Coal Age

DEC 2012

Coal Age Magazine - For more than 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.

Issue link:

Contents of this Issue


Page 34 of 75

foresight energy continued online. "I've got one unit right now just turning up into Headgate No. 2. In the next couple months, I'm going to be starting the main section as you come down to Headgate No. 3," said Francisco. Patton runs three production shifts a day on the longwall, five days a week. Crews perform their own routine maintenance and service on production shifts. Heavy maintenance and power moves are performed on Saturdays. "We're strictly five days a week right now on production, six days a week for the development units. We have to make sure we're staying ahead. The guys have already been up in the mid-90-ft-per-day range. We've reached the 60,000 raw tons per day level already." Built Tough, Engineered for Excellence & High Productivity Patton is built to be resilient and to handle huge volumes of raw coal. "There are four physical things in coal mining that can take a mine down: lack of air, lack of water, belt failure and power failure. If any one of those items stop working, then you're down. Most of the time if something breaks, you fix it, you move it out of the way, you go on. But not if those four shut you down. We have addressed this by ensuring that we have large water mains coming here with a lot of storage capacity. We have big power here. Our 84-inch slope belts can handle more than 8,500 tons per hour (tph). For air, we have a 117-inch Jeffery fan that can pull 1 million cubic feet per minute (cfm) at 20 inches of water gauge as well as big fans in the back that can really lower the gob pressure and move air. We are covered," said Francisco. Patton has three high voltage circuits underground. The belts, miner units and the longwall are all on separate power sources. "We can isolate either one of those at any moment while keeping power on the others. Conversely, not one interferes with the other," said Francisco. With a 9- to 10-ft minimum height throughout, employees are allowed to drive modified Dodge pickups underground. Supplying crews is also much easier. "We use Fletcher diesel tractors to haul supplies. I can take fully assembled belt drives, load them and take them underground." All of Patton's operating systems, the big belts, ventilation and water are all controlled with PLCs. "Every belt drive we've got on the property is controlled by a variable frequency drive [VFD] that can run from zero to up to 650 fpm with a stroke of December 2012 a mouse. Everything's monitored via computer. Our fan is totally PLC controlled, from vibration monitoring and heat monitoring on the bearings to video cameras that watch the coal come from the longwall all the way outside," said Francisco. Though mainly comprised of Caterpillar components, Patton's longwall system uses a Joy shearer. "Basically it's a template of the [longwalls] Sugar Camp and Mach/Pond Creek mine, also known as Williamson, use except for the fact that we run the next larger generation 7LS5 shearer here. It also has 75-inch drums versus the 65-inch that the other mines run. It's just a bigger, more robust machine. It's about 60,000 lb heavier than the other machines, but we have the height to run it. Right now we're mining about 9-ft, though we've got about 8-ft of coal. Almost all of the panels in the first district that we're in will be between 15,000- to 16,000-ft long," said Francisco. On the longwall development section, Patton also employs Joy 12/27 miners, 10SC32B shuttle cars, and Fletcher CHDDR roofbolters with the man ups. All of the mine's rock dust is trucked in and bulk stored in a 150-ton bin. It is transferred straight through to the mine via bore holes down into 20-ton diesel rock dusters. "One man can load a 20-ton duster in about 3 minutes, take off and start dusting," said Francisco. Throughout the mine, much of the roof control Patton does is both extensive and expensive. "We wire mesh everything for several reasons. The first is safety. We have a main roof made up of limestone mixed with siltstone, shales and sometimes even clay under that. This makes up the first 1- to 4-ft thickness of the immediate roof above us. It weathers terribly. With the mesh installed, instead of a 6- to 8-inch piece of rock falling and hitting one of my miners from 9- to 10-ft high—which is truly an accident—we catch it in the mesh. The other thing is production efficiency. Whatever falls on the ground, you've got to scrape and scoop up and get rid of it. You're also re-bolting because your plates are all loose now. Williamson learned this lesson and we've incorporated it here. We all realized that the money you spend on mesh pays for itself tenfold by saving the time you used up doing those other jobs," said Francisco. Patton even installs the mesh on the ribs. "You have a 9-ft rib turn over—that's a little different from West Virginia where you only have a 4-ft rib. We have rib control in our plan but we go above and beyond it. Like Williamson, we put angle brackets in where needed and we install more rib bolts than most mines. We will also deploy cable bolts if we find an area where we can't anchor our normal primary bolts into the limestone. From a supply perspective, my highest cost at this mine is our roof control," said Francisco. Patton produces a relatively high-sulfur coal with a calorific value of 10,800 Btu/lb. "It's got its own kind of niche demand. Us being very, very new to the market, we've got a lot of power plants testing our coal and seeing if they like it. Our salespeople are travelling worldwide to help move it. At our docks, we blend a lot of our coal with Williamson and Sugar Camp's product. We also blend some of it with the Macoupin or Shay mine. Patton uses wire mesh throughout the mine both for safety and roof control. "We all realized that the money you spend on it pays for itself tenfold" by keeping your mine more accessible, according to Francisco. 33

Articles in this issue

Links on this page

Archives of this issue

view archives of Coal Age - DEC 2012