Patents by Inventor Gerald M. Griffin, Jr.

Gerald M. Griffin, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for recycling lead-acid batteries
    Patent number: 6177056
    Abstract: A process for recovery of substantially all the sulfur in a spent lead-acid battery as Na2SO4 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 SO2, (d) scrubbing the SO2 from the off gas stream using a soluble alkaline material such as NaOH, Na2CO3, 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 Na2SO4 or K2SO4, (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.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: January 23, 2001
    Assignee: RSR Corporation
    Inventors: R. David Prengaman, Clifford E. Morgan, Homer P. Hine, Gerald M. Griffin, Jr.