Mr. Scott Monteith reports

AVALON UNDERTAKES A MINERAL RESOURCE ESTIMATE UPDATE FOLLOWING POSITIVE DRILL RESULTS FOR SEPARATION RAPIDS JV, ON

Avalon Advanced Materials Inc., in conjunction with its joint venture (JV) partner, SCR-Sibelco NV (Sibelco), has commenced a mineral resource update for the Separation Rapids project in Kenora, Ont. Managed by the joint venture company, Separation Rapids Ltd. (SRL), the 2024 winter drill campaign focused on a critical part of SRL's strategy to upgrade the 2023 mineral resource estimation (MRE) classification and to expand the mineral resource base.

Key highlights of the 2023/2024 drilling results to date (news release dated July 22, 2024):

• The first batch of the 2024 winter drill campaign demonstrated significant lithium intersections, with key results including:
  • SR24-114 intersected 1.67 per cent Li2O over 105.6 metres from a depth of 313.5 metres and 1.78 per cent Li2O over 21.5 metres from a depth of 143.5 metres.
  • SR24-113 intersected 1.68 per cent Li2O over 66.2 metres from a depth of 292.2 metres and 1.95 per cent Li2O over 32.6 metres from a depth of 121.0 metres.
  • SR24-115 intersected 1.81 per cent Li2O over 13.8 metres from a depth of 93.5 metres.
  • SR24-116 intersected 1.69 per cent Li2O over 8.9 metres from a depth of 313 metres and 1.67 per cent Li2O over 12.7 metres from a depth of 325.3 metres.
• The results confirm the high-grade lithium and the potential to increase the mineral resource base.
• The results for the five remaining drill holes are currently pending and will be released shortly.

Scott Monteith, chief executive officer and a director of Avalon Advanced, commented: "We are excited with the recent drill results, which clearly demonstrate mineralization beyond the current mineral resource base. Sibelco, our JV partner, has been exceptional in selecting drill targets and our technical team is very confident that we will increase the resource base. This update will indicate a true reflection of the potential of this project and indicate additional exploration targets.

"As we eagerly await the results from the second batch of drilling, we are beginning to update the 2023 MRE, which is on track for release in Q3 2024. Avalon is positioned exceptionally well with a lithium resource that will be instrumental in Canada's critical mineral strategy and will help accelerate our corporate strategy with respect to our Thunder Bay processing facility."

The continuing developments at Separation Rapids highlight Avalon's pivotal role in bolstering the supply chain for the burgeoning electric vehicle market in North America, as well as the glass ceramics industry.

Quality assurance and quality control (QA/QC)

QA/QC protocols followed at the insertion of blanks and standards at regular intervals in each sample batch. Drill core is cut in half, with one-half retained at site, the other half tagged and sent to ALS in Thunder Bay.

Prep and analytical methods used

PREP-33D -- log, crush -- fine crushing 90 per cent less than two millimetres, split, pulverize one-kilogram split to 95 per cent less than 106 micrometres:

1. ME-4ACD81 is a multielement analysis using four-acid digestion that includes lithium to 10,000 parts per million (1 per cent) lithium (Li) (2.15 per cent Li2O).
2. ME-ICP06 is a whole-rock analysis that covers components, such as silicon, sodium, potassium and iron, so is useful as a check on rock type, feldspar content and type, and amphibolite content.
3. ME-MS81 is a fusion multielement analysis that includes important pegmatite elements, such as rubidium (Rb), tantalum (Ta), niobium (Nb) and (tin) Sn.
4. F-IC881 is a fluorine-specific analysis that clearly indicates whether lepidolite is present in the rock. Any value over 10,000 parts per million (1 per cent) fluorine (F) is likely to be Unit 6d -- the lepidolite-bearing unit.

Any sample that exceeds the lithium limits for ME-4ACD81 (1 per cent Li or 2.15 per cent Li2O) is reanalyzed using method ME-ICP82b, a lithium-specific method with limit of 10 per cent Li (21 per cent Li2O). Pulps are to be returned to the project site.

Qualified person (QP) and National Instrument 43-101 disclosure

Andrew J. Ramcharan, PEng, vice-president of corporate development for the company, is the designated qualified person for this news release within the meaning of National Instrument 43-101, and has reviewed and verified that the technical information contained herein is accurate, and approves of the written disclosure of same.

About Avalon Advanced Materials Inc.

Avalon Advanced is a Canadian advanced manufacturing company focused on vertically integrating the Ontario lithium supply chain. The company, through its joint venture with SCR-Sibelco NV, is currently developing its Separation Rapids lithium deposit near Kenora, Ont., while also continuing to advance the Snowbank lithium and Lilypad lithium-caesium projects. Avalon is also working to develop its Nechalacho rare earths and zirconium project, located in the Northwest Territories. This deposit contains critical minerals for use in advanced technologies in the communications and defence industries among other sectors.

In addition to these upstream activities, Avalon is executing on a key initiative to develop Ontario's first mid-stream lithium hydroxide processing facility in Thunder Bay, Ont., a vital link bridging the lithium resources of the north with the downstream EV (electric vehicle) battery manufacturing base in the south.

We seek Safe Harbor.