Versatile zone refiner for liquids and low-melting solids

Abstract
A versatile zone‐refining apparatus which employs liquid nitrogen as the refrigerant to maintain the compound to be purified in the solid state while appropriately spaced resistance heaters generate the moving liquid zones to purify compounds whose melting point lies between 200 and 350 K is described. As much as 0.750 kg of substance can be purified at one time to a purity better than 99.95 mole %.