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Rotary lime kiln (rust-colored horizontal tube at right) with preheater, Wyoming, 2010 Traditional lime kiln in Sri Lanka. A lime kiln is a kiln used for the calcination of limestone (calcium carbonate) to produce the form of lime called quicklime (calcium oxide). The chemical equation for this reaction is: CaCO 3 + heat → CaO + CO 2
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.
The necessary ammonia "catalyst" for reaction (I) is reclaimed in a later step, and relatively little ammonia is consumed. The carbon dioxide required for reaction (I) is produced by heating (" calcination ") of the limestone at 950–1100 °C, and by calcination of the sodium bicarbonate (see below).
Limestone is the raw material for production of lime, primarily known for treating soils, purifying water and smelting copper. Lime is an important ingredient used in chemical industries. [ 110 ] Limestone and (to a lesser extent) marble are reactive to acid solutions, making acid rain a significant problem to the preservation of artifacts made ...
In the lime industry, limestone is a general term for rocks that contain 80% or more of calcium or magnesium carbonate, including marble, chalk, oolite, and marl.Further classification is done by composition as high calcium, argillaceous (clayey), silicious, conglomerate, magnesian, dolomite, and other limestones. [5]
Calcium carbonate (limestone or chalk) decomposes into calcium oxide and carbon dioxide when heated. The chemical reaction is as follows: CaCO 3 → CaO + CO 2 The reaction is used to make quick lime, which is an industrially important product. Another example of thermal decomposition is 2Pb(NO 3) 2 → 2PbO + O 2 + 4NO 2.
The limestone blocks were then crushed, afterwards slaked (the process of adding water and constantly turning the lime to create a chemical reaction, whereby the burnt lime, or what is known also as calcium oxide, [7] is changed into calcium hydroxide), and mixed with an aggregate to form an adhesive paste (plaster) used in construction and for ...
Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide (SO 2) from exhaust flue gases of fossil-fuel power plants, and from the emissions of other sulfur oxide emitting processes such as waste incineration, petroleum refineries, cement and lime kilns.