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. 11, 1998
Filed:
Apr. 29, 1997
Stewart T Herman, Hellertown, PA (US);
Robert L Greenawalt, Ottsville, PA (US);
Bethlehem Steel Corporation, , US;
Abstract
A system and method for disposing of vacuum degasser contaminants which includes adjusting the pH, in a reactor vessel, of a vacuum degasser underflow stream to precipitate lead and zinc into particulate matter. The solids are then concentrated in a thickener to produce an underflow stream that is communicated to a holding vessel to settle. The overflow from the thickener is filtered through a sand filter and discharged to meet applicable NPDES permit limits. Lime is added to the slurry in the holding vessel to further settle the solids, to aid in filtration, and to prevent leaching of lead from the filter cake during TCLP testing. An overlaying supernatant is decanted from the holding vessel and returned to the reactor vessel for further treatment. Limestone is added to the underflow stream. The resulting slurry is dewatered to produce a friable, non-hazardous filtrate cake and a filtrate. The filtrate is directed back to reactor vessel prior to discharge for further treatment.