American Rare Earths has achieved a significant metallurgical milestone by successfully removing impurities from allanite-based rare earth ore at its Halleck Creek project, potentially lowering costs and boosting rare earth recovery.
- Successful impurity removal from Halleck Creek allanite ore using magnesium oxide
- Near-complete precipitation of iron, titanium, aluminum, silica, thorium, and uranium
- Minimal formation of problematic byproducts like gypsum and silica gel
- Reduction in rare earth element losses and processing complexity
- Results to inform Pre-Feasibility Study and advance hydrometallurgical testing
Processing Breakthrough at Halleck Creek
American Rare Earths (ASX – ARR) has announced a pivotal advancement in the processing of rare earth elements (REE) from its Halleck Creek project in Wyoming. The company successfully completed impurity removal neutralization tests, a critical step in hydrometallurgical processing that has historically challenged allanite-based ores like those at Halleck Creek. This breakthrough promises to streamline operations, reduce costs, and enhance rare earth recovery.
Overcoming Historical Challenges
Allanite, the host mineral for the rare earths at Halleck Creek, typically complicates processing due to the formation of gypsum and silica gel during impurity removal. These byproducts have traditionally necessitated additional processing steps, increasing both capital and operating expenses while reducing rare earth yields. The recent tests, conducted by SGS in Ontario, Canada, demonstrated that using magnesium oxide (MgO) as the neutralizing reagent effectively precipitated nearly 100% of deleterious elements such as iron, titanium, aluminum, silica, thorium, and uranium, with minimal gypsum and silica gel formation.
Technical Details and Operational Benefits
The impurity removal process was optimized through two neutralization stages at controlled pH levels. Primary neutralization at pH 3.15 removed the bulk of iron, thorium, and titanium, while secondary neutralization at pH 5.0 further eliminated aluminum and uranium. Importantly, rare earth element losses were kept below 1%, a significant improvement over previous methods. The choice of MgO over alternatives like magnesium carbonate was driven by its cost-effectiveness and superior performance in minimizing unwanted byproducts.
Implications for Project Development
This metallurgical milestone de-risks a major technical and economic hurdle for the Halleck Creek project, enhancing the feasibility of producing high-purity rare earth oxides essential for permanent magnets and advanced technologies. The results will feed directly into the Pre-Feasibility Study (PFS) flowsheet, expected to be completed by year-end, alongside ongoing hydrometallurgical and comminution optimization testing. These developments position American Rare Earths to play a critical role in securing U.S. rare earth supply chains.
Looking Ahead
With impurity removal challenges addressed, American Rare Earths is advancing towards solvent extraction and separation phases, aiming to produce separated rare earth oxides. The company is also progressing bulk sample testing with industry partners to refine mining and processing parameters. While environmental permitting and scale-up remain to be navigated, this breakthrough marks a significant step toward commercial viability.
Bottom Line?
American Rare Earths’ impurity removal success at Halleck Creek could redefine allanite-based rare earth processing economics.
Questions in the middle?
- How will full-scale plant operations replicate the laboratory impurity removal results?
- What are the long-term cost implications of using magnesium oxide as the neutralizing reagent?
- How will environmental and permitting factors influence the project timeline post-breakthrough?