Calcium oxide
Calcium oxide CaO, is a chemical compound of calcium and oxygen. It is also known as lime or quicklime, a white or grayish white solid produced in large quantities through the roasting of calcium carbonate so as to drive off carbon dioxide (calcination). At room temperature, CaO will spontaneously absorb carbon dioxide from the atmosphere, reversing the reaction, and absorb water, converting itself into calcium hydroxide and releasing heat. It is called quick or living lime because of the bubbling that occurs during the reaction.
The phrase limelight comes from its use as stage lighting, as when heated to incandescence in an oxyhydrogen flame -a brilliant white light is emitted. It is also sometimes used directly as a fertilizer but is best-known as an alternative to cementitious based mortars, renders and bases.
In large amounts it is used to produce calcium carbide, CaC2 or carbide, (calcium acetylide). This compound decomposes in water, forming acetylene gas which is flammable and calcium hydroxide, Ca(OH)2. It can be used to produce acetylene fuel for welding and it can be used for carbide lamps, such as those used lighthouses. Calcium carbide also is used to make calcium cyanamide, CaCN2, a fertilizer component and starting material for certain plastic resins.
[edit] Related articles on Designing Buildings
Featured articles and news
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
New project and cultural district described in detail.
The nature of EPCs, crticism and inaccuracies.
History, issues and redesign.
From waste recycling to energy performance the hierchy.
An introduction to WERCS and WEEE responsibilities
Dealing with 2 million tonnes of waste equipment a year.
Global BACS Market: analytics and optimisation
A BSRIA glance at building automation and control systems.
What it is and how to use it.
Types of insulating plaster by binder and insulant.
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.
For the World Autism Awareness Month of April.