The Ema rare earth project is a mining development in northern Brazil being advanced by Brazilian Critical Minerals.
A scoping study was completed in February 2025, followed by a bankable feasibility study (BFS) in June 2026.
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The BFS outlines a 20-year life-of-mine (LOM) average processing capacity of 5,500 tonnes per annum, delivered through a two-stage development. Stage one is planned for the first two years with an investment of approximately $74m, followed by a 100% expansion to stage two to reach full nameplate capacity in year four.
With the BFS complete, the project is expected to progress into detailed engineering design, finalisation of offtake arrangements, project financing and permitting.
Ema rare earth project location and geology
The Ema rare earth project is located in the Apui region of Amazonas State in northern Brazil.
The project covers the Ema and Ema East tenement areas, spanning around 189km² of prospective felsic volcanic terrain. The setting hosts extensive weathered, clay-rich saprolite profiles enriched in rare earth elements (REEs), including the high-value magnet rare earths neodymium, praseodymium, dysprosium and terbium.
Mineralisation
Rare earth mineralisation at Ema occurs within the tropical lateritic weathering profile developed over felsic rocks, including rhyolites, in a style comparable to Chinese ionic clay deposits.
REEs are mobilised from primary minerals such as monazite and xenotime and are then adsorbed onto newly formed fine aluminosilicate clay particles including kaolinite, illite and smectite.
Ema rare earth project reserves
The indicated and inferred mineral resources at the Ema rare earth project are estimated to be 1.07 billion tonnes (bt) grading 732 parts per million (ppm) total rare earth oxides (TREO), including 174ppm neodymium-praseodymium, 16ppm dysprosium-terbium and 190ppm mass magnet rare earth oxides (MREO) as of March 2026.
Mining method
The Ema rare earth project is due to be developed as an in-situ recovery (ISR) operation using wellfield pods to leach the mineralisation.
Across the LOM, extraction is forecast at 109,500t of TREO containing 38,000t of MREO. The operation is expected to produce a single product, a mixed rare earth carbonate (MREC) containing all 15 REEs.
In the first year of operation, around half of the proposed Wellfield 1 area is expected to operate to meet a targeted 8,000m³/day lixiviant injection rate. Barren liquor magnesium sulphate will be injected on upper slopes through closely spaced injection wells installed into the top of the orebody.
Injection wells are designed to extend to within 15m of the pregnant leach solution (PLS) collection system and to reach around 1m below the top of mineralisation to support even reagent distribution.
The injection wells will use a one-inch polyvinyl chloride pipe with a 2m screened interval at the base. Reagent delivery will use a tap-style arrangement to adjust flow rates based on well performance and phreatic surface behaviour.
The PLS capture network is designed as a ring around the wellfield, following a contour interval. After injection, fluids will migrate downslope along the saprolite-bedrock contact and report to collection systems at the base of the slope.
The collection system will comprise closely spaced horizontal wells, between 30m and 100m in length, with final well lengths set by local ground conditions and wellfield geometry. Additional subsurface extraction infrastructure may be installed along the saprolite-bedrock contact where required.
Harvested PLS will flow by gravity to PLS ponds before being pumped to the process plant. The barren liquor will be re-treated and returned to the injection wellfield for reuse.
Leaching is expected to end when PLS grades fall below a specified ppm threshold or an economic cut-off, after which the wellfields will be flushed with water and rehabilitated.
The BFS also includes a negative pressure extraction system applying suction to production wells and the collection system to draw PLS through mineralised clays into a controlled recovery network. This is intended to improve solution movement, increase capture of dissolved rare earths and reduce the risk of lixiviant migration outside the wellfield.
Processing methods
The Ema process plant is designed to receive PLS at a nominal flow rate of around 350m³/h. The PLS will contain dissolved REEs along with dissolved impurities including aluminium, iron and other gangue species typical of ionic clay deposits.
The proposed flowsheet is based on recovering rare earths using a magnesium sulphate lixiviant. PLS will be collected and sent to storage before chemical treatment, then moved through impurity removal where reagents such as flocculant and magnesium hydroxide may be added to remove suspended solids and dissolved impurities.
The clarified liquor will report to the mixed rare earth carbonate precipitation circuit, where magnesium bicarbonate and flocculant are used to precipitate rare earths as MREC. The resulting solids are filtered, washed as required and recovered as the final product, while filtrate reports to barren liquor storage for recycling.
Following precipitation, barren liquor is returned to storage, reconditioned with magnesium sulphate where needed and reused for reinjection. The closed-loop approach is aimed at lowering reagent use, reducing water demand and limiting solution losses.
Impurity removal solids will be filtered and may be repulped and washed to recover entrained soluble rare earths before final filtration.
Infrastructure
The Ema project depends on a multi‑mode transport approach, due to the site’s remote location and the poor standard of local roads. It lies roughly 450km from the Madeira River basin, the region’s primary freight route. The operation is also close to the Transamazonica Highway, a key overland link, and also relies on river terminals at Apui, Novo Aripuana and Humaita.
The process plant will be powered by a central diesel power station with N+2 redundancy and generator synchronisation, supported by five 500kW diesel generators.
A raw water storage dam will be located to the south-east of the processing plant to collect and retain water for operational use.
Project financing
In July 2026, Brazilian Critical Minerals secured firm commitments to raise around $6.9m (A$10m) through a two-part institutional placement. The placement is non-underwritten and involves the issue of around 190.1 million new fully paid ordinary shares at A$0.053 per share.
Proceeds are intended to support progress towards a final investment decision, including front-end engineering design, drilling production wells for Wellfield 1 and procurement of early project equipment.
Contractors involved
The environmental impact study was completed by CERN, which coordinated the environmental work and is in the process of submitting the Environmental Control Plan.
The numerical groundwater model was developed by WSP and was used to simulate and design the ISR wellfield. Its work supported the design of injection wells, extraction systems, headworks and related wellfield infrastructure.
Brazilian Critical Minerals commissioned C.Steinweg Group to undertake consumables and an MREC Logistics study in December 2025.
An updated mineral resource estimate for the project was prepared by GE21 Consultoria Mineral.
