Calcium silicate
| Names | |
|---|---|
| IUPAC name
Calcium silicate
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| Other names
Calcium orthosilicate, silicic acid calcium salt, grammite, silene, micro-cell, belite
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.014.282 |
| E number | E552 (acidity regulators, ...) |
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| Ca2SiO4 | |
| Molar mass | 116.16 g/mol |
| Appearance | White or cream powder |
| Melting point | 1,540 °C (2,800 °F; 1,810 K) |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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Irritant |
| NFPA 704 (fire diamond) | |
| Flash point | Not applicable |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Calcium silicate (often referred to by its shortened trade name Cal-Sil or Calsil) is the chemical compound Ca2SiO4, also known as calcium orthosilicate and sometimes formulated 2CaO.SiO2. It is one of group of compounds obtained by reacting calcium oxide and silica in various ratios[1] e.g. 3CaO.SiO2, Ca3SiO5; 2CaO.SiO2, Ca2SiO4; 3CaO.2SiO2, Ca3Si2O7 and CaO.SiO2, CaSiO3. Calcium orthosilicate is a white powder with a low bulk density and high physical water absorption. It is used as an anti-caking agent and an antacid. A white free-flowing powder derived from limestone and diatomaceous earth, calcium silicate has no known adverse effects to health[citation needed]. It is used in roads, insulation, bricks, roof tiles, table salt[2] and occurs in cements, where it is known as belite (or in cement chemist notation C2S).
High temperature insulation
Calcium silicate is commonly used as a safe alternative to asbestos for high temperature insulation materials. Industrial grade piping and equipment insulation is often fabricated from calcium silicate. Its fabrication is a routine part of the curriculum for insulation apprentices. Calcium silicate competes in these realms against rockwool as well as proprietary insulation solids, such as perlite mixture and vermiculite bonded with sodium silicate. Although it is popularly considered an asbestos substitute, early uses of calcium silicate for insulation still made use of asbestos fibers.
Passive fire protection
One of the most successful materials in fireproofing in Europe is calcium silicate. Where North Americans use spray fireproofing plasters, Europeans are more likely to use cladding made of calcium silicate. Calcium silicate is easily damaged by water. Therefore, silicone treated sheets are available to fabricators to mitigate potential harm from high humidity or general presence of water. Fabricators and installers of calcium silicate in passive fire protection often also install firestops.
Calcium silicate in the steel industry
It is also a constituent of the slag that is produced when molten iron is made from iron ore and calcium carbonate in a blast furnace.
As a product of sealants
When sodium silicate is applied as a sealant to cured concrete or the shells of fresh eggs, it chemically reacts with calcium hydroxide or carbonate to form calcium silicate hydrate, sealing pores with a relatively impermeable material.
References
- ^ H F W Taylor, Cement Chemistry, Academic Press, 1990, ISBN 0-12-683900-X, p 33-34
- ^ http://www.mortonsalt.com/faqs/food_salt_faq.html#q6