Coal Age Magazine - For nearly 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.
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2000-2012 Coal Preparation The advent of high-capacity processing equipment, including multi-slope screens and large diameter cyclones, has enabled plant designers to install more raw coal processing capacity per unit of plant volume than ever before. Using modern high- capacity equipment also reduces maintenance time and feed piping and chute work. Plant designers give more thought into making the area around the equipment easier to negotiate. They are more cognizant of overhead cranes and lighting. Prep plant managers are also adopting widespread use of com- pound spirals to process fines. Spirals are popular because they are relatively easy to install, oper- ate and maintain. They do not require reagents or magnetite. The biggest downfall is low capacity. During 2008, Coal Age re- ported the business of building prep plants was brisk with a record number of orders for new plants and upgrades. Many of those projects were complet- ed before the market softened in 2009. The total population of U.S. prep plants now stands at 283. Wetzel Davis operates one of Coal River's continuous miner units in Mine No. 10. *Coal Age, February 2011 W.Va., becomes the first mine in West Virginia to deploy diesel- powered technology underground during July 2003. In October 2003, Joy Mining Machinery announced a major breakthrough. It was applying AC variable frequency drives (VFDs) to shuttle cars, which would provide significant increas- es in power, speed and productivity. In 2000, U.S. longwall population falls to 59. Throughout the decade, the total number of longwalls would hover between a low of 49 and 55. Total production and productivity continues to improve. The Joy 7LS shearer had become very popular among long- wall operators. When the system was introduced in the late 1990s, Joy hailed it as a breakthrough as far as longwall haulage. The system also relies on VFDs, which gives the operator abso- lute speed control with providing greater speed for cutting and flitting. When Joy acquired American Longwall it also gained the knowledge necessary to improve the hydraulic cylinders on the ranging arms. With an improved electronics package, the system provides extreme overload capability to the AC drive. Spurred by the MINER Act of 2006, integrators and OEMs gain approval for various new communication and tracking systems for underground miners. While the range and other specifications have not yet been clearly defined, by December 31, 2007, MSHA has observed 27 communication systems at various mine sites. In general, the technologies can be divided into leaky-feeder (with a redundant backbone), self-healing mesh systems and through the earth (TTE) technologies. In less than 18 months, modern communication equipment was being installed in underground coal mines. August 2012 100th Anniversary Special Issue www.coalage.com 179 PrepTech bank of double-start spirals with a distributor on top. *Coal Age, December 2005