Search results
Results from the WOW.Com Content Network
Calcium oxide (formula: Ca O), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic , alkaline , crystalline solid at room temperature . The broadly used term lime connotes calcium-containing inorganic compounds , in which carbonates , oxides , and hydroxides of calcium, silicon , magnesium ...
Ettringite is the most common and prominent member of the AFt group (X in this case denoting sulfate), and often simply called Alumina Ferrite tri-sulfate (AFt). AFm: abbreviation for "alumina, ferric oxide, mono-substituted" or (Al 2 O 3 − Fe 2 O 3 − mono). It represents another group of calcium aluminate hydrates with general formula [Ca ...
Lime is an inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which is used as an industrial mineral and is made by heating calcium carbonate in a kiln. Calcium oxide can occur as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. [1]
The New York State Agricultural Experiment Station recipe for the concentrate suggests starting with 80 lb. of sulfur, 36 lb. of quicklime, and 50 gal. of water, equivalent to 19.172 kg of sulfur and 8.627 kg of calcium oxide per 100 litres of water. About 2.2:1 is the ratio (by weight) for compounding sulfur and quicklime; this makes the ...
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.
The heating agent and responsible reaction vary from product to product. Calcium oxide is used in the following reaction: CaO(s)+ H 2 O(l) → Ca(OH) 2 (s) Copper sulfate and powdered zinc can also be used, but this process is less efficient: CuSO 4 (s) + Zn(s) → ZnSO 4 (s) + Cu(s) Anhydrous calcium chloride is often used as well.
The root of the word calcination refers to its most prominent use, which is to remove carbon from limestone (calcium carbonate) through combustion to yield calcium oxide (quicklime). This calcination reaction is CaCO 3 (s) → CaO(s) + CO 2 (g). Calcium oxide is a crucial ingredient in modern cement, and is also used as a chemical flux in smelting.
3 A) with calcium sulfate, both present in Portland cement. [15] C 3 A + 3 CaSO 4 + 32 H 2 O → ettringite. Ettringite, the most prominent representative of AFt phases or (Al 2 O 3 − Fe 2 O 3 − tri), can also be directly synthesized in aqueous solution by reacting stoichiometric amounts of calcium oxide, aluminium oxide, and sulfate.