Precautions for Using Flake Graphite

Flake graphite is a naturally occurring crystalline graphite that resembles fish scales. It belongs to the hexagonal crystal system and has a layered structure. It boasts excellent properties such as high-temperature resistance, electrical conductivity, thermal conductivity, lubrication, plasticity, and resistance to acids and alkalis. Below are some precautions for using flake graphite:

1. Applications in Metallurgical Industry: Flake graphite is widely used in refractory materials and coatings, such as magnesia-carbon bricks and crucibles. It is also used as an anti-corrosion material. As an anti-rust primer made from carbon black, talc, and oil, it has good chemical and solvent resistance. Adding chemical pigments like zinc chromate to the formula enhances its anti-rust effect.
2. Heat Shock and Corrosion Resistance: Flake graphite has strong resistance to thermal shock and corrosion, making it a primary carbon material used with refractory materials. It significantly impacts the erosion resistance and high-temperature strength of carbon-bonded refractory materials like magnesia-carbon bricks.
3. Strict Production Requirements: In actual production, carbon-bonded refractory materials require strict control over the purity, ash content, particle size, shape, and amount of flake graphite added. The structure and function of the material after high-temperature firing largely depend on the wettability of the graphite flakes by the high-temperature silicate liquid. When moist, the silicate liquid flows into the particle gaps under capillary force. The flake graphite particles bond together through adhesion, forming a thin film around the flakes, which solidifies upon cooling to form a continuous body with a higher bonding interface.
4. Surface Properties: Flake graphite has low surface tension, is defect-free over large areas, and contains about 0.45% volatile organic compounds on its surface, reducing its wettability. Its strong hydrophobic surface makes the flowability of castables worse. Additionally, it tends to aggregate and cannot disperse evenly in refractory materials, making it challenging to prepare uniform and dense monolithic refractories. If not wetted, the flake graphite particles form aggregates, with the silicate liquid phase restricted to the particle gaps, creating isolated bodies that are difficult to sinter into fine composites at high temperatures.
5. Thermal Expansion: Upon heating, flake graphite can expand up to 300 times its volume, suffocating flames and producing expansion substances that can isolate flames, delaying or interrupting their spread. It is non-combustible, highly flexible, has high surface energy, and forms a strong carbonized layer.
6. Quality Assurance: Imported PerkinElmer testing equipment ensures advanced and stable product quality. We promise superior quality at competitive prices. Our battery-grade graphite powder boasts high quality.

Through the above content, we now have a better understanding of the precautions for using flake graphite. It will no longer seem unfamiliar, and its use will be less problematic. That’s all for today’s content. Stay tuned for more exciting knowledge points in the future.