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As it hydrates, an exothermic reaction results and the solid puffs up. The hydrate can be reconverted to quicklime by removing the water by heating it to redness to reverse the hydration reaction. One litre of water combines with approximately 3.1 kilograms (6.8 lb) of quicklime to give calcium hydroxide plus 3.54 MJ of energy.
To convert the oxide notation in LDH formula, the mass balance in the system has to respect the principle of the conservation of matter. Oxide ions (O 2−) and water are transformed into 2 hydroxide anions (OH −) according to the acid-base reaction between H 2 O and O 2− (a strong base) as typically exemplified by the quicklime slaking ...
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca 2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed with water. Annually, approximately 125 million tons of calcium hydroxide are produced worldwide. [8]
The theoretical heat (the standard enthalpy) of reaction required to make high-calcium lime is around 3.15 MJ per kg of lime, so the batch kilns were only around 20% efficient. The key to development in efficiency was the invention of continuous kilns, avoiding the wasteful heat-up and cool-down cycles of the batch kilns.
Lime is an inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. [1] The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. [2]
Hydraulic lime (HL) is a general term for a variety of lime different from calcium oxide (quicklime), that sets by hydration and consists of calcium silicate and calcium aluminate, compounds that can harden in contact with water. This contrasts with calcium hydroxide, also called slaked lime or air lime that is used to make lime mortar, the ...
Actual formula Name or mineral phase CH: Ca(OH) 2 or CaO · H 2 O: Calcium hydroxide (portlandite) C-S-H: 0.6–2.0 CaO · SiO 2 · 0.9–2.5 H 2 O, with variable composition within this range, and often also incorporating partial substitution of Al for Si: Calcium silicate hydrate: C-A-H: Phase more complex than C-S-H: Calcium aluminate ...
Calcium aluminates phase diagram Crystal structure of dodecacalcium hepta-aluminate, 12CaO·7Al 2 O 3 (C 12 A 7). [1] Calcium aluminates are a range of materials [2] obtained by heating calcium oxide and aluminium oxide together at high temperatures. They are encountered in the manufacture of refractories and cements.