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:
Jul. 19, 1994
Filed:
Apr. 16, 1993
Yoshikatsu Aihara, Anan, JP;
Tomokazu Suzuki, Anan, JP;
Yoshiaki Shizuki, Anan, JP;
Shoichi Bando, Anan, JP;
Katsunori Uchimura, Anan, JP;
Nichia Kagaku Kogyo K.K., Tokushima, JP;
Abstract
A method of reclaiming a phosphor from a recovered phosphor slurry containing carbon, a bichromate, and polyvinyl alcohol, comprises, (a) a decomposition treatment step of adding an alkali to the recovered phosphor slurry after the slurry is heated to prepare a phosphor suspension having an alkali concentration of 0.5N or less in the slurry, and adding an oxidizing agent in an amount of 1.0 to 20.0 wt % with respect to a dry solid component of the suspension, (b) a weak acid treatment step of separating a phosphor from the suspension, and adding a weak acid to a suspension obtained by adding water to the separated phosphor, thereby adjusting a pH to be 3.0 to 5.0, and (c) a surface treatment step of treating the surface of the phosphor separated from the suspension.