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:
Jan. 23, 2001
Filed:
Jan. 13, 1999
R. David Prengaman, Arlington, TX (US);
Clifford E. Morgan, Arlington, TX (US);
Homer P. Hine, Colleyville, TX (US);
Gerald M. Griffin, Jr., Roscoe, NY (US);
RSR Corporation, Dallas, TX (US);
Abstract
A process for recovery of substantially all the sulfur in a spent lead-acid battery as Na,SO,is disclosed. The process comprises (a) breaking the batteries to remove the acid, (b) separating the plastic from the lead bearing materials, (c) smelting the lead bearing materials in a reverberatory furnace in an oxidizing atmosphere to volatilize most of the sulfur in the feed as SO,, (d) scrubbing the SO,from the off gas stream using a soluble alkaline material such as NaOH, Na,CO,, or KOH to produce a soluble sulfite solution, (e) oxidizing the sulfite solution to sulfate, preferably by turbulent mixing of the solution with air, (f) adjusting the pH by adding the sulfuric acid separated from the batteries, (g) removing the contained heavy metals, (h) crystallizing the sulfate as Na,SO,or K,SO,, (i) separating a bleed stream from the crystallizer and removing the contained chlorides as a mixed sulfate-chloride product by evaporation of the bleed stream in another crystallizer. The process produces a high grade Na,SO,or K,SO,product, condensed H,O for recycle to the scrubber, and a mixed sulfate-chloride product while reducing sulfur dioxide, chloride and heavy metal emissions to extremely low levels.