The U.S. Department of Energy is seeking companies to commercialize three innovative federally developed technologies to remove critical minerals and rare earth elements from coal waste.
The coal byproduct commercialization opportunities are being hailed as an opportunity for the fossil fuel to take on a new role as a dynamic part of U.S. national security, especially in producing critical components of a domestic supply chain.
DOE issued a call to private industry through a July 16 web blog from its Office of Technology Commercialization titled, “A New Chapter for Coal: Commercialization Opportunities from DOE Labs.”
“These materials are essential for high-tech manufacturing, but global supply chains are unstable and increasingly controlled by competitors. Building a domestic source using coal byproducts is a practical, strategic move,” the DOE noted. “There is also a regional angle. Many coal communities still have the skills, infrastructure, and interest to participate in industrial recovery. Instead of starting from scratch, we can build from what already exists.”
It emphasized actions by Energy Secretary Chris Wright to restart the National Coal Council and promote tech transfers to companies for existing mineral recovery technologies already developed by the DOE’s national laboratories.
DOE’s Office of Technology Commercialization
The OTC “is central to carrying out Secretary Wright’s direction to commercialize coal-based technologies, helping ensure that coal continues to serve the nation not only as a fuel, but also as a foundation for American energy abundance and economic growth,” the DOE stated.
The OTC can shift federally funded research into the private sector in many ways. These include licensing DOE-developed technologies, connecting businesses with experts from the national labs, intellectual property and unique user facilities. The federal government also can finance partnerships supporting commercialization.
“For coal, OTC’s role is focused on something very specific. DOE labs have developed methods to recover critical minerals from coal byproducts like ash and slag. These materials are often considered waste, but they hold high-value elements that are needed in defense systems, electric machinery, and computing. Instead of discarding them, we now have a way to put these resources to use, DOE stated.
3 Coal-Based Technology Prototypes Available
The three coal-based technologies ready for commercialization by private industry have all been tested at the lab scale and are ready for companies to further develop, refine and scale into commercial systems. Two were developed by the National Energy Technology Laboratory, which has sites in Oregon, Pennsylvania and West Virginia. NETL is DOE’s only national laboratory focused on developing advanced fossil energy technologies.
The other technology is from Sandia National Laboratories, headquartered in New Mexico. Sandia Labs is known for having strong science, technology and engineering capabilities.
Rare Earth Recovery from Fly Ash Using Mild Acids (NETL)
This invention uses room-temperature leaching and mild acids to extract rare earth elements from coal fly ash. It does this through a safer method than traditional high-temperature or high-acid techniques.
“As China currently controls the supply and prices of almost all the world’s REEs [rare earth elements], developing a domestic supply is critical for the continued manufacturing of technologies that support nearly all modern devices, including critical systems for energy and national defense. REE extraction efforts from domestic sources of coal and coal-related resources have emerged as a viable solution, but successful methods must be both cost-effective and environmentally friendly,” the lab noted.
NETL estimates nearly 9,000 metric tons of rare earth oxides can be extracted annually from the U.S. total reserve of unused fly ash. This recovery could contribute to meeting 94% of U.S. annual demand for rare earth. Fly ash is finely divided residue produced by coal-fired electric plants.
The technology enables repurposing 75 million metric tons of coal combustion waste produced yearly in the nation into a needed commodity in an environmentally benign process. Another benefit is the process requires no pretreatment of fly ash.
“Current methods and technologies for REE extraction from ore and other sources can be hazardous and expensive to implement without harming the environment or workers. For example, common practices employ high temperatures and strong acids or bases. This technology seeks to overcome these and other issues with current REE extraction methods by turning to a material that is currently viewed as a waste—coal ash,” NETL says.
Extraction of Rare Earths (Sandia)
“Sandia researchers have developed a new approach for converting coal ash, a byproduct of coal combustion, into a viable domestic source of rare earth elements using just three readily available ingredients: water, supercritical carbon dioxide (SCO2), and food grade citric acid,” noted Sandia Labs patent overview.
This environmentally benign innovation provides a green, lower cost domestic source of rare earth elements.
“In 2019, the U.S. imported nearly its entire supply of REEs for a total estimated value of $160 million. Import reliance creates dependencies on foreign sources, poses supply chain risks, and may constrain potential high-growth sector,” Sandia Labs noted.
Thermal Processing for Concentrating Rare Earth Elements in Coal Slag (NETL)
This patented technology establishes a unique way to concentrate rare earth elements within coal byproducts for extraction. Coal slag (also called boiler slag) is molten bottom ash. The technology uses the slag to combine it with fluxing agents. Then the material is heated followed by controlled cooling, which concentrates rare earths into solids that can be extracted and refined.
“Coal resources used in energy, iron, and steelmaking operations contain quantities of REEs sufficient to meet U.S. needs for years to come, but not as enriched solids. Cost-effective technology that facilitates the recovery of REEs in their most useful form offers the potential to simultaneously boost America’s economy, national security, and independence,” according to a NETL fact sheet.
Benefits include turning existing coal waste into a new commodity and reducing health/environmental risks compared to current leaching processes. The thermal processing technique doesn’t require a controlled atmosphere and relies on low-cost simple temperature changes.
“The method has been shown to achieve a 42% extraction efficiency and can preferentially extract some of the most critical REEs,” Sandia Labs noted.
New Technologies Offer Multiple Benefits
The three creative approaches to turn coal byproducts into domestic sources of critical rare earth elements. Created and funded with public funds, these prototypes are ready for commercialization.
Federal grants are also available to transfer these innovations from national laboratories to the marketplace. In addition, all new methods turn existing waste into useful domestic products in an environmentally friendly manner.
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