to ISO 17/16/13 (c), soot levels were maintained at or below 0.1% vol, copper levels dropped from 118 ppm to 2 ppm, and iron levels dropped from 53 ppm to 7 ppm. Based on life extension projections, cleanliness levels of ISO 17/16/13 (c) in an engine should result in a four-fold increase in engine life. Purchase and installation costs of the engine filtration kit were approximately $3,000, with an annual replacement element cost of about $1,000–$2000. A typical "top end" engine overhaul costs at minimum $12,000–$15,000. Based on the target cleanliness levels achieved, the top end overhaul interval is now projected to increase from an average of 13,500 hours to 54,000 hours, resulting in a net present value savings across the mines fleet of six loaders of $129,841 over five years, at an annualized rate of return of 216%. To date, Des-Case reports that the mine has been able to sustain the improved levels of fluid cleanliness achieved with the engine kit and paid off its investment in the system in a little over five months. Make it Part of the Program The benefits of an oil analysis program can be maximized when it becomes part of a company-wide, management-supported effort. For example, the Hibbing Taconite Co., an 8-million-t/y magnetite operation located in Minnesota's Mesabi Iron Range and managed by Cliffs Natural Resources, won Uptime magazine's Best Lubrication Program award in 2012; an important element of Hibbing's condition-monitoring program is the oil analysis component of its lubrication program. In the first phase of the program, reliability engineers were trained as Level I Machine Lubrication Technicians (MLT1), and dedicated lubrication mechanics were assigned in the plants to monitor equipment oil conditions. During the second phase, MLT1 training continued, involving lubrication mechanics and supervisors. Critical equipment received lubrication upgrades such as desiccant breathers, sight tubes, sample ports and quick couplers for filtering, allowing for safer filter changes and reducing crosscontamination risk. Currently, 80 Hibbing employees have received MLT1 training for machinery lubrication and basic oil analysis. Management reportedly regards the program as an investment. Overall, fluid analysis has been consolidated across all Cliff operations, using a single oil analysis laboratory that was selected after ranking sample results from several labs. This approach provides consistency as well as the ability to review and compare data. Sample standards were determined in accordance with equipment specs, sample ports were installed where needed and personnel were trained on how to collect samples. The CMMS system controls sample frequency. In addition, the maintenance team installed oil moisture sensors to allow real-time condition monitoring, resulting in a reduction in overall site oil consumption by removing water contamination. Dedicated lube carts were made available to enable quick, clean and safe fluid changes with fewer opportunities for spillage. And, all machines were tagged with machine identification and lubrication information to reduce service errors and contamination problems. JUNE 2013 • E&MJ 85

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