Toronto, Ontario--(Newsfile Corp. - July 27, 2026) - Critical One Energy Inc. (CSE: CRTL) (OTCQB: MMTLF) (FSE: 4EF) ("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.
"Initial testing shows that the antimony at Howells Lake is high quality. There is no arsenic, no mercury, and none of the elements that usually make it difficult and expensive to process," said Duane Parnham, Founder, Executive Chairman and CEO of Critical One.
Parnham added, "This kind of clean antimony-bearing material opens up optionality when selecting refinery or offtake partners. Every round of drilling and testwork so far has confirmed that we have high-grade antimony and has given us a lot of confidence to keep pushing this project forward."
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 | 8.8 |
| Alumosilicates | 0.0 | 0.2 | 1.8 | 2.2 |
| Carbonates | 0.2 | 2.4 | 26.1 | 21.9 |
| Other | 0.0 | 0.0 | 0.6 | 0.3 |
| Total | 100 | 100 | 100 | 100 |
Table 2. Mass % of antimony-bearing mineral phases.
| Minerals | Sample 1 | Sample 2 | Sample 3 | Sample 4 |
| Stibnite | 99.8 | 94.1 | 91.5 | 70.6 |
| Berthierite | 0.0 | 5.0 | 8.4 | 29.4 |
| Costibite | 0.0 | 0.0 | 0.0 | 0.0 |
| Tetrahedrite-Tennantite | 0.0 | 0.2 | 0.0 | 0.0 |
| Chalcostibite | 0.2 | 0.7 | 0.0 | 0.0 |
| Total | 100.0 | 100.0 | 100.0 | 100.0 |
Table 3. Mineral liberation of stibnite categorized by volume % of stibnite per grain after grinding to a target size of 106 µm.
| Volume % of Stibnite / Fraction | Sample 1 | Sample 2 | Sample 3 | Sample 4 |
| <10 | 0.0 | 0.5 | 0.2 | 0.6 |
| ≥10<20 | 0.0 | 0.3 | 0.2 | 0.3 |
| ≥20<30 | 0.0 | 0.4 | 0.2 | 0.3 |
| ≥30<40 | 0.0 | 0.4 | 0.2 | 0.4 |
| ≥40<50 | 0.1 | 0.4 | 0.3 | 0.4 |
| ≥50<60 | 0.1 | 0.4 | 0.5 | 0.5 |
| ≥60<70 | 0.1 | 0.7 | 0.7 | 0.9 |
| ≥70<80 | 0.2 | 0.8 | 1.2 | 1.2 |
| ≥80<90 | 0.4 | 2.6 | 3.1 | 2.6 |
| ≥90 | 99.1 | 93.5 | 93.4 | 92.8 |
| All particles | 100 | 100 | 100 | 100 |
Table 4. Mineral liberation of berthierite categorized by volume % of berthierite per grain after grinding to a target size of 106 µm.
| Volume % of Berthierite / Fraction | Sample 1 | Sample 2 | Sample 3 | Sample 4 |
| <10 | 35.2 | 0.9 | 1.0 | 0.8 |
| ≥10<20 | 9.4 | 0.8 | 0.8 | 0.5 |
| ≥20<30 | 6.2 | 0.5 | 0.5 | 0.7 |
| ≥30<40 | 5.8 | 0.5 | 0.8 | 0.5 |
| ≥40<50 | 3.2 | 0.7 | 1.1 | 0.6 |
| ≥50<60 | 5.8 | 0.5 | 0.9 | 0.8 |
| ≥60<70 | 2.2 | 0.7 | 1.7 | 1.2 |
| ≥70<80 | 4.2 | 0.7 | 2.7 | 1.9 |
| ≥80<90 | 4.6 | 5.3 | 5.7 | 3.4 |
| ≥90 | 23.5 | 89.4 | 84.9 | 89.7 |
| All particles | 100 | 100 | 100 | 100 |
Qualified Person
The scientific and technical information in this news release has been reviewed, verified and approved by Matthew Trenkler, P. Geo., Chief Geological Officer of Critical One Energy Inc., a "Qualified Person," as defined under National Instrument 43-101 Standards of Disclosure for Mineral Projects.
About Critical One Energy Inc.
Critical One Energy Inc. is a Canadian critical minerals and upstream energy company focused on metals essential to energy, technology and national defence supply chains. The Company is advancing the Howells Lake Antimony-Gold Project, which provides Critical One with direct exposure to antimony, a critical metal of increasing strategic importance to Western nations, as well as meaningful gold exploration potential across the property. Backed by seasoned management expertise, Critical One is positioned to advance high-value mineral projects aligned with the rising demand for secure critical minerals supply. The Company also holds uranium and copper assets in Namibia, providing additional exposure to critical minerals and energy metals.
Additional information about Critical One Energy Inc. can be found at criticaloneenergy.com and on the Company's SEDAR+ profile at www.sedarplus.ca.
For further information, please contact:
Duane Parnham
Executive Chairman & CEO
Critical One Energy Inc.
+1 (416) 489-0092
ir@criticaloneenergy.com
Media inquiries:
Adam Bello
Manager, Media & Analyst Relations
Primoris Group Inc.
+1 (416) 489-0092
media@primorisgroup.com
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