FREE ESSAY ON ZINC

ZINC

ZINC by JASON GOMEZ
Zinc is a chemical element with the symbol Zn. It is a low-melting metal that belongs to
Group IIb (zinc group) of the periodic table. The atomic number of zinc is 30. With an
atomic weight of 65.39, zinc makes up an average of 65 grams of every ton of Earth's
crust, which makes it a little more abundant than copper. The melting point of zinc is
420 degrees Celsius and its boiling point is 907 degrees Celsius (Britannica Online).
Zinc is the second most common trace metal, after iron, that is found naturally in the
human body. It is also the third most used nonferrous metal (after aluminum and copper),
of which the U.S. consumes more than one million metric tons annually (American Zinc
Association). According to the U.S. Bureau of Mines, the average person will use 730
pounds of zinc in his or her lifetime.
Metallic zinc appeared much later in history than the other common metals. The Ancient
Egyptians were the first to use zinc although they did so unintentionally! They made
their brass from copper ores that were contaminated with zinc (Knapp, 4). There is some
evidence that the Greeks knew of zinc's existence. They called it pseudargyras, or false
silver, but they had no method of producing it in quantity. The Romans produced
considerable quantities of brass, an alloy of zinc and copper, as early as 200 B.C. The
metallurgists of India seem to have isolated the individual metal as early as the 13th
century; and by the 16th century, China had achieved large-scale production. In the West,
commercial zinc production got under way by the middle of the 18th century in England
under the leadership of William Champion (Britannica Online). The first complete study of
zinc was published in 1746 by Sigismund Marggraf, a German chemist (World Book).
Canada is the leading producer of zinc followed by Australia, China, Peru, the U.S. and
Mexico. In the U.S., mine production comes mostly from Alaska, Tennessee, New York, and
Missouri (World Almanac, 151). There are 47 tons of zinc in one cubic mile of seawater.
Zinc deposits occur in two quite different ways: first, as hydrothermal or contact
metamorphic deposits, and second, as sedimentary deposits. Zinc was used as a component
of brass until the 18th century. More than 50% of production is consumed in the
preparation of alloys for die-cast products, and in anticorrosion treatment of iron and
steel (Skinner, 19). A large share of the zinc produced today is used for galvanizing
iron and steel (that is, coating them with zinc to make them rustproof). For many
purposes, zinc is simply flattened into sheets called rolled zinc. These sheets are used
in the manufacture of many roofing products, refrigerator linings, and printing plates.
The compounds of zinc have numerous uses. Because of its high heat conductivity, zinc
oxide is used in rubber as a heat dissipater. It is also used in the making of cosmetics,
plastics, skin ointments, and soaps. Zinc sulfate is used in weed killers. Zinc sulfide
has been used in X-ray screens and in luminous dials for clocks and watches (Compton's
Encyclopedia). Zinc is also used in electric batteries and is required for the normal
growth and healing of plants and animals. Zinc can also be combined with other metals to
form many other alloys (mixtures). For example, brass is an alloy of copper and zinc.
Bronze is copper, tin, and zinc. And nickel silver is copper, nickel, and zinc (World
Book). 
The following statistics are stated in the U.S. Geological survey, U.S. Dept. of the
Interior. As of mid-1996, the world mineral reserve for zinc was 330 million metric
tons.
U.S. Zinc Production, 1950-95 (in thousand metric tons)
1950 565,516 1989 275,883
1960 395,013 1990 515,355
1965 554,429 1991 517,804
1970 484,560 1992 523,440 
1975 425,792 1993 488,283
1980 317,103 1994 570,162
1985 226,545 1995 601,000
In 1950 the total production of zinc was 565,515 thousand metric meters. The estimated
total reserves for 1950 was 85,000,000 metric tons, but that was before the enormous
amount of native zinc was discovered in Australia (Skinner, 62). In the year 2000, the
projected total of zinc production is 550,000 thousand metric meters and the total world
reserve will be at an estimated 320,500,000 metric tons. In the year 2050, I expect the
total production of zinc to be around significantly greater than it was 100 years from
then. From examining the chart above, I have come to the conclusion that the world
reserve will not be that greatly affected (considering the increasing amount of
technology that is available to us and the large amount of the total reserves today). The
mineral zinc has not been over mined since its existence, and I do not expect it to be
completely exhausted by the year 2050. I think that in the year 2050 the world is going
to be completely different as we know it. I expect the downfall of computers to be solved
by then and a huge increase in the industrial development. Hence, creating a greater
demand for all resources including zinc.
Work cited 
Knapp, Brian; Zinc,Cadium,and Mercury. New York: Atlantic Europe Publishing Company
Limited, 1996.
Rosenbaum, Garvin; World Without Plenty. Skokle, Ill: National Textbook Co.,1975.
Skinner, Brian; Earth Resources. New Jersey: Prentice Hall Inc., 1969.
Matthews, Robert; Beyond 2000. Providence, RH: Global Dynamics Press, 1989.
The World Almanac. United States: K-III Reference Corporation, 1996.
Zinc Compton's Encyclopedia Online. *http://www.optonline.com/comptons/ceo* 
Zinc group elements Encyclopedia Britannica Online. *http://www.members.eb.com/bol/*
American Zinc Association *http://www.org/zincfacts.html
World Book http:// medusa.fs.altip.oclc.org/