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WO1995021689A1 - Uree granulaire - Google Patents

Uree granulaire Download PDF

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Publication number
WO1995021689A1
WO1995021689A1 PCT/AU1995/000057 AU9500057W WO9521689A1 WO 1995021689 A1 WO1995021689 A1 WO 1995021689A1 AU 9500057 W AU9500057 W AU 9500057W WO 9521689 A1 WO9521689 A1 WO 9521689A1
Authority
WO
WIPO (PCT)
Prior art keywords
urea
granular urea
granulation
aluminium
conditioning agent
Prior art date
Application number
PCT/AU1995/000057
Other languages
English (en)
Inventor
Anthony Martin Brown
Original Assignee
Incitec Ltd.
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 Incitec Ltd. filed Critical Incitec Ltd.
Priority to AU16609/95A priority Critical patent/AU679330B2/en
Publication of WO1995021689A1 publication Critical patent/WO1995021689A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05C—NITROGENOUS FERTILISERS
    • C05C9/00—Fertilisers containing urea or urea compounds
    • C05C9/005—Post-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
    • B01J2/30—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic using agents to prevent the granules sticking together; Rendering particulate materials free flowing in general, e.g. making them hydrophobic

Definitions

  • the present invention relates to a process for the production of granular urea, and to the granular urea produced by that process.
  • This invention is particularly useful for the production of granular urea of particle size greater than 2 mm, of a greater than 1.5 kg crush test and which remains free-flowing and substantially free from caking during handling and storage.
  • Urea also known as carbamide or carbonyldiamide
  • Urea has a number of important applications, including use as a diuretic, as a partial source of dietary nitrogen in ruminants, in ammoniated dentifrices, in the paper industry to soften cellulose, and in fertilizers. Perhaps the chief among these uses is in agricultural fertilization. In this capacity, urea provides an easily available major source of nitrogen, which is a critical crop nutrient.
  • Urea is often not used as a fertilizer by itself, but rather in combination with other vital plant nutrients. Therefore, in commercial use, urea must often be blended with granular fertilizers to produce a balanced fertilizer blend.
  • fertilizer grade urea has been produced using prilling methods where molten urea is sprayed through a rose at the top of a prilling tower and the resultant droplets of urea solidify as they fall through a cooling stream of air.
  • This technology has several limitations:
  • the size of the urea particle is limited to under 2.00 mm diameter. Hence, the prill does not blend well with other types of fertilizers of larger particle size in mixtures blended to suit crop needs. This results in segregation of the mixture during handling processes and maldistribution of the fertilizer on crops.
  • the prilling process creates significant dust (that is, material under 1.00 mm in diameter).
  • This dust which is usually in excess of 1.0% of manufacture and can be as high as 10%, causes windage losses on application, segregates badly on handling and encourages rapid moisture absorption and caking of the fertilizer on storage.
  • the prills are usually fairly weak in structure- having a crush strength usually of less than 1.5 kg - and tend to break down during handling and storage. This further contributes to dust problems.
  • granulation can be achieved by feeding a stream of urea fines - or other suitable urea particulates - and a conditioning agent to a granulator where granulation is then carried out in the presence of a granulating aid.
  • the resulting product can then, of course, be dried, screened and cooled by way of any suitable available techniques.
  • the conditioning agent is preferably divalent metal oxide.
  • Preferred divalent oxides include calcium, magnesium and zinc oxides.
  • the granulating aid is preferably a metal salt or derivative thereof.
  • Preferred metal salts are mono-, di- or trivalent cation salts or derivatives thereof.
  • the more preferred trivalent cations are aluminium and ferric ions.
  • the most preferred metal salts include aluminium and ferric oxides and sulphates and hydrates thereof.
  • Any conventional granulator may be used, including rotary granulators, pugmills, drums and blungers.
  • the conditioning agent reacts with the granulating aid to prevent the creation of a highly soluble double salt, and it also absorbs moisture thus inhibiting softening of the product and subsequent caking. This is an important property of the conditioning agent because, as mentioned above, wet or soft product in a granulating plant leads to unacceptable blockages of the granulation plant. In combination with the granulating aid, the conditioning agent results in a larger size, hard, free flowing granule of urea.
  • the drawing represents the process diagram for a typical NPK granulation plant.
  • a urea fines feed (7) is fed into the granulation drum or blunger together with a modulated stream of divalent metal oxide (4) at the appropriate composition.
  • Steam (3) is used to sparge under the bed and assist in granulation.
  • a trivalent metal (2) such as aluminium or iron, eg. alum sulf te
  • a spray or scrubber liquor (6) may in some cases be used to add more moisture to the granulation.
  • a recycled stream of fines may also be fed back to the granulation equipment (11).
  • the granulated wet material is then fed to a drier where heat is supplied usually concurrently and moisture is dried off.
  • the dried material (12) is then fed to screens where the product size is separated and either sent direct to storage (14) or cooled and sent to storage.
  • the undersize is recycled and the oversize is crushed and also recycled to the granulator.
  • the air streams from the granulator and drier are scrubbed, usually in venturii scrubbers (10) and (16).
  • the scrubber liquor is recirculated to the scrubbers and a side stream is usually fed to the granulator to supplement the water balance in the granulator. In some cases, this does not occur and the scrubber liquor is accumulated for later disposal.
  • the process of the present invention is conducted in such a plant at a typical production rate of 10 to 20 tonnes per hour.
  • the granulating aid is an aluminium salt
  • the amount of the aluminium salt added to the slurry is sufficient to produce urea granules having an aluminium content of between 0.05% and 1.06% by weight; preferably of between about 0.15% and 1.06% by weight, and most preferably of between about 0.20% and 0.60% by weight.
  • undersize urea fines obtained from prilled urea are fed into a traditional NPK drum granulation plant at 10 tonnes/hr together with 300 kg/hr of ground magnesium oxide powder, using a 1500 kg/hr steam sparge together with 0.2 1/sec 50% alum sulphate solution.
  • the overall moisture content is increased using scrubber liquor sprayed into the granulator.
  • the product is dried to produce urea granules containing 0.3% aluminium and 0.7% magnesium by weight; 90% of the product exceeding 2.00 mm in size; and of 4.0 kg crush strength.
  • Granules produced according to the present invention were subjected to a caking test. Bag tests were conducted using the TVA bag test method described in Bulletin Y-147 and slightly adapted in that material was placed in 40 kg good quality fertilizer bags and stacked four layers or 1 tonne per pallet and then stacked four pallets high for one week, one month and three month trials. The bags were opened and inspected at those times and the degree of set and hardness of set were determined. This material consistently was only partially set and light finger pressure broke the lumps. If a bag was dropped from waist height the light set completely shattered.
  • Granulated urea produced according to the present invention is substantially harder than prilled urea known to the prior art and equal to granular urea produced by other processes.
  • This hardness of the granules was measured with a commercial compression tester, a Chatillon compression tester. At least 25 granules from a given product run were tested individually, and the average of these measurements was taken as the hardness of the product run from which the tested granules were taken.
  • the granules were placed, one at a time, on a flat surface provided on the compression tester. Pressure was applied to each granule using a flat-end rod attached to the compression tester, and a gauge mounted in the compression tester measured the pressure required to fracture the granule.
  • the urea granules produced according to the process of the present invention generally possessed a hardness in the range of from 2.5 to 4.0 kgs. This is to be compared with the prior art where prilled urea has typical hardness values of 1.5 kg or less.
  • Granulated urea produced according to the present invention remains free-flowing and does not consolidate or set to a hard mass upon being allowed to stand in large piles during storage.
  • the granules are of a size (at least 70%, but usually excess of 90%, of the product exceeds 2.00 mm) and hardness (at least greater than 1.5 kg crush strength, usually approximately 4.0 kg) superior to the prilled urea known from the aforementioned prior art.
  • urea produced according to the present invention experiences minimal breakdown into undesirable small fragments during cooling, storage, handling, blending, shipping and spreading.
  • granular urea produced according to the present invention either as a fertilizer per se or as an ingredient in fertilizer blends, produces exceptionally uniform results. This follows from the fact that the mechanics of spreading fertilizer are improved by use of a physically more uniform product, resulting in more uniform spreading.
  • blends using granular urea produced according to the present invention will remain uniformly blended, rather than tending to layer out by component by the time the end use is reached as is often the case with prior art blends.
  • the divalent metal oxide can not only function as a conditioning agent but also as a trace element additive in certain fertilizer blends.
  • the present invention allows urea fines generated from traditional prilling plants to be granulated to a useful end product using traditional granulation plants.
  • the significant capital cost of establishing a specialised urea granulation plant is avoided entirely.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Fertilizers (AREA)

Abstract

Cette invention se rapporte à un procédé pour produire de l'urée granulaire s'écoulant librement et ne s'agglomérant pas, qui présente une granulométrie d'au moins 2,00 mm et une force de cohésion des granules d'au moins 1,5 kg. La granulation est effectuée en présence d'un agent modificateur et d'un auxiliaire de granulation. L'agent modificateur est constitué par un oxyde de métal divalent, tel que l'oxyde de calcium, l'oxyde de magnésium ou l'oxyde de zinc. L'auxiliaire de granulation est constitué par un sel de métal trivalent tel que du sulfate d'aluminium ou du sulfate ferrique.
PCT/AU1995/000057 1994-02-11 1995-02-08 Uree granulaire WO1995021689A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU16609/95A AU679330B2 (en) 1994-02-11 1995-02-08 Granular urea

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPM3835 1994-02-11
AUPM3835A AUPM383594A0 (en) 1994-02-11 1994-02-11 Granular urea

Publications (1)

Publication Number Publication Date
WO1995021689A1 true WO1995021689A1 (fr) 1995-08-17

Family

ID=3778453

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1995/000057 WO1995021689A1 (fr) 1994-02-11 1995-02-08 Uree granulaire

Country Status (2)

Country Link
AU (1) AUPM383594A0 (fr)
WO (1) WO1995021689A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998037037A1 (fr) * 1997-02-20 1998-08-27 Western Industrial Clay Products Ltd. Uree particulaire additionnee de matieres inorganiques finement fractionnees aux fins de l'amelioration des caracteristiques de durete, de non-friabilite et de non agglutination
US7264746B2 (en) 2002-10-18 2007-09-04 Basic Solutions Limited Urea based granule blend for ice-melting and reducing granule caking
CN102369051A (zh) * 2009-03-18 2012-03-07 普拉菲尔有限公司 干法净化空气过滤介质
JP2013177287A (ja) * 2012-02-02 2013-09-09 Toray Ind Inc 窒素肥料の造粒方法、粒状品の窒素肥料の製造方法および粒状品の窒素肥料
EP3542899A1 (fr) 2018-03-20 2019-09-25 Yara International ASA Procédé et réacteur pour produire du sulfate d'ammonium d'urée

Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1311065A (en) * 1969-08-09 1973-03-21 Basf Ag Calcium nitrate-urea double salts capable of being scattered and stored
US3981713A (en) * 1971-07-23 1976-09-21 Mississippi Chemical Corporation Urea-zinc oxide composition and process
SU542750A1 (ru) * 1975-04-18 1977-01-15 Институт Химии Ан Узбекской Сср Способ получени азотного удобрени
AU4264778A (en) * 1977-12-22 1979-06-28 Fisons Ltd A composition comprising urea in association with a salt, and its use as a fertiliser
US4219589A (en) * 1977-06-09 1980-08-26 Compagnie Neerlandaise De L'azote Process for urea granulation
AU6926781A (en) * 1980-03-29 1981-10-26 Unie Van Kunstmestfabrieken B.V. Making urea-prills and prills thus obtained
GB2077722A (en) * 1980-05-20 1981-12-23 Azote Sa Cie Neerlandaise A Process for the Production of Urea Granules
SU1010046A1 (ru) * 1981-12-23 1983-04-07 Белорусский Ордена Трудового Красного Знамени Технологический Институт Им.С.М.Кирова Способ получени азотного удобрени
US4478632A (en) * 1981-07-03 1984-10-23 Compagnie Neerlandaise de l'Azote (Soci'ete' Anonyme) Process for making granules containing urea as the main component
US4494976A (en) * 1981-04-30 1985-01-22 Union Oil Company Of California Fertilizers containing nitrogen and micronutrients
US4500336A (en) * 1981-07-03 1985-02-19 Compagnie Neerlandaise De L'azote (Societe Anonyme) Process for making granules containing urea as the main component
SU1224298A1 (ru) * 1984-07-06 1986-04-15 Белорусский Ордена Трудового Красного Знамени Технологический Институт Им.С.М.Кирова Способ получени гранулированного карбамида
SU1289865A1 (ru) * 1984-08-18 1987-02-15 Предприятие П/Я А-1676 Способ получени гранулированного карбамида
AU6416886A (en) * 1985-10-17 1987-04-30 Nederlandse Stikstof Maatschappij B.V. A method of producing fertilizer granules containing urea and ammonium sulphate, and similar granules
SU1337377A1 (ru) * 1985-02-05 1987-09-15 Предприятие П/Я А-1676 Способ получени сложного удобрени
US4701353A (en) * 1983-08-27 1987-10-20 Unie Van Kunstmestfabrieken B.V. Process for the preparation of granules
SU1421728A1 (ru) * 1986-02-20 1988-09-07 Предприятие П/Я А-1676 Способ получени гранулированного карбамида,содержащего микроэлементы
AU2601188A (en) * 1987-11-02 1989-06-01 Incitec Fertilizers Limited Granular ammonium sulphate and process for the production thereof

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1311065A (en) * 1969-08-09 1973-03-21 Basf Ag Calcium nitrate-urea double salts capable of being scattered and stored
US3981713A (en) * 1971-07-23 1976-09-21 Mississippi Chemical Corporation Urea-zinc oxide composition and process
SU542750A1 (ru) * 1975-04-18 1977-01-15 Институт Химии Ан Узбекской Сср Способ получени азотного удобрени
US4219589A (en) * 1977-06-09 1980-08-26 Compagnie Neerlandaise De L'azote Process for urea granulation
AU4264778A (en) * 1977-12-22 1979-06-28 Fisons Ltd A composition comprising urea in association with a salt, and its use as a fertiliser
AU6926781A (en) * 1980-03-29 1981-10-26 Unie Van Kunstmestfabrieken B.V. Making urea-prills and prills thus obtained
GB2077722A (en) * 1980-05-20 1981-12-23 Azote Sa Cie Neerlandaise A Process for the Production of Urea Granules
US4494976A (en) * 1981-04-30 1985-01-22 Union Oil Company Of California Fertilizers containing nitrogen and micronutrients
US4478632A (en) * 1981-07-03 1984-10-23 Compagnie Neerlandaise de l'Azote (Soci'ete' Anonyme) Process for making granules containing urea as the main component
US4500336A (en) * 1981-07-03 1985-02-19 Compagnie Neerlandaise De L'azote (Societe Anonyme) Process for making granules containing urea as the main component
SU1010046A1 (ru) * 1981-12-23 1983-04-07 Белорусский Ордена Трудового Красного Знамени Технологический Институт Им.С.М.Кирова Способ получени азотного удобрени
US4701353A (en) * 1983-08-27 1987-10-20 Unie Van Kunstmestfabrieken B.V. Process for the preparation of granules
SU1224298A1 (ru) * 1984-07-06 1986-04-15 Белорусский Ордена Трудового Красного Знамени Технологический Институт Им.С.М.Кирова Способ получени гранулированного карбамида
SU1289865A1 (ru) * 1984-08-18 1987-02-15 Предприятие П/Я А-1676 Способ получени гранулированного карбамида
SU1337377A1 (ru) * 1985-02-05 1987-09-15 Предприятие П/Я А-1676 Способ получени сложного удобрени
AU6416886A (en) * 1985-10-17 1987-04-30 Nederlandse Stikstof Maatschappij B.V. A method of producing fertilizer granules containing urea and ammonium sulphate, and similar granules
SU1421728A1 (ru) * 1986-02-20 1988-09-07 Предприятие П/Я А-1676 Способ получени гранулированного карбамида,содержащего микроэлементы
AU2601188A (en) * 1987-11-02 1989-06-01 Incitec Fertilizers Limited Granular ammonium sulphate and process for the production thereof

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998037037A1 (fr) * 1997-02-20 1998-08-27 Western Industrial Clay Products Ltd. Uree particulaire additionnee de matieres inorganiques finement fractionnees aux fins de l'amelioration des caracteristiques de durete, de non-friabilite et de non agglutination
US7264746B2 (en) 2002-10-18 2007-09-04 Basic Solutions Limited Urea based granule blend for ice-melting and reducing granule caking
CN102369051A (zh) * 2009-03-18 2012-03-07 普拉菲尔有限公司 干法净化空气过滤介质
US8247346B2 (en) * 2009-03-18 2012-08-21 Purafil, Inc. Dry scrubbing air filtration media
JP2013177287A (ja) * 2012-02-02 2013-09-09 Toray Ind Inc 窒素肥料の造粒方法、粒状品の窒素肥料の製造方法および粒状品の窒素肥料
EP3542899A1 (fr) 2018-03-20 2019-09-25 Yara International ASA Procédé et réacteur pour produire du sulfate d'ammonium d'urée
WO2019180066A1 (fr) 2018-03-20 2019-09-26 Yara International Asa Procédé et réacteur de production de sulfate d'ammonium et d'urée
US11993557B2 (en) 2018-03-20 2024-05-28 Yara International Asa Method and reactor for producing urea ammonium sulphate

Also Published As

Publication number Publication date
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