Patents Assigned to Tomen Construction Co., Ltd.
  • Process for processing a waste etching solution containing a fluorine component and an ammonia component to recover valuables therefrom
    Patent number: 5281318
    Abstract: A process for recovering valuables from a waste etching solution containing a fluorine component and ammonia component is provided comprising recovering respectively a fluorine component and ammonia component in the waste solution and recovering a potassium and/or sodium component used for processing the waste solution, and utilizing respectively the recovered components for preparation of an etching solution or reusing or recycling for processing the waste solution.
    Type: Grant
    Filed: July 27, 1992
    Date of Patent: January 25, 1994
    Assignee: Tomen Construction Co., Ltd.
    Inventor: Hiroshi Tahara