Engineering & Mining Journal

JUN 2014

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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the cab is sealed. If there are few peaks and the concentration of DPM is consistently above the PEL (see Figure 2b), then it can be assumed there are issues with cab integrity. Using the above technique as part of the evaluations described, one mine was able to detect that a new cab was leaking. This was confirmed at the maintenance shop using a smoke bomb test, and the cab was immediately scheduled for repair. Using Real-time Measurement for Evaluating Ventilation The Airtec has also been used to perform some spot checking to determine the effects of ventilation changes and the need for ven- tilation in specific areas of the mine. For example, a mining engineer at one mine car- ried the Airtec and measured the DPM con- centrations in different areas. Due to high concentrations at one of the faces, he was able to determine that a vent bag needed to be moved in order to provide adequate ven- tilation to a working area (Lethbridge and Good 2010). At two other mines, though the exposures of the blasters were within com- pliance for the eight-hour TWA, the short- term concentration of DPM around the blasters was greater than the MSHA PEL. The blasters were not out of compliance because they were loading faces only part of the shift; however, the real-time data revealed that they could have been out of compliance if they had to load additional faces. Therefore, these mines began investi- gating ventilation techniques to reduce the DPM concentrations at the face. Using a Video Recording System to Assess Sources of DPM Exposures NIOSH has recently developed a video monitoring system, called "Helmet-CAM," where a miner wears a camera and a real- time aerosol monitor while performing work tasks (Cecala et al. 2013). Whenever the work tasks are completed, the video and real-time monitor data are downloaded, then the downloaded files are processed by a software program (EVADE, www.cdc.gov/ niosh/mining/Works/coversheet1867.html) developed by NIOSH. The software program combines the two files and thus aligns the contaminant concentration measurements with the video that documents the task being performed. This method has been successful in identifying specific work tasks and work environments that can cause ele- vated exposures to dust. Using this infor- mation, controls can be implemented to reduce respirable dust exposures. This type of assessment tool can now be used to determine elevated exposures to DPM with the NIOSH-developed software and the Airtec. For example, the Helmet- CAM can be advantageous for determining sources of DPM exposures for mobile work- ers such as surveyors and blasters. Figure 3 shows a still frame of the video and DPM concentration graph generated when a NIOSH researcher demonstrated the Helmet-CAM at a limestone mine. As seen in the graph at the bottom of the figure, the concentration of EC was about 83 µg/m 3 at the time this picture was captured. As can be seen in the picture, a loader, truck, and scaler were working near the researcher at that time, indicating possible DPM sources. This same approach can be used to help determine the sources of DPM exposures to mobile workers. 80 E&MJ; • JUNE 2014 www.e-mj.com COMPANY PROFILE-PAID ADVERTISEMENT Chesterton offers a comprehensive line of application-specific mechanical seals, com- pression packings, gaskets, coatings, clean- ers, industrial lubricants, maintenance prod- ucts and polymer seals designed to withstand the harsh elements of the mining industry. 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Mobile Mining - Hydraulic Sealing Solutions Today's environment has created many unique challenges for the mining industry with emphasis on system availability, equipment productivity, capacity throughput and safety. For decades, Chesterton has been proving value-driven hydraulic sealing solutions to address these challenges for the mobile mining industry. To help reduce costs of downtime, end users must address these critical issues and anticipate the unexpected every day. Whether you're in the metal, mineral, or coal mining markets, we can help you manage costs and improve margins by optimizing the value of your equipment with reliable sealing solutions. Chesterton's hydraulic solutions help increase cylinder reliability by extending the hours of operation between maintenance intervals. Our turnkey cylinder repair kits combine proprietary polymer technologies with unique seal geometries designed to help improve the performance of your heavy-duty mobile mining equipment. Chesterton ® is uniquely positioned, with decades of know-how and experi- ence, to help you drive significant improvements in equipment reliability. Coupling product, service and technical expertise is the value driven approach Chesterton offers to the market. Real world proof comes from the applications perform- ance of our products used in mine after mine, worldwide. The cost of a replacement seal kit is the least expensive aspect of a cylinder rebuild yet can have the greatest impact on impact on production. Chesterton products are designed with the certainty of exposure to corrosion, contamina- tion, side loading and shock loading in mind. To help protect your assets and help lower the overall cost of ownership, we provide high- performance products proven to perform under these demanding conditions. Help pro- tect your assets by upgrading to Chesterton cylinder replacement kits for use in the fol- lowing heavy duty equipment: • Excavators – boom, arm, bucket, dump and level cylinders; • Trucks - hoist, steering, front and rear suspension cylinders; • Wheel loaders - lift, steering and tilt cylinders; and • Dozers - tilt, lift, ripper tilt, and ripper lifter cylinders. Find out why so many upgrade to Chesterton to extend the hours operation for their equipment. D P M M O N I T O R I N G EMJ_pg78-81_EMJ_pg78-81 6/3/14 3:23 PM Page 80

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