Swedish graphite helping advance Leading Edge research

With the help of European consultant ProGraphite, Canada-based Leading Edge Materials (LEM) has put into motion research that will help it produce expandable graphite using feedstock from the Woxna mine in central Sweden
Swedish graphite helping advance Leading Edge research Swedish graphite helping advance Leading Edge research Swedish graphite helping advance Leading Edge research Swedish graphite helping advance Leading Edge research Swedish graphite helping advance Leading Edge research

At the Woxna complex in central Sweden

The company, which has used the Woxna graphite before for its work, explained that expandable graphite is a potential value-add product for larger flake natural graphite. The end product of this will not be for the lithium ion battery anode market, but will rather be used for fire-resistant building products and textiles.

"Expandable graphite exploits some of the remarkable anisotropic properties of natural flake graphite. Expandable graphite is manufactured by treating crystalline graphite with mild non-toxic chemicals that position between individual graphite flakes," LEM said.

"When exposed to heat, the chemical converts from a solid or liquid to a gas phase causing a dramatic accordion-like expansion of the graphite which becomes 200-400 times its previous volume."

Graphite samples from Woxna have already been delivered to ProGraphite's laboratory, where it will be characterised and tested. Those coarser flake sizes, over 100μm, are ideal graphite for graphene and expandable graphite, while that required for lithium ion battery anode manufacture is typically 30-100μm.

Once processed, various test conditions and intercalation chemicals will be applied for the products to be suitable for end-market use.

"Expandable graphite provides potential high value applications for graphite with larger flakes and at a lower purity than that required for battery anode materials," interim CEO Mark Saxon said.

"We are…working…to ensure optimal materials can be produced for building product and graphene supply chains. This work runs in parallel with our ongoing work for battery anode materials and provides potential for a deeper product network."

Leading Edge Materials owns the Woxna graphite mine, which has been in operation since 2014. The company has four divisions: graphite, lithium, rare earth and cobalt.