OD6 Metals (ASX: OD6) selects an innovative flowsheet with high recoveries at Splinter Rock - Is An Australian Rare Earth Story Happening?
- Noel Ong
- 10 hours ago
- 6 min read
Announcement
OD6 Metals (ASX: OD6) has wrapped up its CPC Optioneering Study—backed by ANSTO testwork—and selected a preferred process flowsheet for the clay-hosted rare earths at Splinter Rock. The decision lifts confidence that OD6 can produce low-impurity MREC/MREH products and moves the project into large-scale optimisation at ANSTO alongside the commencement of mining studies at the Inside Centre Deposit (Figure 1).
Figure 1: Location of the Inside Centre Deposit (Source: OD6)
Managing Director Brett Hazelden commented:
“The selection of a preferred flowsheet marks a major milestone for Splinter Rock. This outcome provides confidence in our ability to produce a high-value, low-impurity MREC or MREH product that is highly attractive to global supply chains. With this stage complete, we now move into large-scale testwork at ANSTO and commence mining studies at the Inside Centre Deposit. Importantly, discussions with potential offtake partners, separation facilities, end-users and governments continue to reinforce the strategic value of Splinter Rock..”
Key Highlights - An Australian Rare Earth Mining Proposal
Preferred Flowsheet locked in: Heap Leach → Nanofiltration (NF) → Ion Exchange (IX) → Impurity Removal (IR), designed to optimise recovery and payability while cutting reagent use and downstream volumes (Figure 2).
Recovery & product quality: ~75% overall Nd & Pr recovery; MREC ~56% TREO and MREH ~59% TREO with very low U+Th (<0.001%)—attractive specs for magnet REE supply chains.
Cost levers: NF enables acid recovery and recycle (>80% in tests), reduces liquid volumes; IX concentrates REEs so the IR circuit is smaller; a Chlor-Alkali Facility (CAF) is included to cut operating costs via on-site reagent production.
Scale & timing: Metallurgical diamond core program nearing completion (2–2.5 t of core to be delivered to ANSTO in October); scale-up tests to commence this quarter with progressive results in 1H 2026. Mining study work is also starting.
Market positioning: Final MREC/MREH products are MagREE-rich (Nd, Pr, Dy, Tb). Benchmark payability typically 70–85% of the REO basket value (not guidance, but context for product economics). OD6 is targeting 6,000+ tpa REO in ~5 years (aspirational; see company caution).
Figure 2: Preferred Process Flowsheet from ANSTO Testwork and CPC Optioneering Study. (Source: OD6)
Project Context
Splinter Rock carries a JORC Mineral Resource of 682 Mt @ 1,338 ppm TREO, including Indicated 119 Mt @ 1,632 ppm and Inferred 563 Mt @ 1,275 ppm, with an ~23% MagREE ratio—positioning it among Australia’s largest clay-hosted REE projects (Figure 3). The conceptual development pathway emphasises heap leaching as the lower-cost, higher-recovery option versus agitated tank leaching for Inside Centre.
Figure 3: Table 1: Splinter Rock Rare Earth project Mineral Resource Estimate - by Prospect at 1,000ppm TREO cut off grade (Source: OD6)
How the Selected Flowsheet Improves Outcomes
(Figure 4)
Heap Leach: Simple, low-acid leach of clay ore to generate enriched leachate.
Nanofiltration (NF): Recycles acid (>80%) and concentrates REEs, shrinking downstream volumes and opex.
Ion Exchange (IX): Concentrates REEs and improves impurity control (notably Fe/Al), enabling milder IR pH and lower REE co-precipitation losses.
Impurity Removal (IR): Two-stage polishing (optimised pH ~3.5 then ~4.1–4.4) to reach low-impurity specifications.
Product Precipitation: Flexible end-products as MREC or MREH.
CAF (Chlor-Alkali Facility): On-site reagent generation for material opex reductions and project independence.
Figure 4: Anticipated Inside Centre Total REE Recovery by Element. Utilising the Preferred Process Flow Sheet (Source: OD6)
What Was Tested (and why this one wins)?
OD6 and ANSTO iterated through six flowsheets, progressively adding NF, IX, and a U/Th IX step. The chosen Flowsheet 6 balances higher recovery, better impurity control (Al/Fe/U/Th), smaller circuits downstream (capex/opex benefits), and improved payability—without excessive complexity at scale.
Next Steps
(Figure 5)
Finish metallurgical core drilling (October) and dispatch 2–2.5 t of core to ANSTO.
ANSTO scale-up & optimisation this quarter:
Heap leach kinetics, acid strength/consumption, counter-current configuration, agglomeration.
NF acid recovery verification; IX selectivity/elution (Fe/Al and trace U/Th reduction); IR optimisation.
Bulk MREC/MREH (~>1 kg) for customer qualification & offtake discussions.
Mining study (Inside Centre): pit shells, stripping ratios, scheduling, preliminary costs (Burnt Shirt engaged).
Commercial engagement: offtake partners (payability scenarios); government & potential financiers.
Future options: CAF enables potential on-site oxide separation (Nd, Pr, Dy, Tb; possibly Sm, Y) via chloride-based SX (desktop assessment with ANSTO being advanced).
Figure 5: Inside Centre Composite Sample Locations overlain on airborne electromagnetic survey interpretation. (Source: OD6)
Managing Risk & Disclosures
OD6 flags that its 6,000+ tpa REO aspiration and optioneering ranges are conceptual and not production targets; further drilling, engineering, and feasibility work are required before any final investment decision. Readers should consider the company’s forward-looking statements and cautionary notes in full.
Samso Concluding Comments
This release is all about how Flowsheet selection turns geology into metallurgy and metallurgy into a business plan. In summary, OD6 can now create a concept that allows the business to work. It is now all about the following:
Heap Leach → Nanofiltration → Ion Exchange → Impurity Removal (with a chlor-alkali back-end).
The business now targets the magnet rare earths that matter (NdPr, plus Dy/Tb), it actively strips what hurts payability (Al/Fe/U/Th), and it builds in operating levers through acid recycle and smaller downstream circuits. On paper, that is the working model.
The bigger question from here is the translation from bench recoveries into stacked tonnes, acid recycle into cash cost, and “low-impurity” into genuine payability from end-users. That’s where ANSTO’s scale-up, bulk MREC/MREH samples, and customer qualification loops matter. If those deliver as flagged, the flowsheet’s simplicity and reagent self-sufficiency could become a structural edge rather than a lab result.
According to what OD6 is professing, investors need to keep an eye on the following over the next 122 months:
(1) scale-up data that confirms recoveries and acid balances at meaningful volume;
(2) clarity on mining studies at Inside Centre (strip, scheduling, capex/opex contours); and
(3) any signals on offtake interest tied to product specs and payability.
Positive movement across that trio de-risks both route and revenue. Conversely, any slippage in leach kinetics, impurity control, or acid recycle will show up quickly in capex/opex math—so keep an eye on the details, not just the headlines.
As always, DYOR. Read the fine print around forward-looking statements, note that production targets are not yet defined, and remember that clay-hosted REE success is a chain: geology → metallurgy → specification → payability → financing. OD6 has tightened a key link in that chain. The next test is whether industry validation and engineering studies can pull the rest taut.
The Samso Way – Seek the Research
Always read the source announcement, cross-check the flowsheet details, recoveries, and impurities, and track the ANSTO scale-up milestones and mining study outcomes as they land through 1H 2026. DYOR, and focus on the payability math and capex/opex translation as OD6 moves from bench to scale.
Our mission is simple: cut through the noise and spotlight what matters—genuine stories, grounded insights, and real opportunity.
Our content is well-researched and is only created if the team sees a merit in discussing the company or concept. Investors can explore our three core platforms:
There may be numerous paths to success in investing, but the common thread among successful individuals is that they remain committed to making informed decisions. Equip yourself with the right knowledge and tools, and you will be well on your way to achieving your financial goals.
Most importantly, investors need to be absolutely diligent in understanding their own risk-reward tolerance and capabilities. Never bite off more than you can chew. As they say, Rome wasn’t built in a day, and the Great Wall stood because it took centuries to complete.
The Samso Philosophy:
Stay curious. Stay sharp. And remember—digging deeper always uncovers the real value.
In Life, there is no such thing as a Free Lunch.
Happy Investing, and the only four-letter word you need to know is DYOR.
To support our independent nature of our work, please head over to our Support Page and give us a helping hand in any of the ways listed. This is a new initiate for the Samso Platform, and it was always the concept of Samso when we started this journey in 2018.
Disclaimer
The information or opinions provided herein do not constitute investment advice, an offer or solicitation to subscribe for, purchase or sell the investment product(s) mentioned herein. It does not take into consideration, nor have any regard to your specific investment objectives, financial situation, risk profile, tax position and particular, or unique needs and constraints.
Share to Grow: Your Bonus
Samso has just released an eBook: How to Add Value to your Share Portfolio
A lesson on geological models sought by mining companies that gives insight and an understanding of which portfolios are better - and potentially more lucrative – investments. Click here to download this eBook.
If you find this article informative and useful, please help me share the information. I try and write about topics that are interesting and have the potential to be of investment value. It is not easy to find stories that fit those parameters. If you or your organisation see the benefit of what Samso is trying to achieve and have a need to share your journey, please contact me at noel.ong@samso.com.au.
Samso is a trusted platform that equips dedicated investors with up-to-date industry knowledge and insights from top CEOs and thought leaders. By staying informed on business advancements and market trends, investors can enhance their financial decisions through a combination of expert guidance and their own research.
Comments