Critical One Energy Announces Positive Lab Results from Howells Lake Preliminary Metallurgical Study

Critical One Energy Inc. ("Critical One" or the "Company") is pleased to announce positive results from a preliminary metallurgical study at its flagship Howells Lake Antimony-Gold Project ("Howells Lake Project"), located in the Thunder Bay Mining Division and approximately 120 kilometres west of the Ring of Fire access corridor in northwestern Ontario, Canada. The study, completed by Blue Coast Research Ltd. in Parksville, British Columbia, found that the antimony (Sb) in the samples is hosted mainly in stibnite (Sb₂S₃) and that the principal antimony minerals were highly liberated after grinding. These are encouraging early indications for future concentration, recovery, and concentrate-quality testwork.

Metallurgical Sampling Highlights: Four selected samples from drill hole HWL-2026-006 ("Hole 6"), previously reported in the May 15, 2026 press release, contained between 10.9% and 97.1% stibnite (Sb₂S₃) by modal abundance, demonstrating significant stibnite content across the samples tested. Berthierite (FeSb₂S₄) was identified in three of the four samples ranging from 0.8% to 7.9% modal abundance, together with trace chalcostibite (CuSbS₂), providing additional antimony-bearing mineral content. No arsenic or mercury-bearing minerals or other deleterious materials were identified.

Stibnite liberation ranged from 92.8% to 99.1%, while berthierite liberation ranged from 84.9% to 89.7%, indicating that the principal antimony minerals were largely free from surrounding mineral phases after grinding. Preliminary results indicate that the antimony-bearing minerals in the selected samples may be amenable to concentration by flotation, supporting follow-up metallurgical testwork.

Tables 1 and 2 summarize four Hole 6 samples selected to represent mineralization ranging from massive stibnite to vein- and wall-rock-hosted semi-massive stibnite, with grades from 1.41% to 70.7% Sb. After being ground to a target size of 106 micrometres (µm), the samples were analyzed using TIMA™ (Tescan Integrated Mineral Analyzer), an SEM-based automated mineralogy method used to identify the antimony-bearing minerals and assess their association with other mineral phases. The study provides the mineralogical information needed to design the next phase of metallurgical work. Follow-up testing will assess flotation response, antimony recovery, concentrate quality and variability across a broader range of Howells Lake mineralization, helping define potential processing options as the project advances.

Table 1. Modal mineralogy (%) of stibnite-bearing samples from Howells Lake. Assays listed were reported on May 15, 2026 . Minerals Sample 1 Sample 2 Sample 3 Sample 4 Sample description Massive stibnite Semi-massive stibnite + quartz Massive stibnite + wall rock Semi-massive stibnite, wall rock + quartz Sb % 70.7 22.8 3.01 1.41 Pyrite 0.1 0.1 0.0 0.1 Tetrahedrite-Tennantite 0.0 0.1 0.0 0.0 Stibnite 97.1 10.9 13.4 14.8 Berthierite 0.0 0.8 1.6 7.9 Chalcostibite 0.3 0.1 0.0 0.0 Costibite 0.0 0.0 0.0 0.0 Other sulphides 0.0 0.0 0.1 0.0 FeOx-OH 0.1 0.3 0.2 0.2 Rutile 0.0 0.0 0.5 0.2 Quartz 1.2 82.5 22.0 32.7 Feldspar 0.0 0.1 4.7 2.5 Pyroxene/Amphibole 0.0 0.1 1.3 0.4 Chlorite 0.2 0.8 15.0 6.8 Mica 0.1 0.1 1.1 1.1 Apatite 0.0 0.0 0.0 0.0 Clays 0.6 1.6 11.7 8....