Mr. Scott Monteith reports

AVALON ADVANCED MATERIALS FURTHER INTERSECTS 1.54% LI2O OVER 136.95 METERS AT BIG WHOPPER DEPOSIT, SEPARATION RAPIDS JV

Avalon Advanced Materials Inc., in conjunction with its joint venture partner SCR-Sibelco NV, has released the second and final batch of drill results for the 2024 winter drill campaign (which totalled 10 holes) from the Separation Rapids project in Kenora, Ont. The 2024 winter drill campaign was conducted by the joint venture company Separation Rapids Ltd., which is 60 per cent owned by Sibelco and 40 per cent owned by Avalon.

The results represent 199 assay results from five diamond drill holes completed as part of the 2024 expansion and infill drill campaign at the current 750-metre strike length Big Whopper deposit. The drill program was intended to upgrade the 2023 mineral resource estimation classification, as well as to expand the mineral resources.

Drill highlights include from Big Whopper deposit:

• SR24-121 intersected 1.54 per cent lithium oxide over 136.95 metres from 321.00 m:
  • Including 2.28 per cent Li2O over 4.00 metres from 421.00 m.
• SR24-119 intersected 1.87 per cent Li2O over 17.15 metres from 284.40 m.
• SR24-120 intersected 1.60 per cent Li2O over 12.80 metres from 66.15 m.

All quoted intersections comprise a cut-off grade of 0.5 per cent Li2O. All significant assay intervals with true widths are reported in the attached table.

Scott Monteith, chief executive officer and director, commented: "These exceptional results taken over very long intervals are a clear indication of the highly efficient drilling program by our JV partner Sibelco. Another long, massive intercept on hole SR24-121 will be key to growing the mineral resource base. What is exceptionally exciting is the depth potential, with hole SR24-121 effectively intersecting 136.95-metre mineralization from 321 m downhole.

"This hole supports our belief that we have barely begun to uncover the potential of lithium resources at the Separation Rapids deposit. With our objectives for the 2024 winter drilling campaign accomplished, we look forward to the upcoming mineral resource estimate."

The results from the second batch of the 2024 drill campaign continue to identify mineralization below the current resource pit shell with drill hole SR24-121 intersecting values greater than or equal to 0.5 per cent Li2O over a 136-metre interval, opening the main zone at depth.

An updated mineral resource estimate is planned for third quarter of 2024, which will include results of the 2024 winter drill campaign. Total drill metreage will increase from 18,500 metres of drilling to 26,241 metres.

A property-wide mapping and sampling program was completed in late July, 2024, with a focus on satellite targets and areas of limited geological data for further evaluation of the promising potential on the property. This mapping program covered approximately five kilometres along strike, and is currently being modelled and interpreted for further evaluation.

Qualified person

Disclosure of a scientific or technical nature in this news release was prepared under the supervision of Jessica Borysenko, PGeo, Ontario, member No. 2279, manager of geology and mines, Canada, for Separation Rapids. Ms. Borysenko is a qualified person for the purposes of National Instrument 43-101 who has reviewed and approved the technical information included in this news release.

Quality assurance/quality control

QA/QC protocols include 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, and the other half tagged and sent to ALS in Thunder Bay.

Preparation and analytical methods used

Prep-33D -- log and crush -- fine crushing 90 per cent less than two millimetres -- split and pulverize one kilogram split to 95 per cent:

1. ME-4ACD81: This is a multielement analysis using four-acid digestion that includes lithium to 10,000 parts per million (1 per cent) 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 it 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, tantalum, niobium and tin.
4. F-IC881 is a fluorine specific analysis that clearly indicates whether lepidolite is present in the rock. Any value over 10,000 ppm (1 per cent) fluorine 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 a limit of 10 per cent Li (21 per cent Li2O). Pulps are to be returned to the project site.

About Avalon Advanced Materials Inc.

Avalon 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-cesium projects. Avalon is also working to develop its Nechalacho rare earth 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 electric vehicle battery manufacturing base in the south.

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