What is Silica / silicon-dioxide?
Silicon dioxide, also known as silica (from the Latin silex), is a chemical compound that is a dioxide of silicon with the chemical formula SiO2. It has been known since ancient times. Silica is most commonly found in nature as quartz, as well as in various living organisms. Silica is one of the most complex and most abundant families of materials, existing both as several minerals and being produced synthetically. Notable examples include fused quartz, crystal, fumed silica, silica gel, and aero gels. Applications range from structural materials to microelectronics to components used in the food industry.
Silicon dioxide is obtained by mining and purification of the resulting mineral. Quartz comprises more than 10% by mass of the earth's crust. Commercial silicon dioxide is also produced, almost always via the processing of quartz, synthetically on a very large scale. An estimated 95% of silicon dioxide produced is consumed in the construction industry, e.g. for the production of cement. Silica is used primarily in the production of glass for windows, drinking glasses, beverage bottles, and many other uses. The majority of optical fibers for telecommunication are also made from silica. It is a primary raw material for many ceramics such as earthenware, stoneware, and porcelain. Silicon dioxide is also used to produce elemental silicon. The process involves carbothermic reduction in an electric arc furnace.
A silica-based aero gel was used in the Stardust spacecraft to collect extraterrestrial particles. Silica is also used in the extraction of DNA and RNA due to its ability to bind to the nucleic acids under the presence of chaotropes. As hydrophobic silica it is used as a defoamer component. In hydrated form, it is used in toothpaste as a hard abrasive to remove tooth plaque.
In its capacity as a refractory, it is useful in fiber form as a high-temperature thermal protection fabric. In cosmetics, it is useful for its light-diffusing properties and natural absorbency. It is also used as a thermal enhancement compound in ground source heat pump industry.
Chemical Composition :
Physical Properties :
|Appearance||: White free flowing powder|
|Oil absorption||: 25 to 35%|
|Sp. gravity||: 2.6-2.7|
|Refractive index||: 1.55|
|Loss on ignition||: 0.3% max|
|PH of 10% aqueous solution.||: 7 (neutral)|
Industrial Applications :
- Glass & Pottery : Silica is used in bulk in glass industry, Ferro silicon, Ferro alloys, welding rods, pottery industries. It is also used in making silica Ferro manganese alloys.
- Paints : In wood finish, primers, undercoats, water based paints, distemper, chemical resistance coating, floor coatings etc. It is recommended for texture coating and exterior finishes and .
- Plastic & Rubber : Silica is used as a filler in plastic industry.
- Construction : Silica is also used in construction of Cement and chemicals for spray plasters.
- Food and pharmaceutical : Silica is a common additive in the production of foods, where it is used primarily as a flow agent in powdered foods, or to absorb water in hygroscopic applications. It is the primary component of diatomaceous earth. Colloidal silica is also used as a wine, beer, and juice fining agent. In pharmaceutical products, silica aids powder flow when tablets are formed.
Our Suggested Grades :
|Grade||Particle Size||Top Cut||Iron Content||Application|
|Silica-10||10 micron||40||less than 3%||Glass, Paints|
|Silica-20||20 micron||50||less than 3%||Plastics, Food, Pharmaceutical|
|Silica-50||50 Micron||75||less than 3%||Construction, Rubber|