Caractérisation minéralogique, géochimique et métallurgique des résidus de réduction directe, d'épuration et de forge du centre sidérurgique romain des Martys (Aude, France)

Abstract

During the last excavations (1988-1993) of the huge roman slag heap at Les Martys (Aude, France), important remains of shaft furnaces and smithing heartheswere discovered. Many pieces of wastes produced by iron smelting and smithing are characterized on one hand by their macroscopic features (specially useful during field work), on the other hand by its mineralogy and geochimistry. These evidences allow us to understand better the working order of the shaft furnaces and smithing operations. By the use of oak and beech charcoal, the ancient iron makers could reach easily 1350 degrees centigrade, as we can deduce from the equilibrium of silicates, oxides and spinelles of tap slags. The bloom was hammered under heat (microdrops of slag and microfragments of metal) in order to remove impurities and to obtain iron/stell ingots for sale.