Patents by Inventor Leonard W. Haleen

Leonard W. Haleen 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: 4014985
    Abstract: Aluminum oxide having a sodium oxide content after calcination of less than 0.1% by weight is continuously precipitated as aluminum hydroxide from a Bayer process liquor by a controlled slow precipitation. The controlled, slow precipitation rate required to create a low soda product is achieved by controlling the residence time of liquor in the precipitation vessel so as to provide a constant, low ratio of aluminum oxide to sodium oxide. Residence time control in a Bayer process plant is achieved by controlling green liquor flow rate to the tank, or by sizing the tank for a constant flow. The use of heavy seed charges to increase the seed surface area permits the production of a low soda product at a faster precipitation rate.
    Type: Grant
    Filed: December 22, 1975
    Date of Patent: March 29, 1977
    Assignee: Aluminum Company of America
    Inventors: Leonard W. Haleen, Alan Pearson