GB908609A - Improvements in or relating to the production of nitrogenous vapour mixtures - Google Patents

Improvements in or relating to the production of nitrogenous vapour mixtures

Info

Publication number
GB908609A
GB908609A GB3606960A GB3606960A GB908609A GB 908609 A GB908609 A GB 908609A GB 3606960 A GB3606960 A GB 3606960A GB 3606960 A GB3606960 A GB 3606960A GB 908609 A GB908609 A GB 908609A
Authority
GB
United Kingdom
Prior art keywords
urea
temperature
bath
metal
ammonia
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB3606960A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WR Grace and Co
Original Assignee
WR Grace and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WR Grace and Co filed Critical WR Grace and Co
Publication of GB908609A publication Critical patent/GB908609A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C3/00—Cyanogen; Compounds thereof
    • C01C3/20—Thiocyanic acid; Salts thereof

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Vapour Deposition (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Silicon Compounds (AREA)

Abstract

A mixture of ammonia and cyanic acid vapour is produced by feeding urea into or on to a bath of molten metal at a temperature of at least 230 DEG C., said molten metal being inert to urea, ammonia, and cyanic acid. The process may be continuous, and the molten metal may be lead or tin or a mixture thereof. The temperature of the metal bath is preferably 400 DEG -510 DEG C., and the bath may be agitated. The temperature of the metal bath and the feed rate of the urea may be so chosen that the urea vaporizes substantially immediately but such high feed rates that cyanuric acid and/or ammelide is formed transistorily on the surface of the metal may be used, provided the so-formed surface layer is allowed to vaporize by cutting off the urea supply for a few minutes. The best operating conditions are a temperature of 413 DEG -427 DEG C., and a heat supply of 3,1 106 joules per kilogram of urea. The gaseous mixture of ammonia and cyanic acid may be used directly for producing melamine, or converted to ammonium cyanate by chilling, or treated with alcohols to give urethanes.ALSO:A mixture of ammonia and cyanic acid vapour, for use in the production of melamine is produced by feeding urea into or on to a bath of molten metal at a temperature of at least 230 DEG C., said molten metal being inert to urea, ammonia and cyanic acid. The process may be continuous, and the molten metal may be lead or tin or a mixture thereof. The temperature of the metal bath is preferably 400-510 DEG C., and the bath may be agitated. The temperature of the metal bath and the feed rate of the urea may be so chosen that the urea vaporizes substantially immediately, but such high feed rates that cyanuric acid and/or ammelide is formed transitorily on the surface of the metal may be used, provided that, the so-formed surface layer is allowed to vaporize by cutting of the urea supply for a few minutes. The best operating conditions are a temperature of 413-427 DEG C., and a heat supply of 3.1 X 106 joules per kilogram of urea. The gaseous mixture of ammonia and cyanic acid may be used directly for producing melamine, for example by passing it through hot silica gel.
GB3606960A 1959-10-22 1960-10-20 Improvements in or relating to the production of nitrogenous vapour mixtures Expired GB908609A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US84786859A 1959-10-22 1959-10-22

Publications (1)

Publication Number Publication Date
GB908609A true GB908609A (en) 1962-10-24

Family

ID=25301695

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3606960A Expired GB908609A (en) 1959-10-22 1960-10-20 Improvements in or relating to the production of nitrogenous vapour mixtures

Country Status (1)

Country Link
GB (1) GB908609A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1208306B (en) * 1964-03-28 1966-01-05 Basf Ag Process for the evaporation of urea for the production of melamine
DE1260475B (en) * 1963-09-27 1968-02-08 Shikoku Kasei Kogyo Company Lt Process for the production of cyanuric acid
US3970742A (en) * 1973-12-27 1976-07-20 Stamicarbon B.V. Process for preparing cyanic acid

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1260475B (en) * 1963-09-27 1968-02-08 Shikoku Kasei Kogyo Company Lt Process for the production of cyanuric acid
DE1208306B (en) * 1964-03-28 1966-01-05 Basf Ag Process for the evaporation of urea for the production of melamine
US3970742A (en) * 1973-12-27 1976-07-20 Stamicarbon B.V. Process for preparing cyanic acid

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