Rock Tech Advances Georgia Lake Lithium Project, Identifies Potential Pathway to Reduce Processing CAPEX by Up to 50 per cent

Press Release

Optical sorting test works, co-financed through Ontario Critical Minerals Innovation Fund, identifies a potential pathway to improve project efficiency and lower capital and operating costs

Key program highlights include:

• Ontario’s Critical Minerals Processing Fund (“CMIF”) helped demonstrate potential to unlock real value at the Georgia Lake Project.
• Collaboration with Queen’s University and STARK Resources demonstrated the effectiveness of government, industry, and research partnership.
• Ore-sorting test work removed approximately 25 to 45 per cent of waste material before downstream processing. ¹
• The upgraded material stream improved ore quality by approximately 1.4x to 1.8x¹.
• Early engineering work identified a potential pathway to materially reduce future crushing and concentrator capital costs by up to 50 per cent¹.
• The Georgia Lake Project further supports Rock Tech’s broader Ontario mine-to-converter strategy alongside the planned Red Rock Converter.

Toronto, Ontario – May 19, 2026 – Rock Tech Lithium Inc. (TSX-V: RCK) (OTCQX: RCKTF) (FWB: RJIB) (WKN: A1XF0V) (the “Company” or “Rock Tech”) is pleased to announce the successful completion of its Ontario Critical Minerals Innovation Fund supported ore-sorting program for the Georgia Lake Lithium Project (“the Project”) in Northern Ontario. The Project is part of Rock Tech’s broader Ontario mine-to-converter strategy and, alongside the planned Red Rock Converter, supports the development of a domestic, made-in-Canada sovereign defence and battery materials supply chain.

Completed in partnership with Queen’s University and STARK Resources, the ore sorting program evaluated UV Laser-based sorting from Optimum N.V. and X-ray Transmission (“XRT”) sensor-based sorting from allmineral Aufbereitungstechnik GmbH & Co. KG for the pre-concentration of mineralized material from the Project (refer to Press Release – Rock Tech Lithium Receives $388,074 in Funding from Ontario’s Critical Minerals Innovation Fund, dated June 23, 2025).

Test work was conducted on two sample sets: selected drill core used to establish and calibrate sorting algorithms, and a blended surface-derived sample used for small-scale testing. Testing was completed under controlled conditions at both ore sorting test facilities using pilot-scale equipment.

The program indicates a pathway to improve process efficiency and reduce future capital and operating costs, which, if successful, could strengthen the long-term competitiveness of the Project and support a more resilient Ontario critical minerals supply chain.

The results provide a foundation to restart key Georgia Lake development activities, including drilling, additional cost-optimizing engineering, and workstreams that support a future Definitive Feasibility Study.

“These results demonstrate how government, industry and research partnerships produce innovation that can directly strengthen the economics and competitiveness of strategically important critical minerals projects,” said Mirco Wojnarowicz, CEO of Rock Tech. “Backed by the Ontario government’s investment through the CMIF, our work positions Georgia Lake to be more resilient and competitive through lithium price cycles and supports Rock Tech’s broader integrated lithium strategy in Northern Ontario, which can help bolster economic security and long-term defence readiness through the development of a made-in-Canada critical minerals supply chain.”

Government-Industry-Research Partnership Unlocks Ontario Critical Minerals Innovation

With support from the Ontario government, through the Critical Minerals Innovation Fund, Rock Tech worked with Queen’s University and STARK Resources, a Germany-based specialist in sensor-based ore sorting and mineral processing technology, to evaluate practical technologies that improve processing efficiency, reduce waste, strengthen the long-term competitiveness of the Project, and support Ontario’s efforts to build a more resilient domestic critical minerals supply chain.

“The Critical Minerals Processing Lab is proud to have collaborated with Rock Tech Lithium and Stark Resources on this important project, which advanced our understanding of lithium mineral processing characteristics and contributed to the advancement of the Georgia Lake project” said Charlotte Gibson, Assistant Professor & Associate Head for Robert M Buchan Department of Mining. “This innovative process development work was made possible through the support of the CMIF, whose investment is helping drive critical minerals processing innovation and strengthen Ontario’s critical minerals value chain.”

Advancing the Next Phase of Development at the Georgia Lake Lithium Project

The results arrive at an important moment for Ontario’s critical minerals sector. While lithium markets have experienced near-term volatility, governments and industry across North America and Europe continue to move aggressively to secure regional battery and critical minerals supply chains.

The Project was the subject of a 2022 Pre-Feasibility Study, which outlined a conventional mine and concentrator development concept based on a 1.0 million tonne per year concentrator. The 2022 PFS contemplated a 9-year mine life, targeted production of approximately 100,000 tonnes per year of 6% spodumene concentrate, and an Indicated Mineral Resource of approximately 10.6 million tonnes at 0.88 per cent Li₂O and an Inferred Mineral Resource of approximately 4.2 million tonnes at 1.00 per cent  Li₂O.

The PFS estimated a pre-tax NPV of USD$223 million, an after-tax NPV of USD$146 million, a pre-tax IRR of 47.8 per cent, and an after-tax IRR of 35.6%, based on an average life-of-mine SC6 price of USD$1,500 per tonne. The PFS also estimated pre-production capital costs of USD$192 million, life-of-project capital costs of USD$291 million, total life-of-project operating costs of USD$536 million, and AISC of USD$1,082 per tonne of concentrate (see Press Release – Rock Tech Lithium completes Pre-Feasibility Study for its Georgia Lake Project dated November 16, 2022).

Against this PFS baseline, the CMIF-supported ore sorting results indicate a potential pathway to further improve project economics in future technical studies. The observed 1.4x to 1.8x upgrade factor means that sorted material can carry materially higher lithium grade into downstream processing than the original feed stream, improving concentrator efficiency and potentially allowing lower-grade material to be considered in future mine planning scenarios.

Similarly, the potential to reduce crushing and concentrator plant capital costs by up to 50 per cent is expected to be driven by a combination of ore sorting and plant specification optimization, providing an opportunity to optimize overall plant design. If confirmed through further engineering and study work, this could materially improve the capital intensity and investment case for the next phase of Georgia Lake development.

As part of this renewed focus, Rock Tech has begun preparations for a potential future drilling program and the next phase of technical studies, including workstreams that could support a Definitive Feasibility Study. These activities would be designed to support resource growth, improve geological confidence, and provide additional data for future mine planning and project development work.

Supporting Rock Tech’s Ontario Mine-to-Converter Strategy

The successful completion of the CMIF-supported ore sorting program strengthens this strategy by indicating a potential pathway to improve the cost structure and development flexibility of the Project. By reducing the amount of waste material processed through the concentrator, ore sorting may support lower operating costs, improve processing efficiency, and provide greater optionality in future mine planning and throughput scenarios.

“Georgia Lake remains foundational to Rock Tech’s Ontario strategy,” said Dirk Harbecke, Chairman of Rock Tech. “These results strengthen the project’s long-term economics and profitability and reinforce the strategic importance of an integrated lithium supply chain in Ontario. As North America and Europe work to secure reliable sources of critical minerals, projects like Georgia Lake and the Red Rock Converter become increasingly important pieces of allied industrial infrastructure.”

Next Steps

Building on the successful outcomes of the program, Rock Tech expects that a future value engineering phase would evaluate the combined impact of ore sorting integration, plant design optimization, and alternative execution strategies across the crushing plant, concentrator plant, and related infrastructure. The results of the CMIF-supported program are conceptual in nature and do not define final economic outcomes, mineral reserve estimates, or plant-scale design changes. Any potential impact on capital costs, operating costs, project economics, mineral reserves, or development plans will require further engineering, feasibility-level studies, and appropriate technical disclosure.

Ontario Innovation Supporting a Stronger Critical Minerals Supply Chain

“Ontario is building a made-in-Canada critical minerals supply chain that creates jobs, strengthens our economic security, and reduces our reliance on foreign adversaries,” said Stephen Lecce, Minister of Energy and Mines. “Through the Critical Minerals Innovation Fund, our government is backing Ontario innovation that lowers costs, unlocks investment, and accelerates responsible mining development in the North. The success of this project shows how Ontario can lead the world in critical minerals, battery materials, and the technologies that will power the future.”

Qualified Persons

The technical content of this press release has been reviewed and approved by Cameron Andrews, P.Eng., General Manager, Canada for Rock Tech Lithium, and Dian Heinrich Page, Pr. Sci. Nat., Principal Consultant – Geology for STARK Resources, an independent Qualified Person, each of whom is a Qualified Person as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects. Mr. Cameron Andrews, P.Eng. has reviewed and approved the portions of this news release relating to the 2022 Pre-Feasibility Study on Georgia Lake Project, Mr. Dian Heinrich Page, Pr. Sci. Nat., has reviewed and approved the portions relating to the CMIF ore sorting project and value engineering.

The ore-sorting test work results described above are preliminary in nature and based on limited-scale testing. These results have not been incorporated into any current mineral resource or reserve estimate or pre-feasibility or feasibility study, and do not represent defined economic outcomes.

Mineral resources disclosed in this news release that are not mineral reserves do not have demonstrated economic viability.

On behalf of the Management

Mirco Wojnarowicz

CEO, Rock Tech Lithium Inc.

For further information: Kerstin Wedemann, Chief Legal & Corporate Officer: info@rocktechlithium.com +49 2102 894 1122

Rock Tech Lithium Inc, 2700-40 Temperance Street, Toronto ON M5H 0B4, CAN.

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