Nuinsco Resources Reports Positive Metallurgical Study Results for Prairie Lake Project

TORONTO, Ontario — August 5, 2026 — Leads & Copy — Nuinsco Resources Limited announced highly positive results from metallurgical studies on mineralization from its Prairie Lake Critical Minerals and Phosphate Project, located near Terrace Bay, Ontario. The tests, conducted by SGS Canada Inc (Lakefield), utilized bulk samples representative of the Mineral Resource Estimate grade reported on July 18, 2022, with the metallurgical program continuing to focus on improving phosphate concentrate and recovery.

Paul Jones, Nuinsco’s CEO, stated that the ongoing program at SGS Lakefield is yielding excellent results. The test program analyzed composites from both carbonatite and ijolite portions of the 2022 Mineral Resource Estimate. Laboratory-scale metallurgical tests have demonstrated that both major rock types at the project can produce marketable-grade phosphate (P₂O₅) and rare earth element (REE) concentrates at acceptable P₂O₅ recovery rates, with minimal deleterious elements. These findings, combined with the substantial mineral endowment—871.8 million tonnes inferred grading 3.39% P₂O₅ and 15.6 million tonnes indicated grading 3.71% P₂O₅—and the potential for selective mining of higher-grade domains, suggest significant potential for large-scale mining and processing at the project.

Further testing is underway to explore the use of low-cost dense media separation to isolate low-density carbonate minerals, as well as adjustments to slurry handling and reagent application for higher P₂O₅ grade feed. These methods, particularly the higher-grade feed, are expected to enhance concentrate grades and recoveries. Additionally, the company is evaluating the potential to produce marketable grades of total rare earth oxides (TREO) concurrently with or separately from the phosphate mineralization.

Key test results to date include consistently achieving target concentrate grades exceeding 30% P₂O₅, a significant increase from the initial composite sample feed grades of ≤3.73% P₂O₅ for carbonatite and ≤3.0% P₂O₅ for ijolite. Ijolite test results were strong and repeatable, with stage recoveries of approximately 70% P₂O₅ consistently achieved, with further increases anticipated through reagent dosage tuning. The best single result, from SGS Lakefield Test # F23 on carbonatite, achieved 77.5% overall recovery and a final concentrate grade of 32.8% P₂O₅.

Reducing biotite collector dosage proved beneficial, substantially increasing P₂O₅ reporting to the phosphate circuit while maintaining concentrate grades above 30%. The application of WHIMS (high-intensity magnetic separation) at 8000 Gauss also improved the P₂O₅ concentrate grade from the ijolite composite by removing magnetic and paramagnetic minerals. Rare earth element grades increased in step with P₂O₅ upgrading for both composite types, indicating a favorable byproduct signal for elements including cerium, yttrium, neodymium, praseodymium, lanthanum, samarium, and gadolinium.

Deleterious elements such as thorium, uranium, cadmium, and chloride levels were found to be low or negligible in the concentrate, which is advantageous for processing and regulatory purposes. Prairie Lake is characterized as a significant Critical Minerals asset in North America, possessing a substantial mineral resource of igneous mineral phosphate and one of the world's highest known light rare earth element concentrations in apatite. The Mineral Resource Estimate includes several other REE-bearing minerals and niobium-bearing pyrochlore. The next phase of metallurgical studies is expected to confirm the reliable production of a clean phosphate concentrate, grading over 30% P₂O₅ with over 80% process recovery, along with a valuable rare earth element co-concentrate.

The elements found at Prairie Lake are crucial for applications in transportation, agriculture, power distribution, battery, and other green technologies. The project is considered vital for a secure Critical Minerals supply chain and offers substantial benefits to the region and Canada. Its location is advantageous, being close to the Towns of Marathon, Terrace Bay, and local First Nations, which can provide a skilled workforce and services. The site is accessible via an all-weather forest access road, with provincial TransCanada Highways 17 and 11 nearby, as well as Canadian Pacific Kansas City and Canadian National Railway networks. High-capacity electrical power transmission lines are also accessible, and the project is approximately 50 km from the Marathon deep water port project, with additional deep-water ports at Thunder Bay and Sault Ste. Marie. The Marathon airport is also a nearby facility.

Laura Giroux, P.Geo., Chief Geologist of Nuinsco, and Grant Feasby, P.Eng., Metallurgical Consultant with P&E Mining Consultants Inc., are Qualified Persons under National Instrument 43-101. Mr. Feasby is independent. Both have reviewed and approved the technical content of this news release.

Nuinsco Resources Limited, with over 50 years of exploration success, is a growth-oriented, multi-commodity mineral exploration and development company. Its current portfolio includes the Prairie Lake Project (phosphate, rare earth element, niobium, tantalum), the Zig Zag Lake Property (lithium, tantalum) operated as a joint venture, the Paradise Lake gold project, and a retained NSR royalty on the Sunbeam Gold Property.

Source: Nuinsco Resources Limited