American Rare Earths Ltd (ASX:ARR, OTCQB:ARRNF) continued to strengthen the development pathway for its flagship Halleck Creek Rare Earths Project in Wyoming during the September quarter, achieving major technical milestones and securing funding for the next stage of growth.
The company ended the quarter with A$21.2 million in cash, positioning it well to advance pre-feasibility, permitting and engineering work designed to establish Halleck Creek as the next producing rare earths mine in the United States.
Hydrometallurgical breakthrough
A key highlight was the successful completion of impurity-removal neutralisation tests for Halleck Creek’s allanite-based ore. The test work showed minimal formation of problematic by-products such as gypsum and silica gel — a frequent issue in rare-earths processing — which the company said could translate to lower capital and operating costs.
American Rare Earths described the result as a significant de-risking step for its hydrometallurgical flowsheet and “a major milestone in unlocking Halleck Creek’s vast REE supply potential.”
Strong leach recoveries
Earlier in the quarter, extensive leach testing delivered high recoveries for key light rare earths, including 85% for praseodymium and 84% for neodymium at optimal conditions. Encouraging results were also recorded for heavy rare earths — 52% for terbium and 46% for dysprosium — with impurity levels substantially reduced compared with previous studies.
Atmospheric tank leaching has now been chosen as the preferred method, offering greater energy and reagent efficiency than more intensive acid-bake processes.
Test mining and permitting progress
At the Cowboy State Mine, American Rare Earths successfully excavated and crushed around 3,080 tonnes of ore, providing feed for optimisation programs in the US, Canada and Germany. The company said the work would inform design of a beneficiation demonstration plant and feed into its upcoming permit-to-mine submission.
Permitting also advanced, with groundwater pump testing completed to supply baseline data for the Wyoming Department of Environmental Quality. Environmental monitoring and hydrological modelling are continuing as part of the project’s pre-feasibility study (PFS).
Funding and corporate activity
During the quarter, ARR raised A$15 million through a placement at A$0.32 per share, with strong institutional participation. A further A$1.465 million was generated through options exercises, and the company received the final A$1 million payment from Cobalt Blue Holdings under a promissory note agreement.
ARR also retains access to A$8.8 million (US$5.6 million) in funding under the State of Wyoming’s matching grant program, ensuring coverage for planned activities over the next 18-24 months.
Outlook
In the December quarter, American Rare Earths will integrate the latest test work into Halleck Creek’s PFS and demonstration-plant design, progress engineering and equipment planning, and finalise the mineral processing flowsheet ahead of a technical report in 2026.
The company will also advance CEO recruitment and maintain engagement with US federal and state agencies supporting critical-minerals initiatives, reinforcing Halleck Creek’s role as a cornerstone project in America’s drive to secure a domestic mine-to-magnet supply chain.