• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method for the production of urea of high mechanical strength by the crystallizing process or the evaporation process, including a prilling or granulating step, utilizing 0.01-1% by weight of formaldehyde in the form of a formaldehyde polymer, which comprises, before prilling or granulating, incorporating in the urea, a formaldehyde polymer with a formaldehyde content of 82-97% and with a melting point of about 90 DEG -160 DEG C.
    公开号:SU948289A3
    申请号:SU782663640
    申请日:1978-09-19
    公开日:1982-07-30
    发明作者:Эльстрем Торе；Фредерик Густавсен Пер；Хьель Олав
    申请人:Норск Хюдро А.С. (Фирма)；
    IPC主号:
    专利说明:

    (54) METHOD FOR MAKING GRANULES OF UREA
    one
    This invention relates to improved methods for producing urea with high mechanical strength.
    A known method for producing urea granules with increased mechanical strength, according to which dry paraformal dehydic particles are added to dry urea particles to form a coating on the outer surface of the urea particles 1.
    The disadvantage of this method is the low strength of the urea granules.
    Paraformaldehyde particles passing through a 100 mesh sieve are mixed with urea granules having an average size of 1.5 mm in an 80 rotating drum mixer for a time sufficient to uniformly distribute paraformaldehyde on the surface of the urea particles.
    The strength of an individual urea granule is measured by a value smaller than 1.6 mm and greater than 1.4 mm coated with paraformaldehyde. The results are shown in Table. one.
    The purpose of the invention is to increase the mechanical strength of urea granules.
    This goal is achieved by adding paraformaldehyde containing 82-96% formaldehyde with a melting point of 100-145 ° C and a degree of polymerization of 15-40 in 5 to an amount of 0.01-0.6 wt.% In the melt or cristamum urea before melting .
    It is preferable to use paraformaldehyde with a formaldehyde content of 9092% (90-96%) and a melting point per 10 surfaces of 120-140 ° C).
    The strength of the urea particles is defined as the percent discharged material and o6o3 is measured as a weapon test. This tlashn
    J5 means that particles from the selected separated fraction with a special tube are placed in a stream of air at a fixed speed. The air flow causes the particles to collide with a glacier metal plate surrounding a 0.5-il immetal sieve. The formation of crumbs and dust is determined by sieve analysis. This method is well reproducible and gives the characteristic of fragility of particles. Example 1. In the preparation of crystalline urea by evaporation of the molten glass before crystallization, OjOS-0.6 weight% formaldehyde polymer (p15-35) is added, the latter having a formaldepad content of 92%. Immediately after crystallization, the product is analyzed. The samples are cooled, and the 1.4-2 mm fraction is separated by sieving. The fragility of the urea particles is determined by testing with the arms described above. The fraction containing particles 5 less than 1.4 mm is determined. The resulting dust particles with a diameter of less than 0.5 mm are also determined. Example 2. Fully dried urea crystals at 70-80 ° C combine 0.05-0.30 wt.% Formaldehyde polymer (p 15-35) with formaldehyde content equal to 92%. The resulting mixture is melted and then crystallized. After crystallization, the analysis of the final product is carried out. Further processing is carried out as in Example 1. EXAMPLE 3. To study the effect of formaldehyde on the throughput of crystals with a low content of free ammonia and cyan and ammonia, the crystallizer is filled with a urea solution with a lower content of these two components compared to the norm npHiiHTbiM for such processes by their content. Fully dried urea crystals are treated with approximately 0.20, 4 wt.% Formaldehyde polymer, as in the examples described above. The results are measured using Examples 1-3 GF 1 are given in Table. 2. From table. 2 that the improvement of the business fraction is significantly higher when the content of free ammonia and ammonium cyanate is low, the decrease in the discharge / jun of material R ,. the estimate is as follows R., (ik-N.) - to. where it was destroyed in the experiment without,%: M, - destruction in the experiment of cCILO,%; K - onsta ta dependence of the speed of air used in testing weapons. The decrease in the amount of dust R is calculated from the formula (Sb. - S.) K, de dust content in the experiment without,%; Sp is the dust content in the experiment with CHO,%; K is the constant for the dependence of the air velocity used in weapons and weapons. The strength of the single particles is a force of 1 kg required to break the paste with a size of 1.6 mm. In the following examples, 0.6 g of formaldehyde polymer is used with a CH content, O 82-96%. The formaldehyde polymer is added to 100 g of urea solution at 140 ° C immediately prior to granulation. Example 4 A formaldehyde polymer is used, produced in the form of granules with a content of 82%, a degree of polymerization of 40 and a melting range of 130-155 Or, which is slowly dissolved until complete dissolution within 1 min. 5 s. The studies show that the standard exposure time is too short to dissolve this polymer, which leads to blockage of the pelletizing holes, i.e., the polymer is not suitable for this. At measure 5, grains with a content of 91%, a degree of polymerization of p 60 and a melting interval of 135-160 ° C are used. In this case, the polymer dissolves in 4 microns. Such a long time is unacceptable. Example 6. A formaldehyde polymer is used with a CHO content of 91%, a polymerization degree of 15 and a melting point of 00-130 ° C. The dissolution time in this case is 10-15 seconds. As a result, urea granules with a mechanical strength of 0.8 kg are obtained. FI p and m er 7, Formaldehyde polymer with a content of 96%, ste. Is used. With a polymerization foam of 25 and a melting range of 120-145 ° C, the dissolution time in this case is 15-20 seconds. As a result, urea granules with a mechanical strength of 0.9 kg are obtained.
    Table 1
    权利要求:
    Claims (3)
    [1]
    Claims 1. A method of producing urea granules by adding a formaldehyde polymer, in that, in order to increase the mechanical strength of the granules, the formaldehyde polymer is used as a formaldehyde polymer.
    urea children melting. paraformaldehyde, containing 82-96%, formaldehyde with a temperature of 100145 ° C and a degree of polymerization of 15-40 in an amount of 0.01-0.6 wt.%, which is added to the urea melt or to the crystals
    7 9482898
    [2]
    2. The method according to claim 1, about I l and h aa y and g - formaldehyde content of 90-92% and tems by using paraformal melt dehydration on the surface of 120-140 ° C. with a formaldehyde content of 90-96% n tempe-Sources of information,
    Ratura melting on the surface .printed in vnnma}
    [3]
    3. The method according to claim 1, of tl and h a ch i and -5 1. Patent Akgtt N 1296937, cl. At 44 d, with the use of paraformaldehyde copolymer. 1972 (prototype).
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    同族专利:
    公开号 | 公开日
    FR2403331A1|1979-04-13|
    IE47349B1|1984-02-22|
    GB2004546B|1982-04-15|
    AT363490B|1981-08-10|
    ATA676778A|1981-01-15|
    FR2403331B1|1982-05-28|
    RO75749A|1981-02-28|
    US4204053A|1980-05-20|
    PL119281B1|1981-12-31|
    YU201478A|1983-02-28|
    PL209631A1|1979-07-30|
    NL7808601A|1979-03-21|
    CA1092155A|1980-12-23|
    EG13487A|1981-06-30|
    GB2004546A|1979-04-04|
    NO148744C|1983-12-07|
    NO773201L|1979-03-20|
    ES473443A1|1979-04-01|
    IT1098847B|1985-09-18|
    HU175807B|1980-10-28|
    DE2836511A1|1979-03-29|
    NO148744B|1983-08-29|
    IT7827723D0|1978-09-15|
    IE781848L|1979-03-19|
    DD138540A5|1979-11-07|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE1916368A1|1969-03-29|1970-10-01|Veba Chemie Nord Gmbh|Slow-acting fertilizers|
    JPS5330689B1|1970-03-16|1978-08-29|JP3667418B2|1996-02-01|2005-07-06|東洋エンジニアリング株式会社|Method for producing granular urea|
    US6217630B1|1999-05-03|2001-04-17|Cargill, Incorporated|Conditioned fertilizer product, method for conditioning fertilizer, and method for using conditioned fertilizer product|
    DE19923525A1|1999-05-21|2000-11-23|Saar En Gmbh|Urea-formaldehyde fertilizer preparation, including addition of hexamethylene tetramine and/or tetramethylene diamine to precondensate before final condensation to release ammonia for neutralization in situ|
    GB2394956B|2002-10-18|2004-10-27|Basic Solutions Ltd|A urea based granule blend for ice-melting and reducing granule caking|
    CN1894172A|2003-12-18|2007-01-10|佐治亚-太平洋树脂公司|Extended-release nitrogen-containing granular fertilizer|
    US20050163911A1|2004-01-28|2005-07-28|Cargill, Inc.|Animal feed product containing crushed urea|
    US7862642B2|2006-12-14|2011-01-04|Georgia-Pacific Chemicals Llc|Extended-release urea-based granular fertilizer|
    DE102006061475A1|2006-12-23|2008-06-26|Evonik Degussa Gmbh|Process for the continuous preparation ofaliphatic diisocyanates|
    DE102014108703A1|2014-06-20|2015-12-24|Thyssenkrupp Ag|Urea composition and process for its preparation|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    NO773201A|NO148744C|1977-09-19|1977-09-19|PROCEDURE FOR MANUFACTURING UREA WITH HIGH MECHANICAL STRENGTH|
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