Which elements and compounds have been purified by zone refining?

Zone refining is a highly effective technique used to purify more than one-third of all elements and hundreds of inorganic and organic compounds. By passing molten zones through a solid charge, impurities are redistributed, allowing for the attainment of ultrahigh purity levels.12

Key substances purified by this method include:

• Semiconductors: The process was famously pioneered to purify germanium for transistors and is widely used to produce ultrapure silicon via float zoning.1
• High-Melting-Point Metals: Metals such as tungsten, molybdenum, tantalum, and beryllium are purified using float zoning, which utilizes surface tension to hold the molten zone in place without container contamination.1
• Other Materials: Hundreds of other inorganic and organic compounds have been refined to their highest possible purity, enabling scientists to determine their intrinsic properties for the first time.1

This method is particularly valued for its simplicity and its ability to avoid contamination from containers or chemical reagents.1