What is Nickel?
Nickel is a chemical element with 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. Pure nickel, powdered to maximize the reactive surface area, shows a significant chemical activity, but larger pieces are slow to react with air under standard conditions because an oxide layer forms on the surface and prevents further corrosion (passivation). Even so, pure native nickel is found in Earth’s crust only in tiny amounts, usually in ultramafic rocks and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth’s atmosphere.
Where Nickel is Used?
Nickel-containing materials play a major role in our everyday lives – food preparation equipment, mobile phones, medical equipment, transport, buildings, power generation – the list is almost endless. They are selected because – compared with other materials – they offer better corrosion resistance, better toughness, better strength at high and low temperatures, and a range of special magnetic and electronic properties.
Most important are alloys of iron, nickel and chromium, of which stainless steels (frequently 8-12% nickel) are the largest volume. Nickel based alloys – like stainless steel but with higher nickel contents – are used for more demanding applications such as gas turbines and some chemical plants.
In addition, iron and nickel alloys are used in electronics and specialist engineering, while copper-nickel alloys are used for coinage and marine engineering.
There are about 3000 nickel-containing alloys in everyday use. About 90% of all new nickel sold each year goes into alloys, two-thirds going into stainless steel.
Nickel metal is used to provide hard-wearing decorative and engineering coatings as ‘nickel-plating’ or ‘electroless nickel coating’ or ‘electroforming’. When used with a top layer of chromium, it is popularly known as ‘chrome-plating’. When done in combination with silicon carbide it is known as composite plating.
Nickel is a key part of several rechargeable battery systems used in electronics, power tools, transport and emergency power supply. Most important today are nickel-metal hydride (NiMH).
Nickel is a key ingredient in many catalysts used to make chemical reactions more efficient.
Nickel use is growing at about 4% each year while use of nickel-containing stainless steel is growing at about 6%. The fastest growth today is seen in the newly and rapidly industrializing countries, especially in Asia. Nickel-containing materials are needed to modernize infrastructure, for industry and to meet the material aspirations of their populations.
Much more about all these applications of nickel can be found in Nickel Use in Society and the Material Selection and Use areas of the web site.
A list of some of the major nickel alloy and nickel stainless steel producers in the world is available here.
Also read : Nickel Discovery in Nigeria
Why Nickel is Used?
Most nickel-containing products have long useful lives. Average life is probably 25-35 years, with many applications lasting much longer. Nickel containing products frequently can provide optimum solutions to practical challenges at a lower total cost and with more efficient use of resources, including energy.
At the end of their useful life, nickel-containing products can be collected and recycled for future use and re-use. Nickel is one of the most recycled materials globally. It is collected and recycled, mostly in the form of alloys. About half of the nickel content of a stainless steel product today will have come from recycled sources.
Nickel is of considerable economic and strategic importance to many countries, as can be appreciated from the wide diversity of end-use industries which it serves. It is traded on the London Metal Exchange.
The International Nickel Study Group, based in Lisbon, Portugal, is an inter-governmental body which publishes monthly statistics on nickel supply and demand, and acts as a forum for the exchange of information and views on nickel trends.
Nickel and nickel compounds can in certain circumstances be associated with toxicity, carcinogenicity and with dermal sensitization. Most of the practical risks associated with nickel hazards are seen in certain complex processes used in nickel production and refining. The risks are well known and are managed and controlled by specific workplace regulation.
In the nickel industry’s view, significant risks are not normally associated with the use of nickel, nickel-containing alloys or nickel-containing products, with the exception of the use of nickel and some nickel alloys in jewellery.
Nickel use makes a very high practical contribution to improvements of health, safety and protection of the environment. Society will lose a lot more than it will gain if it adopts an excessively precautionary approach to the assessment and management of the risks associated with nickel.
Photo Credit Nickel Institute