Engineering & Mining Journal

DEC 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 58 of 115

FLOTATION DECEMBER 2018 • E&MJ 57 © 2018 Calumet Branded Products, LLC W W W . B E L R A Y . C O M M a i n t e n a n c e C o s t S a v i n g s D e c r e a s e D o w n t i m e E x t e n d C o m p o n e n t L i f e R e d u c e C o n s u m p t i o n O u t s t a n d i n g E x t r e m e P r e s s u r e , S h o c k L o a d a n d A n t i - W e a r P r o p e r t i e s pretty thoroughly, because if we don't get the oil on the coal or the mineral particle, it doesn't get recovered," Suboleski said. The mix is then piped to a second tank. "These oil-covered particles are attracted to each other," Suboleski said. "They bump into each other and they form agglomerates." Those agglomerates ensconce water droplets. "The impurities are hydrophilic, so they want to go where the water goes," Suboleski said. "And when the moisture is trapped inside, it also raises the impurity level, lowering the ore grade, which is the reason that agglomeration has not been used widely in the past, even though it was first discovered in the early 1900s." The patented method for agitating the mix to release trapped water and waste particles was discovered and invented by Dr. Roe-Hoan Yoon, director, Center of Advanced Separation Technologies, Vir- ginia Polytechnic Institute and State Uni- versity (Virginia Tech). "It largely involves the application of the correct amount of energy, although other factors are in- volved as well," Suboleski said. The agglomerate-breaking compo- nent that is the heart of the technolo- gy is called the Morganizer, after MRC Board Chairman E. Morgan Massey, and former CEO of the A.T. Massey Coal Co. "The name came from the developers of the initial unit several years ago and has stuck, somewhat to Mr. Massey's embar- rassment," Suboleski said. In sync, the oil-coated ore particles rise to the top and the impurities and wa- ter are drain from the bottom of the Mor- ganizer. The oil-ore mix is then piped into a vacuum filter, and then put through an evaporator, which enables 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 "pure carbon," emerges dry from a chute. It is the result of roughly seven years of research and development. MRC began brainstorming and test- tube scale tests on the technology in 2011. A proof-of-concept unit was con- structed the next year. "Based on results of tests from seven different coal plants, we went ahead and commissioned a com- pany that specializes in building pilot plants to build one for us," Suboleski said. "The design and construction consumed all of 2014 and the first part of 2015." The pilot plant was tested for two years. The feed averaged 58% ash, and the result- ing clean coal averaged between 4% and 4.5%. "We discovered then that we could control the moisture," Suboleski said. MRC stopped testing in late 2017 and "started our initial commercial plant design," Suboleski said. "We now have our first plant under contract," he said. And because it uses minimal water and otherwise is self-contained, it will operate under the existing permits for the plant. Meanwhile, the idea was bandied about that HHS could be used in the pro- cess of recovering rare earths from coal waste. That in turn pushed the envelope to develop it for hard rock mining appli- cations, which ran into inevitable hurdles. "Everybody who worked on this thing is a coal person," Suboleski said. The idea, however, had legs, and lab- scale testing of HHS at recovering copper from what was otherwise considered waste has proven successful thus far. "We're get- ting good results from samples of clean- er-stage flotation tails," Suboleski said. "Now we want to broaden out to test sam- ples from more processing plants — and ore types — and make sure it is not a fluke."

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