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:
Aug. 29, 2000
Filed:
Oct. 13, 1998
Katsuhito Kawamura, Chiba, JP;
Fuyuhiko Ishikawa, Chiba, JP;
Kazumitsu Sambonchiku, Chiba, JP;
Kei Yuki, Chiba, JP;
Shinji Kawashima, Tokyo, JP;
Toshimichi Ukena, Tokyo, JP;
Kawasaki Steel Corporation, Hyogo, JP;
Abstract
Improved recovery of tin from sludge formed during a halogen-type electrolytic tinplating of steel sheet comprises leaching the sludge with water at a pH of 7 or less, separating an iron-containing sludge remaining after the leaching, alkalifying the filtrate obtained in the first separation step to deposit tin-containing sludge, separating and recovering the tin-containing sludge deposited in the first alkalifying step, redissolving the tin-containing sludge in an alkaline solution, and electrolytic reduction of the alkaline solution. High purity metallic tin is recovered from sludge, at a high yield. Other materials are also recovered for reuse from the filtrate and precipitation, which are formed during the process, without pollution of the operational environment.