Zinc

Notable characteristics

Applications

• Zinc is used to galvanize metals such as steel to prevent their corrosion.
• Zinc is used in alloys such as brass, nickel silver, typewriter metal, various solder formulas, German silver, etc.
• Brass, in turn, has wide application because of its strength and corrosion resistance.
• Zinc is used in die castings, especially by the automobile industry.
• Rolled zinc is used as part of the containers of batteries.
• Zinc oxide is used as a white pigment in watercolors and paints, and as an activator in the rubber industry. As an over-the-counter ointment, it is applied as a thin coating on the exposed skin of the face and nose to prevent dehydration and thereby protect against sunburn in the summer and windburn in the winter. Applied thinly to a baby's diaper area (perineum) with each diaper change, it protects against rash. As determined in the Age-Related Eye Disease Study, it's part of an effective treatment for age-related macular degeneration in some cases.
• Zinc chloride is used as a deodorant and as a wood preservative.
• Zinc sulfide is used in luminescent pigments, for making the hands of clocks and other items that glow in the dark.
• Zinc methyl (Zn(CH₃)₂) is used in a number of organic syntheses.
• Zinc stearate is a lubricative plastic additive.
• Lotions made of calamine, a mix of Zn-(hydroxy-)carbonates and silicates, are used to treat skin rash.
• Zinc metal is included in most proprietary over-the-counter daily vitamin and mineral preparations. Along with some other metals, it is believed by some to possess anti-oxidant properties, which protect against premature aging of the skin and muscles of the body. In larger amounts, taken as zinc alone in other proprietaries, it is believed by some to speed up the healing process after an injury.
• Zinc gluconate glycine is taken in lozenge form as a remedy for the common cold.
  

  History

  
  Zinc alloys have been used for centuries, as brass goods dating to 1000-1400 BC have been found in Palestine and zinc objects with 87% zinc have been found in prehistoric Transylvania. Because of the low boiling point and chemical reactivity of this metal (isolated zinc would tend to go up the chimney rather than be captured), the true nature of this metal was not understood in ancient times.

Smelting and extraction of impure forms of zinc was being accomplished as early as AD 1000 in India and China. By the end of the 14th century, the Hindus were aware of the existence of zinc as a metal separate from the seven known to the ancients. In the West, the discovery of pure metallic zinc is most often credited to the German Andreas Marggraf, in the year 1746, though the whole story is considerably more involved.

Descriptions of brass manufacture are found in Western Europe in the writings of Albertus Magnus, c. 1248, and by the 16th century, the understanding and awareness of the new metal broadened considerably. Agricola observed, in 1546, that a white metal could be condensed and scraped off the walls of a furnace when zinc ores were smelted. He added in his notes that a similar metal called "zincum" was being produced in Silesia. Paracelsus (died 1541) was the first in the West to say that that "zincum" was a new metal and that it had a separate set of chemical properties from other known metals.

The upshot is that zinc was known by the time Marggraf made his discoveries and in fact zinc had been isolated two years earlier by another chemist, Anton von Swab. However, Marggraf's reports were exhaustive and methodical and the quality of his research cemented his reputation as the discoverer of zinc.

Before the discovery of the zinc sulfide flotation technique, calamine was the mineral source of zinc metal.

Biological role

According to some sources, taking zinc tablets may provide some immunity against colds and flu, although this is disputed.

Eyesight, taste, smell and memory are also connected with zinc and a deficiency in zinc can cause malfunctions of these organs and functions.

Natural food sources of zinc include oysters, red meat and poultry, beans, nuts, whole grains, pumpkin seed or sunflower seeds.

In males, zinc is important for the production of semen. Up to 5 mg of zinc is lost during ejaculation. Deficiencies in zinc in males can lead to reduced sperm count and sex drive. Frequent ejaculations can lead to zinc deficiency.

Abundance

Zinc Production

Compounds

Isotopes

Precautions

References