Purification of Vanadium by Vacuum Melting.
J Vacuum Sci and Technol 1970 7(6):S74-s80
The Bureau of Mines compared the purification of two commercially available vanadium samples by three vacuum melting techniques: consumable-electrode arc melting at the top of the mold (tom); comsumable-electrode arc melting in a conventional deep mold; and conventional electron-beam melting (ebf). The purity of samples melted at the tom approached the purity of samples prepared in the ebf. In some instances, a further decrease in the oxygen and metallic impurity content resulted from remelting selected materials in the electron-beam furnace. Little or no purification resulted from melting vanadium in the conventional deep mold. Purification proceeded faster and more completely on melting vanadium with small additions of yttrium, carbon, or aluminum; aluminum was largely removed on double melting, but carbon and yttrium remained in the products. Metal or carbon additions tended to stabilize the arc and improve metal recovery from 85 percent to greater than 90 percent during a consumable-electrode arc melt.
J. Vacuum Sci. and Technol., V. 7, No. 6, November/December 1970, PP. S74-s80