Patents Assigned to Industrial Gypsum Co., Inc.
  • Method of making silica sand molds and cores for metal founding
    Patent number: 5911269
    Abstract: Thermal expansion defects, i.e. veining, are reduced in iron, steel, and nonferrous castings by adding a lithia-containing material in a sufficient amount to the silica sand mold to provide about 0.001% to about 2.0% of lithia. The addition of lithia is accomplished by adding lithium bearing minerals such as .alpha.-spodumene, amblygonite, montebrasite, petalite, lepidolite, zinnwaldite, eucryptite or lithium carbonate.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: June 15, 1999
    Assignee: Industrial Gypsum Co., Inc.
    Inventors: John J. Brander, Ronald M. Kotschi