Microchemical studies of tuyeres and refractory materials used by Phoenicians and Punics at Tharros (Sardinia, Italy)

A large amount of smelting slags, tuyeres and curved refractory materials used during pyrometallurgical activities have been found at Tharros (western-Sardinia, Italy) during an excavation stratigraphically related to the Phoenician-Punic period (VI-IV BC). The microchemical structure of the vitrified end of tuyeres and of the thick fragments of the smelting furnaces, has been studied by means of scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS). The results indicate that these materials can be associated with an iron smelting process. Furthermore, the temperature and duration of the smelting process has been estimated from the study of vitrification process and penetration depth of vitrification of the tips of some tuyeres combined with the study of pieces of clay taken from a unvitrified fragment of a tuyere and subjected to different thermal treatments under reducing atmosphere.