Australia-headquartered American Rare Earths has made rapid progress on its pilot programme to produce pre-production rare earths concentrate from its flagship Halleck Creek project, in Wyoming, in the US.

Halleck Creek holds one of the largest known rare-earth deposits.

The pilot plant process is being led by metallurgical engineering Jaye Pickarts, who brings deep rare earths and project development experience to this critical phase of American Rare Earths’ work.

As a registered professional engineer and independent contractor with more than four decades of experience in mine development, mineral processing and environmental compliance, Pickarts has successfully commissioned a fair share of rare earth demonstration plants and technical studies advancing projects from scoping to feasibility.

American Rare Earths says his background in both flowsheet development and practical plant execution will be applied to integrate and derisk the Halleck Creek pilot circuit.

To support the pilot plant, the company has produced three key pieces of processing equipment for the front-end of the circuit, including two induced roll magnetic separators and a reflux classifier. The equipment is currently being fabricated on an expedited schedule.

The company advises that the remainder of the pilot circuit will use standard, well-understood processing equipment, which will allow the team to focus on quickly integrating and optimising these critical path units.

Notably, the classifier will perform primary density-based separation to reject lower-density feldspars and quartz while concentrating higher-density minerals, including rare-earth-bearing allanite. In turn, the induced roll magnetic separators will provide secondary separation, exploiting differences in magnetic properties between iron-rich minerals and rare-earth-bearing allanite to further upgrade the concentrate.

Early testwork on the circuit has demonstrated total rare earth oxide recovery rates of about 70% and a grade enrichment of about ten times relative to feed, which confirms the effectiveness of this flowsheet as the front-end of the pilot plant.

American Rare Earths holds an exploration permit to mine up to 60 000 t of ore for testing purposes and has already mined about 3 100 t of Halleck Creek material to feed the pilot plant.

This ore will be used to generate representative pre-production concentrates to validate metallurgical performance, support downstream processing testwork and advance discussions with potential offtakers.

American Rare Earths CEO Mark Wall says the company is moving with speed to produce a pre-production concentrate from ore mined at Halleck Creek. “By combining a large, long-life Wyoming orebody with experienced pilot plant leadership, proven front-end equipment and a permitted bulk sample programme, we are advancing Halleck Creek along a clear and scalable path from resource to production,” he adds.

Wall concludes that the pilot plant process so far is reinforcing the company’s ambition to become a cornerstone of the emerging US rare earths supply chain.