Kelton Smith has more than 20 years of experience designing, constructing and operating hydrometallurgical plants in the mining, mineral and metals sector, and over 10 years of experience in the design, startup and operation of Rare Earth Elements (REE) processing plants.
He held the positions of Operations Manager and Engineering Manager during the construction and startup of the new Mountain Pass mine and processing plant in California—the only rare earth mine in the U.S.
Kelton is a registered member of The Society for Mining, Metallurgy and Exploration, Inc (SME), and is certified to act as a Qualified Person for NI 43-101, S-K 1300 and JORC standards for reporting in the Mining Industry. Kelton holds a Bachelor of Science in Chemical Engineering from the University of Utah. He enjoys the problem-solving aspects of chemical engineering and is a qualified Black Belt in Six Sigma.
What are REE and why is the demand for REE growing rapidly?
REE are a group of 17 elements that are critical to many products we use every day including electronics, Electric Vehicles (EVs), lighting and batteries. They are also essential for national security products such as night vision optics, radar systems, unmanned aerial vehicles and jet engines. REE are also used in the energy sector in wind turbines, oil refining catalysts, solar panels, energy storage and auto catalytic converters. These sectors are vital for our security, economic and technological development, as well as the transition to low carbon economies. As technology adoption grows globally, the demand for, and use of REE will increase in line with those advancements.
REE are part of a wider group classified as Critical Minerals. Critical Minerals are so-called because they are considered essential to a nation’s economy or security, with a high risk of supply disruption. Managing and minimizing supply chain risks for these minerals is a strategic priority for governments worldwide.
Despite their name REE are not especially rare, but high-grade deposits that are suitable for commercial extraction are scarce, and the physical and chemical similarities of REE make the separation and purification of individual rare earth products very challenging.
This shortage of economically viable rare earth resources has led to a supply chain dominated by a small number of resource-rich countries such as China, Brazil, India, and Australia.
What are some of the challenges to expanding REE mining and processing in the U.S.?
Expanding and accelerating REE mining and production in the U.S. presents many challenges. Currently the U.S. has only one high-grade REE deposit at Mountain Pass Mine in California. Locating new, high-quality deposits that are suitable for commercial extraction is challenging and requires detailed and reliable subsurface data.
Developing REE processing capabilities is also complex and lengthy. Under U.S. environmental law, radioactive elements present in the ore must be treated as radioactive hazardous waste or disposed of as tailings at the original mine site, under the Bevill Amendment. This is costly and the solution is generally to process the ore on site. As such, deposits must be large enough, and of a high enough quality to justify a dedicated plant. Development also requires significant capital investment and an extensive permitting process. In practice it can take between 15 and 20 years to go from exploration to full scale production.
REE can also be extracted from coal waste, fly ash, mine tailings and waste from some industrial processes, creating value from waste products. These technologies require a much smaller scale of production and capital cost. This enables operators to start out slowly, scale up, and show the efficiency and profitability to investors which a primary rare earth mine and processing facility cannot. A focus on these types of projects will accelerate the expansion of domestic production and support the diversification of the U.S. supply chain.
What are the latest processing innovations in REE production?
There has been substantial progress made in improving the selectivity and efficiency of chemical extractants used in the leaching steps as well as separation and purification of REE.
Research funded by the U.S. Government and other countries has developed unique new processes for producing REE from electronic waste, spent magnets, and alternate feed sources such as fly ash, coal waste, phosphogypsum, mine tailings and other waste from industrial processes.
There is promising new research looking at shortening REE production processes using proteins such as lanmodulin, which can extract and separate rare earths while rejecting gangue material—the unwanted portion of the ore such as iron, aluminum and other metallic elements. This reduces the number of steps for current hydrometallurgical production, shortening processing time and lowering cost.
There have also been recent innovations in extractants used for separating and purifying rare earths such as ionic solvents or deep eutectic solvents. These are showing great potential to reduce the number of steps in current solvent extraction processing which will reduce capital and operating costs.
Can you share some examples of how Tetra Tech is leveraging partnerships to accelerate domestic REE development?
Tetra Tech is working with federal and state organizations, NGOs, industry bodies and universities across the U.S. to support development, research and funding for the REE and critical mineral industries.
We have active and former partnerships with several universities that are researching REE and critical mineral recovery from mining waste and byproducts, including Penn State, West Virginia University, Virginia Tech, University of Illinois, and University of Wyoming
We regularly engage with federal and state agencies to explore funding opportunities for client REE projects, and we are collaborating with various NGOs on grant applications to support the development of small-scale REE and critical mineral processing projects using coal waste materials. Our experts are also working on a research project with the Department of Energy to support new rare earth technologies.
We also work closely with the mining industry on research and development projects, as well as the assaying of potential REE sources and feedstock, and the location of new processing facilities.
How are we helping clients overcome the challenges of developing REE production?
We are working on rare earth projects with our clients world-wide. These projects cover a wide range of technologies and feedstock types such as coal fly ash, coal seam underclay, hardrock (e.g. bastnasite, alanite) and mineral sands (monazite).
Our teams bring both an environmental and technical perspective, delivering smarter, faster, responsibly managed mining and metals processing solutions for our clients. We draw on the latest knowledge from our research partnerships to design innovative extraction and separation processes and solutions which shorten processing time and reduce costs.
We are working with clients across the whole project life cycle. From identifying REE deposits in the exploration phase, mine design and planning, comminution design, hydrometallurgical testing and flowsheet development, to processing plant design and construction and startup support.
Our experts bring real life expertise to projects, having tested, designed and operated rare earth processing facilities in the U.S. so they deeply understand the operational challenges faced by clients in this geography. We are helping clients to fast-track permitting and navigate changes to policy priorities.