Coal Age

JAN-FEB 2019

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32 January/February 2019 fines dewatering continued The patented method for releasing the trapped water and waste was discovered and invented by Dr. Roe-Hoan Yoon, direc- tor, Center for Advanced Separation Tech- nologies, Virginia Polytechnic Institute and State University (Virginia Tech). "It large- ly involves the application of the correct amount of energy, although other factors are involved as well," Suboleski said. The agglomerate-breaking compon- ent at the heart of the method and tech- nology is called the Morganizer, after MRC Board Chairman E. Morgan Massey, for- mer CEO of the A.T. Massey Coal Co. "The name came from the developers of the initial test unit several years ago and has stuck, somewhat to Mr. Massey's embar- rassment," Suboleski said. The oil-coated coal fines rise to the top and the now-released impurities and water are drained from the bottom of the Morganizer. The oil-coal mix is then piped into a vacuum filter, and then put through an evaporator, which enable the process to capture and recycle the oil. The final product, which has at times been of a reportedly high-enough quality to be categorized as "nearly pure carbon," emerges dry from a chute. It is the result of roughly seven years of research and development. MRC began brainstorming on, and test-tube-scale tests of, the technology in 2011. After making the process con- tinuous at lab scale, a proof-of-concept unit was constructed that processed 100 pounds per hour. "Based on results of tests from seven different coal plants, we went ahead and commissioned a company that specializes in building pilot plants to build one for us," Suboleski said. "The design and construction consumed all of 2014 and the first half of 2015." The pilot plant was tested for two years. The feed solids averaged 58% ash, and the resulting clean coal averaged be- tween 4% and 4.5%. "We discovered then that we could control the moisture," Sub- oleski said, "and typically maintained it between 5 and 9%." MRC stopped testing in late 2017 and "started our initial commercial plant de- sign," Suboleski said. Because it uses only the existing slurry water and otherwise is self-contained, it will operate under a modification to the existing water and air permits for the processing plant. With the long-lead-time equipment ordered, and construction initiated, com- missioning of the plant is scheduled for late 2019. Providing Optionality Energy tech company Arq will start com- missioning this quarter an Arq Fuel pilot plant in Corbin, Kentucky, on a site where U.S. Steel previously operated a process- ing plant. Roughly 75% complete, the $75 million, 50,000-ft 2 plant will produce 12.5 tons per hour of micro-fine hydrocarbon powder from a feed of coal waste. Commissioning the plant will be a stepping stone on the path to going glob- al, Paul Groves, chief operating officer, Arq, said. "We will scale this very quickly around the globe to become a major player in the coal market by creating a product that feeds into the oil market," he said. "We are enter- ing into three further projects with major coal companies around the globe." For ex- ample, within the year, Arq will launch an- other project in the United States and one at a "big site in Australia," Groves said. Groves described the Corbin plant as innovatively engineered to allow the com- pany to trial and compare technologies throughout the process and to determine what fits best. "That is a good thing," he said. "We have done everything that we can to ensure that we have a high-quality consistent product that comes out on spec, on time, every time for our customers." The product, Arq Fuel, is a less-than- 10-micron 99% pure hydrocarbon particle with less than 2% moisture and 1% ash by mass. "Actually, 80% of the particles will have a diameter of less than five microns," Tudor said. The particles are so pure they can be blended with oil products or amal- gamated into Arq Fuel pellets for mixing with met or thermal coals. According to company literature, Arq Fuel is produced using equipment com- monly used in minerals processing and elsewhere. Coal discard such as that headed for a thickener or found in a pond serves as the feed. "Particle size reduction is achieved by ball milling, high-shear grinding or a combination thereof," Arq reported. The biggest ball mill at Corbin is 1.5 mega- watts, Tudor said. Micro-separation is achieved using enhanced froth flotation. "This technolo- gy has traditionally been used to separate microfine particles in the minerals and pre- cious metal mining industries," Arq report- ed. The company deploys a proprietary technique to "enhance that process," Tudor said. "We push that to the limit." The next step, described as a rapid evap- oration system, involves de-watering and thermal drying. It leverages "recent techno- logical advancements in the food processing industry," the company reported. The process ensures the powder is al- most entirely void of moisture and ash, Groves said. Thus, "we can put up to 35% by weight of this microfine powder into an oil." The ratio will depend on the appli- cation. The customers are from different A group touring MRC's first commercial HHS plant strolls past the low-shear mixer, left, the phase separator, middle, and the Morganizer, right. (Photo: Minerals Refining Co.)

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