Terrain Minerals Limited has completed first-stage metallurgical leaching test work for the Larin's Lane Prospect, achieving total rare-earth element recoveries of up to 83% using methanesulphonic acid at 50°C.

The test work was undertaken by Curtin University's Critical Minerals, Metals and Materials for the Energy Transition Research Group as part of Minerals Research Institute of Western Australia Research Project M10528. Previous announcements reported that metallurgical studies were underway for the prospect, which forms part of Terrain Minerals' 100%-owned Smokebush Project in the Yalgoo Mineral Field of Western Australia. Maiden air core drilling in late 2023 intersected broad zones of clay-hosted rare earth and gallium mineralisation over a 9-kilometre by 3-kilometre strike.

The recent testing evaluated several lixiviants and found that methanesulphonic acid outperformed organic acids such as citric and tartaric acid. Total rare-earth element recovery rose to up to 99% when the clay material underwent thermal pre-treatment prior to leaching at 80°C. The program also confirmed a consistent, recoverable scandium credit, with extraction reaching approximately 67% to 79% under elevated-temperature and calcined conditions. Gallium was likewise brought into solution, achieving up to 89% recovery following thermal pre-treatment and subsequent acid leaching at 80°C.

Testing demonstrated that the material did not respond to ammonium sulphate leaching, indicating that the mineralisation is not held in an ion-exchangeable form and requires an acid-based leach mechanism.

“These results are an important technical milestone for Larin's Lane. Working with Curtin University through the MRIWA M10528 program, we now have direct evidence that the rare earths in our clay- hosted material can be recovered at high efficiency, with scandium reporting as a valuable additional credit and gallium offering further upside as metallurgical studies advance.”

“This test work gives Terrain a genuine technical foundation to advance the Project towards resource and scoping-level studies, and to progress discussions with potential partners.”

— Justin Virgin, Executive Director

In the surrounding district, Critica Limited reported multiple shallow, high-grade rare earth intersections, including 14m @ 3,053 ppm TREO from 44m, at its Jupiter and The Brothers project on 27 July 2026. Terrain Minerals plans to use the metallurgical data as a technical input to advance future Mineral Resource estimate and Scoping Study work for Larin's Lane.

Read the full announcement: Larin's Lane 80% plus REE Recovery & Gallium/Scandium Upside