Patents Examined by Eugene T. Wheelock
  • Process for the preparation of phosphoric acid
    Patent number: 3935298
    Abstract: When phosphate rock and sulfuric acid are mixed under such conditions that gypsum dihydrate is stably formed and sulfuric acid is added to the phosphate rock in an amount not exceeding the amount equivalent to a calcium component in the phosphate rock, small masses of the reaction product between the phosphate rock and sulfuric acid can be maintained in the non-disintegrable form throughout extraction of phosphoric acid from said reaction product, and phosphoric acid can be extracted from such reaction product at a high rate in a good yield.
    Type: Grant
    Filed: July 2, 1973
    Date of Patent: January 27, 1976
    Assignee: Mizusawa Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yujiro Sugahara, Yoshibumi Noshi, Hiroyuki Naito, Akira Takahashi, Shoji Shoji
  • Process of manufacturing whisker crystalline silicon carbide
    Patent number: 3933984
    Abstract: Whisker crystalline silicon carbide is prepared by heating a silicon-containing material for example, elemental silicon, silicon oxides, silicon hydroxides, silicon salts and the like with a halogen and carbon-containing material, such as a mixture of hydrocarbon and chlorine-containing material selected from chlorine, hydrogen chloride, tetrachloromethane and phosgene and halogenated hydrocarbon at a temperature of 800.degree.C or higher under a substantial oxygen and nitrogen gas-free condition.
    Type: Grant
    Filed: March 18, 1971
    Date of Patent: January 20, 1976
    Inventors: Isao Kimura, Hidetsugu Habata
  • Process for the manufacture of doped silver halides
    Patent number: 3932292
    Abstract: The process of this invention for the production of doped metal halides, especially silver halides, comprises reacting a doped metal with the vapour of the halogen in a closed vessel. A mono- or polycrystalline metal halide body is built up on a stationary or rotating base. Homogenously doped metal halides are obtained.
    Type: Grant
    Filed: August 1, 1973
    Date of Patent: January 13, 1976
    Assignee: Ciba-Geigy AG
    Inventor: Pierre Junod
  • Producing high purity gold powder
    Patent number: 3930845
    Abstract: Merrill slime is contacted with a gold chloride solution to cement out gold and dissolve base metals. The separated solids are treated in a known type of process by chlorination with elemental chlorine, separation of the chlorinated solution and precipitation of gold powder by means of a reductant. The precipitation is partial and the remaining solution is used for the cementation step. The gold powder is separated and subjected to special washing techniques for the removal of adsorbed impurities. A molar ratio of Cl/Au of about 4 after chlorination is aimed at to minimise the solubility of silver chloride. After removing solid impurities this ratio is raised to ensure that any dissolved silver remains in solution when gold is subsequently precipitated.
    Type: Grant
    Filed: January 22, 1973
    Date of Patent: January 6, 1976
    Assignee: Anglo American Corporation of South Africa
    Inventors: Herbert J. Bovey, Dennis A. Temple, Basil J. Goldswain
  • Process for the catalytic synthesis of ammonia
    Patent number: 3998932
    Abstract: A catalytic process and apparatus for synthesizing ammonia wherein from 30 to 80% of the effluent gases containing at least 12 molar percent ammonia are recycled to the inlet of the catalyst bed.
    Type: Grant
    Filed: February 28, 1975
    Date of Patent: December 21, 1974
    Assignee: Montedison Fibre S.p.A.
    Inventors: Amilcare Collina, Emanuele Malfatti, Antonio Cappelli