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prep plant design Engineering the new Wild Boar Prep Plant The design integrates safety and maintenance consideration with simplified circuits Peabody Energy constructed and commissioned the new Wild Boar preparation plant during 2010. Despite an accelerated construction timeline, developers were able to incorporate ease of maintenance and accessibility into a simplified flowsheet, which included heavy medium cyclones, compound spirals and de-slimed flotation circuit. Strategically located on a rail line near Lynnville, Ind., the 650-ton-per-hour (tph) Wild Boar today processes coal effectively from three local surface mines, main- taining a high availability at a low operating cost. Peabody owns the plant and United Minerals operates the plant. During the front end engineering process, prep profes- sionals from both companies collaborated with General Mine Contractors, the company selected to construct the plant, and Ezra Smith, a consultant who used to manage the Black Beauty prep plants. The design team considered several options to minimize plant construction costs while still building a quality facility with good operating and maintenance features. The options included relocating an existing idled facility, building an all-new plant, and building a plant with as much used equip- ment as possible. They settled on a final design that included several pieces of used equipment, a three-circuit plant for effi- cient processing of each size fraction, and an overhead bridge crane for improved maintenance access. "We considered several options for Wild Boar," said Dan Pilcher, senior preparation manager for Peabody Energy's Midwest Division. "A few idled plants in the region could have been relocated. A cost analysis was performed on that option. New plant construction is the easiest path, but not necessarily the most cost effective. The third option, which is the one we selected, combined used equipment with a new structure. We wanted a low cost facility, not just with construction costs, but also as far as operating costs." One of the more daunting aspects of this project was the accelerated construction schedule. One of the mines that would feed coal to the Wild Boar prep plant came online early. Coal was being trucked to an existing plant one-way 13 miles and those expenses were mounting, Pilcher explained. Construction began during mid-March 2010 and the plant came online and under budget during mid-November 2010—nine months from concept to reality. Process Flowsheet The Wild Boar plant can be broken into three main areas: the raw coal handling system, preparation plant and clean coal handling system. The raw coal system includes a truck dump, rotary break- er and a radial stacker with the ability to divert raw, saleable Figure 1—A simplified Wild Boar plant flowsheet shows the large diameter heavy media cyclone, compound spirals and the flotation circuit. 48 www.coalage.com July 2012