EP0746535A1 - Procede de cristallisation de substances chimiques - Google Patents

Procede de cristallisation de substances chimiques

Info

Publication number
EP0746535A1
EP0746535A1 EP95941633A EP95941633A EP0746535A1 EP 0746535 A1 EP0746535 A1 EP 0746535A1 EP 95941633 A EP95941633 A EP 95941633A EP 95941633 A EP95941633 A EP 95941633A EP 0746535 A1 EP0746535 A1 EP 0746535A1
Authority
EP
European Patent Office
Prior art keywords
particles
melt
container
crystallization
monodisperse
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.)
Withdrawn
Application number
EP95941633A
Other languages
German (de)
English (en)
Inventor
Axel König
Joachim Ulrich
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.)
Santrade Ltd
Original Assignee
Santrade 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
Priority claimed from DE4445880A external-priority patent/DE4445880A1/de
Application filed by Santrade Ltd filed Critical Santrade Ltd
Publication of EP0746535A1 publication Critical patent/EP0746535A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0004—Crystallisation cooling by heat exchange
    • B01D9/0013—Crystallisation cooling by heat exchange by indirect heat exchange
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0036—Crystallisation on to a bed of product crystals; Seeding

Definitions

  • the invention relates to a process for the crystallization of chemical substances, which are first melted and placed in a container, crystallize there under heat removal and can be removed as a product after being conveyed through the container.
  • the invention is therefore based on the object of designing a method of the type mentioned at the outset in such a way that large areas of crystallization nuclei are made available for crystal formation in a simple and reliable manner.
  • small, in particular monodisperse and at least partly solid, particles are introduced into the container in a uniform distribution and conveyed by the container, on which the melt crystallizes.
  • the particles can be formed at least from part of the melt and, after the further crystallization, further particles can be removed as larger particles or as a melt formed from them.
  • This configuration therefore dispenses with the previously customary production of a porridge enriched with crystals and instead provides for the use of solid particles as seed particles or, as a step upstream of the actual cleaning process, for the production of particles which are as small as possible but of the same size and which are then relatively uniform in the Allow known counterflow of the melt to be distributed and therefore because of the large available Crystallization surfaces ensure, in a relatively simple manner, a uniform flow and a large yield.
  • the particles used in the manner according to the invention or initially produced from the melt can also be fed to the cleaning column in large quantities without fear of caking or lump formation which leads to the flow and thus disrupts the operation of the system through axial backmixing. This is jointly responsible for the high production to be achieved by the new method.
  • the particles can be introduced in a simple manner from above into the container through which the flow flows from bottom to top, sink down and be removed or melted there.
  • this configuration makes use of the dead weight of the particles, which become increasingly larger as a result of crystallization, so that complex stirring devices can be dispensed with.
  • the particles can be obtained in a simple manner by dripping the melt onto a solidification belt, which can be done in a simple manner by known devices, e.g. according to DE 28 53 054 C2.
  • the new method allows the larger particles produced in the countercurrent to sink in the case of a direct discharge, used as a product or further cleaned in a subsequent process.
  • a direct discharge used as a product or further cleaned in a subsequent process.
  • fertilizer mixtures can also be produced in a simple manner, as it is characterized in the subclaims.
  • FIG. 4 shows a second exemplary embodiment of an apparatus for carrying out the method according to the invention, in which one component of a melt is crystallized out of a mixed melt with several components,
  • FIG. 5 shows the implementation of the method according to the invention with the device of FIG. 4 using the state diagram
  • FIG. 6 shows a further variant of an embodiment for carrying out the method according to the invention.
  • Fig. 1 shows schematically a crystallization tank (1), the walls of which are provided in a manner not shown with a temperature jacket.
  • a melt is introduced into this container (1) from below through a feed (2) which flows from the bottom upwards and can be removed again as residual melt in the direction of the arrow (3).
  • the melt is in the container (1) up to the level (4) which lies above the discharge line (3).
  • monodisperse solid particles (5) are initially formed from the melt and are introduced into the melt from above, in such a way that the particles (5) added are prevented from caking.
  • this is achieved in that the melt is fed in the direction of the arrow (6) to a so-called rotoformer (according to DE 28 53 054 C2), which drops the melt in individual drops onto a moving cooling belt (8) underneath , where the monodisperse particles can form in large quantities by solidification. These particles (5) are thrown off at the right end during the movement of the belt (8) and can then be fed to the container (1).
  • a so-called rotoformer according to DE 28 53 054 C2
  • the particles (5) formed on the cooling belt which can also have a size below 1 mm in diameter, melt crystallizes inside the container (1), so that the larger particles (9) shown in FIG. 2 are formed, which have the particle (5) in their center.
  • the larger particles (9) can now be removed according to the method according to the invention in the direction of arrow (10) at the lower end of the container (1), for example by means of a discharge screw, and into a further container (11) be included. It is also possible and expedient to subject the particles (5) to a diffusion wash after their production on the cooling belt and before their use, in which the particles are cleaned in a clean melt.
  • FIG. 4 and 5 show a modification of the method according to the invention in that here in a container (15) a separation of two components (A) and (B) of a melt added in the direction of arrow (16) can take place.
  • particles (5) are only produced from the component (A) of the melt (A, B) and placed in the container (15) in the direction of the arrow (17).
  • the component (A) of the melt grows on the particles (5), so that these larger particles (18), which only consist of component (A), in the direction of arrows (19) either as in the container (20) indicated, immediately removed and, similar to FIG.
  • FIG. 6 shows a variant of an embodiment for carrying out the method according to the invention, in which the particles (5) in the neck region of a container (25) are briefly brought to a temperature higher than their melting temperature by a temperature jacket, so that its outer layer is slightly dissolved.
  • the thus pretreated Par ⁇ Tikel then move in counter-current in the container 'downward and, since the temperature is kept a little to achieve the fewer meta stable region smaller than the structure Schmelztempera ⁇ , grow into larger particles, such as the already is the case with the previously described facilities.
  • the melt itself which can consist of one or more components, is added to the container (25) in the sense of the arrow (27) above a settling chamber (28) in such a way that in the area (29) indicated by the broken line the larger particles (30) are kept in a kind of fluidized bed and cleaned by the counterflow.
  • the temperature can correspond to the melting temperature, so that cleaned melt can be removed in the direction of the arrow (31).
  • the residual melt is removed in the direction of arrow (32) in the upper region of the container (25).
  • a particularly advantageous application of the new method is the production of fertilizer pastilles.
  • fertilizer pastilles e.g. as monodisperse particles, i.e. Potassium chloride or ammonium sulfate can be used as the core, on which ammonium nitrate, urea or sulfur is then crystallized.
  • a protective layer made of a polymer which can also be applied using the process according to the invention and which prevents undesired moisture before use, but dissolves in the soil after use.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Fertilizers (AREA)
  • Glanulating (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Abstract

Selon un procédé de cristallisation de substances chimiques, celles-ci sont d'abord fondues et introduites dans un récipient dans lequel elles se cristallisent par extraction de chaleur, puis traversent le récipient et sont prélevées sous forme d'un produit. Le procédé se caractérise en ce que l'on répartit uniformément dans le récipient de petites particules, notamment de la même taille, au moins en partie solides. La masse fondue se cristallise sur ces particules pendant qu'elles sont transportées à travers le récipient. L'invention sert à produire des engrais en pastilles.
EP95941633A 1994-12-22 1995-11-30 Procede de cristallisation de substances chimiques Withdrawn EP0746535A1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE4445880 1994-12-22
DE4445880A DE4445880A1 (de) 1994-12-22 1994-12-22 Verfahren zum Reinigen chemischer Substanzen
DE19507316 1995-03-02
DE19507316A DE19507316A1 (de) 1994-12-22 1995-03-02 Verfahren zur Kristallisation chemischer Substanzen
PCT/EP1995/004708 WO1996019421A1 (fr) 1994-12-22 1995-11-30 Procede de cristallisation de substances chimiques

Publications (1)

Publication Number Publication Date
EP0746535A1 true EP0746535A1 (fr) 1996-12-11

Family

ID=25943149

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95941633A Withdrawn EP0746535A1 (fr) 1994-12-22 1995-11-30 Procede de cristallisation de substances chimiques

Country Status (7)

Country Link
EP (1) EP0746535A1 (fr)
JP (1) JPH10500066A (fr)
KR (1) KR970701162A (fr)
AU (1) AU4300596A (fr)
CA (1) CA2183774A1 (fr)
DE (1) DE19507316A1 (fr)
WO (1) WO1996019421A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19637380C1 (de) 1996-09-13 1998-04-09 Basf Ag Verfahren zur Herstellung von Hydroxipivalinsäureneopentylglykolester-Granulaten
CA2600771C (fr) * 2005-04-18 2016-06-07 Dsm Ip Assets B.V. Procede de production de particules comprenant de l'uree
US7985393B2 (en) * 2009-03-31 2011-07-26 Uop Llc Pastillation of ammonium sulfate nitrate
CN111558332A (zh) * 2020-03-27 2020-08-21 浙江三圣科技有限公司 一种大颗粒复合肥造粒成型装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1592796B2 (de) * 1963-05-22 1973-04-26 Verenigde Kunstmestfabneken Mekog Albatros N V , Utrecht (Niederlande) Duengemittel mit einem ueberzug aus kohlenwasserstoffen
DE1792150A1 (de) * 1968-07-27 1971-10-14 Chemie Appbau Mainz Schmahl & Verfahren zur Herstellung von schwefelhaltigen Duengemittel-Granulaten mit einer harten,abriebfesten Oberflaechenschicht
DE1941460C3 (de) * 1969-08-14 1973-10-04 Gebr. Kaiser, 4150 Krefeld-Uerdingen Verfahren und Vorrichtung zur Er zeugung von Granalien aus einer in einer in einer Schmelzgutwanne befindlichen Schmelze
US4857098A (en) * 1987-08-11 1989-08-15 Pursell Industries Sulfur-coated fertilizer granules and process of making same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9619421A1 *

Also Published As

Publication number Publication date
AU4300596A (en) 1996-07-10
CA2183774A1 (fr) 1996-06-27
DE19507316A1 (de) 1996-09-05
KR970701162A (ko) 1997-03-17
JPH10500066A (ja) 1998-01-06
WO1996019421A1 (fr) 1996-06-27

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