Exhibit 23.18

CONSENT OF QUALIFIED PERSON

Tony O’Connell, M AusIMM, of Optimal Mining, in connection with Sayona Mining Limited’s registration statement on Form F-4 and the joint proxy statement/prospectus included therein and any amendments or supplements or exhibits thereto (collectively, the “Registration Statement”), consents to:

The incorporation by reference of the technical report summary titled “Authier Lithium Technical Report Summary” (the “Technical Report Summary”), with an effective date of June 30, 2024, filed with Piedmont Lithium Inc.’s Annual Report on Form 10-K February 26, 2025, into the Registration Statement;

2.	The use of and references to my name, including my status as an expert or “qualified person” (as defined in Item 1300 (Definitions) of Regulations S-K 1300 promulgated by the Securities and Exchange Commission), in connection with the Registration Statement and the Technical Report Summary; and

Any extracts from or a summary of the Technical Report Summary included in or incorporated by reference in the Registration Statement and the use of any information derived, summarized, quoted or referenced from the Technical Report Summary, or portions thereof, that was or were prepared by me, that I supervised the preparation of and/or that was or were reviewed and approved or certified to by me, that is or are included or incorporated by reference in the Registration Statement.

I am responsible for authoring or co-authoring, and this consent pertains to, the following sections of the Technical Report Summary:

Section 1: Executive Summary

Section 2: Introduction

Section 3: Property Description

Section 4: Accessibility, Climate, Physiography, Local Resources and Infrastructure

Section 5: History

Section 6: Geological Setting, Mineralisation and Deposit

Section 7: Exploration

Section 8: Sample Preparation, Analyses and Security

Section 9: Data Verification

Section 10: Mineral Processing and Metallurgical Testing

Section 11: Mineral Resource Estimates

Section 12: Mineral Reserve Estimates

Section 13: Mining Methods

Section 14: Processing and Recovery Methods

Section 15: Infrastructure

Section 16: Market Studies and Contracts

Section 17: Environmental studies, Permitting, Social or Community Impacts

Section 18: Capital and Operating Costs

Section 19: Economics Analysis

Section 20: Adjacent Properties

Section 21: Other Relevant Data and Information

Section 22: Interpretation and Conclusions

Section 23: Recommendations

Section 24: References

Section 25: Reliance on Information Supplied by Registrant

I certify that I have read the descriptions and references to the Technical Report Summary in the Registration Statement and the documents incorporated by reference therein and that such descriptions and references fairly and accurately represent the information in the Technical Report Summary for which I am responsible.

Dated June 5, 2025

/s/ Tony O’Connell
TONY O’CONNELL