Silica (Partner Lead: EVONIK)

Real-time in-situ monitoring of the genesis of nanostructured silica
under different precipitation conditions.

The initial materials for obtaining silica by a wet process are solutions of alkali silicate, preferably sodium silicate, from which amorphous silica is precipitated by adding acid. The silica suspension is conveyed to filter presses in which salts, formed as a result of the precipitation is washed out.

The filter cake still contains considerable quantities of water, making it necessary to evaporate up to six times the amount by weight of water in the drying stage. For this reason, drying accounts for a considerable portion of the production costs. Drying is carried out depending on the target properties of the final products. After filtration washing and drying, the precipitated product consists of 86-88% SiO2 and 10 -12% water; the latter being present both in the molecular structure and physically found on the surface. The drying process is frequently followed by grinding, classifying and/or granulating steps.

Figure 1: Production steps

Silica can be designed and tailored to a wide range of applications.
Our precipitated silica benefits a wide variety of industries:

  • Tires
  • Chemical industry
  • Rubber additives
  • Fire extinguishers
  • Superabsorbents
  • Defoamer/antifoam agents
  • Printing inks
  • Paints and coatings
  • Feed additives
  • Plastics industry
  • Paper products
  • Newsprint
  • Inkjet coating
  • Thermal paper
  • Plant protection
  • Pharmaceutical industry
  • Polyester resins (unsaturated)
  • Silicone rubber
  • Detergent additives