The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 07, 1988
Filed:
Aug. 31, 1987
Hiroshi Ishizuka, Shinagawa-ku, Tokyo, JP;
Other;
Abstract
A method of purifying refractory metal, comprising: providing a distillation space, said space comprising both a heatable portion and a condensation portion in communication with each other, and being closed but provided with gas inlet- and gas outlet openings, said degassing opening being located in the condensation portion, placing a mixed deposit of a refractory metal with magnesium metal and magnesium chloride in said heatable portion, heating said deposit under a subatmospheric pressure to temperatures high enough to cause evaporation of magnesium and magnesium chloride, degassing the space through the gas outlet opening, cooling magnesium and magnesium chloride to deposit in the condensation portion, starting introduction of an inert gas, through the gas inlet opening, at a timing where there is a steady, substantially decreased pressure of the thus forming vapor on the order of 10.sup.-2 Torr in the space, keeping supply of the inert gas while degassing through said openings, respectively, so that an increased but still subatmospheric pressure less than 1 Torr is maintained in the space.