Patents by Inventor Sataro Nakajima

Sataro Nakajima 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).

  • Process for the manufacture of a slurry containing highly concentrated phosphoric acid and calcium sulfate hemihydrate in a readily filterable form
    Patent number: 4101638
    Abstract: The present invention relates to a wet process for the manufacture of phosphoric acid, which process essentially comprises a digestion step in which phosphate rock is digested by means of phosphoric acid and sulfuric acid to form a slurry containing highly concentrated phosphoric acid together with calcium sulfate hemihydrate, and a separation step in which the slurry is filtered for separation of calcium sulfate hemihydrate from the highly concentrated phosphoric acid (in which the concentration of P205 in the product acid is higher than 40% by weight, based on the weight of the product acid) and which is characterized by supplying active silica at a ratio of 0.2-5% by weight, based on the weight of phosphate rock, in order that active silica may be present in the above mentioned digestion step.
    Type: Grant
    Filed: August 2, 1976
    Date of Patent: July 18, 1978
    Assignee: Nissan Chemical Industries, Ltd.
    Inventors: Takasuke Inoue, Yuzo Itoh, Sataro Nakajima, Shin-Ichi Tajika, Yoshio Saiki