a refining process for nonoxidizing metals,such as silver and gold,in which a metallic mixture is oxidized at high temperatures and base metals are separated by absorption into the walls of a cupel是什么意思_a refining process for nonoxidizing metals,such as silver and gold,in which a metallic mixture is oxidized at high temperatures and base metals are separated by absorption into the walls of a cupel在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句