Claims
- 1. A method for the purification of a metal chosen from the group consisting of cadmium and tellurium which comprises adding to an ingot of the metal an amount of a gettering substance chosen from the group consisting of tellurium, cadmium and cadmium telluride, subjecting the metal with added gettering substance to multiple-pass zone refining, said amount of tellurium or the amount of tellurium in cadmium telluride added in the zone refining of cadmium being less than the amount of tellurium in the cadmium rich eutectic composition between cadmium and tellurium, and said amount of cadmium or the amount of cadmium in cadmium-telluride added in the zone refining of tellurium being less than the amount of cadmium in the tellurium-rich eutectic composition between cadmium and tellurium, and cropping said ingot after multiple zone refining to recover a product of reduced impurity content.
- 2. A method as claimed in claim 1 wherein, the metal to be purified is cadmium, the gettering substance is tellurium, and the tellurium is added at the leading end of the ingot of cadmium prior to zone refining in an amount less than about 10 parts per million by weight of said ingot of cadmium.
- 3. A method as claimed in claim 1 wherein the metal to be purified is cadmium, the gettering substance is cadmium telluride, the cadmium telluride is added at the leading end of the ingot of cadmium prior to zone refining, and the amount of tellurium in the added cadmium telluride is in an amount less than about 10 parts per million by weight of said ingot of cadmium.
- 4. A method as claimed in claim 1 wherein the metal to be purified is tellurium, the gettering substance is cadmium, and the cadmium is added at the leading end of the ingot of tellurium prior to zone refining in an amount less than about 1% by weight of said ingot of tellurium.
- 5. A method as claimed in claim 1 wherein the metal to be purified is tellurium, the gettering substance is cadmium telluride, the cadmium telluride is added at the leading end of the ingot of tellurium prior to zone refining, and the amount of cadmium in the cadmium in the added cadmium telluride is in an amount less than about 1% by weight of said ingot of tellurium.
Government Interests
The U.S. Government has rights in this invention pursuant to Contract No. F33615-82-C-5128 awarded by the Department of the Air Force.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
770574 |
Oct 1967 |
CAX |