Advantages Of Using Colloidal Silica & Gel Bond In Monolithic Refractories

This bonding works by creating a gel out of a solid. A network skeleton surrounds the refractory Aggregates and, through further heating, develops strength. Finally, the network skeleton is sintered to form ceramic bonding. Thixotropy refers to the fact that certain substances can change their state when they are agitated. Thixotropy’s phenomenon is based on the theory that ultrafine powders are dispersed and flocculated. There are many different sols available for bonding. Silica (Alumina, Zircon) and Titania can all be used in the bonding process. The incorporation of gel bond (High Alumina Resistive Cement) instead of the conventional binder has allowed castable refractories to have significantly improved high-temperature properties.

Gel Bond Offers Many Benefits

There are several benefits to gel-bond compositions compared to LCC & ULCC.

  • Requires no other minor additives/deflocculants.
  • Faster drying times, and therefore fewer drying flaws. This is possible because water isn’t added or required to mix.
  • Improved refractoriness as a result of the absence of low melting stages like- anorthite/gehlinite.
  • Since colloidal silica has a viscosity that is higher than water, it allows for more separation between refractory and reactive particles, which results in better thermal shock resistance.
  • Increased chemical resistance
  • Gel bond castables/pumpable offer superior performance and longer campaign duration. They also have lower downtime and cost to operate the furnace.
  • It has a longer shelf life than LCC or ULCC because it does not contain a hydratable component.

Gel Bond Castables/Pumables

Gel bond castings / pumpable give better results for almost all types of industries.

  • In cement industries, high-temperature rotary fire zone, rotary-kiln incinerators line
  • in the glass industries – outside of the Glass Melting Tank furnace. Sidewalls and roofs
  • in Blast furnace funnel – these can be easier installed by a pump, which has a shorter installation time.
  • in Torpedo & other transfer ladles, Tundish backup lining, Electric Furnace Deltas, and Runners

Collodial silica refractory (or Silica Sol) is a stable solution of amorphous silica. This requires that silica particles are small enough to not be affected by gravity. Silica particles usually have sizes of less than 100 micrometers. Colloid silica was used initially in refractories as a coating agent in various applications like investment casting and ingot cast. In monolithic resins, colloidal silica became a bonding agent during the ’80s. Colloid silica refractories were introduced to the market in the late 1980s. They are available in ramming or gunning formulations. The breakthrough in refractory technologies has been the gel bond refractories, which use colloidal silica as the bonding agent. Because the colloidal silicona used in refractories was commercially available, many were able to take advantage. Colloidal silica may be used instead of conventional binding agents in monolithic and monolithic materials like castables, gunning mixes, and even ramming. Its use in castings has made it possible to pump refractory solutions, which offers a significant advantage over conventional binders.

 Another advantage is the fact that, unlike calcium Aluminate Cement Bonded Refractories, they don’t need to follow specific temperature parameters for drying. This helps reduce installation time and drying flaws. Not only are they more efficient and less expensive to operate, but they also pose no dangers for workers.

Advantages Of Using Colloidal Silica & Gel Bond In Monolithic Refractories
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