Zone Refining

Name:
Zone Refining
Detailed information:
A purification process that involves repeated melting and crystallization. The sample to be purified is placed in a relatively long, narrow tube and then passed slowly through a furnace having short, alternate hot and cold zones. Melting occurs opposite the hot zones and crystallization opposite the cold zones. As the rod moves through the furnace the zones move along the rod. Impurities remain in the molten zones and so are carried to one end of the rod. The process has been most used for relatively high-cost materials used in small quantities at very high purities, as for solid-state electronic purposes.