Nechalacho Basal Zone Selected for Canada Investment Summit Prospectus as Strategic Canadian Rare Earths Project

September 15, 2026

TORONTO, ON – September 15, 2026 – Avalon Advanced Materials Inc. (“Avalon” or the “Company”) (TSX: AVL and OTCQB: AVLNF) is pleased to announce that its Nechalacho Rare Earths Project (“Nechalacho”) in the Northwest Territories has been selected for inclusion in the Canada Investment Summit Prospectus and will be showcased by the Government of the Northwest Territories (“GNWT”) as a strategic critical minerals development opportunity.

 

The inaugural Canada Investment Summit, hosted by the Government of Canada in partnership with Canada’s major institutional investment organizations, is bringing together global investors and Canadian companies to highlight investment opportunities across the country. The Summit’s official prospectus features 167 investment opportunities, including 63 projects in the minerals and metals sector, providing Nechalacho with exposure to international investors seeking opportunities across Canada’s strategic resource industries.

 

Nechalacho’s inclusion provides an important national and international platform to showcase both the project and the Northwest Territories’ broader critical minerals potential. Premier R.J. Simpson and the GNWT are highlighting Nechalacho as one of the territory’s key resource development opportunities, positioning the project among a select group of Canadian rare earth and critical minerals projects being presented to global investors at the Summit.

 

The selection comes as governments in Canada, the United States and allied markets increasingly focus on establishing secure, diversified supply chains for critical minerals. It also highlights the important role the Northwest Territories can play in strengthening Canada’s domestic supply of critical minerals while creating opportunities for investment, economic development and long-term benefits for the territory.

Nechalacho is one of Canada’s most advanced undeveloped rare earth assets, benefiting from substantial historical technical work, including a historical 2013 Definitive Feasibility Study, extensive drilling and supporting technical studies. Avalon recently announced an updated Mineral Resource Estimate for the Basal Zone prepared in accordance with U.S. SEC S-K 1300 requirements, providing an updated technical foundation for the project as the Company advances its U.S. listing and capital markets strategy.


Avalon is also advancing a Preliminary Economic Assessment intended to modernize the development and processing approach contemplated in the historical feasibility study and evaluate the project’s economics. The work forms part of Avalon’s broader strategy to advance Nechalacho toward development while evaluating potential processing pathways, strategic partnerships and financing opportunities.

Avalon believes Nechalacho’s scale, advanced technical foundation, exposure to both light and heavy rare earth elements and location within a stable Canadian jurisdiction position the project as a compelling opportunity within North America’s critical minerals industry.

 

About Avalon Advanced Materials Inc.

Avalon Advanced Materials Inc. is a Canadian critical minerals company focused on advancing lithium and rare earth elements—two of the fastest-growing segments of the global energy transition. The Company is developing strategic assets to participate in high-growth markets and support the build-out of secure North American supply chains. Avalon is advancing the Nechalacho Rare Earth Elements and Zirconium Project in the Northwest Territories, which contains all light and heavy rare earth elements, as well as zirconium, tantalum, and niobium—critical minerals used in advanced technologies across the communications, defense, advanced technologies, and energy sectors. The Company is also focused on vertically integrating the Ontario lithium supply chain through the development of Lake Superior Lithium Inc., Ontario’s first midstream lithium hydroxide processing facility, located in Thunder Bay. This facility is expected to serve as a cornerstone of North America’s integrated battery materials supply chain, transforming northern Ontario lithium into essential inputs for transportation, grid storage, and advanced manufacturing.

For further information regarding Avalon Advanced Materials Inc., please visit www.avalonadvancedmaterials.com, email ir@avalonam.com, or call 416-364-4938.

 

Cautionary Statement Regarding Forward-Looking Information

This news release contains “forward-looking information” within the meaning of applicable Canadian securities legislation. Generally, forward-looking information can be identified by the use of forward-looking terminology such as “add” or “additional”, “advancing”, “anticipates” or “does not anticipate”, “appears”, “believes”, “can be”, “conceptual”, “confidence”, “continue”, “convert” or “conversion”, “deliver”, “demonstrating”, “estimates”, “encouraging”, “expand” or “expanding” or “expansion”, “expect” or “expectations”, “forecasts”, “forward”, “goal”, “improves”, “increase”, “intends”, “justification”, “plans”, “potential” or “potentially”, “promise”, “prospective”, “prioritize”, “reflects”, “robust”, “scheduled”, “suggesting”, “support”, “top-tier”, “updating”, “upside”, “will be” or “will consider”, “work towards”, or variations of such words and phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, or “will be taken”, “occur”, or “be achieved”.

Forward-looking information is subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information, including those risk factors discussed or referred to in the annual information form of the Company dated November 26, 2025 (the “AIF”) under the heading “Description of the Business – Risk Factors”. Forward-looking information is based on the reasonable assumptions, estimates, analysis and opinions of management made in light of its experience and perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances at the date that such statements are made, but which may prove to be incorrect. Although the Company believes that the assumptions and expectations reflected in such forward-looking information are reasonable, undue reliance should not be placed on forward-looking information because the Company can give no assurance that such expectations will prove to be correct. Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such information. Accordingly, readers should not place undue reliance on forward-looking information. The Company does not undertake to update any forward-looking information, except in accordance with applicable securities laws.

Mark N.J. Ashcroft, P.Eng, is a seasoned professional in the mining, resource and finance sectors with a legacy as a sixth-generation miner, who first went underground at 12 years old. Beginning his career underground in Thompson, MB, he later earned an engineering degree and gained extensive experience across North and South America and Australia. He has held roles in mining operations, corporate development, and finance, including President and CEO of Stonegate Agricom, where he managed a pivotal $51.75 million IPO on the Toronto Stock Exchange. Currently, he is the CEO of Aurelius Minerals Inc., focusing on gold projects in Nova Scotia and Ontario.

Mark’s background includes investment banking and corporate finance positions in London, New York, and Toronto at firms like Barclays Capital, Standard Bank, Versant Partners, and Toll Cross Securities, dealing primarily with resource companies. He has served on various public mining and exploration boards, advising on governance and capital markets. Mark is a licensed Professional Engineer in Ontario, and holds a Bachelor of Engineering in Mining Engineering from Laurentian University and a Master of Science in Finance, Regulation, and Risk Management from the University of Reading..

Cindy Hu joined Avalon in 2007. Prior to joining the company, Ms. Hu was a senior manager with the accounting firm Andersen & Company Professional Corporation. She is a Chartered Professional Accountant with over 20 years of experience in public accounting practice and financial reporting, primarily for junior public companies and private wealth management portfolios.

MS. Hu earned her B.Com from Laurentian University in 1996.

Scott Monteith is President and Chief Executive Officer of Avalon Advanced Materials Inc. He is an accomplished clean-tech executive and entrepreneur with more than 30 years of experience advancing innovative technologies from concept through commercialization. Throughout his career, Mr. Monteith has focused on building and scaling companies that support the transition to a more sustainable and secure global economy.
 
As CEO of Avalon, Mr. Monteith is leading the Company’s strategic transformation into a vertically integrated critical minerals and advanced manufacturing company focused on supporting secure North American supply chains. Under his leadership, Avalon is advancing the Nechalacho Rare Earth Elements and Zirconium Project in the Northwest Territories and Lake Superior Lithium Inc., a proposed midstream lithium hydroxide processing facility in Thunder Bay, Ontario. 
 

Mr. Monteith holds a Bachelor of Business Administration from Toronto Metropolitan University and has been a member of the Young President’s Organization for over 20 years.