High concentrations of rare earth elements found in many coal fields in the United States
Washington, DC - US Department of Energy (DOE) National Energy Technology Laboratory (NETL) found in coal mine samples in Illinois, North Appalachian Mountains, Central Appalachian, Rocky Mountain Coalfields, and Pennsylvania Anthracite High concentration of rare earth elements (REE). These high concentration samples are greater than 300 parts per million (ppm).
US Energy Secretary Rick Perry said: "Rare earth elements are critical to the development and manufacture of high-tech equipment such as computers, mobile phones and defense systems," "The current difficulties and high costs of rare earth mining have made the United States dependent on foreign rare earth imports. Supporting innovative research and development to establish efficient, low-cost REE extraction methods is critical to China's energy and national security."
The 300 ppm rare earth concentration is an integral part of the commercial viability of extracting rare earth from coal and coal by-products, which makes NETL's efforts to develop the domestic supply of these elements economically particularly important.
The discovery was done in collaboration with West Virginia University (WVU), University of Kentucky (UK), Tetra Tech and XLight. WVU explored acid mine wastewater from the Yanacai Mountains in the Northern Appalachian and Central Appalachian Basins, while Tetra Tech sought out from bituminous, sub-bituminous and anthracite coals in the same basin. At the same time, the UK analyzed Kentucky bituminous coal in the western Illinois oil field, and XLight investigated coal-related materials in anthracite coal areas in eastern Pennsylvania.
These findings can encourage technology developers to recover rare earth elements from these basins and help them find high-quality raw materials – the raw materials needed for rare earth recycling processes. The high rare earth element concentration in the raw materials will increase the prospect of producing high purity rare earth materials. An independent research program focuses on the US Department of Energy's cost-sharing research project to design, develop, and test technologies to recover rare earths from coal-related materials in diverse US coal fields.
These recycling projects began in October 2017 and will use materials from high rare earth element coal fields as raw materials. These include WVU's use of bituminous acid mine wastewater from the North Appalachian and Central Appalachian Basins as raw materials, and the final design and construction of the experimental research facility began in January 2018. The second pilot scale facility is being designed by North Dakota University to recover rare earth elements from lignite feedstock.
In addition, the UK began to use the Western Kentucky bituminous coal to prepare plant waste for the pilot scale system design and construction in the Illinois coalfield in October 2017. The second pilot plant is being designed and built by Physical Sciences Inc.
As part of the first phase of the project design for a small pilot-scale saleable rare earth element recovery system, the other two pilot plants began in September 2017. These include InventureRenewables using materials from the eastern Pennsylvania anthracite area and Marshall Miller & Associates using the North Appalachian Upper Freeport bituminous coal preparation plant coal gangue.
It is found that the prospective resources of domestic coal and coal by-products containing high REE concentration are the key milestones for the recovery of the US REE economy. Additional analysis of relevant materials for rare earth coals at the state and/or county level can be found on the NETL Rare Earth Energy Data Exchange website.