Patents Assigned to Chemie AG Bitterfeld-Wolfen
  • Patent number: 5310530
    Abstract: A method for purifying phosphorus to insure a low sulfur content involves intensively mixing phosphorus and concentrated sulfuric acid to form an emulsion, breaking the emulsion by contact with water or dilute sulfuric acid, and then immediately separating the phosphorus and diluted sulfuric acid. The separated phosphorus is then stored in water until further processing is desired and is characterized by a sulfur content as low as about 50 ppm.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: May 10, 1994
    Assignee: Chemie AG Bitterfeld-Wolfen
    Inventors: Arndt Zschalich, Rudolf Schumann
  • Patent number: 5296212
    Abstract: A method for purifying white phosphorus contaminated with sulfur bound thereto involves contacting contaminated white phosphorus with water, steam, aqueous solutions, or vaporized aqueous solutions, preferably alkaline, to remove bound sulfur from the phosphorus. The purified phosphorus is characterized by a sulfur content as low as 50 ppm.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: March 22, 1994
    Assignee: Chemie AG Bitterfeld-Wolfen
    Inventors: Arndt Zschalich, Rudolf Schumann
  • Patent number: 5147621
    Abstract: The invention relates to a method for stabilizing phosphorus trichloride. In order to delay the formation of phosphorus oxychloride in phosphorus trichloride and to reduce it to a minimum value which no longer adversely affects further processing, one or more amines which have at least two aromatic hydrocarbon groups linked to one nitrogen atom, such as diphenylamine, phenothiazine, phenyl-4-methylphenylamine and triphenylamine, are added to the phosphorus trichloride. The amines can also be added in the form of their salts, including their quaternary ammonium compounds, or their reaction products with phosphorus halides. The amounts of amines, added fall within the range of 10.sup.-6 % to 10.sup.-1 %, based on the amount of phosphorus trichloride.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: September 15, 1992
    Assignee: Chemie AG Bitterfeld-Wolfen
    Inventor: Rudolf Schumann
  • Patent number: 5147622
    Abstract: The invention relates to a method for the stabilization of phosphorus trichloride, wherein one or more derivatives of dithiocarbamic acids are added to the phsophorus trichloride. As derivatives, salts, esters or thiuram sulfides of the dithiocarbamic acids, individually or as a mixture, are preferred. The amounts used generally fall within the range of 10.sup.-4 % to 10.sup.-2 %, based on the amount of phosphorus trichloride. Derivatives, which are only slightly soluble in phosphorus trichloride are advantageously used in amounts of more than 10.sup.-2 %. Due to the inventive addition of derivatives of dithiocarbamic acids, the formation of phosphorus oxychloride in the phosphorus trichloride is delayed significantly and reduced to a minimum value.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: September 15, 1992
    Assignee: Chemie AG Bitterfeld-Wolfen
    Inventor: Rudolf Schumann