Atomic Number: 30
Atomic Symbol: Zn
Atomic Weight: 65.38
Melting Point: 787.1 F (419.5 C)
Boiling Point: 1,664.6 F (907 C)
Word origin: Zinc comes from the German Zink, but little is known of how the term originated.
Discovery: Zinc has been used for thousands of years to make brass products. Evidence of zinc alloys were found in prehistoric ruins in Transylvania. It was first produced as a metal in 13th century India by reducing zinc carbonate (smithsonite) or zinc silicate (calamine) with organic substances like wool. Zinc was rediscovered in Europe in 1746 by Andreas Sigismund Marggraf, who obtained zinc by reducing calamine with charcoal.
Properties of zinc
Zinc is a bluish-white metal and a fair conductor of electricity. Zinc can be brittle but at 212 to 302 F (100 to 150 C) it becomes malleable. Zinc has super-plastic properties. At temperatures below 35 Kelvin, a zinc-zirconium alloy, ZrZn2, can exhibit ferromagnetic properties. However, natural zinc and zirconium are not ferromagnetic. Zinc has unusual electrical, thermal, optical and solid-state properties that have yet to be explored. [See Periodic Table of the Elements]
Zinc has 16 unstable isotopes. Five stable isotopes are found in naturally occurring zinc.
Sources of zinc
Zinc ores include sphalerite (sulfide), smithsonite (carbonate), calamine (silicate), and franklinite (zinc, manganese, iron oxide).
One method of extracting zinc involves roasting the ore to form the oxide and reducing the oxide with carbon, with subsequent distillation of the metal.
Uses of zinc
Zinc is used to form alloys with a variety of metals. Some of these alloys are brass, nickel silver, typewriter metal, commercial bronze, spring bronze, German silver, soft solder and aluminum solder.
Because it resists corrosion, zinc is often plated to other metals in a process called galvanization and used in steel, nails, wire, pipe, etc.
Zinc oxide is found in many common products, including paint, plastics, rubber products, pharmaceuticals, floor coverings, inks, cosmetics, soap, batteries and textiles.
Zinc is used widely by the automotive and hardware companies to create die castings. A patented alloy, Prestal, is 78 percent zinc and 22 percent aluminum, is said to be as moldable as plastic while being as strong as steel. The alloy could be used to mold cement or ceramic die casts.
Zinc sulfide is a compound used to make glow dials, X-ray and TV screens and fluorescent lights.
Zinc is also a necessary nutritional element for humans and animals found easily in nuts, seeds and other food. Scientists say animals suffering from a zinc deficiency must eat about 50 percent more food to gain the same weight as an animal supplied with sufficient zinc.
(Source: Los Alamos National Laboratory)