Eclipse Metals Confirms Up to 94% of NdPr Sits in Targetable Minerals at Grønnedal

Eclipse Metals' Grønnedal mineralogical testwork confirms 87.5–94.3% of NdPr is hosted in targetable REE mineral groups — a critical foundation for the flotation program now advancing on a 208Mt rare earth resource in Greenland.
By William Hadrian -
  • Quantitative mineralogical analysis by ALS Metallurgy confirmed that 87.5–94.3% of contained NdPr across four composite samples is hosted in identifiable REE-bearing mineral groups, establishing a clear beneficiation target.
  • Between 77.2% and 92.6% of NdPr is concentrated in the two principal flotation candidates — REE fluorocarbonates and REE carbonates — providing a direct basis for targeted reagent optimisation.
  • Liberation data at a P80 of approximately 102–107 µm showed 63.3–75.3% of REE fluorocarbonate mass and 61.1–79.1% of REE carbonate mass with at least 30% surface exposure, with locked fractions below 14% across all composites.
  • Early density and magnetic separation testing on Composite 2 demonstrated that combining both steps could remove 39% of total mass while retaining approximately 70% of TREEs, producing a concentrate of approximately 12,700 ppm TREE.
  • Eclipse has engaged Tetra Tech to lead the next-stage program, which will advance to rougher and scavenger flotation screening, cleaner flotation, and hydrometallurgical testing against the 208Mt at 0.72% TREO resource containing approximately 456,000 tonnes of Nd₂O₃ and Pr₂O₃.
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Testwork confirms NdPr mineralogical pathway at Grønnedal

Quantitative automated mineralogical analysis completed by ALS Metallurgy on four composite samples from Eclipse Metals’ Grønnedal project has returned results the company describes as an important step toward defining a potential beneficiation pathway. The core finding: between 87.5% and 94.3% of contained neodymium (Nd) and praseodymium (Pr) is hosted in identified REE-bearing mineral groups across the four composites, meaning the value-driving rare earths sit in targetable minerals rather than being scattered through surrounding waste rock.

That distinction matters enormously. Between 77.2% and 92.6% of NdPr is hosted specifically in the two principal groups being evaluated for flotation: REE fluorocarbonates and REE carbonates. The dominant mineral assemblage is interpreted as synchysite-type fluorocarbonates and calcioancylite-type REE carbonates, with subordinate bastnäsite, parisite, monazite and xenotime.

The testwork also confirmed four things the company needed to establish before advancing to metallurgical development:

  1. NdPr deportment into identifiable REE mineral groups
  2. Meaningful surface exposure at the tested grind size
  3. The principal processing objective: selective rejection of carbonate gangue
  4. A clear basis for targeted flotation reagent and regrind optimisation

It is important to note what these percentages do and do not represent. They describe mineralogical deportment and surface exposure, not flotation recoveries or concentrate grades. Those figures will only emerge from the next phase of metallurgical test work.

Executive Chairman Carl Popal

“These results are encouraging because they indicate that the value-driving NdPr is hosted in identified REE-bearing mineral groups with meaningful surface exposure, rather than being widely dispersed through the gangue… we now have a sound mineralogical basis for the next phase of metallurgical development.”

What the Grønnedal project brings to the table

A large-scale REE system in a strategically significant jurisdiction

Grønnedal is a carbonatite-hosted rare earth element system located within Eclipse’s Ivigtût multi-commodity critical minerals project in southwest Greenland, near established maritime infrastructure and deep-water access, subject to future infrastructure assessment and permitting.

The current Mineral Resource Estimate (MRE) stands at 208 Mt at 0.72% TREO, comprising approximately 6 Mt Indicated and 202 Mt Inferred, reported at a 2,000 ppm TREO cut-off. The MRE, announced on 29 April 2026, contains approximately 1.5 Mt TREO, including approximately 456,000 tonnes of Nd₂O₃ and Pr₂O₃. That NdPr inventory is the value-driving magnet rare-earth component of the resource.

Grønnedal Mineral Resource Estimate (MRE) Breakdown

The Grønnedal resource upgrade to 208Mt at 0.72% TREO, announced in April 2026, established the scale context within which this mineralogical testwork now operates, with the approximately 456,000 tonnes of Nd2O3 and Pr2O3 inventory making the deportment question strategically significant rather than academic.

Greenland sits in a jurisdiction attracting increasing interest as European and North American governments and industry seek more diversified critical mineral supply chains. Eclipse considers the project’s scale, magnet rare earth inventory, and proximity to established maritime infrastructure relevant to these evolving supply chain priorities.

Why NdPr mineralogy matters before metallurgy begins

From rock to rare earth: the beneficiation basics

Before any processing flowsheet can be designed, geologists and metallurgists need to know where the target element physically resides inside the rock. If NdPr is dispersed evenly through gangue (the surrounding waste minerals), selective recovery becomes extremely difficult and expensive. When it concentrates in specific, identifiable mineral types, those minerals become discrete targets for processing.

Liberation is the key concept here. It refers to the degree to which a target mineral is exposed at the surface of a ground particle after crushing and milling. Higher surface exposure means the mineral can interact with flotation reagents; locked particles, where the target mineral is enclosed within other minerals, are much harder to recover. Knowing that REE fluorocarbonates and REE carbonates are the principal hosts provides a clear basis for targeted reagent-optimisation test work directed at those mineral surfaces.

The liberation data returned from the four composites were encouraging. At sample P80 values of approximately 102–107 µm, between 63.3% and 75.3% of REE fluorocarbonate mineral mass and between 61.1% and 79.1% of REE carbonate mineral mass occurred in particles with at least 30% target-mineral surface area. The locked fraction (particles with less than 10% target-mineral surface area) represented 5.6–8.0% of REE fluorocarbonates and 3.8–13.4% of REE carbonates.

The table below summarises the liberation sub-totals and locked fractions across the four composites for the two principal mineral groups.

Mineral Group Liberation Metric Comp 2 Comp 9 Comp 10 Comp 12
REE Fluorocarbonates ≥30% surface (Sub Total %) 75.3% 63.3% 72.8% 63.5%
REE Fluorocarbonates Locked (<10% surface %) 5.61% 8.03% 6.98% 6.78%
REE Carbonates ≥30% surface (Sub Total %) 61.1% 79.1% 70.1% 78.6%
REE Carbonates Locked (<10% surface %) 13.4% 4.21% 6.44% 3.85%

Surface-association data further indicated that the two principal REE mineral groups preferentially occur together, with approximately 36–47% free surface and the principal remaining association being with the complementary REE mineral group rather than silicate gangue. That provides additional rationale for evaluating a combined REE mineral concentrate.

Physical separation results and the road to flotation

Early density and magnetic separation results

Ahead of flotation, Eclipse tested whether simpler physical separation steps could pre-concentrate the ore and reduce the volume of material requiring more intensive downstream processing.

Initial density-based testing indicated that low-grade silicates below 3.1 SG can be removed while retaining approximately 75% to 90% of total rare earth elements (TREE), with an upgrade factor of 1.1 to 2.3. Magnetic separation also showed promise: early results recorded 12% mass rejection, an upgrade factor of 1.1, and removal of approximately 19% of total iron, which could reduce downstream leaching costs.

Based on Composite 2 results, combining the density and magnetic separation steps could remove 39% of total mass while recovering approximately 70% of TREEs, producing an upgrade factor of 1.3 and a concentrate of approximately 12,700 ppm TREE. Critical minerals including strontium and gallium follow a similar trend to the TREEs, suggesting potential for additional byproduct recovery. Eclipse noted that because approximately 97% of the silicates are non-magnetic, these steps can be applied in series.

Next steps toward a complete flowsheet

Eclipse has engaged Tetra Tech to support test work and develop a process design for critical mineral recovery. The next-stage program includes:

  • Rougher and scavenger flotation screening across collector, depressant, pH and conditioning regimes
  • Cleaner flotation and selective regrind tests to improve concentrate grade
  • Targeted rejection of siderite, calcite, strontianite and apatite
  • Assessment of magnetic removal of magnetite and hematite where relevant
  • Hydrometallurgical testing of the resulting REE concentrate
  • LA-ICP-MS and Raman confirmation of the interpreted synchysite, calcioancylite and associated REE phase compositions
  • A single sample to be processed through the full test sequence to generate a rough concentrate for leaching trials, which will help define overall recovery

The mineralogical foundation established by this testwork gives the program a specific set of targets. The processing question now moves from “where does the NdPr live?” to “how efficiently can it be separated and concentrated?” That answer will emerge from the flotation and hydrometallurgical phases ahead.

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Frequently Asked Questions

What is NdPr mineralogical deportment and why does it matter for rare earth processing?

Mineralogical deportment describes which specific minerals within a rock host the target element — in this case, neodymium and praseodymium. It matters because NdPr concentrated in identifiable, surface-exposed mineral groups can be selectively targeted by flotation, whereas NdPr dispersed through waste rock is far harder and more expensive to recover.

What did Eclipse Metals' Grønnedal testwork actually find?

ALS Metallurgy's quantitative mineralogical analysis of four composite samples confirmed that 87.5–94.3% of contained NdPr is hosted in identifiable REE-bearing mineral groups, with 77.2–92.6% concentrated specifically in REE fluorocarbonates and REE carbonates — the two mineral groups being evaluated for flotation.

What is the Grønnedal mineral resource and how large is the NdPr inventory?

The Grønnedal Mineral Resource Estimate, announced in April 2026, stands at 208Mt at 0.72% TREO, containing approximately 1.5Mt of total rare earth oxides including approximately 456,000 tonnes of Nd₂O₃ and Pr₂O₃ — the magnet rare earth fraction that drives project value.

What are the next steps for Eclipse Metals' Grønnedal metallurgical program?

Eclipse has engaged Tetra Tech to develop a process design, with the next-stage program covering rougher and scavenger flotation screening, cleaner flotation and regrind optimisation, targeted carbonate gangue rejection, and hydrometallurgical testing of the resulting REE concentrate.

Do the mineralogical testwork results tell investors what the flotation recovery will be at Grønnedal?

No — the mineralogical results confirm where NdPr is hosted in the rock and how exposed it is at the tested grind size, but flotation recoveries and concentrate grades will only be determined in the next phase of metallurgical test work, which has not yet been completed.

William Hadrian
By William Hadrian
Partnerships Director
William supports Discovery Alert subscribers across Australia and overseas, helping them tailor alerts, troubleshoot technical issues, and optimise platform settings to suit their workflow.
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