Preparation of High Purity Cadmium by Vacuum Distillation and Zone-melting Method

Vacuum distillation and zone-melting method have been applied for the purification of commercial 4 nine Cadmium. Purity of the samples were analyzed by glow discharge mass spectroscopy (GDMS) and estimated by the measurement of residual resistivity ratio (RRR). Highest RRR value of 21000 was obtained at the central part of the overlap zone-melted specimen. Analytical results of the specimen by GDMS showed that total amount of detected metallic impurities was less than 0.1 mass ppm at this part. High purity cadmium could be successfully prepared by the vacuum distillation-zone melting method.