In conventional pyrometallurgical processing the ore is dried and calcined in a rotary kiln before being smelted in an electric arc furnace in the presence of carbon. Depending on the Fe/Ni ratio, the tapped ferronickel from the EAF can be treated further in vertical converters by top blown oxygen lances to slag the iron and to increase the nickel content in the final product.

If matte is the desired product, then sulfur is added to the kilns. The crude metal/matte is further refined to produce the final product. For refining of matte mostly different kinds of converters are used.