While junior explorer Altona Rare Earths is undertaking metallurgy work at its Monte Muambe rare earths and Monte Muambe fluorspar and gallium projects, in Mozambique, it is prioritising the latter, with construction anticipated to start next year, says CEO Cedric Simonet.

Although both projects are located on the same mining concession and geological feature, with the rare earths mineralisation concentrated at the centre of the carbonatite, and the fluorspar and gallium occurring around the edge of the intrusion, the projects remain independent and are unlikely to be fully integrated, he explains.

This independence, which extends to funding arrangements, enables Altona Rare Earths to advance both projects simultaneously, with meaningful synergies existing between them, including shared resources and infrastructure development.

Given that the Monte Muambe fluorspar and gallium project presents an opportunity for relatively rapid mine development, with construction scheduled for 2027, revenue from this project is expected to materialise first and will subsequently support the development of the Monte Muambe rare earths project.

The rare earths project, funded by the US Trade and Development Agency, is larger and substantially more capital-intensive, and its development path is expected to take several years before reaching production.

The current focus of the prefeasibility study is on metallurgy and process engineering, with contractor selection under way, explains Simonet.

Monte Muambe Fluorspar and Gallium project
The fluorspar Joint Ore Reserves Committee-compliant mineral resource estimate (MRE), released last month, is 3.48-million tonnes grading at 20.6% of calcium fluoride (CaF₂) at the Fluorite zone and Python target, which is sufficient to sustain production of 50 000 t/y of acid-grade fluorspar, with the potential to scale towards 100 000 t/y, depending on further drilling results.

Fluorspar metallurgy is a critical parameter for the project’s viability, with ongoing metallurgical work to confirm process parameters, expected recovery rates and characteristics of the final product.

“The objective is to produce a 97.5% CaF₂ acid-grade fluorspar concentrate with acceptable levels of impurities,” adds Simonet.

A scoping study, anticipated in the third quarter of this year, will confirm the project’s viability through a technoeconomic model, providing a first-pass valuation of the project.

Upon confirmation of the study, as well as metallurgical testing, Altona will execute a drilling campaign as part of the definitive feasibility study (DFS) to increase the MRE and expand production capacity. An exploration target of up to 3.2-million tonnes of contained CaF₂ has been defined at the Kudu target, with additional anomalies awaiting drilling, he says.

“Additional drilling will be done later this year in the context of the fluorspar project DFS, which we expect will result in an increase in the production capacity and the life-of-mine,” elaborates Simonet.

Altona also discovered gallium in 2025, materially expanding the project’s scope.

With the size potential of the gallium now established, at 11.73-million tonnes grading 54.7 g/t gallium oxide, Altona’s focus has turned to metallurgical testing, with results anticipated during the third quarter of this year.

Simonet notes that gallium associated with carbonatites and rare earth deposits is a relatively new concept. While some exploration companies have reported such occurrences, academic research remains largely limited and metallurgical pathways to extract gallium must be defined.

Upon successfully extracting a gallium concentrate or product, Altona will start a drilling campaign to enhance the tonnage and confidence level of the gallium MRE. Leveraging synergies with the fluorspar drilling campaign, the gallium drilling campaign is expected to be partially undertaken later this year, explains Simonet.

“While we were initially considering gallium as a potential by-product of fluorspar, the geological models constructed from the 2025 drilling campaign show that gallium mineralisation occurs in proximity with fluorspar mineralisation, but in a wider zone.”

As a result, there is a tonnage difference between the respective MREs. Gallium could be recovered as either a by-product or a standalone product, with Altona including the possibility of producing a heavy rare earths concentrate as a by-product during fluorspar recovery within the scope of ongoing fluorspar metallurgy testwork.

To date, a heavy-to-total rare earths ratio of about 40% has been identified within the fluorspar and gallium mineralisation, with results of the ongoing heavy rare earths mineralogy work expected by the end of the second quarter.

Simonet notes that the assessment of the gallium opportunity and the fluorspar-associated heavy rare earths remains limited to first-pass mineralogy and metallurgical testwork, with limited costs.

Consequently, Altona can conduct multiple value-adding workstreams concurrently, resulting in sustained news flow.

“The gallium and heavy rare earths opportunities are treated as potential add-ons to the fluorspar project and do not affect the overall timeline of the fluorspar project,” says Simonet, asserting Altona’s established priority is to develop the fluorspar mine and become a revenue-generating company.