Zinc is a chemical element with the symbol Zn. It is a low-melting metal thatbelongs to Group IIb (zinc group) of the periodic table. The atomic number ofzinc is 30. With an atomic weight of 65.
39, zinc makes up an average of 65 gramsof every ton of Earth’s crust, which makes it a little more abundant thancopper. The melting point of zinc is 420 degrees Celsius and its boiling pointis 907 degrees Celsius (Britannica Online). Zinc is the second most common tracemetal, after iron, that is found naturally in the human body. It is also thethird 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 ofzinc in his or her lifetime.
Metallic zinc appeared much later in history thanthe other common metals. “The Ancient Egyptians were the first to use zincalthough they did so unintentionally! They made their brass from copper oresthat were contaminated with zinc” (Knapp, 4). There is some evidence thatthe Greeks knew of zinc’s existence. They called it pseudargyras, or “falsesilver,” but they had no method of producing it in quantity. The Romansproduced considerable quantities of brass, an alloy of zinc and copper, as earlyas 200 B.C.
The metallurgists of India seem to have isolated the individualmetal as early as the 13th century; and by the 16th century, China had achievedlarge-scale production. In the West, commercial zinc production got under way bythe middle of the 18th century in England under the leadership of WilliamChampion (Britannica Online). The first complete study of zinc was published in1746 by Sigismund Marggraf, a German chemist (World Book). Canada is the leadingproducer of zinc followed by Australia, China, Peru, the U.S. and Mexico. In theU.S.
, mine production comes mostly from Alaska, Tennessee, New York, andMissouri (World Almanac, 151). There are 47 tons of zinc in one cubic mile ofseawater. Zinc deposits occur in two quite different ways: first, ashydrothermal or contact metamorphic deposits, and second, as sedimentarydeposits.
Zinc was used as a component of brass until the 18th century. Morethan 50% of production is consumed in the preparation of alloys for die-castproducts, and in anticorrosion treatment of iron and steel (Skinner, 19). Alarge 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.” Thesesheets are used in the manufacture of many roofing products, refrigeratorlinings, and printing plates. The compounds of zinc have numerous uses.
Becauseof its high heat conductivity, zinc oxide is used in rubber as a heatdissipater. It is also used in the making of cosmetics, plastics, skinointments, and soaps. Zinc sulfate is used in weed killers. Zinc sulfide hasbeen used in X-ray screens and in luminous dials for clocks and watches(Compton’s Encyclopedia). Zinc is also used in electric batteries and isrequired for the normal growth and healing of plants and animals.
Zinc can alsobe 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.
Andnickel silver is copper, nickel, and zinc (World Book). The following statisticsare stated in the U.S. Geological survey, U.S. Dept. of the Interior.
As ofmid-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 275,8831960 395,013 1990 515,355 1965 554,429 1991 517,804 1970 484,560 1992 523,4401975 425,792 1993 488,283 1980 317,103 1994 570,162 1985 226,545 1995 601,000 In1950 the total production of zinc was 565,515 thousand metric meters. Theestimated total reserves for 1950 was 85,000,000 metric tons, but that wasbefore the enormous amount of native zinc was discovered in Australia (Skinner,62). In the year 2000, the projected total of zinc production is 550,000thousand metric meters and the total world reserve will be at an estimated320,500,000 metric tons.
In the year 2050, I expect the total production of zincto be around significantly greater than it was 100 years from then. Fromexamining the chart above, I have come to the conclusion that the world reservewill not be that greatly affected (considering the increasing