Also found in: Encyclopedia, Wikipedia.
zone meltingor zone refining
A purification technique for crystalline substances in which a heating system passes slowly over a bar of the material to be refined, creating a molten region that carries impurities with it across the bar.
(Chemical Engineering) a technique for producing solids of extreme purity, esp for use in semiconductors. The material, in the form of a bar, is melted in one small region that is passed along the solid. Impurities concentrate in the melt and are moved to the end of the bar