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. 23, 1987
Filed:
Dec. 05, 1985
Shigeki Kubo, Niihama, JP;
Osamu Yamamoto, Niihama, JP;
Sumitomo Metal Mining Company Limited, Tokyo, JP;
Abstract
Finely-divided particulate bismuth oxide is produced by the steps of heating bismuth at 800.degree. C. or above in a first compartment of a sealed vessel divided into two compartments by a partition wall, the two compartments communicating with each other by a hole provided on the partition wall, feeding an inert gas such as nitrogen and argon into the first compartment so that the bismuth vapor formed by heating bismuth has a bismuth concentration of 0.1 to 0.5 g/liter, blowing air into the bismuth vapor introduced from the first compartment into the second compartment through the hole on the partition wall, permitting the air to mix with the bismuth vapor to form bismuth oxide and simultaneously cooling the thus formed bismuth oxide to 250.degree. to 300.degree. C., discharging by suction the bismuth oxide from the sealed vessel at a flow rate of 1 to 5 m/sec, and cooling the discharged bismuth oxide by supplying cooling air outside the sealed vessel.