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:
Sep. 09, 1997
Filed:
Jul. 14, 1995
Teruyoshi Izawa, Kasugai, JP;
Kazunori Kudo, Mizunami, JP;
Yoshihiro Kani, Tajimi, JP;
Ken Araki, Hirakata, JP;
Tamotsu Kato, Hirakata, JP;
Takashi Furui, Hirakata, JP;
Taihei Chemical Industrial Co., Ltd., Osaka, JP;
C. Uyemura & Co., Ltd., Osaka, JP;
Abstract
Valuable substances are recovered from a spent electroless nickel plating solution containing a water-soluble nickel salt, organic complexing agent, hypophosphite, phosphite, and alkali metal ion by adding oxalic acid to the plating solution for causing a nickel ion to precipitate as nickel oxalate for removal and recovery; optionally adding a sulfide to the plating solution for causing a heavy metal ion to precipitate as a heavy metal sulfide for removal; adding a mineral acid and calcium oxide, calcium hydroxide, calcium carbonate, calcium sulfate, calcium chloride or a calcium salt of organic acid to the plating solution from which the nickel ion has been removed; firing solids of the solution in air for converting the alkali metal ion into an alkali metal salt of mineral acid, converting phosphorus into hydroxyapatite, and pyrolyzing off the organic material; and pouring a solid mixture of the alkali metal salt of mineral acid and hydroxyapatite into water for dissolving the alkali metal salt of mineral acid in water for separate recovery of hydroxyapatite and the alkali metal salt of mineral acid.