Nickel & Nickel Alloys

NICKEL

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. Nickel occurs most often with Iron and is commonly found in iron metereorites as the alloys kamacite and taenite.

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.

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

The largest producers of Nickel are Russia, Canada, Australia, Indonesia and the Philippines and Australia is considered to have the largest reserves. 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.

USES OF NICKEL

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 specialized 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.

As a chemical compound, Nickel is also an essential nutrient for plants and it is found naturally in most vegetables, fruits and nuts.

NICKEL ALLOYS

Any alloy containing Nickel as the chief alloying element or as the base metal is a Nickel Alloy. It used to raise the melting point of copper alloys and is added to brasses and bronzes for the colour effect and for toughening and strengthening the alloys. Nickel is added to both ferrous and non-ferrous alloys to produce heat-resistant and acid resistant metals.