Information AboutCalcium Oxide |
| CATEGORIES ABOUT CALCIUM OXIDE | |
| oxides | |
| calcium compounds | |
| bases | |
| limestone | |
| alchemical substances | |
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Calcium oxide ('''CaO'''), commonly known as '''burnt lime''', '''caustic lime''', '''lime''' or '''quicklime''', is a widely used Chemical Compound . It is a white, Caustic and Alkali ne Crystalline solid. As a commercial product lime often also contains Magnesium oxide, Silicon oxide and smaller amounts of Aluminium oxide and Iron oxide. ) in a Lime Kiln . This is accomplished by heating the material to above 825° C ,Merck Index of chemicals and Drugs , 9th ed. monograph 1650 a process called Calcination or ''lime-burning'', to liberate a molecule of Carbon Dioxide (CO2); leaving CaO. This process is reversible, since once the quicklime product has cooled, it immediately begins to absorb Carbon Dioxide from the air, until, after enough time, it is completely converted back to Calcium Carbonate . Calcination of limestone is one of the first chemical reactions discovered by man and was known in Prehistory . USAGE As hydrated or ), it is used in Mortar and Plaster to increase the rate of hardening. Hydrate d lime is very simple to make as lime is a basic Anhydride and reacts vigorously with Water . Lime is also used in Glass production and its ability to react with silicates is also used in modern metal production ( Steel , Magnesium , Aluminium and other non-ferrous metals) industries to remove impurities as Slag . It is also used in water and sewage treatment to reduce Acid ity, to soften, as a Flocculant , and to remove Phosphate s and other impurities; in Paper making to dissolve Lignin , as a Coagulant , and in Bleach ing; in agriculture to improve acidic Soil s; and in Pollution control, in gas scrubbers to Desulfur ize waste gases and to treat many liquid effluents. It has traditionally been used in the burial of bodies in open graves, to hide the smell of decomposition, as well as in forensic science, to reveal fingerprints. It is a refractory and a dehydrating agent and is used to purify Citric Acid , Glucose , Dye s and as a CO2 absorber. It is also used in Pottery , Paint s and the food industry. Furthermore, quicklime is used in epidemics, plagues, and disasters to disintegrate bodies in order to help fight the spread of disease. CaO is a key ingredient in the '' Nixtamalization '' process used to create Corn Hominy and Masa or tortilla dough. A relatively inexpensive substance, CaO produces Heat Energy by the formation of the hydrate, as in the following equation:US Patent 3,955,554, '' Solar heating system.'' ::CaO + H2O ↔ Ca(OH)2 + 488 BTU/lb of CaO The hydrate can be reconverted to calcium oxide by removing the water in the reversible equation. If the hydrated lime is heated to redness, the CaO will be regenerated to reverse the reaction. As it hydrates, an exothermic reaction results. One pound of water combines with approximately 3 1/9 pounds of calcium oxide to give calcium hydroxide plus 1618 BTU 's of energy. This process can be used to provide a convenient portable source of heat, as for on-the-spot food warming in a Self-heating Can . World lime annual production is around 130 million tonnes, with the USA and China the largest producers, each producing around 20 million tonnes. {Link without Title} SEE ALSO EXTERNAL LINKS
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