The archaeological excavations at San Bennato (Cavo), have allowed the recovery and museumization of some technological components that are fundamental to the understanding of the production cycle of hematite reduction. The system, used extensively during the second century BC, must have been characterized by the presence of low-fire furnaces of the fireplace type, equipped with a high stone superstructure internally covered with clay. At the base there was the channel for the outflow of slag (production waste) in the molten state. The aeration, necessary to obtain the correct melting temperature, was forced through the use of terracotta tubules. The presence of water was necessary: the mineral had in fact to be washed inside the tanks to minimize the presence of impurities. These plants had a frenetic and continuous activity, in a very similar way to what happened in the nearby beach of Baratti (Piombino - Li), where continuous accumulations of slag were leveled to build on other furnaces, once the previous ones had. Although the excavated materials do not attest to the presence of the San Bennato plant prior to the second century BC. (and therefore to the Roman control on the island), laboratory analyzes on the remains of the ovens seem to indicate a first installation of the workshops, perhaps as early as the fifth century BC, in the Etruscan - classical age.
