Critical One Energy Announces Favorable Metallurgical Findings for Howells Lake Antimony-Gold Project in Northwestern Ontario

High-Quality Antimony Mineralogy Enhances Processing Prospects

The preliminary metallurgical study focused on four samples from drill hole HWL-2026-006, previously disclosed in the company’s May 15, 2026 press release. Results confirmed that antimony at Howells Lake is mainly hosted in stibnite (Sb2S3), a key antimony mineral exhibiting favorable processing traits. Antimony grades in the samples ranged from 1.41% to 70.7% Sb, covering mineralization styles from massive stibnite to vein- and wall-rock-hosted semi-massive stibnite.

Importantly, the study found no arsenic- or mercury-bearing minerals, which are commonly associated with antimony deposits and complicate processing. Duane Parnham, Founder, Executive Chairman and CEO of Critical One, highlighted that the absence of these deleterious elements enhances flexibility in selecting refinery or offtake partners. The company emphasized that this clean antimony mineralogy distinguishes the project and mitigates processing challenges.

Outstanding Mineral Liberation Indicates Strong Flotation Potential

The study utilized TIMA17; (Tescan Integrated Mineral Analyzer), an SEM-based automated mineralogy technique, to assess liberation of antimony minerals. Liberation measures the extent to which target minerals are freed from surrounding phases during grinding, a key factor influencing concentration efficiency and costs. Results showed high liberation rates for primary antimony minerals.

Stibnite liberation, defined as the percentage of stibnite per grain after grinding to 106 micrometres, ranged from 92.8% to 99.1%. Berthierite (FeSb2S4), a secondary antimony mineral present in three samples with modal abundance between 0.8% and 7.9%, exhibited liberation rates from 84.9% to 89.7%. These elevated liberation levels suggest antimony minerals are largely free from other mineral phases post-grinding, supporting effective flotation concentration. The findings indicate the antimony minerals may be amenable to conventional flotation processing methods.

Varied Antimony Mineralogy Across Samples

The four samples from drill hole HWL-2026-006 exhibited diverse antimony mineral assemblages reflecting multiple mineralization styles within the project. Sample 1, a massive stibnite with 70.7% Sb grade, had the highest stibnite content at 97.1% modal abundance. Sample 2, semi-massive stibnite with quartz grading 22.8% Sb, contained 10.9% stibnite and 0.8% berthierite. Sample 3, massive stibnite with wall rock grading 3.01% Sb, included 13.4% stibnite and 1.6% berthierite. Sample 4, semi-massive stibnite with wall rock and quartz grading 1.41% Sb, had 14.8% stibnite and the highest berthierite content at 7.9%.

Trace amounts of chalcostibite (CuSbS2), another antimony-bearing mineral, were found in Samples 1 and 2. Mineralogical data show stibnite comprises between 70.6% and 99.8% of total antimony mineral mass, with berthierite making up the remainder. This compositional diversity within a single drill hole implies multiple mineralization styles that will be considered in future processing design. Follow-up metallurgical tests will assess concentrate quality and variability across broader Howells Lake mineralization.

Strategic Significance of Antimony and Project Location

Antimony is a critical mineral of growing strategic importance to Western countries, particularly for energy, technology, and defense supply chains. The Howells Lake Antimony-Gold Project in the Thunder Bay Mining Division of northwestern Ontario offers Critical One Energy direct exposure to this vital metal, alongside significant gold exploration potential. Located about 120 kilometres west of the Ring of Fire access corridor, the project is positioned within a region attracting substantial mineral exploration and development activity.

Critical One Energy describes itself as a Canadian critical minerals and upstream energy company with assets beyond Howells Lake. Besides its Ontario antimony-gold focus, the company holds uranium and copper properties in Namibia, enhancing exposure to critical minerals and energy metals. This announcement underscores the company’s strategic alignment with metals essential to securing Western supply chains and supporting emerging energy and technology sectors.

Analytical Techniques and Qualified Person Verification

The preliminary metallurgical study was conducted by Blue Coast Research Ltd., located in Parksville, British Columbia. The study used advanced automated mineralogy methods, grinding samples to 106 micrometres before analysis with TIMA17;, a scanning electron microscope-based instrument providing detailed modal mineralogy, liberation, and mineral association data.

Matthew Trenkler, P. Geo., Chief Geological Officer of Critical One Energy Inc. and a "Qualified Person" under National Instrument 43-101 standards, reviewed and approved the scientific and technical information. This verification ensures compliance with Canadian securities regulations and professional geological standards.

Next Steps in Metallurgical Testing and Project Development

The preliminary study lays the groundwork for the next phase of metallurgical testing. Critical One plans to evaluate flotation response across mineralization samples, quantifying antimony recovery under various flotation conditions and processing flowsheets. The program will also assess concentrate quality and variability across a broader range of Howells Lake mineralization.

These studies aim to define processing options as the project advances. The company noted that "every round of drilling and testwork so far has confirmed that we have high-grade antimony," indicating consistent geological results supportive of project progression. The absence of deleterious elements and favorable liberation characteristics reduce technical risks often associated with antimony projects, potentially enhancing economic and operational feasibility.

Project Location and Infrastructure Advantages

Situated in the Thunder Bay Mining Division of northwestern Ontario, the Howells Lake Project benefits from established mining infrastructure and geological expertise related to precious and critical metals. Its location approximately 120 kilometres west of the Ring of Fire access corridor is significant, as the Ring of Fire is an emerging major mineral development zone. Proximity to infrastructure and access improvements may provide logistical benefits for future development and concentrate transport.

Northwestern Ontario’s long mining history and supportive regulatory environment offer a stable framework for mineral project advancement. The project’s geographic details and access considerations are important factors for investors and partners evaluating long-term development potential.

Company Profile and Asset Diversification

Critical One Energy Inc. trades on the Canadian Securities Exchange as CRTL, OTCQB as MMTLF, and Frankfurt Stock Exchange as 4EF. The company focuses on critical minerals and upstream energy, emphasizing metals vital to energy, technology, and national defense supply chains. Supported by experienced management, Critical One aims to advance high-value mineral projects aligned with increasing demand for secure critical mineral supplies.

In addition to the Howells Lake Project in Ontario, Critical One holds uranium and copper assets in Namibia, providing geographic and commodity diversification. This multi-jurisdictional portfolio aligns with global trends in energy transition, technological innovation, and defense needs. More information is available at criticaloneenergy.com and the company’s SEDAR+ profile at www.sedarplus.ca.

Market Impact and Investor Considerations

The release of positive preliminary metallurgical results marks a key milestone in the Howells Lake project’s development, enhancing technical understanding of processing characteristics. For investors, this reduces project risk and informs timeline expectations as the company moves toward prefeasibility or feasibility stages. The absence of arsenic and mercury, which typically increase refining costs and complexity, may lower perceived technical risks.

Immediate effects on share price were not publicly clear; investors should monitor market activity and commentary following this announcement. While the results reinforce the company’s narrative on project quality, investors should independently assess economic viability considering capital and operating costs, commodity prices, and global antimony market dynamics. Continued metallurgical testing will refine development plans, though production timelines and commercial viability depend on future outcomes and financing.