Minerals and Metals in Ancient India v1.c20.s1.9

v1.c20.s1.9

Caught up in the spongy solid mass was slag, mostly fusible ferrous silicate or fayalite (melts at 1170°C). The slag had to be squeezed out of the sponge iron by hammering at or above the temperature (1170°C) — a process known as forging. Hammering produced a continuous network of iron grains, sometimes interrupted by stringers of remaining slag elongated in the direction of the deformation of the iron bloom.