Nuinsco Resources Limited has achieved consistent phosphate concentrate grades exceeding 30% P₂O₅ from metallurgical testing at its Prairie Lake project in Ontario. The program, conducted by SGS Canada Inc. in Lakefield, successfully processed both carbonatite and ijolite rock types, confirming the ability to produce marketable phosphate and rare earth element (REE) concentrates.

The test work achieved a peak recovery of 77.5% for P₂O₅ on carbonatite samples, with ijolite samples delivering consistent stage recoveries of approximately 70%. Researchers found that reducing the biotite collector dosage in the flotation circuit improved the reporting of P₂O₅ to the concentrate while maintaining grades above 30%. High-intensity magnetic separation (WHIMS) was also successfully used to improve concentrate quality in ijolite by removing magnetic and paramagnetic minerals.

Notably, rare earth element grades increased in the final concentrate in alignment with the phosphate upgrading. The test results also indicated that levels of deleterious elements, including thorium, uranium, cadmium, and chloride, remain low or negligible.

“The continuing Prairie Lake metallurgical program at SGS Lakefield is producing great results.”

— Paul Jones, CEO, Nuinsco Resources Limited

The metallurgical program is ongoing, with further work aimed at identifying additional improvements in concentrate grades and recovery rates. The project team has now commenced supplementary testing to investigate the potential for dense media separation to isolate low-density carbonate minerals from the feed. Future test work will also evaluate adjustments in reagent application and slurry handling using higher-grade feed material, as well as the potential to produce marketable rare earth element co-concentrates.

Read the full announcement: Nuinsco Reports Very Positive Metallurgical Results from Prairie Lake Critical Minerals Project