Press Release: Rock Tech Lithium Announces Total Capital Costs of Approximately CAD$600 Million for Red Rock Converter based on Preliminary DFS Results

Preliminary results of the Definitive Feasibility Study ("Preliminary DFS Results") for the Red Rock converter in Ontario indicate total capital costs of approximately CAD$600 million. -- Preliminary DFS Results are based on a further optimized, industry-proven converter design with an annual production capacity of about 30,000 tonnes of lithium salts. -- Preliminary DFS Results confirm Rock Tech's chosen path toward cost-competitive, sustainable and clean Lithium salts production in the Western world. -- The results of the final DFS are expected in December 2026. TORONTO, Oct. 7, 2026 // - Rock Tech Lithium Inc. (TSXV: RCK) (OTCQX: RCKTF) (FWB: RJIB) (WKN: A1XF0V) (the "Company" or "Rock Tech") is pleased to announce preliminary results from the ongoing Definitive Feasibility Study ("Preliminary DFS Results") for its Red Rock Converter in Ontario ("Red Rock Converter" or "Project"), which commenced in June 2026. The Preliminary DFS Results indicate total capital costs of CAD$596 million, comprising CAD$546 million of direct capital costs, and CAD$50 million of owner's costs, with a tolerance of +/-20%. The study is based on a production capacity of about 30,000 tonnes per