the branch of metallurgy involving processes performed at high temperatures, including sintering, roasting, smelting, casting, refining, alloying, and heat treatment
pyrometallurgy in American English
(ˌpaɪrəˈmɛtəˌlɜrdʒi)
noun
metallurgy using high temperatures, as in roasting, smelting, etc., for the extraction of metals from their ores