出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/04/18 05:55 UTC 版)
Cupellation is a metallurgical process in which ores or alloyed metals are treated under high temperatures and carefully controlled operations in order to separate noble metals, like gold and silver, from base metals like lead, copper, zinc, arsenic, antimony or bismuth, that might be present in the ore. This process is based on the principle that precious metals do not oxidise or react chemically, contrary to what happens to the base metals; so that when they are heated at high temperatures, the precious metals remain apart and the others react forming slags or other compounds.