Milestone for USA Rare Earth production
Lab tests confirm process for Colorado REE separation pilot Metal Tech News Weekly Edition – May 27, 2020
Last updated 6/27/2020 at 6:15am
USA Rare Earth LLC and Texas Mineral Resources Corp. May 26 reported another milestone along the path to developing a rare earths and critical minerals mine and processing facility in the United States.
Texas Mineral Resources is an El Paso, Texas-based mineral exploration company targeting the heavy rare earths and other technology and industrial minerals found at Round Top, and USA Rare Earth is a New York City based company that is funding the project's development.
The partners have also opened a pilot plant facility in Wheat Ridge, Colorado to separate the rare earths and suite of other critical minerals found at their Round Top project about 85 miles southeast of El Paso.
"Our Colorado pilot plant will have the ability to produce the full range of high purity, separated rare earths as well as other critical minerals such as lithium," said USA Rare Earth CEO Pini Althaus.
Toward this objective, the companies announced the completion of the initial phase of bench scale testing at Inventure Renewables, Inc.'s laboratory in Alabama.
Utilizing a rare earth and critical minerals bearing solution that is representative of the solution that will be the product of the heap leach recovery process at Round Top, Inventure was able to increase the rare earth concentrations by 6.3 times and remove impurities with continuous ion exchange.
This process, which involves the use of special resins to capture the rare earths and the use of a weak acidic solution that rinses the captured REEs from the resins, is the first stage of the continuous ion exchange and chromatography recovery process being developed by USA Rare Earth and Texas Minerals.
"The success of this first phase of work, concentrating the rare earths and obtaining a clean separation from other minerals, is an important validation of our processing, using CIX (continuous ion exchange)," said Richard Shaw, principal of Fenix NZ, a company that specializes in ion exchange. "In the coming months, we expect to achieve the goal of separated, high purity rare earth compounds and other targeted metals such as lithium as we scale up towards a commercial pilot plant."
Previous laboratory work shows that effective separation and purification of REEs could be achieved directly from the original heap leach-like solution from Round Top ore. The concentrated solutions from the ion exchange process should provide an excellent starting point for chromatographic separation, which utilizes substances that cause the various components of a mixture to flow at different speeds, to separate the notoriously tightly interlocked rare earths into individual elements.
"This is an important step towards USA Rare Earth's objective to build the first rare earth and critical minerals processing facility outside China and to bring the Round Top project into full commercial production," said Althaus.
Colorado pilot plant
The results from the lab testing in Alabama provide the baseline for the pilot plant at USA Rare Earth's REE and critical minerals processing facility in Colorado.
This pilot plant work builds on previous lab scale success of producing high-purity rare earth compounds from material from Round Top and other sources.
The first of three continuous ion exchange units was delivered to the pilot plant facility in early March and is planned to be commissioned in early June as COVID-19 related travel restrictions are relaxed. The 30-column units readily enable rinsing, washing, and solution recycling in a fully automated process which greatly simplifies the optimization of the process now that the base case parameters have been established in the laboratory.
USA Rare Earth said the ion exchange and chromatography units at the Wheat Ridge pilot facility will be capable of processing several thousand liters of leach solution per day. The ion exchange process concentrates large volumes of leach solution to smaller volumes of higher-grade solution.
The next phase of USA Rare Earth's pilot work will focus on group separating the entire suite of 15 rare earth elements concentrated in the initial phase into heavy (dysprosium, terbium), middle, and light REEs (neodymium, praseodymium).
The third and final phase of the pilot work will be the further separation of high purity individual REE compounds.
In parallel piloting a process to create high purity rare earths in the U.S., USA Rare Earth will advance work to recover the other critical minerals that have been separated from the REEs from the Round Top project in Texas.
Completion of this work – which will focus on lithium, uranium, beryllium, gallium, zirconium, hafnium and aluminum – will support a preliminary feasibility study for developing a mine at Round Top project in Texas, including non-REE processing that is expected to support upgrading the measured and indicated resources to proven and probable reserves, with no in-fill drilling required.
"Our pilot plant is the second link in a 100% U.S.-based rare earth oxide supply chain, drawing on feedstock from our Round Top deposit," said Altius. "Together with our recently acquired rare earth magnet platform, Round Top and our pilot plant constitute essential links in restoring a mine-to-magnet domestic U.S. rare earth supply chain without the material ever leaving the United States, thereby alleviating the current dependence on China for both raw materials and mineral processing. Aside from Round Top's potential to supply a significant amount of material for U.S. defense as well as commercial applications, we believe our initiative will reinvigorate advanced technology manufacturing in the U.S. for companies currently dependent on foreign sources for supply."
Further details on the magnet platform acquired by USA Rare Earth and the company's mine-to-magnets strategy can be read at USA Rare Earth adds magnet equipment in the April 10 edition of Metal Tech News.