O3 Mining Reports Positive Metallurgical Results from Marban Engineering; 96% Gold Recoveries at Marban Pit

TSXV:OIII| OTCQX:OIIIF - O3 Mining

TORONTO, Feb. 8, 2022 /PRNewswire/ - O3 Mining Inc. (TSXV: OIII) (OTCQX: OIIIF) ("O3 Mining" or the "Corporation") is pleased to report the results of gold recovery test work conducted on drill core samples from its 100 percent ("%") owned Marban Project located in Val-d'Or, Québec, Canada. The results were produced from the recent metallurgical testing program completed by Base Metallurgical Laboratories in Kamloops, British Columbia, under the overall supervision of Ausenco Engineering Canada Inc. ("Ausenco"). Additionally, the Corporation has appointed Ausenco to lead the Pre-Feasibility Study ("PFS") for the Marban project, which O3 Mining intends to have completed by Q3 2022.

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Highlights From the Cyanidation Test Work

• Overall gold extraction at Marban Pit South of 96.7%; Marban Pit North of 95.8%; Norlartic Pit of 91.2%; versus Preliminary Economic Assessment ("PEA") overall gold extraction of 93.7%
• Enhanced Gravity Recovery Gold testing resulted in 61%-65% recovery of gold
• Recovery of gold achieved after 24 hours of leach time; versus PEA 28 hours
• Average Bond ball mill work index at 13.2 kWh/t.

O3 Mining's President and Chief Executive Officer, Mr. Jose Vizquerra commented, "We are very pleased the test work has confirmed excellent gold recoveries at the Marban project. Our test work supports and improves PEA assumptions of quick leach times, strong recoveries, and a simple flowsheet comparable to peers in the Abitibi-Témiscamingue region. These results provide an excellent foundation for the project and represent a significant milestone for the company as the Marban project moves towards the completion of the PFS. Additional metallurgical work is planned that will feed into in the final stages of the economic study."

The metallurgical gold recovery test-work was conducted to assess the potential gold recoveries and optimum process flow sheet for the Marban Project. Testing started in late 2021 on composite and variability samples from the Marban and Norlartic pits and variability samples from North Zone, Norlartic-Kierens and Golden Bridge. The program included comminution testing, grind optimization, gravity concentration, and leach testing. Cyanide destruction and solid liquid separation testing are still ongoing and will be completed in Q1 2022.

Gold Recovery Test Work Results Summary
The program evaluated 24 discrete composite samples ("composite" or "composites") representing 375 kilograms of material from across the four deposits. Each composite consisted of multiple samples collected from diamond drill core and coarse rejects. Primary composites were selected for the Marban (two samples) and Norlartic pits to reflect grade, spatial and lithological distributions. The primary pit composites were designed to have average grades reflecting the PEA average pit grades. Variability samples were selected to reflect the grade ranges present and other lithological units.

Table 1: Marban Project Total (gravity and leach) Gold Recoveries

Crushing and Grinding Testing

• Comminution testing characterized ore hardness by Bond Ball Mill Work Index ("BWI")
• The Bond Ball Mill Work Index median of 13.2 kilowatt hours per tonne ("kWh/t") is within the range of medium to medium-hard material
• Bond Abrasion Index ("AI") was 0.194 g, which indicates low to medium abrasion.

Gravity Concentration Testing

• Marban and Norlartic pit composite samples were tested with the Extended Gravity Recoverable Gold ("E-GRG") protocol to determine their amenability to gravity concentration
• Results showed very high Gravity Recoverable Gold ("GRG") content ranging from 61% to 65% gold.

Leach Testing
A total of 41 leach tests were conducted, including initial screening tests and a bulk leach test (pending). The results showed:

• Batch gravity recovery of gold ranging from 9% to 50%, averaging 29%
• Gold leach extractions after batch gravity processing ranging from 48% to 88%, averaging 65%, with final residue values of 0.01 g/t to 0.65 g/t gold, averaging 0.10 g/t gold
• Combined overall gold extraction ranging from 77% to 99%, averaging 94% and
• Calculated gold head grades ranging from 0.46 g/t to 8.47 g/t gold, averaging 1.55 g/t gold.

Plant recoveries will be estimated using grades from the Mine Plan along with typical plant losses.

Process Criteria
Table 2 shows the selected mineral processing design parameters resulting from the test work program. These values are typical for leaching of gold and achievable with commonly used technologies.

Table 2: Flowsheet Parameters

Qualified Person
The metallurgical information in this news release has been reviewed and approved by Robert Raponi, P. Eng. of Ausenco Engineering Canada Inc. All other scientific and technical content of this news release has been reviewed, prepared, and approved by Mr. Sébastien Vigneau. (OGQ #993), Principal Geologist of the Corporation. Messrs. Raponi and Vigneau are "Qualified Persons" as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101").

About O3 Mining Inc.
O3 Mining Inc., an Osisko Group company, is a gold explorer and mine developer on the road to produce from its highly prospective gold camps in Québec, Canada. O3 Mining benefits from the support, previous mine-building success, and expertise of the Osisko team as it grows towards being a gold producer with several multi-million-ounce deposits in Québec.

O3 Mining is well-capitalized and owns a 100% interest in all its properties (137,000 hectares) in Québec. O3 Mining trades on the TSX Venture Exchange (TSXV: OIII) and OTC Markets (OTCQX: OIIIF). The Corporation is focused on delivering superior returns to its shareholders and long-term benefits to its stakeholders. Further information can be found on our website at https://o3mining.com

About Ausenco
Ausenco is a global company redefining what's possible. Their team is based across 26 offices in 14 countries, with projects in over 80 locations worldwide. Combining their deep technical expertise with a 30-year track record, they provide innovative, value-add consulting and engineering studies and project delivery, asset operations and maintenance solutions to the mining & metals, oil & gas and industrial sectors.

Cautionary Note Regarding Forward-Looking Information

This news release contains "forward-looking information" within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections, and interpretations as at the date of this news release. The information in this news release about the transaction; and any other information herein that is not a historical fact may be "forward-looking information". Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as "expects", or "does not expect", "is expected", "interpreted", "management's view", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation, at the time it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the companies to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the restart of operations; further steps that might be taken to mitigate the spread of COVID-19; the impact of COVID-19 related disruptions in relation to the Corporation's business operations including upon its employees, suppliers, facilities and other stakeholders; uncertainties and risk that have arisen and may arise in relation to travel, and other financial market and social impacts from COVID-19 and responses to COVID 19. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, the parties cannot assure shareholders and prospective purchasers of securities that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither the Corporation nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. The Corporation does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

SOURCE O3 Mining Inc.