No financial details were disclosed, though the companies said the facility will be designed to process lithium concentrates from Avalon's Separation Rapids lithium project north of Kenora and Rock Tech's Georgia Lake lithium project northeast of Thunder Bay.

It may also use the material from other new and emerging lithium operations in northern Ontario.

The facility is to produce lithium sulphate, but the companies did not elaborate on planned volume. 

Avalon and Rock Tech are now working on a process flowsheet for petalite and spodumene treatment as well as other potential lithium mineral concentrates. The produced lithium sulphate will be either shipped off-site or locally upgraded to lithium carbonate or lithium hydroxide.

The companies will subsequently use the process flowsheet in a pilot campaign to prove the scalability of its designed process to an industrial scale and feasibility level.

The partners will also determine alternative applications for high-purity aluminum silicate by-product in other industries, such as the cement or ceramics industry.

Avalon's 100%-owned Separation Rapids lithium deposit is one of the world's largest "complex-type" lithium-cesium-tantalum pegmatite deposits.

Rock Tech Lithium, meanwhile, is aiming to build the first lithium hydroxide converter in Europe, the feed for which will come from its 100%-owned Georgia Lake spodumene project in Ontario.