Pyrrhotite and nickel
Pyrrhotite is an iron sulphide, but it is not the iron or the sulfur that is interesting in the pyrrhotite from Agder. It contains small inclusions of the nickel mineral pentlandite, and this provided the basis for the nickel mine at Flåt in Evje. Chalcopyrite also occurs here, and copper was initially mined in the Flåt mine (1844-1846). Trial operation on nickel was started in 1869, and full-scale operation took place in the periods 1872-1894, 1899-1920 and 1927-1946. A total of 20,000 tonnes of nickel and 14,500 tonnes of copper were extracted from 12.8 million tonnes of ore. The sample on display is pyrrhotite with small amounts of chalcopyrite.
The nickel plant in Kristiansand was founded in 1910, and in the first years it was the Flåt mine that supplied the nickel ore to the plant. After World War I, it was clear that the Flåt mine alone could not meet the needs of the nickel plant. Economically difficult times and low nickel prices meant that the owners agreed to be bought by the Canadian Falconbridge Nickel Mines in 1929. From now on, it was ore from the large deposit in Sudbury in Canada that was refined in Kristiansand. In 2006 Falconbridge was acquired by Xstrata, and in 2013 Xstrata was merged with Glencore. The name today is Glencore nickel works.
Nickel has many uses. The metal is used in many different steel alloys, in coins and jewellery, in sterling silver, and for surface treatment of other metals to make them more resistant to scratching and corrosion.