Nomenclature
CAS number: 1305-78-8
Lime; burnt lime; calx; quicklime.
CaO; mol wt 56.08.
Ca 71.47%, O 28.53%.
Description and references
Properly stored lime of commerce contains 90-95%
free CaO. Commercial production from limestone: W. L. Faith et al., Industrial Chemicals (John Wiley, New York, 3rd ed., 1965) pp 482-487. Lab prepn by
ignition of CaCO3: Ehrlich in Handbook of Preparative Inorganic Chemistry vol.
1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963)
p 931. Review: R. S. Boynton in Kirk-Othmer Encyclopedia of Chemical Technology vol. 14 (Wiley-Interscience, New York, 3rd ed., 1981) pp 343-382.
Properties
Crystals, white or grayish-white lumps, or granular
powder; commercial material sometimes has a yellowish or brownish
tint, due to iron. mp 2572°; bp 2850°; d 3.32-3.35. Readily absorbs
CO2 and H2O from air, becoming air-slaked.
Sol in water forming Ca(OH)2 and generating a large quantity
of heat; sol in acids, glycerol, sugar soln; practically insol in
alc. Corrosive. Keep tightly closed and dry.Caution
Potential symptoms of overexposure
are irritation of eyes, skin, upper respiratory tract; ulceration
or perforation of nasal septum; pneumonia; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 48.Use
In bricks, plaster, mortar, stucco and other building
and construction materials; manuf of steel, aluminum, magnesium, and
flotation of non-ferrous ores; manuf of glass, paper, Na
2CO
3 (Solvay process), Ca salts and many other industrial
chemicals; dehairing hides; clarification of cane and beet sugar juices;
in fungicides, insecticides, drilling fluids, lubricants; water and
sewage treatment; in laboratory to absorb CO
2 (the combination
with NaOH is known as
soda-lime,
q.v.).