An anonymous director reports

AVALON CANCELS SPECIAL MEETING OF SHAREHOLDERS

Avalon Advanced Materials Inc.'s special meeting of shareholders scheduled for Oct. 7, 2025, has been cancelled. The decision follows the company's determination that quorum requirements (that is, not fewer than 20 per cent of the issued and outstanding shares of the company carrying voting rights) for the special meeting had not been met by the extended proxy voting deadline of Oct. 6, 2025, at 4 p.m. Eastern Time.

The board of directors expects that the matter originally scheduled for shareholder consideration at the special meeting -- adoption of a shareholder rights plan -- will be considered for approval at a later date.

Proxies submitted for the special meeting will not carry over to any future meeting of the company's shareholders at which a shareholder rights plan is considered and are no longer effective.

Avalon remains committed to engaging its shareholders and ensuring broad participation on matters of importance to the company and its future. Avalon shareholders may contact Avalon investor relations at ir@avalonam.com or 416-364-4938 for further information about the cancelled special meeting.

About Avalon Advanced Materials Inc.

Avalon is a Canadian critical mineral company advancing the supply of materials essential for Canada's future. The company is focused on developing strategic assets that support secure, domestic supply chains and long-term economic growth. Avalon is focused on vertically integrating the Ontario lithium supply chain through the development of Lake Superior Lithium Inc., Ontario's first mid-stream lithium hydroxide processing facility, located in Thunder Bay. This facility will serve as a vital link between Northern Ontario's lithium resources and the growing electric vehicle battery manufacturing base in Southern Ontario and North America. Through a joint venture with SCR-Sibelco NV, Avalon is advancing the Separation Rapids lithium project near Kenora, Ont., as well as continuing exploration at its Snowbank lithium and Lilypad lithium-cesium deposits. The company is also advancing the Nechalacho rare earth and zirconium project in the Northwest Territories. This deposit contains all light and heavy rare earth elements, as well as yttrium, zirconium, tantalum and niobium -- critical minerals used in advanced technologies across the communications, defence, cleantech and energy sectors.

We seek Safe Harbor.