Multiple pathways to value-add caesium chemicals identified during bench-scale extraction testwork at SGS Lakefield and through Koch Technology Solutions Phase 1 program

HIGHLIGHTS  

SGS CANADA CAESIUM EXTRACTION TEST PROGRAM

• Leaching of pollucite concentrate using sulphuric acid was highly successful with >97% recovery of the caesium (Cs) into solution achieved.  
• Bench-scale testwork on impurity removal was also successful, demonstrating efficient removal of key impurities such as aluminum.
• Opportunity identified to potentially recover a rubidium by-product.
• Primary objective of program was fully realized – that being to identify a preliminary set of conditions to extract caesium from pollucite concentrate (produced from the Vega Zone) at high recovery while characterizing (and limiting) the impurity profile.
• Next steps will build upon this extraction phase of work with a primary objective to produce gram quantities of high-purity Cs-sulphate, Cs-carbonate, Cs-formate, and potentially Rb-carbonate.

KOCH TECHNOLOGY SOLUTIONS CAESIUM EXTRACTION TEST PROGRAM

• PMET is working with Koch Technology Solutions, part of Koch Inc., evaluating advanced processing pathways to value-added caesium products.
• Preliminary results from Phase 1 indicate both synthetic and live Pregnant Leaching Solution yield very selective high loading factors of caesium recovery using Koch’s proprietary flow sheet.

PMET RESOURCES INC. (TSX: PMET) (ASX: PMT) (OTCQX: PMETF) (FSE: R9GA) is pleased to provide an update on two parallel bench-scale testwork programs focused on caesium (Cs) extraction from pollucite samples from the Shaakichiuwaanaan Project. Both approaches – conventional by SGS Canada, and proprietary by Koch Technology Solutions – offer attractive process routes for caesium extraction from pollucite concentrate into marketable chemical products. The Company is motivated to consider caesium value-added chemical production (with key partners) to unlock maximum value from its globally significant caesium resource and its pollucite concentrates produced at site.

In addition to being one of the largest lithium-tantalum pegmatite Mineral Resources¹ and lithium pegmatite Mineral Reserves² globally, the Property also hosts the world’s largest in-situ pollucitehosted caesium pegmatite Mineral Resource, comprising 0.69 Mt at 4.40% Cs₂O (Indicated) and 1.70 Mt at 2.40% Cs₂O (Inferred). The CV13 Pegmatite, host to the caesium Mineral Resource, is located <3 km along trend from the CV5 Pegmatite, which is situated approximately 13 km south of the regional Trans-Taiga Road and powerline infrastructure corridor, and is accessible year-round by road.

The pollucite concentrate used as feed for both extraction testwork programs (Figure 1, top) was produced by X-Ray Transmission (XRT) ore sorting of drill core material from the Vega Caesium Zone at the CV13 Pegmatite (see news release dated October 9, 2025) and assayed 12% Cs₂O (Figure 2).

SGS Canada Caesium Extraction Testwork Program

At SGS Lakefield, a conventual process approach (Figure 1, bottom) for caesium extraction from pollucite concentrate is being advanced using sulphuric acid digestion (H₂SO₄) and subsequent impurity removal. The primary objective of this initial bench-scale test program is to identify a preliminary set of conditions to extract caesium at high recovery while characterizing (and limiting) the impurity profile.

The pollucite concentrate sample (~15 kg) was ground to varying sizes (P₈₀ of 75 µm to 212 µm) and a portion (<4 kg) subjected to sulphuric acid (H₂SO₄) leaching at varying temperatures (up to 120°C). The program was highly successful with the testwork achieving consistently high extractions of 97-98% Cs while maintaining significantly lower extractions of key impurities (e.g., Al). Further, subsequent impurity tests successfully removed the remaining aluminum (Al) and a majority of the sulphur (S) with negligible caesium (Cs) losses.

Additionally, the program also identified a potential opportunity to recover a rubidium byproduct from one of the waste streams. Further characterization of this opportunity was not undertaken during this initial bench-scale caesium extraction test phase and will be investigated as a secondary objective in future work.

The testwork was completed at SGS Canada’s Lakefield, Ontario, facility with support from Primero Group Americas and a Company-retained Subject Matter Expert (“SME”) specializing in caesium extraction and recovery from pollucite. These three parties, in addition to TOMRA Mining, are also key contributors to the design and execution of the Company’s ore sorting programs.

Figure 1: Simplified conceptual flowsheet for conventional processing of pollucite pegmatite through to pollucite concentrate (top) and from pollucite concentrate to final marketable caesium salts/brine (bottom). The bench-scale testwork carried out by SGS Canada is focused on the caesium extraction and impurity removal steps. The stated >97% Cs recovery is with respect to the pollucite concentrate feed through to initial impurity removal.

Figure 2: Pollucite concentrate (~12% Cs₂O) produced from prior XRT ore sorting program (see news release dated October 9, 2025), of which a portion was used as feed for the bench-scale caesium extraction and recovery program at SGS Canada and Koch Technology Solutions discussed herein.

Next steps will build upon this bench-scale testwork with a primary “proof-of-concept” objective to produce gram quantity samples of high-purity Cs-sulphate, Cscarbonate, Cs-formate, and potentially Rb-carbonate. This test program is currently underway at SGS Canada’s facility in Lakefield, Ontario, with results expected circa Q4 2026.

Koch Technology Solutions Caesium Extraction Testwork Program

The testwork program with Koch Technology Solutions has been developed as part of a strategic relationship that has evolved following the Company’s investigations of the caesium industry, commercial engagement, and research. The program will leverage KTS’s demonstrated capabilities in engineering, development and commercialization of critical minerals extraction technologies to produce a range of value-added caesium chemical compounds.

The bench-scale test program being advanced by KTS is designed to assess the application of their proprietary flowsheet technology, to produce a range of value-added caesium chemical compounds. Approximately 6 kg of pollucite concentrate is being used to support the testwork.

Preliminary results from Phase 1 of the program indicate a strong and selective caesium recovery. The testwork will now move onto Phase 2 and the Company anticipates expanding the mandate to produce gram quantities of caesium derivative products as a complete bench-scale proof-of-concept.

STUDY WORK UNDERWAY

A Preliminary Economic Assessment for the broader Project, incorporating lithium, caesium, and tantalum, is scheduled for completion in Q4 2026. The PEA will complement the Feasibility Study for the CV5 Pegmatite (lithium and tantalum), which is also scheduled for completion in Q4 2026, and will provide the first economic assessment of the Project’s caesium potential.

ABOUT KOCH TECHNOLOGY SOLUTIONS

Koch Technology Solutions is a global leader in technology development, commercialization and licensing. KTS works with owners, developers, and investors in the process manufacturing and critical minerals sectors to solve complex technical and investment challenges before large capital is committed, helping clients make confident decisions from early concept through EPC-ready design. With a global network and rich history of domain experience and expertise, KTS gains additional strength from its position within Koch Engineered Solutions (KES). This backing enhances our ability to partner with companies developing chemical process technologies, create attractive licensing solutions for commercial deployment, and bring the next generation of technologies to the market.

QUALIFIED/COMPETENT PERSON

The technical and scientific information in this news release that relates to the Mineral Resource  Estimate, exploration, and metallurgical results for the Company’s properties is based on, and fairly represents, information compiled by Mr. Darren L. Smith, M.Sc., P.Geo., who is a Qualified Person as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”), and member in good standing with the Ordre des Géologues du Québec (Geologist Permit number 01968), and with the Association of Professional Engineers and Geoscientists of Alberta (member number 87868). Mr. Smith has reviewed and approved the related technical information in this news release.

Mr. Smith is an Executive and Vice President of Exploration for PMET Resources Inc. and holds common shares, Restricted Share Units (RSUs), Performance Share Units (PSUs), and options in the Company.

Mr. Smith has sufficient experience, which is relevant to the style of mineralization, type of deposit under consideration, and to the activities being undertaken to qualify as a Competent Person as described by the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code). Mr. Smith consents to the inclusion in this news release of the matters based on his information in the form and context in which it appears.

The information in this news release that relates to the Mineral Reserve Estimate and Feasibility Study is based on, and fairly represents, information compiled by Mr. Frédéric Mercier-Langevin, Ing. M.Sc., who is a Qualified Person as defined by NI 43-101, and member in good standing with the Ordre des Ingénieurs du Québec. Mr. Mercier-Langevin has reviewed and approved the related technical information in this news release.

Mr. Mercier-Langevin is the Chief Operating and Development Officer for PMET Resources Inc. and holds common shares, RSUs, PSUs, and options in the Company.

ABOUT PMET RESOURCES INC.

PMET Resources Inc. is a pegmatite critical mineral exploration and development company focused on advancing its district-scale 100%-owned Shaakichiuwaanaan Property located in the Eeyou Istchee James Bay region of Quebec, Canada, which is accessible year-round by all-season road and proximal to regional hydro-power infrastructure.

In late 2025, the Company announced a positive lithium-only Feasibility Study on the CV5 Pegmatite for the Shaakichiuwaanaan Property and declared a maiden Mineral Reserve of 84.3 Mt at 1.26% Li₂O (Probable)³. The study outlines the potential for a competitive and globally significant high-grade lithium project targeting up to ~800 ktpa spodumene concentrate using a simple Dense Media Separation (“DMS”) only process flowsheet. Further, the results highlight Shaakichiuwaanaan as a potential North American critical mineral powerhouse with significant opportunity for tantalum and caesium in addition to lithium.

The Project hosts a Consolidated Mineral Resource⁴ totalling 108.0 Mt at 1.40% Li₂O and 166 ppm Ta₂O₅ (Indicated) and 33.4 Mt at 1.33% Li₂O and 155 ppm Ta₂O₅ (Inferred), and ranks as a top ten lithium pegmatite globally in size. Additionally, the Project hosts the world’s largest pollucite-hosted caesium pegmatite Mineral Resource at the Rigel and Vega zones with 0.69 Mt at 4.40% Cs₂O (Indicated), and 1.70 Mt at 2.40% Cs₂O (Inferred).