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GB800722A - Improvements in the production of melamine from urea - Google Patents

Improvements in the production of melamine from urea

Info

Publication number
GB800722A
GB800722A GB7297/56A GB729756A GB800722A GB 800722 A GB800722 A GB 800722A GB 7297/56 A GB7297/56 A GB 7297/56A GB 729756 A GB729756 A GB 729756A GB 800722 A GB800722 A GB 800722A
Authority
GB
United Kingdom
Prior art keywords
per cent
melamine
urea
dehydrated
cent
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
GB7297/56A
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.)
Montedison SpA
Original Assignee
Montedison SpA
Montecatini Societa Generale per lIndustria Mineraria e Chimica SpA
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 Montedison SpA, Montecatini Societa Generale per lIndustria Mineraria e Chimica SpA filed Critical Montedison SpA
Publication of GB800722A publication Critical patent/GB800722A/en
Expired legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D251/00Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/12Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D251/26Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
    • C07D251/40Nitrogen atoms
    • C07D251/54Three nitrogen atoms
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D251/00Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/12Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D251/26Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
    • C07D251/40Nitrogen atoms
    • C07D251/54Three nitrogen atoms
    • C07D251/56Preparation of melamine
    • C07D251/60Preparation of melamine from urea or from carbon dioxide and ammonia

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Catalysts (AREA)

Abstract

Melamine is prepared under conditions in which corrosion to apparatus is reduced by first dehydrating urea by heating it to 135 DEG to 150 DEG C. for 1 to 12 hours under atmospheric or sub-atmospheric pressure and subsequently passing the dehydrated urea through an enclosure heated to a temperature of from 350 DEG to 450 DEG C. under a pressure of between 20 and 100 atmospheres in the presence of ammonia. The urea may be dehydrated in a stainless steel vessel and the conversion to melamine may be carried out in a reactor constructed of an alloy consisting of 14 per cent Cr, 58 per cent Ni, 17 per cent Mo, 6 per cent Fe and 5 per cent W, or of 19-21 per cent Cr, 46-53 per cent Co, 9-11 per cent Ni, 3 per cent Fe, 14-16 per cent W and minor percentages of Si and Mg.ALSO:Chemical apparatus for use in the preparation of melamine is constructed of alloys consisting of 14 per cent Cr, 58 per cent Ni, 17 per cent Mo, 6 per cent Fe, and 5 per cent W, or of 19-21 per cent Cr, 46-53 per cent Co, 9-11 per cent Ni, 3 per cent Fe (mamximum), 14-16 per cent W and mior percentages of silicon and magnesium.
GB7297/56A 1955-03-12 1956-03-08 Improvements in the production of melamine from urea Expired GB800722A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT800722X 1955-03-12

Publications (1)

Publication Number Publication Date
GB800722A true GB800722A (en) 1958-09-03

Family

ID=11316864

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7297/56A Expired GB800722A (en) 1955-03-12 1956-03-08 Improvements in the production of melamine from urea

Country Status (1)

Country Link
GB (1) GB800722A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995001345A1 (en) * 1993-07-01 1995-01-12 Kemira Oy Process for the preparation of melamine
WO1996020182A1 (en) * 1994-12-23 1996-07-04 Agrolinz Melamin Gmbh Process for producing high-purity melamine
WO1996023778A1 (en) * 1995-02-03 1996-08-08 Agrolinz Melamin Gmbh Process for purifying melamine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995001345A1 (en) * 1993-07-01 1995-01-12 Kemira Oy Process for the preparation of melamine
US5731437A (en) * 1993-07-01 1998-03-24 Kemira Agro Oy Process for the preparation of melamine
WO1996020182A1 (en) * 1994-12-23 1996-07-04 Agrolinz Melamin Gmbh Process for producing high-purity melamine
US5721363A (en) * 1994-12-23 1998-02-24 Agrolinz Melamin Gmbh Process for the production of highly pure melamine
CN1082951C (en) * 1994-12-23 2002-04-17 阿格罗林茨蜜胺有限公司 Process for producing high purity melamine
WO1996023778A1 (en) * 1995-02-03 1996-08-08 Agrolinz Melamin Gmbh Process for purifying melamine

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