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30 www.coalage.com July/August 2017 reclaiming rare earths continued arrived at a flowsheet for a processing fa- cility to produce a REE oxide concentrate "from the waste streams of an existing coal preparation plant." A related group produced a paper this year titled Concentration of Rare Earth Minerals From Coal by Froth Flo- tation based on an SEM-EDX analysis of Fire Clay fine coal refuse. It reported, "Unliberated monazite particles with an REE content of around 60% were dis- covered having particle sizes less than two microns." Flotation release analysis found heavy REEs "were likely associated with finely dispersed ash materials with- in the organic matrix. (M)aximum REE content occurred in particles with an ash content of around 80%." The group rec- ommended column flotation at a pH of nine and grinding for 60 minutes. Such reports add to a growing body of knowledge on the possibility of prof- itable REE extraction from coal. Concur- rently, the federal government observed, conducted its own research, and is in- creasingly putting skin in the game. Government Involvement Recently, the Department of Energy's (DOE) National Energy Technology Laboratory (NETL) announced the re- sults of multiple in-house projects centered on sampling and processing optimization. One of the highlights was the suc- cessful development of a procedure to arrive at accurate concentration data. Conventional methods were assessed for determining the markers, overlays, and interferences that caused a couple of the elements, such as scandium, to be reported at inaccurate concentra- tions, Mary Anne Alvin, REE technology manager, NETL, said. "Depending on what laboratory you go to, you may get the same concentrations for cerium, lanthanum, gadolinium or other REEs plus or minus some variation," she said. "NETL worked out a better set of pro- cedures to be able to obtain the best concentration data relative to whatever your sample is." Those procedures are available to researchers and miners on the NETL website. A separate NETL project arrived at a REE recovery process for acid mine drainage. "External researchers are re- covering nearly 100% of all the REEs," Alvin said. "When you think about clean- ing up or adding value to a waste pro- duct, extracting REEs out of acid mine drainage sludge, you've got to see that as a win." Currently, NETL is developing com- putational fluid dynamics modeling for REEs extraction from clays using ammo- nium sulfate, Alvin said. "You can design your reactor, change the parameters of your reactor, change your feed and pro- cess conditions," she said. "And by doing this, you can save time and cost, ironing out many of the problems before you ac- tually go into full design, construction and operation." NETL assigns its projects a technical readiness level, a score based on degree of development of the subject technol- ogy or process. "The fundamental work being done at NETL's in-house research is more on the lower TRL levels, maybe two or three, possibly four," she said. The DOE funding opportunities now avail- able are for projects that would end at a five or six, she said. In June, the DOE's Office of Fossil Energy announced three funding op- portunities for research into processing technologies potentially capable of pro- ducing salable REEs from coal, byprod- ucts and waste. Targeted are REEs from the lanthanide series (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), including scandium and yttrium, Jess Szymanski, DOE spokeswoman, said. "Of particular interest are the REEs that have been defined as critical ele- ments: Nd, Eu, Tb, Dy and Y." Three grants valued at roughly $1 million each are available to three corporate entities. Equinox Chemicals was selected to conduct lab testing and produce a technical design for a plant to process byproducts from an exist- ing eastern Kentucky coal preparation plant. Inventure Renewables was se- lected to do the same using coal-related materials from an eastern Pennsylva- nia anthracite mine. Marshall Miller & Associates was selected to do the same with byproducts from a West Virginia coal preparation plant. Success brings increased competition for a possible second round of funding to further de- velop initial plans. The focus is to validate the feasi- bility of prototype REE separation and extraction systems, Szymanski said. The goal is to have an operational plant within a couple of years. "Validation is to demonstrate production of 10 pounds per day of at least three rare earth el- ements, as oxides, that are present in concentrations that are 90%-99% pure," she said. "After that, advancements and improvements in efficiency and optimization of either the equipment, technologies and/or overall systems will follow." Many of the technologies and sys- tems are already established. Inventure Renewables, for example, will be using an ion exchange process that is based on the one used to separate uranium for the Manhattan Project. "What our part- ners have done is refine that process from a batch process to a continuous process," Anthony Marchese, chairman, Texas Mineral Resources Corp. ( TMR), said. TMR is part of the consortium that includes Inventure, K-Technologies and Penn State. "What it does is it saves a tre- mendous amount of time, and it is way more efficient to do it on a continuing basis rather than a batch process." TMR will process coal overburden into a purified liquid solution, which will serve as a feedstock for continuous ion exchange, continuous ion chromatog- raphy (CIX/CIC). The primary target is scandium. Currently, roughly 10 tons of scandium are produced globally per year. Commercial applications include laser crystals and minor aerospace compo- nents. "We will also target the REEs that have higher market values, which tend to be the magnet-related elements, things like dysprosium and neodymium," Marchese said. "When we actually pro- cess it, we will determine which material we want to selectively extract." Currently, TMR likes its prospects, he said. "We are using a process that has been tested over time," Marchese said. "We are confident that if we can produce a purified liquid solution, we can separate it and extract the REEs." The Actinides Problem At the same time Marchese was being interviewed for this article, the CEO of American Elements Corp., Michael Silver,