PMET Unlocks Cheaper Caesium Path at World’s Largest Deposit Ahead of Q4 PEA
Key Takeaways
- Koch Technology Solutions' proprietary flowsheet delivered high caesium selectivity and a significantly reduced impurity profile from just 6 kg of pollucite concentrate assaying 12% Cs2O, confirming the potential to bypass conventional impurity removal stages.
- Shaakichiuwaanaan hosts the world's largest pollucite-hosted caesium Mineral Resource, with 0.69 Mt Indicated at 4.40% Cs2O and 1.70 Mt Inferred at 2.40% Cs2O — a scale that is globally exceptional for this commodity.
- Caesium carbonate currently trades at approximately US$250/kg, and PMET's co-product thesis positions caesium revenue as a potential credit against lithium production costs at a project that already holds an 84.3 Mt Probable Lithium Reserve.
- A follow-up bench-scale proof-of-concept program is now being designed, targeting production of marketable caesium product samples and an initial OPEX-CAPEX assessment using concentrate from the BerryPick Program.
- A Preliminary Economic Assessment targeting Q4 2026 will deliver the first formal economic valuation of the caesium credit alongside Shaakichiuwaanaan's lithium operations.
Phase 2 caesium testwork delivers simplified processing pathway for PMET’s world-class resource
PMET Resources Inc. (ASX: PMT) has reported results from its Phase 2 bench-scale caesium testwork program, completed by Koch Technology Solutions (“KTS”), part of Koch Inc., on pollucite concentrate from the Shaakichiuwaanaan Project. The results demonstrate high selectivity for caesium and a much-reduced impurity profile using KTS’s proprietary flowsheet technology, confirming the potential for a simplified, more cost-effective processing pathway to produce a wide variety of high-purity caesium chemical products from pollucite concentrate.
The feed material for the program was approximately 6 kg of pollucite concentrate assaying 12% Cs2O, produced via X-Ray Transmission (XRT) ore sorting from the Vega Caesium Zone at the CV13 Pegmatite (news release, 9 October 2025). Conventional caesium recovery requires additional impurity removal stages to reach the desired product purity; KTS’s proprietary highly selective media has the potential to bypass much of this, potentially lowering recovery costs significantly. A follow-up proof-of-concept program is now being designed.
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What is pollucite and why does caesium matter to investors?
Pollucite-hosted caesium deposits are extremely rare globally. They represent the most fractionated component of Lithium-Caesium-Tantalum (LCT) pegmatite systems, which are effectively the only known primary economic source of caesium supply.
Economic caesium pegmatite deposits are typically small, ranging from less than 10 kt to around 350 kt in size. This stands in sharp contrast to lithium pegmatites, which typically range from less than 10 Mt to over 100 Mt, making the scale of Shaakichiuwaanaan’s caesium resource globally exceptional.
The market for caesium is niche and largely opaque. Unlike copper or gold, it is not publicly traded but transacted through private bilateral and term contracts, with pricing varying by purity, contained caesium form, and end-product use. As an indicative market reference, caesium carbonate (Cs2CO3 ≥99%) currently trades at around US$250/kg (source: Shanghai Metal Market (SMM), excluding VAT). Investors should note that SMM publishes an indicative spot price for the Chinese market and, given the small and relatively opaque nature of the global caesium market, this should be regarded as a market reference rather than a directly achievable price for PMET’s potential caesium products.
Current applications for caesium include:
- Oil and gas drilling fluids
- Medical imaging
- Atomic clocks and precision GPS navigation
- Emissions reduction
- Next-generation solar panel efficiency, stability, and lifespan
- Lithium-ion battery performance (as an additive in certain cathode, anode, and electrolyte chemistries, under active exploration)
Caesium is currently supply constrained, with only limited global sources. Shaakichiuwaanaan has the potential to be a long-term primary supplier to global markets.
World’s largest caesium resource underpins the processing opportunity
Shaakichiuwaanaan hosts the world’s largest pollucite-hosted caesium pegmatite Mineral Resource, located at the Rigel and Vega zones within the CV13 Pegmatite. This sits alongside a substantial lithium Mineral Reserve and a consolidated Mineral Resource spanning multiple commodities, as summarised in the table below.
| Resource Category | Tonnage | Grade | Commodity |
|---|---|---|---|
| Indicated (Caesium) | 0.69 Mt | 4.40% Cs2O | Caesium (Pollucite) |
| Inferred (Caesium) | 1.70 Mt | 2.40% Cs2O | Caesium (Pollucite) |
| Indicated (Lithium/Tantalum) | 108.0 Mt | 1.40% Li2O / 166 ppm Ta2O5 | Lithium / Tantalum |
| Inferred (Lithium/Tantalum) | 33.4 Mt | 1.33% Li2O / 155 ppm Ta2O5 | Lithium / Tantalum |
The project also hosts a Probable Mineral Reserve of 84.3 Mt at 1.26% Li2O at the CV5 Pegmatite. The co-product thesis is central to understanding the investment case:
- Caesium and tantalum are anticipated co-products alongside lithium at Shaakichiuwaanaan
- Revenue from caesium (and tantalum) has the potential to be credited against the cost of lithium production
- A Preliminary Economic Assessment (PEA), targeted for Q4 2026, will provide the first economic evaluation of the caesium credit
For investors, this means the caesium processing program is not a standalone pursuit — it is a potential value layer on top of an already significant lithium project.
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Next steps: proof-of-concept program and strategic partner engagement
The follow-up testwork program is now being designed and is anticipated to comprise a complete bench-scale proof-of-concept, processing pollucite concentrate from Shaakichiuwaanaan through to gram quantities of marketable caesium products — for example, caesium formate and caesium carbonate — as well as an initial OPEX-CAPEX assessment.
This program is anticipated to utilise a larger quantity of concentrate, targeted to be sourced from the ongoing BerryPick Program (news release, 8 September 2026). The BerryPick Program’s sample collection methodology is designed to produce >500 kg to potentially >1 tonne of pollucite concentrate to support ongoing development and downstream caesium chemical testwork initiatives.
PMET is also advancing discussions with strategic caesium players downstream and deepening its existing relationship with KTS for future chemical processing opportunities. KTS is a global leader in technology development, commercialisation, and licensing, operating as part of Koch Inc., one of the largest privately held companies globally. KTS specialises in critical minerals extraction technologies, working with clients from early concept through EPC-ready design.
The milestone roadmap connecting current testwork to the next major investor catalyst is:
- BerryPick Program produces >500 kg to potentially >1 tonne of pollucite concentrate
- Follow-up bench-scale proof-of-concept testwork commences
- Marketable caesium product samples produced
- Initial OPEX-CAPEX assessment completed
- PEA released (targeted Q4 2026) — first economic evaluation of the caesium credit
Each of these milestones carries its own potential to add definition to the caesium credit, with the Q4 2026 PEA representing the first opportunity for the market to place a formal economic value on Shaakichiuwaanaan’s globally significant caesium resource alongside its lithium operations.
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