Patents by Inventor H. David Prior, Jr.

H. David Prior, 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).

  • Cristobalite-free mullite grain having reduced reactivity to molten aluminum and method of producing the same
    Patent number: 6548436
    Abstract: A method of making a cristobalite-free, mullite grain capable of withstanding reaction with molten aluminum, comprising the steps of: producing a clay slurry comprised of water and kaolin clay of a specific particle size; mixing a water insoluble barium or strontium containing compound into the clay slurry in an amount wherein the barium or strontium containing compound content of the slurry is equal to about 8% by weight of the kaolin clay in the slurry; removing sufficient water from the slurry to form a material having an pelletizable consistency; forming the material into pellets; heating the pellets by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2,650° F. (1,455° C.) for at least 30 minutes.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: April 15, 2003
    Assignee: North American Refractories Co.
    Inventors: H. David Prior, Jr., Daniel F. Fura
  • Cristobalite-free mullite grain having reduced reactivity to molten aluminum and method of producing the same
    Patent number: 6407023
    Abstract: A method of making a cristobalite-free, mullite grain capable of withstanding reaction with molten aluminum, comprising the steps of: producing a clay slurry comprised of water and kaolin clay of a specific particle size; mixing a water insoluble barium or strontium containing compound into the clay slurry in an amount wherein the barium or strontium containing compound content of the slurry is equal to about 8% by weight of the kaolin clay in the slurry; removing sufficient water from the slurry to form a material having an pelletizable consistency; forming the material into pellets; heating the pellets by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2,650° F. (1,455° C.) for at least 30 minutes.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: June 18, 2002
    Assignee: North American Refractories Co.
    Inventors: H. David Prior, Jr., Daniel F. Fura