Nickel
Overview
Nickel is a chemical element with the symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile. It is one of four elements that are magnetic at or near room temperature, the others being iron, cobalt and gadolinium.
History
Nickel was first isolated and classified as a chemical element in 1751 by Axel Fredrik Cronstedt, who initially mistook the ore for a copper mineral. Its most important ore minerals are laterites, including limonite and garnierite, and pentlandite. The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick), who personified the fact that copper-nickel ores resisted refinement into copper.
Characteristics
Nickel is a hard, ductile, magnetic, highly resistant and ferromagnetic metal. It is capable of maintaining its strength and toughness at both high and low temperatures. The metal is resistant to corrosion, even at high temperatures and to alkalis. It is also characterized by a high melting point and possesses good thermal and electrical conductivity properties.
Applications
Nickel is used in many specific and recognizable industrial and consumer products, including stainless steel, magnets, coinage, rechargeable batteries, electric guitar strings, microphone capsules, and special alloys. It is also used for plating and as a green tint in glass. Nickel is preeminently an alloy metal, and its chief use is in the nickel steels and nickel cast irons, of which there are many varieties. It is also widely used for many other alloys, such as nickel brasses and bronzes, and alloys with copper, chromium, aluminium, lead, cobalt, silver, and gold.
Health effects
Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site. However, in larger amounts, it can be harmful to human health, particularly if it is inhaled as a dust or fume. Exposure to nickel and its compounds may lead to a type of skin rash known as "nickel dermatitis" in sensitive individuals. Long-term exposure can lead to decreased lung function, heart disorders, and allergic reactions.
Production and reserves
Nickel is obtained from two main types of deposits from the mineral garnierite (Ni-silicate) in nickel-rich laterite soils, and from sulfides such as pentlandite. Major production sites include the Sudbury region in Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, and Norilsk in Russia.