Patents by Inventor Frank Caldon

Frank Caldon 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).

  • Treatment of metal bearing mineral material
    Patent number: 4084961
    Abstract: Pressure leaching metal bearing mineral material such as silver and copper bearing mineral material, e.g. sulfide and/or oxide, with an aqueous liquid containing sulfuric acid and very low concentration nitric acid under oxygen pressure, to dissolve out the corresponding desired metal values from such mineral material with nitric acid regeneration;Acid pretreatment of such metal bearing mineral material by preliminary leaching with an aqueous liquid containing sulfuric acid and very low concentration nitric acid under normal ambient pressure, to dissolve substantially attendant acid soluble metal carbonate values, e.g.
    Type: Grant
    Filed: September 10, 1976
    Date of Patent: April 18, 1978
    Assignee: Sunshine Mining Company
    Inventor: Frank Caldon