Sinter plants agglomerate iron ore fines (dust) with other fine materials at high temperature, to create a product that can be used in a blast furnace. The final product, a sinter, is a small, irregular nodule of iron mixed with small amounts of other minerals. The process, called sintering, causes the constituent materials to fuse to make a single porous mass with little change in the chemical properties of the ingredients. The purpose of sinter are to be used converting iron into steel.
Sinter plants, in combination with blast furnaces, are also used in non-ferrous smelting. About 70% of the world's primary lead production is still produced using the sinter plant–blast furnace combination, and this combination was formerly often used in copper smelting (at the Electrolytic Refining and Smelting smelter in Wollongong, New South Wales, for example).