Metals and Metalworking Residues

Metallurgical processes include the operations involved in the extraction, refinement, alloying, working and recycling of metals. The actual operational chain of the ancient metallurgical processes as investigated by archaeometallurgy is rather complex. The chapter considers those steps of the processes that can leave traces in soils and sediments and that can be identified and investigated by micromorphological techniques. The considered metals and alloys are those abundantly used in the past: Cu and Cu-alloys, Fe and steel and Pb. Smelting slags are the product of an essential step (slagging) of metal production (i.e., reduction to metal state) and refinement. At the temperature of operation (1000-1200 °C) the slag is fluid whereas the metal is solid, so that the separation requires a great deal of high temperature metalworking (smithing) of the wrought iron produced in the furnace. Refractory ceramics used in medieval or later metallurgical operations have a specific refractory character.