Roasting (metallurgy) - Wikipedia
Roasted gold ore from Cripple Creek, Colorado. Roasting has driven off the tellurium from the original calaverite, leaving behind vesicular blebs of native gold. Roasting is a process of heating of sulphide ore to a high temperature in presence of air. It is a step of the processing of certain ores. More specifically, roasting is a metallurgical process involving gas–solid reactions at ...