113-5 Characterizing battery-grade graphite in metacarbonate and metasilicate host rocks

Session: Mineralogical Characterization of Economic Resources: From Critical Minerals to Gemstones (Posters)

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Abstract:

Graphite is a critical mineral due to its high supply risk and its importance in green-energy technologies, notably being used as the anode in rechargeable lithium-ion batteries. Properties of natural flake graphite that make it optimal for battery manufacturing include: high crystallinity, large flake size, and an absence of microscopic inclusions and limited atomic substitution of cations (e.g., Ca, Mg, Si). High crystallinity and lack of inclusions are important for conductivity whereas large flake size is better for effective beneficiation. Potentially economic deposits of graphite occur in both metacarbonate and metasilicate rocks. However, it is unclear which of these rock types contains graphite with properties more amenable to downstream battery manufacturing. We investigate several graphite occurrences in each rock type in the southwestern Grenville Province of Ontario, Canada, using scanning electron microscopy to quantify graphite flake size, inclusions, and substitution impurities, as well as Raman spectroscopy to assess graphite crystallinity. In general, graphite hosted by metacarbonate rocks is more consistently of a higher crystallinity with negligible microscopic inclusions and fewer substitution impurities. Although both carbonate-hosted and metasilicate-hosted graphite have potential for downstream battery manufacturing, flake graphite hosted by metacarbonate rocks appears to be better. We suggest that host rocks should be an important consideration when prospecting for flake graphite to be used in rechargeable battery manufacturing. 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-6915

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