Lime slaked

The mode of action of lime as a bonding agent is based on the reaction of calcium hydroxide with carbon dioxide in the air  

Quicklime must therefore be first converted into slaked lime  

Strength of hardened lime is based on intergrowth of CaCOj crystals 

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It is used for the preparation of benzaldehyde. For (his purpose it is usually heated with slaked lime and water under pressure. 

By addition of slaked lime, in calculated quantity for the par ticular degree of hardness (Clark s method) ... 

Its natural and prepared compounds are widely used. Quicklime (CaO), which is made by heating limestone that is changed into slaked lime by carefully adding water, is the great base of chemical refinery with countless uses. 

Mir-slaked lime contains various proportions of the oxides, hydroxides, and carbonates of calcium and magnesium which result from excessive exposure of quicklime to air that vitiates its quaUty. It is partially or largely decomposed quicklime that has become hydrated and carbonated. 

Slaked lime is a hydrated form of lime, available as a dry powder, putty, or aqueous suspension. 

The softened seawater is fed with dry or slaked lime (dolime) to a reactor. After precipitation in the reactor, a flocculating agent is added and the slurry is pumped to a thickener where the precipitate settles. The spent seawater overflows the thickener and is returned to the sea. A portion of the thickener underflow is recirculated to the reactor to seed crystal growth and improve settling and filtering characteristics of the precipitate. The remainder of the thickener underflow is pumped to a countercurrent washing system. In this system the slurry is washed with freshwater to remove the soluble salts. The washed slurry is vacuum-filtered to produce a filter cake that contains about 50% Mg(OH)2. Typical dimensions for equipment used in the seawater process may be found in the Hterature (75). 

Strontium hydroxide, Sr(OH)2, resembles slaked lime but is more soluble in water (21.83 g per 100 g of water at 100°C). It is a white dehquescent sohd with a specific gravity of 3.62 and a melting point of 375°C. Strontium soaps are made by combining strontium hydroxide with soap stocks, eg, lard, tallow, or peanut oil. The strontium soaps are used to make strontium greases, which are lubricants that adhere to metallic surfaces at high loads and are water-resistant, chemically and physically stable, and resistant to thermal breakdown over a wide temperature range (11). 

Caustic soda is removed from the carbonate—bicarbonate solution by treating with a slight excess of hard-burned quicklime (or slaked lime) at 85—90°C in a stirred reactor. The regenerated caustic soda is separated from the calcium carbonate precipitate (lime mud) by centrifuging or rotary vacuum filtration. The lime mud retains 30—35% Hquid and, to avoid loss of caustic soda, must be weU-washed on the filter or centrifuge. Finally, the recovered caustic solution is adjusted to the 10% level for recycle by the addition of 40% makeup caustic soda. 

Morta.r, Mortar, principally slaked lime and sand, sets because of the evaporation of water, the deposition of calcium hydroxide, and the absorption of water by the bricks or cement blocks, foUowed by hardening as a result of the absorption and reaction of carbon dioxide. 

In a batch process, NaOH is chlorinated in the presence of recycled neutral Ca(OCl)2 mother Hquor. After separation of salt, lime slurry is added and chlorinated (205). The Ca(OCl)2 2H20 crystals are recovered by filtration. In another version, classification of the Ca(OCl)2—NaCl slurry gives a Ca(OCl)2-rich fraction that is filtered and the filtrate recycled along with the NaCl-rich fraction to the first chlorinator (206). Also, 50% NaOH and soHd slaked lime are used in the second chlorination. 

The General Electric in-duct scmbbing (IDS) process involves the atomization of a slaked lime slurry, using a rotary disk atomizer A test at the 12 MWe scale at the Muskingum River Station of Ohio Power, performed in a duct with a 4.3-m cross section, achieved 50% SO2 removal with good lime utilization... 

Calcium hydroxide (Ca(OH)2 (slaked lime) ) White powder soluble in water yielding lime water. Alkaline... 

Ammonia can be made on a small scale by heating an intimate mixture of ammonium chloride and dry slaked lime in a ratio of 1 3, respectively ... 

A base is any material that produces hydroxide ions when it is dissolved in water. The words alkaline, basic, and caustic are often used synonymously. Common bases include sodium hydroxide (lye), potassium hydroxide (potash lye), and calcium hydroxide (slaked lime). The concepts of strong versus weak bases, and concentrated versus dilute bases are exactly analogous to those for acids. Strong bases such as sodium hydroxide dissociate completely while weak bases such as the amines dissociate only partially. As with acids, bases can be either inorganic or organic. Typical reactions of bases include neutralization of acids, reaction with metals, and reaction with salts ... 

Chemical Designations - Synonyms Slaked Lime Chemical Formula Ca(OH)2. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Corrosive to most metals with the evolution of flammable and explosive hydrogen gas Stability During Transport Stable Neutralizing AgerUs for Acids and Caustics Flush with water and apply powdered limestone, slaked lime, soda ash, or sodium bicarbonate Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Agents for Acids and Caustics Flush with water and apply powdered limestone, slaked lime, soda ash, or sodium bicarbonate Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Bleaching powder patented by C. Tennant (CI2 4- slaked lime) following preparation of bleaching liquors from CI2 and lime solutions by T. Henry (1788)... 

Atzkalk) m. caustic time (gebrannter) quicklime geldschter) slaked lime), -loeung) /. lime water. 

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