Unlike all the other metals used in the past, iron was produced and worked only in the solid state. This technology is called the ‘Direct Process’ of iron manufacture, ie the production of malleable iron direct from the ore. By contrast, in the later ‘Indirect Process’, the blast furnace produced liquid pig iron which had to be refined into malleable iron. This datasheet only deals with the direct process.
The direct or bloomery process comprised several stages. Metal was extracted from ore by smelting; raw iron was refined by primary smithing and was then manufactured into artefacts by (secondary) smithing. All these processes generated slags and residues as by-products.