O3 Mining : Management Information Circular – YE 2023

O3 MINING INC.

NOTICE OF MEETING

and

MANAGEMENT INFORMATION CIRCULAR

for the

ANNUAL AND SPECIAL MEETING OF SHAREHOLDERS

to be held on

June 14, 2024

DATED as of April 22, 2024

NOTICE AND ACCESS NOTIFICATION OF

ANNUAL GENERAL & SPECIAL MEETING OF SHAREHOLDERS

to be held on June 14, 2024

O3 Mining Inc. ("O3" or the "Corporation") has chosen to use the notice and access model for delivery of meeting materials to its shareholders. Under notice and access, shareholders still receive a proxy or voting instruction form enabling them to vote at the shareholders' meeting. However, instead of receiving a paper copy of the Information Circular (as defined herein), shareholders receive this notice explaining how to access such materials electronically.

The meeting will be held on Friday, June 14, 2024 at 10:00 a.m. (Toronto time) at the offices of Bennett Jones LLP, located at One First Canadian Place, Suite 3400, Toronto, Ontario, Canada, M5X 1A4 (the "Meeting").

The Meeting is being held for the following purposes:

1. to receive and consider the consolidated financial statements of the Corporation for the year ended December 31, 2023, together with the report of the auditor thereon, as more particularly described under heading "Business of the Meeting - Financial Statements" of the Information Circular;
2. to elect directors of the Corporation for the ensuing year, as more particularly described under heading "Business of the Meeting - Election of Directors" of the Information Circular;
3. to appoint PricewaterhouseCoopers LLP, Chartered Professional Accountants, as the auditor of the Corporation for the ensuing year and to authorize the directors to determine the remuneration to be paid to the auditor, as more particularly described under heading "Business of the Meeting - Appointment of Auditor" of the Information Circular;
4. to consider, and if deemed advisable, to pass, with or without variation, an ordinary resolution to approve the 10% rolling Stock Option Plan of the Corporation, as more particularly described under heading "Business of the Meeting - Re-Approval of Existing 10% Rolling Stock Option Plan" of the Information Circular; and
5. to transact such other business as may properly come before the Meeting or any adjournments or postponements thereof.

The nature of the business to be transacted at the Meeting is described in further detail in the management information circular of the Corporation dated April 22, 2024 (the "Information Circular").

Registered shareholders who are unable to attend the Meeting are requested to complete, sign, date and return the enclosed proxy. A proxy will not be valid unless it is returned to the Corporation's registrar and transfer agent, Odyssey Trust Company: (i) by mail to Odyssey Trust Company, 702-67 Yonge Street, Toronto, Ontario, M5E 1J8, Attention: Proxy Department; (ii) by hand delivery to Odyssey Trust Company, 702-67 Yonge Street, Toronto, Ontario, M5E 1J8; or (iii) by internet by using the control number located at the bottom of your form of proxy at https://login.odysseytrust.com/pxlogin, in each case, not less than 48 hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto) before the time fixed for the Meeting or any adjournments or postponements thereof.

If you are a non-registered Shareholder of the Corporation and received this Notice and accompanying materials through a broker, a financial institution, a participant, or a trustee or administrator of a retirement savings plan, retirement income fund, education savings plan or other similar savings or investment plan registered under the Income Tax Act (Canada), or a nominee of any of the foregoing that holds your securities on your behalf (each, an "Intermediary"), please complete and return the materials in accordance with the instructions provided to you by your Intermediary.

Notice and Access

The Corporation is utilizing the Notice-and-Access Provisions that came into effect on February 11, 2013 under National Instrument 54-101 - Communication with Beneficial Owners of Securities of a Reporting Issuer ("NI 54-101") and National Instrument 51-102 - Continuous Disclosure Obligations ("NI 51-102") for distribution of this Information Circular to Shareholders.

The Notice-and-Access Provisions are a set of rules which allow reporting issuers to post electronic versions of proxy-related materials (such as proxy circulars and annual financial statements) on-line, via the System for Electronic Document Analysis and Retrieval+ ("SEDAR+") and one other website, rather than mailing paper copies of such materials to Shareholders. Electronic copies of this Information Circular, financial statements of the Corporation for the year ended December 31, 2023 ("Financial Statements") and the related management's discussion and analysis of the Corporation's for the year ended December 31, 2023 (the "Annual MD&A") are available on SEDAR+ (www.sedarplus.ca) under the Corporation's issuer profile and also on the Corporation's website (https://o3mining.com/investors/#inv-shareholders).

The Corporation will not use procedures known as "stratification" in relation to the use of Notice-and- Access Provisions. Stratification occurs when a reporting issuer using the Notice-and-Access Provisions provides a paper copy of this Information Circular to some Shareholders with the notice package. In relation to the Meeting, all Shareholders will receive the required documentation under the Notice-and-Access Provisions, which will not include a paper copy of this Information Circular. Shareholders are reminded to review this Information Circular before voting.

Although this Information Circular, the Financial Statements and the related Annual MD&A will be posted electronically on-line as noted above, Shareholders will receive paper copies of a "notice package" via prepaid mail containing information prescribed by NI 54-101 and NI 51-102, a form of proxy or voting instruction form, and supplemental mail list return card for Shareholders to request they be included in the Corporation's supplementary mailing list for receipt of the Corporation's annual and interim financial statements for the 2023 fiscal year.

The Corporation anticipates that notice-and-access will directly benefit the Corporation through a substantial reduction in both postage and material costs, and also promote environmental responsibility by decreasing the large volume of paper documents generated by printing proxy-related materials.

Shareholders with questions about notice-and-access can contact the Corporation's registrar and transfer agent, Odyssey Trust Company, only at www.odysseycontact.comor by phone at 1-888-290-1175(toll-free within North America) or 1-587-885-0960 (direct from outside North America). Shareholders may also obtain paper copies of the Information Circular, the Financial Statements and the related Annual MD&A free of charge by contacting the Corporation's Corporate Secretary at [e-mail].

Reference is made to the Information Circular of the Corporation dated April 22, 2024, which contains additional details concerning the matters outlined above.

SHAREHOLDERS ARE REMINDED TO REVIEW THE INFORMATION CIRCULAR PRIORTO VOTING. SEE BELOW FOR HOW TO VIEW AND ACCESS OF COPY OF THE INFORMATION CIRCULAR.

WEBSITES WHERE THE INFORMATION CIRCULAR IS POSTED

The Information Circular can be viewed online:

• on SEDAR+ (www.sedarplus.ca) under O3 Mining's issuer profile; or
• at the Corporation's website (https://o3mining.com/investors/#inv-shareholders).
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HOW TO OBTAIN PAPER COPIES OF THE INFORMATION CIRCULAR

Shareholders may request paper copies of the Information Circular be sent to them by postal delivery at no cost to them. Requests may be made up to one year from the date the Information Circular was filed on SEDAR+.

To request paper copies of the Information Circular before the Meeting, e-mail the Corporation's Corporate Secretary at [e-mail]. The Information Circular will be sent to you within three business days of receiving your request. Requests for paper copies must be received by at least June 4, 2024 in order to receive the Information Circular in advance of the proxy deposit date and Meeting. The Information Circular will be sent to such shareholders within three business days of their request if such requests are made before the Meeting. Those shareholders with existing instructions on their account to receive a paper copy of meeting materials will receive a paper copy of the Information Circular with this notification. Shareholders are able to request to receive copies of the Corporation's annual and/or interim financial statements and relevant management's discussion and analysis on the accompanying return card.

VOTING

PLEASE NOTE - YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your securities you must vote using the methods reflected on your enclosed Proxy or Voting Instruction Form. Your Proxy or Voting Instruction Form must be received by 10:00 a.m. (Toronto time), on June 12, 2024 or at least 48 hours (excluding Saturdays and holidays) before any adjournment or postponement thereof.

PLEASE VIEW THE INFORMATION CIRCULAR PRIOR TO VOTING

Shareholders with questions about notice and access can contact Odyssey Trust Company, via www.odysseycontact.comor by phone at 1-888-290-1175(toll-free within North America) or 1-587-885-0960 (direct from outside North America).

BOARD RECOMMENDATION

The Board of Directors of O3 unanimously recommends that Shareholders VOTE FOR all of the proposed resolutions.

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TABLE OF CONTENTS
GENERAL INFORMATION RESPECTING THE MEETING	1
Solicitation of Proxies	1
Voting of Proxies	2
Appointment of Proxies	2
Revocation of Proxies	2
Voting by Non-Registered Shareholders	3
NOTICE-AND-ACCESS RULES	4
INTEREST OF CERTAIN PERSONS OR COMPANIES IN MATTERS TO BE ACTED UPON	4
VOTING SECURITIES AND PRINCIPAL HOLDERS OF VOTING SECURITIES	5
BUSINESS OF THE MEETING	5
Financial Statements	5
Appointment of Auditor	5
Election of Directors	6
Re-Approval of Existing 10% Rolling Stock Option Plan	8
Other Matters	9
Normal Course Issuer Bid	9
STATEMENT OF EXECUTIVE COMPENSATION	10
Components of the Compensation Program	11
Long-Term Incentive Compensation	14
Summary Compensation Table Excluding Compensation Securities	16
Compensation Securities	17
Pension Plan Benefits	19
Termination and Change of Control Benefits	19
SECURITIES AUTHORIZED FOR ISSUANCE UNDER EQUITY COMPENSATION PLANS	22
Stock Option Plan	22
Deferred Share Unit Plan	24
Restricted Share Unit Plan	27
Employee Share Purchase Plan	30
Equity Compensation Plan Information	33
Executive Share Ownership Requirements	34
STATEMENT OF CORPORATE GOVERNANCE	34
Board of Directors	34
Other Public Company Directorships	37
Board Mandate	38
Lead Director Mandate	38
Audit Committee	39
Nomination of Directors	39
Corporate Governance and Nomination Committee	40
Compensation Committee	42
Sustainable Development Committee	43
Business Conduct and Ethics Policy	48
Assessments	48
Diversity Policy	49
Corporate Disclosure Policy	49
Confidentiality and Insider Trading Policy	49
Board and Executive Officers	50
INDEBTEDNESS OF DIRECTORS AND EXECUTIVE OFFICERS	50

AUDIT COMMITTEE	50
The Audit Committee's Charter	50
Composition of the Audit Committee	50
Relevant Education and Experience	51
Reliance on Exemptions in NI 52-110 regarding De Minimis Non-Audit Services or on a Regulatory
Order Generally	51
Pre-Approval Policies and Procedures	51
External Auditor Service Fees	51
Exemption	52
INTEREST OF INFORMED PERSONS IN MATERIAL TRANSACTIONS	52
ADDITIONAL INFORMATION	52
APPROVAL	52
SCHEDULE "A" STOCK OPTION PLAN	A-1
SCHEDULE "B" BOARD CHARTER	B-1
SCHEDULE "C" AUDIT COMMITTEE CHARTER	C-1
Appendix "A"	POSITION DESCRIPTION FOR THE CHAIRMAN OF THE AUDIT COMMITTEE ....	C-7
Appendix "B"	NATIONAL INSTRUMENT 52-110 AUDIT COMMITTEES ("NI 52-110")	C-9
Appendix "C"	PROCEDURES FOR APPROVAL OF NON-AUDIT SERVICES	C-11

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GENERAL INFORMATION RESPECTING THE MEETING

In this management information circular ("Circular") of O3 Mining Inc. (the "Corporation") dated April 22, 2024, unless otherwise stated: (i) references to the "Meeting" (as defined herein) include any adjournment(s) or postponement(s) thereof, (ii) references to "$" refer to Canadian dollars, and (iii) the information contained herein is provided as of the date hereof.

Solicitation of Proxies

This Circular is furnished in connection with the solicitation of proxies by the management of the Corporation for use at the annual and special meeting (the "Meeting") of the shareholders of the Corporation (the "Shareholders") to be held at 10:00 a.m. (Toronto time) on June 14, 2024 at the offices of Bennett Jones LLP, located at One First Canadian Place, Suite 3400, Toronto, Ontario, Canada, M5X 1A4, for the purposes set forth in the notice of meeting accompanying this Circular (the "Notice").

It is expected that the solicitation of proxies will be primarily by mail; however, proxies may also be solicited by the officers, directors and employees of the Corporation by telephone, telecopier or personally. These persons will receive no compensation for such solicitation other than their regular fees or salaries. The Corporation will bear all expenses in connection with the solicitation of proxies. In addition, the Corporation shall, upon request, reimburse brokerage firms and other custodians for their reasonable expenses in forwarding proxies and related material to beneficial owners of common shares of the Corporation ("Common Shares").

The board of directors of the Corporation (the "Board") has fixed the close of business on April 22, 2024 as the record date, being the date for the determination of the registered Shareholders entitled to receive notice of, and to vote at, the Meeting.

Voting by Registered Shareholders

All duly completed and executed proxies must be received by the Corporation's registrar and transfer agent, Odyssey Trust Company: (i) by mail to Odyssey Trust Company, 702-67 Yonge Street, Toronto, Ontario, M5E 1J8, Attention: Proxy Department; (ii) by hand delivery to Odyssey Trust Company, 702-67 Yonge Street, Toronto, Ontario, M5E 1J8; or (iii) by internet by using the control number located at the bottom of your form of proxy at https://login.odysseytrust.com/pxlogin, in each case, not later than forty-eight (48) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto, Ontario) prior to the time set for the Meeting or any adjournments or postponements thereof.

You can vote your proxy (i) by mail, (ii) by hand delivery, (iii) by facsimile, or (iv) on the Internet, as follows:

By Mail and Hand Delivery

You can complete, sign and date your form of proxy and return it in the envelope provided to the offices of Computershare Investor Services Inc. at:

ODYSSEY TRUST COMPANY

Proxy Department, Trader's Bank Building,

702 - 67 Yonge Street, Toronto, Ontario M5E 1J8 Canada

By Facsimile

You can complete, sign and date your form of proxy and return it by facsimile to Odyssey Trust Company at: 1-800-517-4553.

On the Internet

To Vote Your Proxy Online please visit: https://login.odysseytrust.com/pxlogin.

Voting of Proxies

In respect of registered Shareholders, the Common Shares represented by the form of proxy (if same is properly executed and is received at the offices of Odyssey Trust Company at the address provided herein, not later than forty-eight (48) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto) prior to the time set for the Meeting or any adjournment(s) or postponement(s) thereof, will be voted at the Meeting, and, where a choice is specified in respect of any matter to be acted upon, will be voted or withheld from voting in accordance with the specification made on any ballot that may be called for. In the absence of such specification, proxies in favour of management will be voted in favour of all resolutions described below. The form of proxy confers discretionary authority upon the persons named therein with respect to amendments or variations to matters identified in the Notice and with respect to other matters which may properly come before the Meeting. As of the date of this Circular, management knows of no such amendments, variations or other matters to come before the Meeting. However, if any other matters that are not now known to management should properly come before the Meeting, the form of proxy will be voted on such matters in accordance with the best judgment of the named proxies.

Appointment of Proxies

The persons named in the form of proxy are officers and/or directors of the Corporation. A registered Shareholder desiring to appoint some other person, who need not be a Shareholder, to represent him or her at the Meeting, may do so by inserting such person's name in the blank space provided in the form of proxy or by completing another proper form of proxy and, in either case, depositing the completed and executed proxy at the offices of Odyssey Trust Company, at the address provided herein, not later than forty-eight (48) hours (excluding Saturdays, Sundays and statutory holidays in the City of Toronto) prior to the time set for the Meeting or any adjournment(s) or postponement(s) thereof.

A registered Shareholder forwarding the form of proxy may indicate the manner in which the appointee is to vote with respect to any specific item by checking the appropriate space. If the Shareholder giving the proxy wishes to confer a discretionary authority with respect to any item of business, then the space opposite the item is to be left blank. The Common Shares represented by the form of proxy submitted by a Shareholder will be voted in accordance with the directions, if any, given in the form of proxy.

To be valid, a form of proxy must be executed by a Shareholder or a Shareholder's attorney duly authorized in writing or, if the Shareholder is a body corporate, under its corporate seal or, by a duly authorized officer or attorney.

Revocation of Proxies

A proxy given pursuant to this solicitation may be revoked at any time prior to its use. A Shareholder who has given a proxy may revoke the proxy by: completing, signing and dating a proxy bearing a later date, and depositing it at the offices of Odyssey Trust Company at Proxy Department, Trader's Bank Building, 702 - 67 Yonge Street, Toronto, Ontario M5E 1J8, Canada; depositing an instrument in writing executed by the Shareholder or by the Shareholder's attorney duly authorized in writing or, if the Shareholder is a body corporate, under its corporate seal or by a duly authorized officer or attorney either with (i) Odyssey Trust Company at Proxy Department, Trader's Bank Building, 702 - 67 Yonge Street, Toronto, Ontario M5E 1J8, Canada at any time up to and including the last business day preceding the day of the Meeting or any adjournment(s) or postponement(s) thereof, (ii) the Chairman of the Meeting prior to the commencement of the Meeting on the day of the Meeting or any adjournment(s) or postponement(s) thereof, or (iii) in any other manner permitted by law.

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