Minerals and Metals in Ancient India v1.c26.s6.t5.12

v1.c26.s6.t5.12

On the basis of their assumptions and the observation that the residue in each retort weighed about 1 kg and contained about 50 g of unrecovered zinc metal, Freestone et al. (1985a and b) speculated the 200-500 g of zinc vapour condensate might have been recovered per retort. This range corresponds to 80-90 per cent recovery from the retort charge assaying 20-33 per cent in elemental zinc. While Freestone et al. accepted the upper limit of the range for further calculations, we propose the conservative value or the lower limit of the proposed range.