Silica sol for special building materials

#Application ·2025-08-21 16:54:32

• Characteristics
  • Small particle size and uniform distribution: The particle size of special building materials dedicated silica sol is usually between a few nanometers and tens of nanometers, and the distribution is relatively uniform. For example, LUDOX® silica sol products are solid spherical nano-scale amorphous silica dispersed in water, and usually have a narrow particle size distribution.
  • Good high-temperature resistance: Silica sol can remain stable at high temperatures and can withstand temperatures ranging from 1200 to 1700℃, making it an irreplaceable high-temperature binder in the refractory materials industry.
  • Strong adhesion: Silica sol can firmly adhere to solid surfaces and form a strong film. It can function by itself without the need for a curing agent, and the film-forming temperature is very low.
  • High stability: Silica sol has coalescence stability and kinetic stability. Its particles are nearly spherical and negatively charged. Coupled with sufficient solvent barriers, it is less likely to precipitate or stratify during storage and use.
  • Good environmental friendliness: Silica sol is a water-based system, odorless, non-toxic, and free of harmful chemicals. It does not release any harmful substances during use, meeting modern environmental protection requirements.
• Function and Application
  • In the field of refractory materials: As a binder for unshaped refractory materials, such as in the castables and plastic materials of high-temperature parts like the lining of steelmaking furnaces and the inner lining of ladles, at room temperature, through water evaporation or the addition of curing agents, silica sol colloidal particles coagulate to form a SiO₂ gel network, providing initial strength. At high temperatures, the gel dehydrates and sinteres, chemically bonding with refractory aggregates to maintain high-temperature strength. Meanwhile, silica sol can also be used for coating and surface modification of refractory materials, enhancing their resistance to slag erosion, oxidation and thermal shock. It can also be used to prepare special refractory materials and composite products such as ceramic fiber products and refractory ceramic cores.
  • In the field of concrete: Nanoparticles in silica sol can fill the fine pores in cement paste, enhance the structural stability of the paste, and improve the pumpability and construction fluidity of concrete. Meanwhile, silica sol can promote the hydration process of cement, accelerate the formation rate of gel, shorten the setting time and enhance the early strength. During the curing and hardening stage, silica sol continuously fills the capillary pores, enhancing the compactness and impermeability of the concrete, and strengthening its resistance to erosion by freeze-thaw cycles and chloride ions.
  • In the field of coatings: Silica sol can be used as the base material for architectural coatings, which can make the coating firm, have good adhesion, and also has functions such as anti-fouling and dust-proofing, anti-aging, and fire resistance. For instance, silica sol can be compounded with emulsion to produce exterior wall coatings, waterproof coatings, etc. When used in combination to produce anti-corrosion coatings and zinc-rich paints, it can enhance water resistance.
  • In the field of precision casting, silica sol is an excellent binder for the overall molding of precision casting. It is convenient to prepare coatings, the strength of the mold shell is high, and the surface finish of the casting is good, which can greatly improve the quality and dimensional precision of the casting.
  • In the field of cold-rolled silicon steel sheets: The use of inorganic insulating coatings mainly based on silica sol can provide insulation between silicon steel sheets, preventing metal oxidation and corrosion.