By Steve Fiscor, Editor-in-Chief

The coal business in the United States softened during 2009 and that is evident on the drawing boards at many of the engineering, procurement, construction, and maintenance (EPCM) firms that build prep plants. During 2008, business was brisk with a record number of orders for new plants and upgrades being placed worldwide. Many of those projects have been completed. Early this year, mining companies did cancel a few orders for new installations. While a few firms have a couple of large projects on the books, the volume of business certainly slowed in 2009.

The 2009 U.S. Prep Plant Census includes information on 283 prep plants. The largest change had to do with Alpha Natural Resources’ acquisition of Foundation Coal, and its associated prep plants. Those names have been updated accordingly. Kentucky and West Virginia are the leaders with 76 and 73 plants respectively. With a raw feed capacity of 6,200 tons per hour (tph), CONSOL Energy’s Bailey is the largest plant. There are now a dozen prep plants processing 2,000 tph or more.

Nine new plants where added to the annual U.S. Prep Plant Census: the Signal Peak plant in Montana; Buckingham Coal, Cline Resources’s Buckeye plant, and Rosebud Mining’s Tusky plant in Ohio; Imagin Natural Resources’ Saunders plant, Licking River Resources, Mepco’s Coresco plant, and Patriot Coal’s Blue Creek plant in West Virginia; and PBS Coal’s Cambria Plant in Pennsylvania. All of these plants were constructed by Taggart Global, one of the largest prep plant EPCM firms.

Last year, Taggart built 14 plants around the world, which was a really incredible pace. “In the last year, we have completed seven plants in the U.S., which represents about 75% of the greenfield projects in the U.S.,” said Rick McCormick, president and CEO, Taggart Global. Taggart is on schedule to commission two more prep plants by the end of 2009. The combined processing capacity for the eight new plants constructed by Taggart in 2009 will be in excess of 40 million tons per year.

Even though the dynamics within the industry have changed, some notable trends have also emerged. As it is with any aspect of mining, safety is the utmost concern and that is now a factor in plant design. The industry continues to migrate toward larger equipment and away from dual arrangements, which has brought plant costs down in relative terms (e.g., construction costs per ton per hour). Dewatering and capturing fines are two areas that remain important and the mines will focus their attention on in the future.

Circuit Design
Similar to the mines, plant construction is really site specific. What works in southern Indiana may not work in eastern Kentucky and/or West Virginia. “EPCM companies have to evaluate plant design needs on  a case-by-case basis,” said Surendra Jain, president, The Daniels Co., a leading prep plant EPCM firm based in Bluefield, W.Va. “There is an application for large-diameter, heavy-media cyclones (HMC)and there is also an application for heavy media vessels (HMV) along with heavy media cyclones to process raw coal down to 1 mm size. Many of the new plants being built in the Illinois Basin now prefer HMV over large diameter cyclones. The same is true for southern West Virginia,” Jain said.

“When a plant is pumping 2-1/2- and 3-inch raw coal, a lot of wear and tear takes place in the pumps and pipes,” Jain said. “Why not increase the top size in the plant feed to 8 inches unless the chemistry suggests otherwise and let the HMV handle everything from 8-inch down to 1/2-inch?”

Banana screens give the prep plant added flexibility. Raw coal sizing and desliming can all be handled on one set of screens, Jain explained. “In the old days, we used to have raw coal and desliming screens,” Jain said. “Now with the Banana screens the top deck reports to the vessel; the bottom deck reports to the HMC circuit, and it is all done with one set of screens.”

Jain also cautions prep plant managers/designers about overloaded screens. “A lot of new plants have been built wherein a Banana screen is constantly operating under its maximum capacity and/or overloaded cond