Rare Earths Oxide Produced From Halleck Creek Ore
MWN-AI** Summary
American Rare Earths (ASX: ARR) has reached a significant milestone in its Halleck Creek Project by successfully producing mixed rare earth oxides (MREO) from its ore. This achievement follows the use of an updated preliminary Pre-Feasibility Study (PFS) mineral processing flowsheet, which was instrumental in transforming the pregnant leach solution (PLS) derived from impurity removal tests into two end products: a mixed rare earth oxalate and MREO powder. This development confirms the feasibility of extracting rare earth elements into metallic oxides from Halleck Creek ore, marking a crucial advancement for the project.
The produced MREO is particularly important as it serves as the precursor for generating individual rare earth products such as Neodymium-Praseodymium (NdPr), Terbium (Tb), and Dysprosium (Dy) through further solvent extraction—a process that is well-established compared to the complexities of MREO production. The successful generation of MREO not only represents a major technical step but also enhances the project’s potential to supply critical minerals and lessen U.S. reliance on imports, primarily from China.
The production process involved integrating a two-step method executed by SGS in Ontario, Canada, which included precipitating rare earths with oxalic acid and subsequently calcining the material to convert it into an oxidized form. This meticulous approach effectively removed impurities like uranium from the solution.
Next, the company will focus on detailed solvent extraction simulations, process optimization, and testing of various mineral processing methods to refine the PFS. With goals set for onsite processing facilities, the Halleck Creek Project stands at the forefront of advancing U.S. rare earth supply chain security, aligning with broader economic and technological needs for these essential elements.
MWN-AI** Analysis
American Rare Earths (ASX: ARR | OTCQX: ARRNF | ADR: AMRRY) has made significant strides in its Halleck Creek project by successfully achieving the production of Mixed Rare Earth Oxides (MREO) using an updated preliminary Pre-Feasibility Study (PFS) mineral processing flowsheet. This milestone underscores the project's potential, particularly in the current context of heightened geopolitical tensions that emphasize the need for U.S. critical mineral independence.
The process of extracting MREO from Halleck Creek ore via a purified leachate solution has positioned ARR as a promising player in the rare earth sector. The successful completion of impurity removal testing, which facilitated high recovery rates of rare earth elements (REEs) through rigorous precipitation and calcining processes, highlights the project’s technical viability. The feedback loop generated by the solvent extraction simulation further enhances the efficiency of extracting valuable rare earths such as Neodymium and Dysprosium, which are critical for the tech and defense industries.
Moreover, with U.S. legislation increasingly aimed at minimizing reliance on Chinese imports, companies like ARR are strategically positioned to benefit from this demand surge. Investors may want to consider ARR as a compelling opportunity in a sector expected to grow as global economies pivot toward greener technologies and national security concerns rise.
However, investors should remain cautious, as mining operations and production processes are often subject to regulatory hurdles and environmental considerations, which can impact timelines and profitability. Continuous monitoring of the company's updating progress, as well as developments in R&D for innovative extraction methods, will be crucial for informed decision-making.
In summary, with its recent achievements and the broader market dynamics favoring domestic rare earth production, American Rare Earths is well-positioned for future growth. Investors should keep a close watch on the upcoming PFS results, which may provide further validation of its operational capabilities and market potential.
**MWN-AI Summary and Analysis is based on asking OpenAI to summarize and analyze this news release.
Highlights
- Rare earth oxides were produced from Halleck Creek ore using the updated preliminary Pre-Feasibility Study (“PFS”) mineral processing flowsheet 1
- A Mixed Rare Earth Oxalate and Mixed Rare Earth Oxide were created from purified leachate solution using the material from the impurity removal testing 2
- This is the most significant technical milestone achieved for the Project to date
DENVER, Dec. 16, 2025 (GLOBE NEWSWIRE) -- American Rare Earths ( ASX: ARR | OTCQX: ARRNF | ADR: AMRRY) ( “ARR” or the “Company” ) has successfully completed another critical stage in its mineral processing program by producing a mixed rare earths oxide (“ MREO ”) using the updated preliminary PFS mineral processing flowsheet.
MREO from Halleck Creek (“ the Project ”) was produced using the material – a pregnant leach solution (“ PLS ”) – from the impurity removal testing campaign 3 . This was achieved through precipitating a mixed rare earth oxalate and then creating MREO powder (see Figure 1). This major technical milestone confirms that rare earths can be extracted into metallic oxides from Halleck Creek ore using the updated preliminary PFS mineral processing flowsheet currently being finalized for the upcoming PFS. Solvent extraction computer simulation is now underway, using the results of these tests.
SGS in Lakefield, Ontario, Canada created the MREO from the Halleck Creek PLS through a two-step process. The first step consists of precipitating the metals in solution using oxalic acid to create a mixed rare earth oxalate. Oxalic acid is highly selective in precipitating rare earth elements (“ REE ”) from PLS while other elements stay in solution. SGS performed three precipitation tests using variable oxalic acid addition rates. The second step, called calcining, involved SGS heating the combined mixed rare earth oxalates to 1,000 o C to oxidize the material into a MREO. A beneficial effect of calcining is that it oxidizes the cerium, converting it from Ce 3+ to Ce 4+ . Ce 4+ is not soluble in the reagent which will be used to dissolve REEs from the MREO for solvent extraction.
Figure 1 – Halleck Creek Mixed Rare Earth Oxalate (left) and Mixed Rare Earth Oxide (right)
Why it matters?
Producing a MREO from Halleck Creek ore, using the updated preliminary PFS mineral processing flowsheet currently being finalized for the upcoming PFS, is the most significant technical milestone achieved for the Project to date.
MREO is the precursor used to produce individually separated rare earth products through solvent extraction, such as Neodymium-Praseodymium (“ NdPr ”), Terbium (“ Tb ”), and Dysprosium (“ Dy ”). In general, producing MREO is the most challenging technical step in manufacturing separated rare earth oxides. By comparison, the subsequent solvent-extraction stage is a well-established, relatively straightforward process.
Next steps in Halleck Creek’s updated preliminary PFS mineral processing flowsheet development include:
- Solvent extraction simulation, using MetSim, is underway using the analytical results of the MREO. The simulated solvent extraction flowsheet will be used to model and define specifications and costs for a solvent extraction refinery, which is typical for a PFS.
- Process optimization using bulk samples continues in parallel with metallurgy. Comminution testing of test pit ore, from the Cowboy State Mine area, is nearing completion at FL Smidth and Loesche. Bulk ground material from the comminution testing is scheduled for reflux classifying concentrator (“ RCC ”) separation and induced roll magnetic (“ IRM ”) concentration at Nagrom. Additional, wet high intensity magnetic separation (“ WHIMS ”) of fines <53µm is scheduled with Eriez.
- Using a mineralized concentrate from the on-going optimization work, complete a single pass-through mineral processing flowsheet to replicate and validate all hydrometallurgical test results completed to date.
Additional technical details
SGS conducted a small bench scale test for uranium removal using a PLS from multiple secondary neutralization tests. The 24-hour test was conducted using Dowex/Ambersep 21K XLT ion exchange resin. The test reduced the uranium content from 1.27ppm to 0.04ppm, effectively removing 97% of the remaining uranium from solution. Between primary and secondary neutralization, and ion exchange 99% of uranium is removed from the REE enriched PLS.
SGS conducted REE precipitation on the PLS using oxalic acid in a 5% solution at 90%, 100% and 110% stoichiometric doses. The average recovery of REE sharply increased between the three tests, showing an average REE recovery of approximately 97% and the average recovery of the magnet REE (Nd, Pr, Sm, Tb and Dy) is approximately 98% under 110% stoichiometric conditions and , see Table 1Table 1, and Figure 2.
Table 1 – REE Precipitation Results from Oxalic Acid Additions
Figure 2 - Calculated Precipitation Percentage of REE
SGS heated the combined mixed rare earth oxalates from sample RP3 at 1,000 o C for two hours to oxidize the material into a mixed rare earth oxide, MREO. During the calcining process water and carbon were driven off and the elements were converted to rare earth oxides. Most notably, as stated above, calcining oxidizes cerium, converting it from Ce 3+ to Ce 4+ . The benefit is that Ce 4+ is not soluble in the reagent which will be used to dissolve REEs from the MREO for solvent extraction. The assayed results of the MREO are shown in Table 2.
Table 2 – Assay Results of Calcine Test 1
This release was authorized by the board of American Rare Earths.
Investors can follow the Company’s progress at www.americanree.com
Please see here for the full JORC technical report.
About American Rare Earths Limited:
American Rare Earths (ASX: ARR | OTCQX: ARRNF | ADR: AMRRY) is a critical minerals company at the forefront of reshaping the U.S. rare earths industry. Through its wholly owned subsidiary, Wyoming Rare (USA) Inc. (“WRI”), the company is advancing the Halleck Creek Project in Wyoming—a world-class rare earth deposit with the potential to secure America’s critical mineral independence for generations. Located on Wyoming State land, the Cowboy State Mine within Halleck Creek offers cost-efficient open-pit mining methods and benefits from streamlined permitting processes in this mining-friendly state.
With plans for onsite mineral processing and separation facilities, Halleck Creek is strategically positioned to reduce U.S. reliance on imports—predominantly from China—while meeting the growing demand for rare earth elements essential to defense, advanced technologies, and economic security. As exploration progresses, the project’s untapped potential on both State and Federal lands further reinforces its significance as a cornerstone of U.S. supply chain security. In addition to its resource potential, American Rare Earths is committed to environmentally responsible mining practices and continues to collaborate with U.S. Government-supported R&D programs to develop innovative extraction and processing technologies for rare earth elements.
For additional information
Media Contact:
Susan Assadi
sassadi@americanree.com
347 977 7125
Investor Relations US Contact:
Beverly Jedynak
Beverly.jedynak@viriathus.com
312 943 1123
________________________
1 See ASX release dated November 10, 2025
2 See ASX release dated October 13, 2025
3 See ASX release dated October 13, 2025
Figures and tables accompanying this announcement are available at:
https://www.globenewswire.com/NewsRoom/AttachmentNg/88a9e78d-cd82-48ce-88a2-3a92c546aa70
https://www.globenewswire.com/NewsRoom/AttachmentNg/f82fafa0-42fe-4331-ab98-8343b2a2a9d4
https://www.globenewswire.com/NewsRoom/AttachmentNg/4778f2da-649d-49db-94de-7efdedd04b0e
https://www.globenewswire.com/NewsRoom/AttachmentNg/11d49aa6-1b2e-4240-a324-2fff29ae79d9
FAQ**
How does the production of mixed rare earth oxides (MREO) from Halleck Creek ore position ARMOUR Residential REIT Inc. ARR in the broader rare earth industry landscape and its potential impact on supply chain security?
What implications do the successful impurity removal tests have for ARMOUR Residential REIT Inc. ARR's mineral processing efficiency and the overall economics of the Halleck Creek Project's PFS?
Can the advancements in the updated preliminary PFS mineral processing flowsheet enhance ARMOUR Residential REIT Inc. ARR's reputation as a leader in environmentally responsible mining practices?
How might the outcomes of the solvent extraction simulations affect the project valuation for ARMOUR Residential REIT Inc. ARR, considering potential market demand for separated rare earth products?
**MWN-AI FAQ is based on asking OpenAI questions about American Rare Earths Limited (OTC: ARRNF).
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