Patents by Inventor Adrian E. Albrethsen

Adrian E. Albrethsen 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).

  • Patent number: 4985216
    Abstract: A process is provided for the reduction roasting of ores using a C.sub.2 to C.sub.8 hydrocarbon. The process is particularly applicable to manganese dioxide containing ores and provides enhanced reduction of the manganese to lower oxidation states at low operating temperatures for manganese dioxide ores and provides increased silver recoveries from refractory manganese-silver ores.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: January 15, 1991
    Assignee: ASARCO Incorporated
    Inventors: Mamdouh M. El Tawil, Adrian E. Albrethsen
  • Patent number: 3969202
    Abstract: Tetrahedrite ore concentrate, sodium sulfide added as such or formed in situ, calcium values preferably supplied as lime, and a reducing agent, e.g. coke, are smelted for a period sufficient to convert a major portion or substantially all of the antimony to a water-soluble sodium compound of antimony and sulfur and a major portion or substantially all of the arsenic also contained in the concentrate to a water-insoluble calcium compound of arsenic and oxygen. The sodium sulfide is incorporated into the charge for the smelting in an amount sufficient to convert at least a major portion of the antimony into the water-soluble sodium compound of antimony and sulfur; and the lime is incorporated into the smelting charge in amount sufficient to convert at least a major portion of the arsenic into the water-insoluble calcium compound of arsenic and oxygen.
    Type: Grant
    Filed: June 2, 1975
    Date of Patent: July 13, 1976
    Assignee: Asarco Incorporated
    Inventors: Adrian E. Albrethsen, Max L. Hollander, William H. Wetherill