Patents Assigned to Tandy Coporation
  • Method for waste treatment of organic strippers containing metals
    Patent number: 5308502
    Abstract: A method for treating liquid wastes containing photoresist polymers and heavy metals is disclosed. The method includes adding to the liquid wastes an aqueous solution of water soluble FE.sup.+3 and Al.sup.+3 salts at a pH in the range of from about 0.1 to 1.0, and a water soluble salt of Mg.sup.+2 or Ca.sup.+2. The ratio of the amount of the Fe.sup.+3 and Al.sup.+3 to the amount of the Mg.sup.+2 or Ca.sup.+2 is in the range of from 2 to 3 moles to 1 to 3 moles. A precipitate containing the heavy metals and photoresist polymers is formed.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: May 3, 1994
    Assignee: Tandy Coporation
    Inventor: James A. Brown