History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c12.s1.t13.3

v1.c12.s1.t13.3

Most of the workings of ancient age (Fig 10) so far revealed are opencast, down to contact zone, with some 30-40% extraction on one section across the width (130m) of lode, to some 15 m depth. Slag dumps occupy some 1800 sq.m. of surface area and are approximately 1 m deep. Analysis of the slag suggests that zinc oxides were being deliberately produced there some 2000 years ago.