Key highlights

• American Rare Earths has enlarged the proposed first development phase of its Halleck Creek project in Wyoming.

• An updated scoping study for the Cowboy State Mine sets out the scale-up, with a pilot plant and recovery work supporting the model.

• The company is moving downstream, while the policy backdrop supports US rare earths development.

American Rare Earths (ASX:ARR) has enlarged the proposed first development phase of its Halleck Creek Rare Earths Project in Wyoming. The company's September quarter report, lodged with the ASX on 29 October, described an updated scoping study for the Cowboy State Mine targeting throughput of 4.5 million tonnes a year over a 26-year mine life.

That compares with the previous case of three million tonnes a year over 20 years. The larger case now forms the basis for pre-feasibility and supporting technical work. A scoping study is preliminary, so the expanded case is a planning basis rather than a confirmed development.

Drilling supports the model

The company completed an 18-hole feasibility-stage drilling programme in the Cowboy State Mine area at Red Mountain. Certified assays from the first six holes confirmed broad, near-surface mineralisation consistent with the geological model.

About 93% of reported intervals exceeded the company's 1,000 ppm total rare earth oxide (TREO) resource cut-off, with a mean grade of 3,497 ppm TREO. Hole HC26-RM056 returned 191 metres of continuous mineralisation, and the highest individual assay was 9,084 ppm TREO over 3.02 metres. Results from the remaining 12 holes were outstanding at quarter-end.

Those grades are modest compared with some high-grade rare earth deposits, which is why scale, Mining cost and recoveries matter so much at Halleck Creek. Hard-rock projects of this type depend on efficient bulk mining and effective concentration.

Pilot plant and recoveries

The pilot plant programme moved into physical processing during the quarter, with crushing of Halleck Creek ore under way. The programme is designed to test concentration, leaching, impurity removal and oxide separation, with the aim of showing a pathway to separated rare earth oxides.

Recovery optimisation remained a focus. Test work is under way on a large sample at Nagrom, while a 40-kilogram concentrate sample is undergoing further work with US-based Novex. Recovery data from pilot work will be central to any pre-feasibility study. Rare earth separation is technically complex, and many projects around the world have struggled to move from laboratory tests to consistent commercial production. Demonstrating a workable flowsheet at pilot scale would therefore be a meaningful step, while setbacks at this stage could extend the timetable or raise costs.

Moving downstream

American Rare Earths signed a memorandum of understanding with Novex to evaluate converting NdPr oxide into NdPr metal. The aim is to extend the company further down the US rare earth Supply chain and support domestic production of material used in permanent magnets. An MOU is non-binding, so commercial terms remain to be negotiated.

The policy backdrop

The United States has made domestic rare earth supply a strategic priority because China dominates mining, separation and magnet manufacturing. Projects such as Halleck Creek may benefit from that focus through government support or interest from manufacturers. However, policy can change, and support is not guaranteed for any individual project.

Broader property assessment

Work also continued on a Whole of Property Assessment covering the wider Halleck Creek tenure, which could inform future expansion Options beyond the Cowboy State Mine area. Results of that assessment were not available in the material reviewed. The scale of the tenure, more than 8,000 acres, gives the company room to consider later phases, but each would need its own drilling, studies and approvals before forming part of any mine plan.

What to watch

Investors may watch for assays from the remaining 12 holes, pilot plant outcomes, progress on the pre-feasibility study and developments with Novex. The company also lodged its notice of Annual General Meeting on 30 October.