Information on Zinc

ZINC (Zn)

Zinc is a versatile element that we encounter in our daily lives. It is found in a variety of products including zinc creams, sunblocks and vitamins. However, zinc is primarily used for the galvanizing of steel, die-castings, and in the production of brass and zinc oxides.

History

Brass, a zinc copper alloy has been used by numerous cultures (Chinese, Indians, Greeks, and Romans) in ancient times. Recognition and smelting of the metal is recent compared to the other common metals. Recoginition of the metal occurred between the 14th and 16th centuries and it attributed to Agricola (1490-1555) and Paracelsus (1493-1541) whom both spoke of a metal they referred to as “zinke”. The name “Zinc” is generally considered to be derived from the German word “zinke” meaning pointed with reference to the pointed crystals the metals forms after smelting. The discovery of Zinc in its metallic form is credited to German chemist Andreas Marggraf in 1746. Commercialised smelting of the metal began in earnest in Europe and the United States in the 18th and 19th centuries.

Occurrence

Zinc is a naturally occurring element in the Earth’s crust with an average concentration of 70 to 80 ppm. It is most commonly found in the mineral sphalerite (Zn,Fe)S also known by its nickname zinc blende. Uncommon zinc minerals include, smithsonite (ZnCO₃) a zinc carbonate also known as calamine, hemimorphite (Zn₄Si2O₇(OH)₂.H₂O), franklinite (ZnFe₂O₄) and zincite (ZnO).

Where zinc is naturally concentrated through geological and geochemical processes deposits can form with the potential to be mined. Some common zinc deposit types include Volcanic hosted Massive Sulphides (VMS), Carbonate hosted (Mississippi or Irish type), Sediment hosted (SEDEX type), or Intrusion related (High sufidation, skarn, manto or veins). Zinc deposits are found across the globe with Australia, China, Canada, India, Peru and Europe among the largest producers.

Did you know? – One of the largest zinc mines in the world is the Red Dog Mine operated by Teck Resources and is located in northwest Alaska approximately 170 kilometres north of the Arctic Circle.

Physical Properties

Zinc is a “Transition Metal” on the periodic table of the elements and is described as a bluish-white, lustrous metallic element that is brittle at room temperature but malleable with heating. It is a fair conductor of electricity as well.

Production and Use

Globally the world produced 12.8Mt of zinc ore, produced 13.7Mt of zinc and consumed 13.9Mt of zinc in 2016. The metal is used in a wide variety of industries ranging from construction, transportation, household products, health, and others. Zinc is the 4th most commonly used metal after Iron, Copper, and Aluminum.

World Refined Zinc Supply and Usage 2012 - 2017

_{From the International Lead Zinc Study Group (http://www.ilzsg.org/static/statistics.aspx?from=3)}

There are five primary uses for Zinc in industry. By far the primary use for zinc is the galvinisation of steel products to protect against the effects of corrosion. This is followed by die-casting, production of brass and bronze, other zinc alloys, chemicals, and zinc semi-manufactures.

Some of the specific uses of zinc in industry are summarised below.

Construction

Builders depend on the structural strength and corrosion resistance of zinc-coated (galvanized) steel. Products include structural framing, railings, garage doors, roofing, pre-painted exterior wall panels and zinc-protected fastening devices, such as screws, nails and brackets. In your yard, such everyday functional and recreational items as garbage cans, swing sets, fences and gates, garden tools, patio furniture, storage sheds, cutters and swimming pools all contain zinc, the one metal that assures maximum rust protection.

Transportation

Zinc castings, which have excellent dimensional stability, are used in everything from automobiles and electronic components to children’s toys. Zinc components can be large, such as truck axle tubes or so small that they are barely visible and weigh only a fraction of an ounce. Today’s automobiles contain about 40 pounds of zinc, primarily in the zinc coating on galvanized steel body panels. The delicate instrument panels in today’s jet airliners are fabricated from zinc. And today’s ship builders use zinc anodes to protect the steel hulls of ships against the highly corrosive effects of salt water.

Household Products

Your refrigerator, dishwasher, washing machine and clothes dryer are just a few of the labor-saving devices in your home that contain a host of zinc die-cast components. Zinc sulfide enables your TV picture tube to display blue and green. Zinc is alloyed with copper to form brass, which increases the strength and castability, and imparts an appealing golden color.

Did you know – Since 1982 U.S. minted "copper" pennies are comprised of 97.6% zinc with just a 2.4% copper coating.

Recycling

Zinc is unique in that the metal can be recycled indefinitely without suffering from any degradation of its physical and or chemical properties. Globally approximately 70% of the annual consumption of zinc is obtained from mining activities while 30% is reclaimed, recycled and reused. The reclamation rate of available zinc is high at 80%.

Did you know – In 1996, an estimated 355,000 tons of zinc in waste and scrap was recovered in the form of slab zinc, brass, zinc-base alloys, dust, oxide, and other chemicals.

Health

Zinc is essential to life. Every cell requires zinc to multiply. Your body requires zinc to make white blood cells. Zinc is essential for healthy skin. It is a natural element found in every cell of your body, in the earth, in the food you eat and in products everywhere. Zinc is a vital nutrient. It stimulates growth, fights infection and heals wounds. Zinc is essential to both our physical and mental health. From healthy skin, hair and nails, to muscle, nerve and brain functions, zinc plays a key role. Teeth, bones, the healing process, and the immune and reproduction systems are all dependent on sufficient amounts of zinc in our bodies.

Zinc is vital during pregnancy. It is essential for the developing fetus where cells are rapidly dividing. A zinc deficiency is implicated in deteriorating vision that accompanies the aging process. Zinc boosts brain activity. Zinc oxide has been used for years to soothe diaper rash and relieve itching. Zinc stimulates the transport of Vitamin A from the liver to the skin. Zinc gluconate lozenges taken at the first sign of a cold reduces duration and symptom severity by 42%. Insufficient zinc has been linked to anorexia, which responds well to zinc replacement treatment. Zinc abnormalities also often exist in mood disorder patients.

Did you know - The best source of zinc is lean red meats and seafoods, especially oysters.

References

www.zinc.org
www.ilzsg.org
www.galvanizeit.org
www.mindat.org