Monte Muambe

Monte Muambe is a carbonatite rare earth project in the Moatize District of Tete Province, northwest Mozambique (RNS via Investegate, October 2023). It is held by Monte Muambe Mining Ltda, a Maputo-based company majority-owned by NeoTerra Group (USTDA), the London-listed company called Altona Rare Earths until June 2026 (RNS via Investegate, June 2026). As of October 2026, the project's rare earths component is at the prefeasibility stage, with metallurgy and process engineering funded by a U.S. government grant (RNS via Investegate, February 2026; RNS via Investegate, August 2026).

What kind of deposit is Monte Muambe?

Monte Muambe is a carbonatite intrusion about 3.3 kilometers wide at surface, hosted by Upper Karoo sandstones of the Cádzi Formation, according to Snowden Optiro's 2023 Competent Person Report (RNS via Investegate, October 2023). The report says the intrusion's age is unknown and that the basin inside its sandstone ridge holds fenites, several carbonatite types, breccias and pyroclastic rocks (RNS via Investegate, October 2023).

The planned process floats bastnaesite, the rare earth host mineral (RNS via Investegate, October 2023). Altona reported a maiden JORC Mineral Resource of 13.6 million metric tons (RNS via Investegate, February 2026). USTDA says the planned mine would produce mixed rare earth carbonate containing neodymium, praseodymium, dysprosium and terbium (USTDA).

Ownership and mining license (as of October 2026)

Altona has been earning into the project under a June 2021 farm-out agreement: 51% for a scoping study and 70% for a prefeasibility study (RNS via Investegate, October 2023). Its stake in Monte Muambe Mining rose from 20% to 51% in December 2023 (RNS via Investegate, December 2023), and Mozambique's mining minister approved the increase in January 2024 (RNS via Investegate, January 2024). In June 2026, the company said Phase 3 spending was close to the minimum commitment that lifts its holding to 70% (RNS via Investegate, June 2026).

In January 2025, the company reported that mining license 11854 showed as active on Mozambique's mining cadastre, valid until December 20, 2049, and that it covers rare earths and associated minerals, which the company says includes fluorspar (RNS via Investegate, January 2025). The company describes it as a 25-year license granted in December 2024 (RNS via Investegate, February 2026).

Monte Muambe studies, funding and offtake (as of October 2026)

The October 2023 scoping study outlined an open-pit mine processing 750,000 metric tons of ore a year over an 18-year life, producing on average 15,000 metric tons a year of mixed rare earth carbonate for export through the port of Beira (RNS via Investegate, October 2023). The study states it is not enough to support Ore Reserves or assure an economic development (RNS via Investegate, October 2023).

Altona submitted its USTDA proposal in August 2025 (REEx, August 2025). On February 27, 2026, the company's Mozambican subsidiary signed a US$1,875,000 grant agreement with the U.S. Trade and Development Agency (USTDA) to fund a prefeasibility study's metallurgy and process engineering (RNS via Investegate, February 2026). The program covers metallurgical sample drilling, testing that includes separating NdPr oxide from the carbonate, engagement with potential U.S. offtake partners and an updated financial model (RNS via Investegate, February 2026).

On August 20, 2026, NeoTerra selected Valentine Enterprises to lead the study, subject to final USTDA approval (RNS via Investegate, August 2026).

In July 2026, NeoTerra said its planned heavy rare earth byproduct and gallium work had drawn interest from specialty metals traders and a potential Japanese strategic partner, and that it hoped to turn that interest into formal agreements over the coming months (RNS via Investegate, July 2026).

NeoTerra is also developing a planned 50,000-metric-ton-a-year fluorspar mine within the same concession, which its management sees as a potential pathway to near-term production (RNS via Investegate, June 2026). Environmental permitting for that mine has started (RNS via Investegate, September 2026). Based on an Inferred resource, NeoTerra estimates the fluorspar operation could also recover up to 650 metric tons a year of a concentrate rich in heavy rare earths, subject to metallurgical optimization (RNS via Investegate, July 2026).

Why Monte Muambe matters for rare earth supply

USTDA says the study will define the technical and financial pathways needed to attract funding for full-scale development and connect the developer with potential U.S. buyers (USTDA, February 2026). REEx noted the funded work includes separating NdPr oxide, the core feedstock for permanent magnets (REEx, February 2026). After the grant signing, REEx said Monte Muambe was still at the prefeasibility stage, with no construction capital, offtake agreements or final investment decision in place (REEx, February 2026).

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