Minerals and Metals in Ancient India v1.c26.4

v1.c26.4

Reduction of zinc oxide around 1000°C is crucially important; below 950°C no zinc is produced. If there is a trace of oxygen then zinc vapour would be reoxidised and hence the successful operations must have been done in closed crucibles. If the temperature was higher than 1083°C, copper melted and flowed down to the bottom of the crucible forming a puddle there, exposing very small surface area of the metal for alloy formation.