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Method for purifying nitrogen trifluoride gas

  • US 4,933,158 A
  • Filed: 10/24/1989
  • Issued: 06/12/1990
  • Est. Priority Date: 10/25/1988
  • Status: Expired due to Term
First Claim
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1. A method for purifying a nitrogen trifluoride gas which comprises the steps of thermally treating, at a temperature of 250°

  • to 700°

    C., a natural zeolite selected from the group consisting of analcime, clinoptilolite, mordenite, ferrierite, phillipsite, chabazite, erionite and laumontite;

    forming a packed bed of said treated zeolite; and

    passing said nitrogen trifluoride gas containing gaseous impurities at a temperature of -125°

    to 50°

    C. through said packed bed.

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