Patents by Inventor Kojur N. Subramanian

Kojur N. Subramanian 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).

  • Nickel recovery from sulfur-deficient mattes
    Patent number: 4201648
    Abstract: A nickel matte in which the atomic ratio of S:(Ni+Co+Cu) is less than 0.7 is fragmented and slurried with water or an aqueous nickel sulfate solution to ensure that the S:(Ni+Co+Cu) ratio for the slurry as a whole exceeds 0.4, the slurry is heated under pressure in the presence of oxygen to form a basic nickel sulfate and the reacted slurry is treated with lime to convert the basic nickel sulfate to nickel hydroxide. The nickel hydroxide is then separated from gypsum by physical separation and thereafter dissolved in spent sulfate electrolyte to generate fresh electrolyte from which nickel can be electrowon.
    Type: Grant
    Filed: April 2, 1979
    Date of Patent: May 6, 1980
    Assignee: The International Nickel Co., Inc.
    Inventors: Kojur N. Subramanian, Norman C. Nissen, John A. Thomas