O3 Mining Inc. provided a progress update on the mining, metallurgical, geomechanical, geotechnical, environmental and community engagement work components of the Pre-Feasibility Study for the Marban Engineering Project. O3 Mining remains committed to completing the study on schedule in Third Quarter 2022. The Marban project is in the heart of the Malartic gold mining camp.

It covers 7,525 hectares and is located 12 kilometres from the Canadian Malartic Mine (owned equally by Agnico Eagle Mines Limited and Yamana Gold Inc.). Activity at Marban in 2022 has been focused on Marban Engineering and working towards completion of the PFS and future economic studies. PFS Progress Highlights: A trade-off study has been completed on mine/mill throughput, indicating a 50% increase from the Preliminary Economic Assessment ("PEA") estimate of 4 Mt per year to 6 Mt per year to mill; The geotechnical and geomechanical testing has been completed; The mineral processing and metallurgical testing program has been completed; Environmental baseline studies are ongoing and dialogue has been initiated with First Nations communities, host communities around the project and government representatives from all levels of government.

Mining: Improved mine sequencing to limit peak mining rate increase to 15% with the increase of 50% in mill feed throughput and reduced peak stockpile under 2Mt vs 12Mt at PEA; Improvements made to the productivity with; increased truck size to 150 tonnes from 100 tonnes in PEA and increased bench size from 5 metres to 10 metres; The Mineral Resource Estimate dated March 1, 2022 will be used as the resource base for the PFS together with the completed and reported metallurgical testwork results; Additional work to be completed includes: Mine sequencing and stockpile design; Detailed mine capital cost and operational cost. Geotechnical, Geomechanical, and Hydrogeological Programs: Geotechnical and geomechanical testing has been completed in Second Quarter (interpretation ongoing); Hydrogeological modelling has been completed. Mineral Processing and Tailings Management: The metallurgical testing program has been completed; Trade-off study on CAPEX to recovery for grinding and leach circuit design has been completed.

A reduction of target grind size from 100 microns to 85 microns and optimized leach-CIP circuit will be integrated in the mill design. Combined with improved results from testwork program and the inclusion of solution losses the recovery for the PFS is: 94.9% for Marban and 91.9% for Norlartic. The tailings management trade-off study has been completed, with an improved conventional tailings scenario selected.

This scenario combines a smaller tailing management facility and in-pit tailings deposition enabling a project footprint reduction. Environmental Baseline Studies and Community Relations: O3 Mining has advanced environmental baseline studies as stated in the 2021 ESG Report, as well as, initiated dialogue with First Nations communities, government representatives from all three levels: municipal, provincial and federal, host communities around the project and other relevant stakeholders. O3 remains committed to the responsible development of its projects by incorporating a holistic sustainability approach to generate value for all stakeholders and to handle environmental concerns.

Additionally, O3 Mining has taken supplementary steps towards the social acceptability of the project. The company intends to implement a participatory approach and met with the citizens located in the project's proximity to obtain their feedback to determine the most suitable and effective mechanism to exchange through the continuation of discussions. Marban Engineering 2022: The Corporation will continue to advance the Marban Engineering project towards production by completing the PFS by Third Quarter 2022 as planned.

O3 Mining aims to become a leading gold producer and put the Marban project into production by 2026. In 2022, 18,000 metres have been drilled on Marban Engineering, with an additional 40,000 metres planned until the end of the year. Drilling will be focused on infill and expansion drilling, as well as exploration drilling in the Marban Fold area.