OPTIMAL ZONE LENGTHS IN MULTIPASS ZONE-REFINING PROCESSES

A method for determining the optimum zone length for maximum separatio n in multi-pass zone-refining processes is described. Numerical values of the optimum zone lengths and their corresponding maximum separatio ns for up to ten passes are presented. The optimum zone length is foun d to increase with the distribution coefficient but decreases when the pass number increases. Considerable improvement in separation may be obtained if zone refining is operated at the optimum zone length, exce pt for higher distribution coefficients.