What is the Difference Between Fumed Silica and Silica Fume?

Bisley InternationalFAQs

concrete industry

When it comes to the world of construction materials and industrial applications, the terminology can sometimes be confusing. Two terms that often get mixed up are “fumed silica” and “silica fume”. While they might sound similar, they are distinct materials with different properties, production methods, and applications.

Production Differences

  • Fumed Silica: Also known as pyrogenic silica, fumed silica is produced through a flame process where silicon tetrachloride reacts with oxygen at high temperatures. The result is ultra-fine, pure, and amorphous silicon dioxide particles. These particles are primarily spherical in shape.
  • Silica Fume: This is a byproduct of producing silicon metal or ferrosilicon alloys. When silicon tetrachloride is reduced in an electric furnace, silica fume is released as a byproduct. Unlike fumed silica, silica fume particles are not entirely spherical.

Key Properties

  1. Particle Size: Fumed silica particles are typically larger than those of silica fume. This difference in particle size affects how each material interacts with other substances and their overall performance in various applications.
  2. Specific Surface Area: Due to its smaller particle size, fumed silica generally has a higher specific surface area compared to silica fume. This means it can cover a larger area when dispersed in a medium, making it particularly valuable in certain applications.
  3. Bulk Density: Fumed silica has a lower bulk density compared to silica fume. This makes it lighter and can influence its behavior in mixtures.

Applications in Concrete, Plastic, and Coatings

  1. Concrete: Silica fume is often used as a supplementary cementitious material in concrete. Its small particle size allows it to fill the spaces between cement particles, leading to high-strength concrete. On the other hand, fumed silica can be used to control the rheology of cement-based materials, improving workability. Learn more.
  2. Plastic: Fumed silica acts as a reinforcing filler in plastics. Its spherical particles help increase the plastic’s tensile strength and improve its overall durability. Learn more.
  3. Coatings: In coatings, fumed silica is used to adjust the viscosity, preventing sagging and ensuring a smooth application. Its high specific surface area allows it to effectively thicken and stabilize formulations. Learn more.

In Conclusion

While fumed silica and silica fume might sound similar, understanding their differences is crucial for their effective application in various industries. From their production methods to their unique properties and applications, these materials play a pivotal role in enhancing the quality and performance of numerous products.

For those in the market for high-quality fumed silica, silica fume, or related products, Bisley International is your go-to supplier. We pride ourselves on offering a diverse range of high-quality materials tailored to your needs. So, whether you’re looking to supply, have a specific requirement, or simply want to browse our range, Bisley International has got you covered.