As progress was made in the development of Allegheny Metallurgical’s Longview longwall mine in central West Virginia, crews at its coal preparation plant were also working hard to bring it online. NAM takes an exclusive look at the High Carbon Processing Plant.
By Donna Schmidt
Hard work and dedication are well-rewarded, and that has certainly been the case with the growth of Allegheny Metallurgical as a company with the newest longwall mine to open in the United States. It, too, has reflected fantastically on its coal preparation plant, High Carbon Processing, that sits adjacent to the mine portal on the Longview mine complex property in Volga, Barbour County, West Virginia.
This central Appalachian newcomer has not for one moment slowed its advancement since taking its first shovel for site work. Construction on the plant was monumental, with first steel construction kicking off August 5, 2021. Each step with partner Powell Construction was a purposeful dance of precision and integration of modern engineering to bring the plant vision to life.
Getting online
During design and construction, quality was a key factor for the operator. One of the most significant priorities for the plant was to remove oversized material prior to entering the plant via a scalping system that included a sizing screen, rotary breaker and refuse crusher.
The scalping system was customized to allow up to 150 tons per hour of refuse material to be discarded directly on a refuse conveyor to reduce the rock the plant must process. Overall, the goal was to have a maintenance-friendly plant. The design included the ability to drive through the plant basement with equipment and parts to support ongoing operations.
“Plant design had safety and maintenance at the forefront,” said Allegheny Metallurgical General Manager Ryan Toler, who added that it received everything on the company’s list: a personnel and material handling hoist to access six floors with an enclosed car, access platforms for maintenance, a remote-controlled 25-ton crane and LED lighting throughout. It also requested and received a motor control center and plant control room in an adjacent building to limit vibration and dust issues.
Six weeks before the plant officially opened, Allegheny Metallurgical brought its new plant employees in to High Carbon Processing to be trained on all plant-related equipment and work areas.
“Also, prior to full plant production, employees were put through an extensive training program for all areas of the plant related to environmental [issues such as chemical spills], fire protection/prevention, fall protection/prevention, equipment training and first aid training,” Toler noted.
The plant was commissioned January 7, 2023, and the first clean coal train shipment left the complex just a month later on February 8. The staff of 59, in part due to their pre-training initiative, are mostly cross-trained and can operate anything and everything plant-related.
While High Carbon Processing is running at nameplate now with minimal issues, it wasn’t a straight-lined journey to this point, Toler explained.
“Construction during COVID and dealing with equipment and parts issues was the most difficult physical issue,” he said. Toler added that staffing, which involved recruiting and hiring an all-new workforce that was comprised of both experienced and inexperienced individuals, proved to be an obstacle – but it was one the facility was clearly able to overcome.
An equipment symphony
Looking through the metaphorical window of the 1,400-ton-per-hour plant, it rapidly becomes evident how HCP was able to get to its throughput goal so quickly and why it remains running as well as it does now.
High-vol A metallurgical coal from the adjacent Longview longwall mine, which mines the Lower Kittanning seam, arrives to the plant via direct conveyor feed. The prep work then kicks off with a band of equipment manufacturers that include McLanahan, the maker of its rotary breaker and refuse crusher; FLSmidth and Conn-Weld for its varied run of screens; spirals by Mineral Technologies; vessels from Peters Equipment; and Eriez column flotation cells. For dewatering, the plant employs four FLSmidth 44×32 screen bowl centrifuges (two per circuit), and three FLSmidth VM 400 centrifugal dryers with two on met coal and one on thermal.
Yes, to repeat: Allegheny Metallurgical’s mine produces both met and thermal tonnage. Toler explained: “Clean product from plant yields 80% metallurgical coal and a byproduct of 20% midds (thermal) coal. Two separate clean coal conveyor systems transport coal to the clean coal stockpile, segregating the met and midds product into two met and one midds pile.” (More on that ahead.)
The plant’s overall flow sheet breakdown is proof that simplicity is often also the most efficient avenue to take; with two separate 700-tph circuits (A & B) with a common rewash circuit, the operator knew what it wanted from the beginning: maximized efficiency in the met/thermal split, and to minimize downtime (another positive point it has been successful in achieving, with average availability exceeding 97%).
Keeping an eye on things
The mine’s raw coal stockpile is managed via seven underground feeders, all loading a 60-inch reclaim conveyor which feeds the scalping system where the scalping screen, rotary breaker and refuse crusher are housed. This is done in order to manage the oversized material, liberate additional coal and bypass rock from the plant at a rate of up to 150 tph. The plant is then fed via a 48-inch conveyor.
With the plant running 24/7, much like the crews at the longwall, the High Carbon Processing facility needed a control room that matches efforts. It’s safe to say that it was able to meet that goal. Its PLC is an Allen Bradley Control Logic system with a FactoryTalk graphical interface station. A digital camera system provides plant operators with monitoring capabilities from the raw coal piles, inside the plant, the clean coal piles, train loadout, slurry refuse and dry refuse systems. Crews report an excellent relationship with all of their control system suppliers.
As for maintenance, a commitment was made by the operator at the start of design to incorporate preventive maintenance (PM); as a result, its extensive PM program is performed daily. Idle maintenance is performed weekly, on Wednesdays.
Ready to roll
Once the plant’s preparation circuit is complete and the met and thermal coals are separated, the clean coal travels via a 42-in. met clean coal conveyor and 36-inch midds clean coal conveyor system on the now-processed coal’s final journey out of the plant and to the loadout. A 42-in. dry refuse conveyor system handles the coarse refuse product.
“A 4,000-ton-per-hour loadout is utilized to load up to 150 car trains around a flat rail loop,” Toler said of the line, on which it partners with CSX and A&O (Appalachian and Ohio) railroads for transport to customers.
Added Hainer: “[We] designed a rail track and material handling system which, in full operation, will allow the loading process to occur in less than four hours. The area is situated in tight quarters and required some study to come up with the best design for their needs. The idea of the loop design was to reduce disruptions to the flow of traffic on Route 119 in Barbour County while creating a highly efficient train loading design.
“The rail loop system that we have established is unique in West Virginia … [as it] allows a 130-car train to cross Route 119 without having to stop.
This increases the efficiency of filling the train cars and keeps traffic interruptions to a minimum so we aren’t disrupting commuters, buses, and other travelers along the road,” he said.
A side track allows a 130-car train to be separated into two strings of 65 cars each once the train is on-site. The train’s front section (1 – 65) can be backed down the sidetrack, pulled through, loaded and then pushed back down the flat sidetrack to storage. The back half (66 – 130), then, can be pulled up, loaded and backed up and coupled to the front string; the entire train is then pulled around the loop and out to the main rail, departing the mine site.
Hainer said several options were examined for the rail design in regard to handling options, a difficult loading puzzle to sort out, and his team came up with the loop system as the best choice to reduce traffic delays and still efficiently load out coal.
Allegheny Metallurgical’s current customer portfolio is international, via the CSX Curtis Bay or CONSOL Marine Terminal facility at the Port of Baltimore, but as market conditions permit it has the ability to ship both domestic and global tons via rail and truck.
The truck transport is made easier, Toler said, with its capability to bypass the clean coal rail loadout stockpile to a separate stockpile for loading of either met or midds clean coal.
“The overall concept for the High Carbon Processing coal handling facility from ROM [run-of-mill] product to the shipment of clean coal was to be functional, efficient, maintenance friendly and provide optionality to supply a high-quality product to our current and future customers,” Hainer said.
“We succeeded in this endeavor and coupled with a top-quality workforce, we will be able to thrive in the coal market. We dedicated a lot of time and effort to effectively train our plant employees ahead of full-scale operation, which will pay dividends as we mature. The Allegheny Met team is thankful and excited for this opportunity to bring a new longwall and coal handling facility on-line and supply a much-needed product, globally.”
Coal sent by rail from Allegheny Metallurgical’s High Carbon Prep travels to the Curtis Bay facility or CONSOL