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(German Zink, of obscure origin) Centuries before zinc was recognized as a distinct
element, zinc ores were used for making brass. Tubal-Cain, seven generations from Adam, is
mentioned as being an "instructor in every artificer in brass and iron." An
alloy containing 87 percent zinc has been found in prehistoric ruins in Transylvania.
Metallic zinc was produced in the 13th century A.D. in India by reducing calamine with
organic substances such as wool. The metal was rediscovered in Europe by Marggraf in 1746,
who showed that it could be obtained by reducing calamine with charcoal.
The principal ores of zinc are sphalerite (sulfide), smithsonite (carbonate), calamine
(silicate), and franklinite (zine, manganese, iron oxide). One method of zinc extraction
involves roasting its ores to form the oxide and reducing the oxide with coal or carbon,
with subsequent distillation of the metal.
Naturally occurring zinc contains five stable isotopes. Sixteen other unstable isotopes
Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but
malleable at 100 to 150oC.
It is a fair conductor of electricity, and burns in air at high red heat with evolution of
white clouds of the oxide.
It exhibits superplasticity. Neither zinc nor zirconium
is ferromagnetic; but ZrZn2
exhibits ferromagnetism at temperatures below 35oK. It has unusual electrical, thermal, optical, and solid-state
properties that have not been fully investigated.
The metal is employed to form numerous alloys with other metals. Brass, nickel silver,
typewriter metal, commercial bronze, spring bronze, German silver, soft solder, and
aluminum solder are some of the more important alloys.
Large quantities of zinc are used to produce die castings, which are used extensively
by the automotive, electrical, and hardware industries. An alloy called Prestal(R),
consisting of 78 percent zinc and 22 percent aluminum,
is reported to be almost as strong as steel and as easy to mold as plastic. The alloy said
to be so moldable that it can be molded into form using inexpensive ceramics or cement die
Zinc is also used extensively to galvanize other metals such as iron to prevent corrosion. Zinc oxide is a unique
and very useful material for modern civilization. It is widely used in the manufacture of
paints, rubber products, cosmetics, pharmaceuticals, floor coverings, plastics, printing
inks, soap, storage batteries, textiles, electrical equipment, and other products.
Lithopone, a mixture of zinc sulfide and barium sulfate, is an important pigment.
Zinc sulfide is used in making luminous dials, X-ray and TV screens, and fluorescent
The chloride and chromate are also important compounds. Zinc is an essential element in
the growth of human beings and animals. Tests show that zinc-deficient animals require 50
percent more food to gain the same weight as an animal supplied with sufficient zinc.
Zinc is not considered to be toxic, but when freshly formed ZnO is inhaled a disorder
known as the oxide shakes or zinc chills sometimes occurs. Where zinc oxide
is encountered, recommendations include providing good ventilation to avoid concentration
exceeding 5 mg/m3,
(time-weighted over an 8-hour exposure, 40-hour work week).
The price of zinc was roughly $0.70/lb in January 1990.
Sources: CRC Handbook of Chemistry
and Physics and the American Chemical Society.