THE ORIGIN AND ARCHAEOMETALLURGY OF A MIXED SULPHIDE ORE FOR COPPER PRODUCTION ON THE ISLAND OF KEA, AEGEAN SEA, GREECE

At the hill of Agios Symeon, on the island of Kea, Aegean Sea, Greece, ancient metallurgical slags with a high Pb-Zn-Cu content have been found. Thermodynamic simulations have been carried out, using the FactSage thermodynamic database computing system, with a view to understanding the ancient metallurgical processes that produced the observed slag compositions and morphologies. The simulations demonstrate that the slag samples resulted from Cu-making processes. It would thus appear that mixed ores were used, containing Cu2S-FeS-PbS with significant amounts of sphalerite (ZnS) as impurity. The roasted ores were reduced at relatively high oxygen potentials at approximate to 1125 degrees C to form Cu containing low levels of Pb, Fe and Zn.