West Virginia University researchers are opening a new facility to capture valuable materials from a novel source – acid mine drainage from coal mining – turning the unwanted waste into critical components used in today’s technology-driven society.
Through a collaborative research and development program with the National Energy Technology Laboratory, part of the U.S. Department of Energy, WVU is opening the Rare Earth Extraction Facility to bolster domestic supplies of rare earths, reduce the environmental impact of coal-mining operations, reduce production costs and increase efficiency for processing market-ready rare earths.
Additionally, the technology could create jobs, helping to revive economies that have been historically dependent on the coal industry.
“Research on rare-earth extraction is one way that our University is fulfilling its most important mission—which is the land grant mission—to advance the prosperity of the people of this state,” President Gordon Gee said in a statement.
WVU is partnering with Rockwell Automation to facilitate market readiness through use of their sensor and control technologies in the new WVU facility.
Paul McRoberts, regional industry mining, metals and cement manager at Rockwell Automation, a 30-year veteran of the industry, said that this is one of the most exciting projects he has been a part of during his career and is excited to see the results of the new facility.
The facility is the researchers’ phase two project, worth $3.38 million, funded by NETL with substantial matching funding from WVU’s private sector partners. It follows on an earlier, phase one project, worth $937,000, to study acid mine drainage as feedstock for rare-earth extraction. The goal of the pilot facility is to test the technical and economic feasibility of scaling-up the technology to commercialize the separation and extraction process.
In addition, the team will be working to define a U.S.-based supply chain including the sludges created during acid mine drainage treatment and upstream to the acid-mine drainage source.
Ziemkiewicz, Xingbo Liu, professor of mechanical engineering in the Statler College of Engineering and Mineral Resources, and Aaron Noble, associate professor of mining and minerals engineering at Virginia Tech, have designed the processing facility from the ground up using advanced separation technologies. Chris Vass, a WVU graduate student and Summersville, West Virginia, native is the operator of the new facility.
The researchers are using a two-step process to separate the rare earths from acid mine drainage: acid leaching and solvent extraction, which they call ALSX.
Researchers will dissolve the sludge in an acid. That solution will then be transferred to glass mixers and settlers that will make an emulsion that allows the oil phase and its extractant chemical to grab rare earths from the water, leaving the non-rare earth base metals like iron in the water.
When that process is completed, the rare-earth-laden organic liquid enters another series of mixers and settlers that will strip the rare earths out as a concentrated solution and precipitate the rare earths as a solid, creating a concentrated rare earth oxide that can then be refined and further concentrated into pure rare earth metals to supply the metal refining industry.
The goal of the project is to produce three grams of rare earth concentrate per hour.