Nickel is a silvery-white metal related to iron and cobalt. Although it is not one of the metals known in antiquity, it was used in the form of naturally-occurring copper-nickel alloys. Nickel-bearing weapons and coins made by China and its trading partners date to the first century BC and before.
Until early modern times, nickel ores were often mistaken for copper-bearing ones, hence the name kupfernickel ("devil copper"). Since nickel melts at a much higher temperature and has very different chemical properties, attempts to smelt the false copper were unsuccessful.
In 1751, the Swedish chemist Axel Fredrik Cronstedt working with a supposed copper mineral extracted the white metal now called nickel. The identity of the new metal was in doubt for a generation – it was, perhaps, some whitish copper alloy – but eventually, the new element was confirmed.
Mining and Production
Nickel occurs in some iron-bearing ores and separately in sulphide minerals. It is not very common in the Earth's crust. The largest concentrations are in Russia (mined by Norilsk Nickel) and Ontario, Canada (mined by Vale Inco). The Ontario location is believed to be the site of an ancient strike by a nickel-bearing asteroid. Nickel is also often mined in conjunction with iron or cobalt. Nickel is extracted by both surface mining and deep tunneling. 2.1 million tonnes were mined in 2017. The largest producers were Indonesia (19%), the Phillippines (11%), and Canada (10%).
Sulfide ores are concentrated by flotation and then roasted to drive off sulfur dioxide, leaving an impure (75%) metal. This is reacted with carbon monoxide (the Mond Process) to produce a gas that can be easily decomposed, depositing pure nickel. Alternatively, the impure nickel can be purified by electroplating, particularly if plating is the intended use.
Properties and Uses
Nickel is lustrous and doesn't oxidize or tarnish. It is hard, malleable, and fairly conductive. Nickel atoms are about the same size as iron atoms, meaning they can be substituted in alloys and also alloy with each other. Nickel responds to magnetism.
By far the largest demand for nickel (65%) is in making stainless steel. Nickel is also used to plate steel, molybdenum, and other metals because of its silvery appearance and resistance to oxidation. Nickel alloyed with copper makes cupronickel, a hard metal resembling bronze that does not corrode in seawater
New York's Chrysler building is topped with brilliant nickel stainless steel.
For use in circulating coins, nickel is cheaper than silver but more expensive than copper. Modern mid-range coins that would traditionally be silver now commonly use some combination of copper and nickel. For example, the 2 euro coin is primarily copper over a nickel core.
The majority of rechargeable batteries are based on nickel cadmium or nickel hydride. Although lithium batteries have greater performance, their greater cost is a significant factor. Therefore, nickel is in demand for powering everything from camcorders to hybrid automobiles.