zone refining/zōn rəˈfīniNG, , zoʊn rəˈfaɪnɪŋ, rēˈfīniNG, riˈfaɪnɪŋ/
▸nouna method of purifying a crystalline solid, typically a semiconductor or metal, by causing a narrow molten zone to travel slowly along an otherwise solid rod or bar to one end, at which impurities become concentrated.
EnglishOxford New American Dictionary
