Published in the March 2006 American Longwall Magazine
Peabody’s Eastern Associated Federal No. 2 mine in Fairview, West Virginia, about 30 minutes west of Morgantown, produced 4.1 million clean tons in 2005 and is aiming for 4.95Mt in 2006. The operation is one of Peabody’s largest.
Thanks to its long history, Federal boasts an experienced workforce. Longwall maintenance manager Allen Pollastrini, an employee of Federal for 10 years but a miner for more than 30, is clearly in the majority at the operation. Workers boast their mining experience like a badge of honor, with many proudly sharing a memory from 25-plus years underground.
Federal, which mines the Pittsburgh seam with a shale and coal roof, has a seam height of 92-96in, and mining height of a comfortable 86-90in under 750-1250ft of cover depth at any given time. On the face 166 Joy 2 legged shields with a yield load 5719psi and RS20 control are employed.
Mining is performed on the 959ft wide, 6900ft long panel with a 662hp Joy 7LS shearer, its 63.5in drum diameter on a machine running at 45rpm. Each full pass takes about 45 minutes with a cutting height of 88in and cutting web of 36in.
The 890mm wide, 289fpm Joy face conveyor gets the coal moving via a twin 42mm Theile chain running at 2300tph, 54in Continental Conveyor panel belts run by a dual 500hp drive. There are areas in the current panel where sandstone and sandstone channels exist in the immediate roof; however, head coal is left intact mainly for roof control.
Once coal reaches the head, it is dropped to a Joy stageloader with a 2700tph capacity belt crusher, keep things moving at swift pace.
Once the output reaches the Continental Conveyor main line drive, also dual 500hp, and 60in belt running at 4000tph, it rapidly arrives at Federal’s skip hoist for outbound transport. Longwall manager Keith Garletts said there are options to take if needed: “If the coal feed exceeds the skip capacity, a flop gate is opened and the coal is diverted into mine cars. The cars can then be dumped after the peak load has passed.”
Workers travel to the face in DC-powered mantrips; the trip to the active panel, about five miles, takes about 20 minutes.
“Methane is an issue at Federal No. 2,” said Garletts as he explained that the operation’s development sections and outby areas are ventilated with the use of four fans. There is a separate split for the bleeder system, equipped with an independent fan to remove the gas from the gobs. “Bleeder [vertical] boreholes with exhausters are also used,” he noted.
Examining the surroundings during the mantrip ride to the company’s 7 Left panel, it is clear the operation is skilled at bolt installation and maintenance and the result is a solid, well supported roof and ribs. However, Garletts said, roof control is another one of their main issues, as is continuous miner development.
Maintenance is given high priority at Federal as well. Because of the mine’s age and remaining reserves – the operation is currently projected to mine until 2012 – the option to replace major equipment with new is financially unsound. When a longwall move occurs, which Garletts and Pollastrini said takes about 12 days on average, all equipment reconditioned two panels prior is brought back to use in the new panel (except shields, which move with every changeover).
Garletts noted that the operation does not incorporate any special bolting processes to recover the longwall. “The face is bolted using a single boom bolter and an ARO Longwall Face Bolter that install two hole straps and 6-foot torque tension bolts,” he said.
However, mine manager John Kucish said Federal does incorporate 3-entry development for the longwall. Workers install two 8ft combination bolts with a strap every 4-5ft on the advance, and center bolts are installed after the miner has been removed from the face. Cable bolts in 12ft lengths are an option to replace the center bolt or they can be added as supplemental support in areas of bad top.
Regular maintenance is conducted within a two-hour window each morning from Monday through Saturday, and a full eight-hour shift is devoted to it on Sundays. In addition, an OEM service technician is available at the operation on a daily basis.
Pollastrini consistently and closely keeps abreast of maintenance issues throughout the day via a computer monitoring system. With a delay of just a few seconds, he can determine shield movement, belt temperature and more. The program can also be used to create work orders for items requiring attention and can monitor the overall performance of the longwall.
With three, nine-hour shifts six days a week, and constant movement at the longwall face due to Federal’s “hot seat” changeouts, one would think there would be an overwhelming amount of information to analyze. Not so, said Pollastrini. The monitoring system puts all the important details right there for viewing.
At the surface, Federal’s preparation facility mirrors the thorough, safe production found underground. The plant, with output at a nominal feed rate of 1300rtph (and a yield of 82%,) cleans the coal using heavy media, spirals and froth flotation method.
Federal then ships the prepped coal to multiple clients by rail, though Garletts said truck shipment is available.
With a total payroll of 467 (381 hourly and 86 salaried), Federal makes maintaining a commitment to safety throughout the ranks look easy.
Federal’s commitment to safety recently earned the company a state recognition: the operation won the Barton B Lay Jr Milestone of Safety award for its safety performance last year – the incidence rate for the year was a commendable 4.18. The award was bestowed at the West Virginia Coal Association’s 33rd annual Mining Symposium in the state’s capital city of Charleston on January 19.
While the operation serves as an example for others in its class for safety, Federal’s staff feels that what’s good can always be made better. Garletts said a continuous improvement program is currently underway at the complex to investigate methods to improve the operations from all sides into the future.
