Patents by Inventor Donald E. Leonard

Donald E. Leonard 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).

  • Solid-solid separations utilizing alkanol amines
    Patent number: 5244155
    Abstract: The separation of silica or siliceous gangue from one or more desired minerals in an aqueous slurry via mechanical apparatus is improved by the addition of a small amount of an alkanol amine to the slurry. Examples of separation techniques benefiting from this technology include cyclones, tables and spiral separators.
    Type: Grant
    Filed: June 24, 1991
    Date of Patent: September 14, 1993
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Basil S. Fee, Donald E. Leonard
  • Dialkylated aryl monosulfonate collectors useful in the flotation of minerals
    Patent number: 5173176
    Abstract: Dialkylated aryl monosulfonic acids or salts thereof or their mixture are useful as collectors in the flotation of minerals, particularly oxide minerals. Particularly useful are those sulfonic acids or salts in which the alkyl substituents are unsymmetrical. Collector compositions comprising these salts and sulfide collectors such as xanthates are useful in flotations conducted at natural pH of the slurry.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: December 22, 1992
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Donald E. Leonard, Kevin A. Frazier
  • Sulfonated and carboxylate collector compositions useful in the flotation of minerals
    Patent number: 5171427
    Abstract: Dialkylated aryl sulfonic acids or salts thereof or their mixture are useful as collectors in the flotation of minerals, particularly oxide minerals. Collector compositions comprising these salts and oleic acid are particularly useful in hard water. Collector compositions comprising these salts and sulfide collectors such as xanthates are useful in flotations conducted at natural pH of the slurry.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: December 15, 1992
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Donald E. Leonard, Gordon D. McCann
  • Alkanol amine grinding aids
    Patent number: 5131600
    Abstract: The efficiency of grinding of silica-containing solids such as mineral ores is improved by the addition of alkanol amines as a grinding aid. Examples of useful amines include diethanol amine, ethanol amine, triethanol amine and mixtures thereof.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: July 21, 1992
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Donald E. Leonard, Basil S. Fee
  • Depression of the flotation of silica or siliceous gangue in mineral flotation
    Patent number: 5057209
    Abstract: A flotation process is disclosed wherein the selectivity to the valuable mineral is improved by the depression of silica or siliceous gangue by the use of a hydroxy-containing compound such as an alkanol amine. The process is useful in the flotation of oxide minerals as well as in sulfide flotation.
    Type: Grant
    Filed: February 23, 1990
    Date of Patent: October 15, 1991
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Donald E. Leonard, Robert D. Hansen, Basil S. Fee
  • Alkylated diaryl oxide monosulfonate collectors useful in the floatation of minerals
    Patent number: 5015367
    Abstract: Alkylated diaryl oxide monosulfonic acids or salts thereof or their mixture are useful as collectors in the flotation of minerals, particularly oxide minerals.
    Type: Grant
    Filed: February 23, 1990
    Date of Patent: May 14, 1991
    Assignee: The Dow Chemical Company
    Inventors: Richard R. Klimpel, Donald E. Leonard