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. 05, 2000
Filed:
Dec. 04, 1997
Celia L Alexander, Salem, MA (US);
Anthony M Mariniello, Peabody, MA (US);
Brian A McBride, Charlestown, MA (US);
Michael M Cook, Boxford, MA (US);
David A Dunn, Santa Ana, CA (US);
Morton International Inc., Chicago, IL (US);
Abstract
An efficient and economical process for the waste treatment of spent metal plating solutions, primarily spent electroless nickel solutions, to significantly reduce the metal content therein, so as to permit direct discharge to municipal water systems without violation of the law. The waste treatment process is a sequential two-step chemical precipitation process, whereby the dissolved metal content is precipitated first by sodium borohydride reduction, followed by sodium dimethyldithiocarbamate precipitation, with an intermediate filtration step and pH adjustment step interposed there between. The amount of metal-bearing sludge produced is minimal. Furthermore, the bulk of the metals in the sludge may be recovered and reused, resulting in significant reduction in hazardous waste disposal costs.