Basics of Zinc
History of Zinc
Centuries before zinc was discovered in the metallic form, its ores were used for making brass and zinc compounds for medicinal purposes. Zinc compounds were in the ores smelted certainly as early as 200 B.C. to obtain copper and which gave alloys of copper and zinc – the brass family. The Romans certainly were major users of brass. The Greeks also appeared to know zinc, even if not by name.
Commercial smelting of zinc began in Europe in the middle of the 18th century when the first European zinc smelter was established in Bristol in the United Kingdom using a vertical retort procedure. But the real advent of modern techniques dates from the introduction of the horizontal retort process in the early 19th century. In 1836 hot-dip galvanizing – the oldest anti-corrosion process – was introduced in France.
Zinc Natural Occurrence
Zinc is a natural component of the earth’s crust and an inherent part of our environment. Zinc is present in rock, soil, air, and water. Plants, animals and humans also contain zinc.
Zinc ore deposits are widely spread throughout the world. Zinc ores are extracted in more than 50 countries. Australia, Canada, China, India, Peru and Europe are the largest producers. Zinc is normally associated with lead and other metals including copper, gold and silver.
The most commonly found zinc mineral is sphalerite (ZnS) also known as zinc blende, which is found in almost all currently mined zinc deposits. The mineral crystallizes from the hydrothermal solution as pure zinc sulfide.
Zinc deposits close to the earth’s surface are often converted to oxides and carbonates. Small quantities of zinc carbonate – the mineral calamine (smithsonite) in North America – often refer to the hydrated silicate mineral also known as hemimorphite.
Zinc Production from Ore to Metal
More than 13 million tons of zinc was produced in 2013 worldwide. Sixty percent of this is used for galvanizing to protect steel from corrosion thus prolonging the service life of steel products significantly. Approximately 15% goes into the production of zinc base alloys, mainly to supply the die casting industry, 14% goes into the production of brass and bronze and 8% into the production of compounds including zinc oxide and zinc sulfate. The remainder is zinc alloys, mainly rolled, utilized in semi-manufactured applications including coinage and architectural applications..
These first-use suppliers then convert zinc into in a broad range of products. By far the largest application area is construction with 45% of all first-use zinc products used in this area. The transportation sector consumes 25% of global zinc consumption and consumer goods – including electrical and electronic appliances – accounts for 23%. The remaining 7% is used for the manufacture of industrial machinery.
For more info please go to ‘The International Zinc Association’