NICKEL & NICKEL ALLOYS
About Nickel & Nickel Alloys:
Nickel is a transition metal and naturally occurs extensively in the earth’s crust although the majority of it lies within the earth’s core so cannot be mined. It is a silvery-white lustrous metal & is the fifth most common element on earth.
The bulk of the Nickel mined comes from two types of ore deposits; laterites and magmatic sulphide deposits. Nickel was first classified as a chemical element in 1751.
Key Properties of Nickel
Nickel is resistant to corrosion (due to its slow rate of oxidation at room temperature) and to most acids except nitric acid. It has a high melting point and is very ductile. It is also magnetic at room temperature.
Production of Nickel
Nickel is extracted from its ores by extractive metallurgy including conventional roasting and reduction processes that yield a metal of greater than 75% purity. It can then be further purified using pyrometallurgical methods and then further refined to a final Nickel concentration of over 99% by removing Copper by adding hydrogen sulphide and removing cobalt by solvent extraction.
The first uses of Nickel date back to ancient times (as far back as 3500BC) and was referred to as a “white copper” until it was recognised as a separate element.
The biggest use of Nickel is in alloying – particularly with chromium and other metals to produce stainless and heat-resisting steels. These are used for pots and pans, kitchen sinks as well in buildings, food processing equipment, medical equipment and chemical plants.
About 65% of the Nickel which is produced is used to manufacture stainless steels. Another 20% is used in other steel and non-ferrous alloys – often for highly specialised industrial, aerospace and military applications. About 9% is used in plating and 6% in other uses, including coins, electronics, and in batteries for portable equipment and hybrid cars. In many of these applications there is no substitute for nickel without reducing performance or increasing cost.