grafitflak

Grafitflak, or graphite flakes, are natural graphite crystals with a flaky, plate-like morphology. They form in certain metamorphic and igneous rocks when carbon-rich fluids crystallize in layered structures. As a commodity, they are valued for high in-plane electrical conductivity, lubricity, and chemical inertness.

The flakes consist of carbon with a layered hexagonal structure. Properties are highly anisotropic: along the basal planes they conduct electricity and heat well and provide good lubricating behavior, while perpendicular to the planes the properties are reduced. They are chemically inert and stable at high temperatures, though oxidation can occur above several hundred degrees Celsius in air. Flake quality is influenced by purity, crystallinity, and the size distribution of particles.

Production and processing involve mining and crushing the ore, followed by milling and flotation to separate graphite from gangue. Purification and sometimes roasting reduce impurities. Flake concentrates are classified by size, commonly into jumbo (>1 mm), large (0.3–1 mm), medium (0.1–0.3 mm), fine (0.05–0.1 mm), and micro (<0.05 mm).

Applications are diverse. Graphite flakes are used as solid lubricants in bearings and sliding interfaces, as reinforcing fillers in polymers and coatings, and as conductive additives in plastics, rubbers, and paints. They serve as a feedstock for producing graphite powders used in lithium-ion battery anodes and other electrochemical applications. They also find use in foundry facings, brake materials, and specialty coatings.

Safety and environmental aspects include the inhalation risk of fine graphite dust and the environmental footprint of mining and processing, which underscores the importance of dust control and responsible sourcing.