source：Charleston Gazette-Mail
A 21st century version of alchemy of sorts is underway within the Mountain State’s research facilities and, increasingly, in the field and throughout Appalachia and other parts of the nation.
Last year, researchers at West Virginia University opened and began their work at a site at the school’s Energy Institute to extract valuable rare earth materials from an improbable source — acid mine drainage, the acidic outflow of water from coal mining — and convert the materials into technological and economic assets.
High-tech products reliant upon rare earth elements include not only aircraft, satellites and other national defense equipment, but also cellphones, flat-screen televisions, electric cars and dozens of other everyday consumer and business applications.
Working with the U.S. Department of Energy’s National Energy Technology Laboratory, WVU launched the Rare Earth Extraction Facility to increase domestic supplies of rare earths, reduce the environmental impact of coal-mining operations, lower production costs and increase efficiency for processing market-ready rare earths.
The technology could also bolster the state and local economies by creating jobs in areas that have long depended upon on the coal industry as a major employment and revenue source.
Others partnering in the WVU efforts include members of the coal industry, the West Virginia Department of Environmental Protection, Rockwell Automation Inc. and Charleston-based Shonk Investments LLC.
Elements unraveled
Researchers have known about the presence of rare earth elements in coal material for more than a half-century, but attention has amplified in recent years due to a reduction in the supply of the elements and a subsequent pursuit of economical and sustainable ways to extract them from coal and its byproducts.
According to WVU assistant professor of mining engineering Qingqing Huang, China supplies more than 80 percent of rare earth elements for global consumption and holds nearly 40 percent of reserves worldwide.
The U.S. Department of Energy is funding more than 30 projects, such as WVU’s Rare Earth Extraction Facility, to develop sufficient domestic sources of rare earth elements from coal and coal refuse.
Toward this effort, Huang has been awarded the 2019 Freeport-McMoRan Inc. Career Development Grant by the Society for Mining, Metallurgy and Exploration. The grant will allocate $300,000 over a three-year period for her to use at the Morgantown extraction facility.
“The grant will provide financial support to nontenured faculty and researchers,” Huang said. “There were only two recipients of the $300,000 grants. They want to provide financial support to all young faculty to help them achieve tenure and promotion. I can use the money to hire students, work on the rare earth projects and diversify my research into some other areas.”
Huang said the project leader for the extraction facility’s direction and output is West Virginia Water Research Institute Director Paul Ziemkiewicz. “We’re working on the process with him and several other professors from WVU. It’s a team effort. Our work consists of trying to optimize the results of the whole project,” she said.
“The grade of product we’re able to produce in our labs right now is about 80 percent. That’s a high level of purity,” Huang said.
The WVU extraction facility researchers are also part of cohort teams at the University of Kentucky and Virginia Tech pursuing other rare earth element recovery techniques from coal and its byproducts, such as coal ash.
Mine drainage extraction
Two years ago, Ziemkiewicz began leading a WVU team to study the occurrence of rare earth elements at 120 acid mine drainage treatment sites throughout West Virginia, Ohio and Pennsylvania.
Ziemkiewicz identified the potential of extracting rare earth elements from acid mine drainage after analyzing U.S. Geological Survey data sets from the 1990s, according to a 2017 WVU Today article written by Jake Stump. Ziemkiewicz “noticed high concentrations of the metals coming out of the mines but none in the treated effluent, which is the water discharged to a stream. That meant that the rare earths are concentrated in the treatment sludge, which is the solid material from the raw acid mine drainage,” the article said.
Ziemkiewicz said it was the discovery of a natural process for concentrating rare earth metals, which eliminates additional environmental threats and costs less than conventional extraction methods. His WVU team focused on the solid residues left over after acidic coal mine drainage.
According to a July 2018 Chemical & Engineering News article, the team ran a series of samples and determined that acid mine drainage sludge contains an average of 2,600 times as many rare earths as the raw acid mine drainage itself. The WVU researchers have been able to produce an enriched solid that contains more than 90 percent, or 900,000 ppm, total rare earths using the sludge as their beginning material.
“The coal market may fluctuate over time, but acid mine drainage will be constant,” Ziemkiewicz said in the article. “Long after mining is done, there will still be acid-generating coal mines. In fact, some of our richest rare earth concentrations have come from sites where mining ceased 30 years ago.”
And that could prove beneficial to communities buffeted economically by the decline of coal mining.
In mid-May, Ziemkiewicz testified before the U.S. Senate Committee on Energy and Natural Resources on research advances on the development of a domestic source of rare earth elements.
“WVU researchers have found REE concentrations in acid mine drainage from various Appalachian sources that exceed many of the world’s best commercial deposits,” he reported to the Senate committee. “Where most conventional rare earth deposits are encased in hard rock and located in the remote wilderness, AMD sludge is already extracted from the host rock and easily accessible, resulting in modest processing costs.
“Recovering rare earths from acid mine drainage doesn’t require much permitting. You’ve already got infrastructure, you’ve got a workforce, you’ve got SMCRA permits required by the Surface Mining Control and Reclamation Act, and the state and federal clean water permits. Northern and central Appalachian coal mines generate about 800 tons of rare earths per year,” Ziemkiewicz told the committee. “That’s a fraction of total U.S. AMD production, but that’s still enough for the U.S. defense establishment. The overall economy uses much more, about 16,000 tons per year.”
Department of Energy grant
The U.S. Department of Energy awarded the West Virginia Water Research Institute a $5 million grant in September to launch a 30-month, collaborative project in Grant County.
“The grant will allow us to build a continuous plant in conjunction with the West Virginia Department of Environmental Protection near Mount Storm to extract rare earth elements while treating acid mine drainage in the headwaters of the Potomac River,” Ziemkiewicz explained.
The West Virginia Water Research Institute will partner with the DEP’s Office of Special Reclamation to design and build the plant, Rockwell Automation will provide sensor and control technology and the TenCate Corporation will engineer materials for rare earth element extraction.
“It was one of three awards made nationally by the DOE in the rare earth recovery area,” he said. “Essentially, it is Phase 3 of a project that started in 2016. At that time, the DOE put out a national competition for extracting rare earth elements from coal and coal byproducts.
“Our idea here at WVU is using acid mine drainage as that feedstock,” Ziemkiewicz said. “We know a lot about where it is and how to treat it. This is an adjunct to our work with acid mine drainage. To a large extent, you’ll be able to treat acid mine drainage and improve the environment, incentivize people to treat acid mine drainage and, to some extent, to pay for acid mine drainage restoration.
“A lot of rare earth element sources developed commercially in the mining sector and a lot of other sources contain a lot of radioactive thorium and uranium. Acid mine drainage does not.
“The objective of the whole program is to develop a domestic source of rare earth elements and develop a process that can turn those into commercial projects relatively economically while being environmentally benign,” Ziemkiewicz said. “Congress does not want a process that just makes an environmental shambles of things. One of the attractions of the strategy we’re taking is that it cleans up the environment in a very benign way.”
Through the Grant County project, he said, “we’ll actually scale up from the laboratory pilot plan in the facility here in our building we’ve been doing for the last two and a half years.”
Working with the DEP and industrial partners, he said, “we’ll develop a design where we would configure the DEP plant and develop a sidestream of rare earth products that would go into our refining plant at the site. We hope we can generate enough revenue if we develop enough markets downstream. That should pay for a lot of the chemical costs, if not all of them, for acid mine drainage treatment at this large plant the DEP is building.”
Old mines a prime source
As he told members of Congress earlier this year, Ziemkiewicz said West Virginia and the surrounding region are prime sources for the endeavor and could lead to a range of employment opportunities.
“Acid mine drainage in the state is almost all on old mines still under permit or abandoned mines,” Ziemkiewicz said. “People could start collecting at them and invest in concentrating and refining rare earth products. Personally, I’d like to see the refining process done here in West Virginia. ... We’re close to our market, we have good power supplies in the state and we have a trained workforce in mining and operations. I don’t see why we couldn’t make this the center of our rare earth production and product generation.”
He said it may take up to six years from inception earlier this decade to mass production of significant quantities of rare earth elements. “Right now, this is limited by our Department of Energy work. They’re wise in giving us specific objectives at each step,” he said.
“In the early stages of the competition, the technology development was on proving if fundamental ideas were feasible. ... We went through several stages and each had a go/no-go stage through the Department of Energy. We had to keep passing tests to scale up. Congress is certainly very much encouraging us to move rapidly toward commercial application. They have an aggressive schedule for it, and a number of research organizations are meeting that schedule and making great progress,” Ziemkiewicz said.
Delegates support research
West Virginia congressional delegates expressed their support for the research in an Oct. 1 WVU media release.
“I am ecstatic that the Department of Energy continues to recognize the value of the critical work Dr. Ziemkiewicz and his team are doing at West Virginia University in extracting rare earth elements from acid mine drainage,” Sen. Shelley Moore Capito, R-W.Va., said. “REEs are essential to modern advanced manufacturing, and WVU’s technology will help provide a domestic source of this material while cleaning up legacy mine waste. This is a win-win-win for our economy, our national security and the environment.”
“From your cellphone to weapons systems, rare earth elements are increasingly important in manufacturing,” said Rep. David B. McKinley, R-W.Va. “Currently, China controls the vast majority of the rare earth element supply, which puts the United States at risk. WVU’s work to develop a domestic source is critical, and this funding will go a long way in helping them continue their research. The research being done by WVU will help to build an American supply chain and ensure that we are not dependent on other nations for our supply.”
“Dr. Ziemkiewicz and his team at West Virginia University are performing groundbreaking research that is leading the way in innovating our energy industry,” Rep. Carol Miller, R-W.Va., said in the release. “The ability to extract rare earth minerals from acid mine drainage would dramatically invigorate our economy by creating new, stable jobs and increasing our export capabilities. West Virginia energy already powers our nation, and this research could significantly advance U.S. independence in the rare earth mineral marketplace and provide much-needed resources to our technology and defense industries from right here in Appalachia.”