CA2975179A1 - Method for conditioning fertilizer granules - Google Patents
Method for conditioning fertilizer granules Download PDFInfo
- Publication number
- CA2975179A1 CA2975179A1 CA2975179A CA2975179A CA2975179A1 CA 2975179 A1 CA2975179 A1 CA 2975179A1 CA 2975179 A CA2975179 A CA 2975179A CA 2975179 A CA2975179 A CA 2975179A CA 2975179 A1 CA2975179 A1 CA 2975179A1
- Authority
- CA
- Canada
- Prior art keywords
- granules
- moistened
- air
- fertilizer
- water
- 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.)
- Abandoned
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- 239000008187 granular material Substances 0.000 title claims abstract description 158
- 239000003337 fertilizer Substances 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 title claims abstract description 37
- 230000003750 conditioning effect Effects 0.000 title claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 27
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims abstract description 23
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 claims abstract description 16
- 229910052939 potassium sulfate Inorganic materials 0.000 claims abstract description 16
- 235000011151 potassium sulphates Nutrition 0.000 claims abstract description 16
- 235000011164 potassium chloride Nutrition 0.000 claims abstract description 11
- 239000001103 potassium chloride Substances 0.000 claims abstract description 11
- -1 e.g. Substances 0.000 claims abstract description 5
- 230000018044 dehydration Effects 0.000 claims description 19
- 238000006297 dehydration reaction Methods 0.000 claims description 19
- 238000005469 granulation Methods 0.000 claims description 16
- 230000003179 granulation Effects 0.000 claims description 16
- 239000007858 starting material Substances 0.000 claims description 16
- 238000003860 storage Methods 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 12
- 230000001143 conditioned effect Effects 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- 238000007602 hot air drying Methods 0.000 claims description 2
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 8
- 238000001035 drying Methods 0.000 description 15
- 239000000047 product Substances 0.000 description 12
- 238000009434 installation Methods 0.000 description 10
- 238000001816 cooling Methods 0.000 description 8
- 239000000428 dust Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 238000005299 abrasion Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229910052700 potassium Inorganic materials 0.000 description 4
- 239000011591 potassium Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 150000003863 ammonium salts Chemical class 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
- C01D5/004—Preparation in the form of granules, pieces or other shaped products
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
- C05D1/00—Fertilisers containing potassium
- C05D1/005—Fertilisers containing potassium post-treatment
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
- C05D1/00—Fertilisers containing potassium
- C05D1/02—Manufacture from potassium chloride or sulfate or double or mixed salts thereof
-
- 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
- B01J2/22—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by pressing in moulds or between rollers
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Fertilizers (AREA)
Abstract
The invention relates to a method for conditioning granular fertilizer material, e.g., potassium chloride granular fertilizer material or potassium sulfate granular fertilizer material, wherein granular material is first provided, wherein the granular material is moistened with, e.g., water, and wherein an air flow is then applied to the moistened granular material and the moistened granular material is strengthened in the process, namely possibly by utilizing the granular material's own heat. Vapor is preferably removed from the moistened granular material by means of an air amount of at least 100 m3 per metric ton of granular material at an air temperature of below 45 °C.
Description
=
METHOD FOR CONDITIONING FERTILIZER GRANULES
Description:
The invention relates to a method for conditioning fertilizer granules. Within the scope of the present invention, the phrase "fertilizer granules" refers in particular to potassium fertilizer granules and especially preferably potassium chloride fertilizer granules or potassium sulfate fertilizer granules. However, the invention also includes the conditioning of other fertilizer granules, e.g., ammonium sulfate granules.
Fertilizer granules, e.g., potassium sulfate fertilizer granules or potassium chloride fertilizer granules, are produced, for example, by press granulation (compacting) in roller presses where the starting material (e.g., fine-grained salts) is compacted in roller presses and consequently pressed to form so-called slabs. These flat slabs are then pulverized (e.g., in impact mills) and classified.
In the production of potassium chloride fertilizer granules, the starting material (for example, potassium chloride salts) is usually charged to the roller press in a hot dry condition. Then the granules are conditioned by moistening them with water and then exposing the moistened granules to a stream of air and solidifying them by utilizing the inherent heat of the granules.
This should improve the abrasion resistance, so that unwanted production of dust and/or fine particles is reduced. To do so, for example, DD 136 956 proposes that the dust and fines should first be removed from the (raw) granules in a fluidized bed, then wetted with water, and next the surface of the granules is solidified by recrystallization processes utilizing the thermal capacity of the granules. The moistened granules are then dried with a strong stream of air and next cooled with air, where both the drying and the cooling may take place in the fluidized bed (cf.
DD 136 956).
On the other hand, in the production of potassium sulfate fertilizers, the starting materials are not pressed while dry in practice but instead the finely crystalline potassium sulfate is usually pressed with the addition of water in the roller press to form the slab. Next the slab can be dried in a dryer according to a first process variant and then granulated. No conditioning of the granules is provided. In this case, the granules have a low final moisture content but the abrasion resistance is also low. In a second process variant, there is no drying of the slab before granulation, so the slab is granulated while moist. To increase the quality of the raw granules, they can be moistened by adding water after granulation. The moistened granules are then stored in large product storage devices for a period of several weeks so that the surface of
METHOD FOR CONDITIONING FERTILIZER GRANULES
Description:
The invention relates to a method for conditioning fertilizer granules. Within the scope of the present invention, the phrase "fertilizer granules" refers in particular to potassium fertilizer granules and especially preferably potassium chloride fertilizer granules or potassium sulfate fertilizer granules. However, the invention also includes the conditioning of other fertilizer granules, e.g., ammonium sulfate granules.
Fertilizer granules, e.g., potassium sulfate fertilizer granules or potassium chloride fertilizer granules, are produced, for example, by press granulation (compacting) in roller presses where the starting material (e.g., fine-grained salts) is compacted in roller presses and consequently pressed to form so-called slabs. These flat slabs are then pulverized (e.g., in impact mills) and classified.
In the production of potassium chloride fertilizer granules, the starting material (for example, potassium chloride salts) is usually charged to the roller press in a hot dry condition. Then the granules are conditioned by moistening them with water and then exposing the moistened granules to a stream of air and solidifying them by utilizing the inherent heat of the granules.
This should improve the abrasion resistance, so that unwanted production of dust and/or fine particles is reduced. To do so, for example, DD 136 956 proposes that the dust and fines should first be removed from the (raw) granules in a fluidized bed, then wetted with water, and next the surface of the granules is solidified by recrystallization processes utilizing the thermal capacity of the granules. The moistened granules are then dried with a strong stream of air and next cooled with air, where both the drying and the cooling may take place in the fluidized bed (cf.
DD 136 956).
On the other hand, in the production of potassium sulfate fertilizers, the starting materials are not pressed while dry in practice but instead the finely crystalline potassium sulfate is usually pressed with the addition of water in the roller press to form the slab. Next the slab can be dried in a dryer according to a first process variant and then granulated. No conditioning of the granules is provided. In this case, the granules have a low final moisture content but the abrasion resistance is also low. In a second process variant, there is no drying of the slab before granulation, so the slab is granulated while moist. To increase the quality of the raw granules, they can be moistened by adding water after granulation. The moistened granules are then stored in large product storage devices for a period of several weeks so that the surface of
2 the granules, which is partially dissolved due to the addition of water, becomes crystallized and solidified. This yields an end product with a higher moisture content but also with a greater abrasion resistance.
__ The methods used in practice to produce fertilizer granules, e.g., potassium chloride ¨ or potassium sulfate fertilizer granules ¨ have proven to be fundamentally successful in practice but they could be improved upon. That is where the present invention begins.
DE 28 10 640 Al also discloses a method for producing granular products from a fine-grained __ material consisting essentially of sulfatic potassium or ammonium salts by using a high-pressure roller press, wherein the material to be pressed is treated with water and/or water vapor at elevated temperatures before being introduced into the roller press. This should adjust a moisture content of 0.5 to 2.0% by weight and a temperature of 40 C to 50 C in the material to be pressed. The temperature of the material to be pressed should be kept below the __ condensation temperature of water vapor during the entire pressing operation. The product removed from the high-pressure roller press, preferably at a temperature of 55 to 95 C, consists of slabs which are then milled. Next the correctly sized particles are separated from the milled product, in particular separating particles with an average grain diameter of 1 mm to 4 mm as the product from the coarse grain and fine grain and cooled to room temperature.
Furthermore, DE 39 18 523 Al describes a method for preventing dust from forming when loading or transporting granules or pellets, in particular fertilizer granules, wherein such granules are prepared by dry press granulation. The formation of dust during loading or shipping is prevented by the use of a conditioning agent, such that a liquid mixture (dust binding mixture) __ consisting of at least two organic substances that are completely soluble in one another is added.
The invention is based on the object of creating a method with which fertilizer granules and potassium fertilizer granules in particular, especially preferably potassium chloride fertilizer __ granules or potassium sulfate fertilizer granules can be conditioned with little effort in terms of plant technology and economically, such that a storable product with low production of undersized grain and fine dust and with a high abrasion resistance is made available.
To achieve this object, the invention teaches according to a first aspect a method for __ conditioning fertilizer granules, for example, potassium chloride fertilizer granules, wherein first granules are made available at a temperature of more than 40 C, wherein the granules are moistened with water, and
__ The methods used in practice to produce fertilizer granules, e.g., potassium chloride ¨ or potassium sulfate fertilizer granules ¨ have proven to be fundamentally successful in practice but they could be improved upon. That is where the present invention begins.
DE 28 10 640 Al also discloses a method for producing granular products from a fine-grained __ material consisting essentially of sulfatic potassium or ammonium salts by using a high-pressure roller press, wherein the material to be pressed is treated with water and/or water vapor at elevated temperatures before being introduced into the roller press. This should adjust a moisture content of 0.5 to 2.0% by weight and a temperature of 40 C to 50 C in the material to be pressed. The temperature of the material to be pressed should be kept below the __ condensation temperature of water vapor during the entire pressing operation. The product removed from the high-pressure roller press, preferably at a temperature of 55 to 95 C, consists of slabs which are then milled. Next the correctly sized particles are separated from the milled product, in particular separating particles with an average grain diameter of 1 mm to 4 mm as the product from the coarse grain and fine grain and cooled to room temperature.
Furthermore, DE 39 18 523 Al describes a method for preventing dust from forming when loading or transporting granules or pellets, in particular fertilizer granules, wherein such granules are prepared by dry press granulation. The formation of dust during loading or shipping is prevented by the use of a conditioning agent, such that a liquid mixture (dust binding mixture) __ consisting of at least two organic substances that are completely soluble in one another is added.
The invention is based on the object of creating a method with which fertilizer granules and potassium fertilizer granules in particular, especially preferably potassium chloride fertilizer __ granules or potassium sulfate fertilizer granules can be conditioned with little effort in terms of plant technology and economically, such that a storable product with low production of undersized grain and fine dust and with a high abrasion resistance is made available.
To achieve this object, the invention teaches according to a first aspect a method for __ conditioning fertilizer granules, for example, potassium chloride fertilizer granules, wherein first granules are made available at a temperature of more than 40 C, wherein the granules are moistened with water, and
3 wherein the moistened granules are next exposed to a stream of air and solidified utilizing the inherent heat of the granules. It is provided according to the invention that the moistened granules (for solidification) are dehydrated with an air flow rate of at least 100 m3 (cubic meters) per metric ton of granules (i.e., specific air flow rate of 100 m3/t) at an air temperature of less than 45 C. The reference to weight is based on the moistened granules exposed to air.
The present invention is based on the finding that it is quite advantageous to moisten the (raw) granules and to expose them to a stream of air by utilizing the inherent heat so that the surface is solidified and smooth if necessary and so that the abrasion and the unwanted formation of undersized grain and/or fine dust is reduced. However the invention has recognized that is not necessary to dry the moistened granules (with hot air) and then cool them (with cool air) but instead that a product of high quality and with an excellent storage capacity can be obtained if (only) dehydration is carried out with very strong streams of air. Whereas with a traditional installation, for example, drying with hot air and then cooling with air first take place with hot air in a fluidized bed when the (cooling) air at room temperature and a very high air flow rate of at least 100 m3 per metric ton of granules, preferably at least 300 m3, for example, at least 600 m3 per metric ton is selected. In terms of the installation technology, it is therefore not necessary to set up both a drying zone and a cooling zone in a fluidized bed installation, for example, but instead the [dehydration] can take place in a single zone in the fluidized bed and/or in several (identical) zones in which only air at room temperature and/or at ambient temperature with a very strong stream of air is supplied. The water vapor escaping from the moist granules (i.e., the vapors) is removed with strong streams of air, so that the moisture is effectively removed from the granules and the desired solidification takes place. The fact that the air used for dehydration is at a relatively low temperature in the range of room temperature is especially important, so that it is possible in particular to omit complex burners and/or burner stages for heating the air.
Only when such an installation is operated in an extremely cold environment and consequently it is necessary to intake air at very low temperatures (e.g., close to or below the freezing point) may it be expedient to have a slight preheating of the air within the scope of the invention, but without exceeding temperatures of 45 C. Consequently, on the whole, the installation operates very favorably in terms of energy and plant technology. Within the scope of the invention, the air for dehydration especially preferably has a maximum temperature of up to 35 C.
The air flow rate can be selected as a function of the air temperature and the relative atmospheric humidity (i.e., that of the air supplied).
It is provided that the moistened granules are preferably dehydrated in a fluidized bed installation. Basically, however, the dehydration may also take place in installations of another type.
The present invention is based on the finding that it is quite advantageous to moisten the (raw) granules and to expose them to a stream of air by utilizing the inherent heat so that the surface is solidified and smooth if necessary and so that the abrasion and the unwanted formation of undersized grain and/or fine dust is reduced. However the invention has recognized that is not necessary to dry the moistened granules (with hot air) and then cool them (with cool air) but instead that a product of high quality and with an excellent storage capacity can be obtained if (only) dehydration is carried out with very strong streams of air. Whereas with a traditional installation, for example, drying with hot air and then cooling with air first take place with hot air in a fluidized bed when the (cooling) air at room temperature and a very high air flow rate of at least 100 m3 per metric ton of granules, preferably at least 300 m3, for example, at least 600 m3 per metric ton is selected. In terms of the installation technology, it is therefore not necessary to set up both a drying zone and a cooling zone in a fluidized bed installation, for example, but instead the [dehydration] can take place in a single zone in the fluidized bed and/or in several (identical) zones in which only air at room temperature and/or at ambient temperature with a very strong stream of air is supplied. The water vapor escaping from the moist granules (i.e., the vapors) is removed with strong streams of air, so that the moisture is effectively removed from the granules and the desired solidification takes place. The fact that the air used for dehydration is at a relatively low temperature in the range of room temperature is especially important, so that it is possible in particular to omit complex burners and/or burner stages for heating the air.
Only when such an installation is operated in an extremely cold environment and consequently it is necessary to intake air at very low temperatures (e.g., close to or below the freezing point) may it be expedient to have a slight preheating of the air within the scope of the invention, but without exceeding temperatures of 45 C. Consequently, on the whole, the installation operates very favorably in terms of energy and plant technology. Within the scope of the invention, the air for dehydration especially preferably has a maximum temperature of up to 35 C.
The air flow rate can be selected as a function of the air temperature and the relative atmospheric humidity (i.e., that of the air supplied).
It is provided that the moistened granules are preferably dehydrated in a fluidized bed installation. Basically, however, the dehydration may also take place in installations of another type.
4 If working with a fluidized bed system, the invention proposes that the moistened granules are dehydrated in a dehydration zone of the fluidized bed system with a stream of air that has been described here and without an upstream drying zone using hot air.
The moistening may be carried out in a fundamentally known way in a drum and/or a drum mixer. Such mixing in the drum should at the same time ensure rounding of particles. However, in a preferred further embodiment, the present invention has recognized that moistening need not necessarily be carried out in a drum but instead, for example, moistening may also take place in a shaft mixer, for example, a dual-shaft mixer. This makes it possible to further reduce the complexity of the system.
Due to the dehydration, the water content of the granules is reduced to less than 1%, preferably less than 0.5%, for example, less than 0.2% (based on weight).
The subject matter of the invention is also a device for conditioning fertilizer granules with a method of the type described here. Such a device has a mixing device for moistening the (raw) granules and a dehydration device in which the moistened granules are dehydrated with an air flow rate of at least 100 m3 per metric ton of granules at an air temperature of less than 45 C.
The dehydration device is especially preferably designed as a fluidized bed system and the dehydration consequently takes place in the fluidized bed.
According to a second aspect, the invention discloses a method for conditioning fertilizer granules, for example, potassium sulfate fertilizer granules, wherein moist granules produced by granulation of a moist slab emerging from a roller press are made available first, wherein the granules are moistened with water, for example, and wherein the moistened granules are next treated with a stream of air and thereby dehydrated and solidified. Moist granules produced from the slab within the scope of the invention preferably refers to granules with a moisture content of 0.5% by weight to 2.0% by weight.
According to this invention, however, these granules which are already moist are moistened (again) by the addition of water, namely preferably with the addition of 0.5%
by weight to 5.0%
by weight, especially preferably 1% by weight to 3% by weight water, each based on the weight of the granules. The granules produced from the slab has a relatively low temperature because the starting material charged previously to the press is not (actively) heat and at any rate heating takes place (passively) due to the pressing and/or granulating process in the wake of press granulation.
In this second aspect, the invention is directed first to the finding that it is not (always) necessary following the production of fertilizer granules, for example, potassium sulfate fertilizer granules, to dry the slab before granulation, so that expensive drying equipment can be omitted according to the invention. The granules produced by press granulation are consequently
The moistening may be carried out in a fundamentally known way in a drum and/or a drum mixer. Such mixing in the drum should at the same time ensure rounding of particles. However, in a preferred further embodiment, the present invention has recognized that moistening need not necessarily be carried out in a drum but instead, for example, moistening may also take place in a shaft mixer, for example, a dual-shaft mixer. This makes it possible to further reduce the complexity of the system.
Due to the dehydration, the water content of the granules is reduced to less than 1%, preferably less than 0.5%, for example, less than 0.2% (based on weight).
The subject matter of the invention is also a device for conditioning fertilizer granules with a method of the type described here. Such a device has a mixing device for moistening the (raw) granules and a dehydration device in which the moistened granules are dehydrated with an air flow rate of at least 100 m3 per metric ton of granules at an air temperature of less than 45 C.
The dehydration device is especially preferably designed as a fluidized bed system and the dehydration consequently takes place in the fluidized bed.
According to a second aspect, the invention discloses a method for conditioning fertilizer granules, for example, potassium sulfate fertilizer granules, wherein moist granules produced by granulation of a moist slab emerging from a roller press are made available first, wherein the granules are moistened with water, for example, and wherein the moistened granules are next treated with a stream of air and thereby dehydrated and solidified. Moist granules produced from the slab within the scope of the invention preferably refers to granules with a moisture content of 0.5% by weight to 2.0% by weight.
According to this invention, however, these granules which are already moist are moistened (again) by the addition of water, namely preferably with the addition of 0.5%
by weight to 5.0%
by weight, especially preferably 1% by weight to 3% by weight water, each based on the weight of the granules. The granules produced from the slab has a relatively low temperature because the starting material charged previously to the press is not (actively) heat and at any rate heating takes place (passively) due to the pressing and/or granulating process in the wake of press granulation.
In this second aspect, the invention is directed first to the finding that it is not (always) necessary following the production of fertilizer granules, for example, potassium sulfate fertilizer granules, to dry the slab before granulation, so that expensive drying equipment can be omitted according to the invention. The granules produced by press granulation are consequently
5 available in a moistened condition. Nevertheless, according to the invention, there is (additional) moistening due to the addition of water in order to trigger partial dissolution of the surface of the granules. Then there is cold hardening of the surface of the granules due to crystallization of the dissolved salts. According to the invention, this is supported and accelerated by the fact that the granules are exposed to a stream of air and thereby solidified without input of heat and consequently the granules are conditioned. Due to this exposure to air, the granules are dehydrated without being dried out due to a supply of heat. Such an exposure to air and consequent dehydration can preferably take place in a fluidized bed system and consequently dehydration can preferably take place in a fluidized bed system, namely especially preferably with relatively high air flow rates. Thus, the moistened granules are preferably dehydrated in an air flow rate of at least 100 m3, preferably at least 300 m3, for example, at least 600 m3 per metric ton of granules. In doing so, the process is carried out at relatively air temperatures so that drying with hot air is avoided and instead preferably air at room temperature is used, so this makes it possible to eliminate the use of burners and/or burner stages for heating the air. Only when such an installation can be operated in an extremely cold environment and consequently air at very low temperatures must be taken in (for example, temperatures close to the freezing point or even lower) may a slight preheating of the air be expedient within the scope of the invention, but still without exceeding temperatures of 45 C. Consequently, such a plant can operate very favorably with regard to plant technology. The air to which the moistened granules are exposed and with which they are consequently dehydrated especially preferably is at a temperature of up to 35 C. The air flow rate can be selected as a function of the air temperature and the (relative) atmospheric humidity (of the air supplied).
The conditioning of the granules according to the invention, for example, in a fluidized bed apparatus without input of heat, results in the abrasion resistance being improved by 30% to 50% in comparison with traditional methods in which the (moistened) granules are stored in large product storage devices over a period of several weeks. Furthermore, the storage times, which may optionally still be necessary until achieving a market-ready product with a moisture content of 50.5(Y0 by weight, can be reduced greatly and then the required storage capacities can also be reduced accordingly.
According to the second aspect of the invention, the subject matter of the invention is in particular not only the method described here for conditioning but also a method for producing
The conditioning of the granules according to the invention, for example, in a fluidized bed apparatus without input of heat, results in the abrasion resistance being improved by 30% to 50% in comparison with traditional methods in which the (moistened) granules are stored in large product storage devices over a period of several weeks. Furthermore, the storage times, which may optionally still be necessary until achieving a market-ready product with a moisture content of 50.5(Y0 by weight, can be reduced greatly and then the required storage capacities can also be reduced accordingly.
According to the second aspect of the invention, the subject matter of the invention is in particular not only the method described here for conditioning but also a method for producing
6 fertilizer granules, for example, potassium fertilizer granules, especially preferably potassium sulfate fertilizer granules. Within the scope of this production process, - starting material, for example, fine-grained potassium salt is moistened with the addition of water for example, - the moistened starting material is compacted in a roller press to form a slab, and - the slab is pulverized (i.e., granulated) to form the granules and is optionally classified.
Next the granules are then conditioned in the manner described above, i.e., the granules are moistened with water and the moistened granules are then exposed to a stream of air and thereby solidified.
The starting material is preferably not heated before being compacted, so that it preferably has temperatures of less than 40 C. In the wake of press granulation, i.e., compacting, on the one hand, and granulation, on the other hand, there is also no (active) heating of the material but instead there is at any rate a (passive) heating due to the pressing operation and/or the granulation process. The starting material is preferably moistened by adding water in an amount of 0.5% by weight to 2% by weight, for example, 0.5% by weight to 1.5% by weight, based on the weight of the starting material. The slab formed by compacting is especially preferably pulverized in a moist condition without first drying it so that moist granules are made available and can then be moistened in the manner described above within the context of conditioning (additionally). Fundamentally, however, the invention also includes production processes in which the slab is optionally dried before being granulated.
The (conditioned) granules are stored in a storage device, for example, a storage building, in air for a predetermined period of time, as needed. According to the invention, this period of time can be reduced significantly in comparison with the known methods, so that the storage capacities can also be reduced on the whole.
The starting material is preferably moistened immediately before being charged to the roller press, namely in a mixer, for example, a drum mixer or a dual-shaft mixer.
For moistening of the granules produced by press granulation, preferably a mixer, for example, a drum mixer is also used. Such mixing in the drum can at the same time ensure rounding of the particles. However, in a preferred further embodiment, the invention has recognized that moistening in a drum is not absolutely necessary but that instead the moistening may also take
Next the granules are then conditioned in the manner described above, i.e., the granules are moistened with water and the moistened granules are then exposed to a stream of air and thereby solidified.
The starting material is preferably not heated before being compacted, so that it preferably has temperatures of less than 40 C. In the wake of press granulation, i.e., compacting, on the one hand, and granulation, on the other hand, there is also no (active) heating of the material but instead there is at any rate a (passive) heating due to the pressing operation and/or the granulation process. The starting material is preferably moistened by adding water in an amount of 0.5% by weight to 2% by weight, for example, 0.5% by weight to 1.5% by weight, based on the weight of the starting material. The slab formed by compacting is especially preferably pulverized in a moist condition without first drying it so that moist granules are made available and can then be moistened in the manner described above within the context of conditioning (additionally). Fundamentally, however, the invention also includes production processes in which the slab is optionally dried before being granulated.
The (conditioned) granules are stored in a storage device, for example, a storage building, in air for a predetermined period of time, as needed. According to the invention, this period of time can be reduced significantly in comparison with the known methods, so that the storage capacities can also be reduced on the whole.
The starting material is preferably moistened immediately before being charged to the roller press, namely in a mixer, for example, a drum mixer or a dual-shaft mixer.
For moistening of the granules produced by press granulation, preferably a mixer, for example, a drum mixer is also used. Such mixing in the drum can at the same time ensure rounding of the particles. However, in a preferred further embodiment, the invention has recognized that moistening in a drum is not absolutely necessary but that instead the moistening may also take
7 place in a shaft mixer, for example, a dual-shaft mixer. The complexity of the installation can be further reduced in this way.
The water content of the granules is especially preferably reduced to less than 1%, preferably less than 0.5%, for example, less than 0.2% based on weight, in the wake of conditioning by exposing the granules to the stream of air. If the desired levels are not reached directly due to the air exposure within the context of conditioning, the value can then be reached by relatively short storage times.
An installation for producing fertilizer granules of the type described here will have at least one (high-pressure) roller press (compacting press) and a pulverizing device (e.g., impact mill) downstream from the roller press. A moistening device, for example, a mixer, may be arranged upstream from the roller press. For conditioning of the granules produced by press granulation, a mixing device is then preferably also made available for moistening the granules, for example, a shaft mixer (e.g., a dual-shaft mixer). This is then preferably followed by a device with which the moistened granules can be exposed to a stream of air, for example, a dehydration device which is preferably designed as a fluidized bed system, i.e., the dehydration takes place in the fluidized bed, especially preferably without an upstream hot air drying zone.
The invention will now be explained in greater detail below on the basis of a drawing which shows only one exemplary embodiment, in which:
Fig. 1 shows a device for conditioning fertilizer granules, in particular potassium chloride fertilizer granules in a highly simplified schematic diagram, in particular according to the first aspect of the invention and Fig. 2 shows a device for producing and conditioning fertilizer granules, in particular potassium sulfate fertilizer granules, in particular according to the second aspect of the invention.
Fig. 1 shows a device for conditioning fertilizer granules, in particular potassium chloride fertilizer granules in a greatly simplified schematic diagram. Fig. 1 relates in particular to the first aspect of the invention.
The device according to the invention has a mixing apparatus 1 and a dehydration apparatus 2 downstream from a mixing device 1, which is designed as a fluidized bed system 2, in the exemplary embodiment shown here.
The water content of the granules is especially preferably reduced to less than 1%, preferably less than 0.5%, for example, less than 0.2% based on weight, in the wake of conditioning by exposing the granules to the stream of air. If the desired levels are not reached directly due to the air exposure within the context of conditioning, the value can then be reached by relatively short storage times.
An installation for producing fertilizer granules of the type described here will have at least one (high-pressure) roller press (compacting press) and a pulverizing device (e.g., impact mill) downstream from the roller press. A moistening device, for example, a mixer, may be arranged upstream from the roller press. For conditioning of the granules produced by press granulation, a mixing device is then preferably also made available for moistening the granules, for example, a shaft mixer (e.g., a dual-shaft mixer). This is then preferably followed by a device with which the moistened granules can be exposed to a stream of air, for example, a dehydration device which is preferably designed as a fluidized bed system, i.e., the dehydration takes place in the fluidized bed, especially preferably without an upstream hot air drying zone.
The invention will now be explained in greater detail below on the basis of a drawing which shows only one exemplary embodiment, in which:
Fig. 1 shows a device for conditioning fertilizer granules, in particular potassium chloride fertilizer granules in a highly simplified schematic diagram, in particular according to the first aspect of the invention and Fig. 2 shows a device for producing and conditioning fertilizer granules, in particular potassium sulfate fertilizer granules, in particular according to the second aspect of the invention.
Fig. 1 shows a device for conditioning fertilizer granules, in particular potassium chloride fertilizer granules in a greatly simplified schematic diagram. Fig. 1 relates in particular to the first aspect of the invention.
The device according to the invention has a mixing apparatus 1 and a dehydration apparatus 2 downstream from a mixing device 1, which is designed as a fluidized bed system 2, in the exemplary embodiment shown here.
8 In the inventive process, first granules (and/or raw granules) are made available, namely from a granulation system 4, which is merely indicated. This usually consists of one (or more) roller presses with downstream milling and classification stages. The starting material, for example, fine dried salt, is compacted in this roller press and thereby pressed to form so-called slabs.
These slabs are then pulverized, i.e. ground and classified, so that the granules, i.e., raw granules, are made available for the subsequent conditioning. After press granulation, the raw granules have relatively high temperatures of more than 40 C. This residual heat is utilized as part of the following conditioning. This conditioning is represented in the figure. The (hot) raw granules G are moistened in the mixing device 1. This moistening mixer 1 is designed as a dual-shaft mixer in the exemplary embodiment. This is followed by the dehydration device 2 and consequently also the fluidized bed system. The moistened granules B are dehydrated in this fluidized bed system 2 with an air flow rate of at least 100 m3 per metric ton of granules at an air temperature of less than 45 C and thereby solidified. The air L thereby supplied consequently has a temperature in the range of room temperature. The step of drying with hot air is eliminated, so that not even a subsequent cooling is required. The fluidized bed system 2, which is used within the scope of the invention, can consequently be shortened, i.e., reduced in size, in comparison with traditional fluidized bed systems, which have a drying zone, on the one hand, and also have a cooling zone, on the other hand, so that the system complexity is reduced. Then corresponding hot gas generators for heating the drying air can also be omitted.
With the method according to the invention, a product P, i.e., conditioned granules with a high quality and long storage life are obtained by a simple method in terms of the plant technology.
Fig. 2 shows schematically in a highly simplified diagram a device for producing (and conditioning) fertilizer granules, in particular potassium sulfate fertilizer granules. Fig. 2 relates in particular to the second aspect of the invention.
The essential component of such a plant is a roller press 5 in which the starting material (e.g., potassium sulfate) is pressed and consequently compacted. The starting material A supplied to the roller press however is moistened first with water, namely in a mixing device 6, which is arranged upstream from the roller press 5.
The moist slab S emerging from the roller press 5 is pulverized and granulated in a granulating device 7, which may be designed as an impact mill, for example. It is especially preferably provided that the slab S is pulverized in a moist condition without prior drying. This is usually followed by a classification (not shown here).
These slabs are then pulverized, i.e. ground and classified, so that the granules, i.e., raw granules, are made available for the subsequent conditioning. After press granulation, the raw granules have relatively high temperatures of more than 40 C. This residual heat is utilized as part of the following conditioning. This conditioning is represented in the figure. The (hot) raw granules G are moistened in the mixing device 1. This moistening mixer 1 is designed as a dual-shaft mixer in the exemplary embodiment. This is followed by the dehydration device 2 and consequently also the fluidized bed system. The moistened granules B are dehydrated in this fluidized bed system 2 with an air flow rate of at least 100 m3 per metric ton of granules at an air temperature of less than 45 C and thereby solidified. The air L thereby supplied consequently has a temperature in the range of room temperature. The step of drying with hot air is eliminated, so that not even a subsequent cooling is required. The fluidized bed system 2, which is used within the scope of the invention, can consequently be shortened, i.e., reduced in size, in comparison with traditional fluidized bed systems, which have a drying zone, on the one hand, and also have a cooling zone, on the other hand, so that the system complexity is reduced. Then corresponding hot gas generators for heating the drying air can also be omitted.
With the method according to the invention, a product P, i.e., conditioned granules with a high quality and long storage life are obtained by a simple method in terms of the plant technology.
Fig. 2 shows schematically in a highly simplified diagram a device for producing (and conditioning) fertilizer granules, in particular potassium sulfate fertilizer granules. Fig. 2 relates in particular to the second aspect of the invention.
The essential component of such a plant is a roller press 5 in which the starting material (e.g., potassium sulfate) is pressed and consequently compacted. The starting material A supplied to the roller press however is moistened first with water, namely in a mixing device 6, which is arranged upstream from the roller press 5.
The moist slab S emerging from the roller press 5 is pulverized and granulated in a granulating device 7, which may be designed as an impact mill, for example. It is especially preferably provided that the slab S is pulverized in a moist condition without prior drying. This is usually followed by a classification (not shown here).
9 The (moist) granules G produced in this way are then conditioned according to the invention ¨
optionally after storage and/or temporary storage. To do so, the granules G
are moistened with water in a mixing device 1 to partially dissolve the surface of the granules.
Next the moistened granules B are sent to a device 2, which is designed as a fluidized bed system in this exemplary embodiment, and in which the moistened granules B are exposed to a stream of air L and thereby dehydrated and solidified. Drying with hot air is not necessary here, so that then cooling is not necessary either. Consequently, the fluidized bed system 5, which is used within the scope of the invention, can be shortened, i.e., reduced in size in comparison with traditional fluidized bed systems, which have a drying zone, on the one hand, and have a cooling zone, on the other hand, so that the system complexity is reduced. Corresponding hot gas generators may then also become unnecessary for heating the air for drying.
The granules conditioned in this way as the product P have a very low moisture content, so that they are directly available and market ready. If the moisture does not meet requirements, there is the possibility of storing the granules from the fluidized bed system 2 in air in a storage device, for example, a storage building, so that a saleable product is available after a relatively short period of time.
optionally after storage and/or temporary storage. To do so, the granules G
are moistened with water in a mixing device 1 to partially dissolve the surface of the granules.
Next the moistened granules B are sent to a device 2, which is designed as a fluidized bed system in this exemplary embodiment, and in which the moistened granules B are exposed to a stream of air L and thereby dehydrated and solidified. Drying with hot air is not necessary here, so that then cooling is not necessary either. Consequently, the fluidized bed system 5, which is used within the scope of the invention, can be shortened, i.e., reduced in size in comparison with traditional fluidized bed systems, which have a drying zone, on the one hand, and have a cooling zone, on the other hand, so that the system complexity is reduced. Corresponding hot gas generators may then also become unnecessary for heating the air for drying.
The granules conditioned in this way as the product P have a very low moisture content, so that they are directly available and market ready. If the moisture does not meet requirements, there is the possibility of storing the granules from the fluidized bed system 2 in air in a storage device, for example, a storage building, so that a saleable product is available after a relatively short period of time.
Claims (16)
1. A method for conditioning fertilizer granules, for example, potassium chloride fertilizer granules, wherein first granules at a temperature of more than 40°C are made available, wherein the granules are moistened with water and wherein the moistened granules are then exposed to a stream of air and thereby solidified by utilizing the inherent heat of the granules, wherein the moistened granules are dehydrated at an air flow rate of at least 100 m3 per metric ton of granules at an air temperature of less than 45°C.
2. The method for conditioning fertilizer granules, for example, potassium sulfate fertilizer granules, wherein first moist granules produced by granulation of a moist slab coming from a roller press are made available, wherein the granules are moistened and wherein the moistened granules are then exposed to a stream of air and thereby solidified.
3. The method according to claim 2, wherein the granules are moistened with the addition of water, e.g., 0.5% by weight to 5% by weight, preferably 1% by weight to 3% by weight water.
4. The method according to claim 2 or 3, wherein the moistened granules are dehydrated with an air flow rate of at least 100 m3 per metric ton of granules and/or an air temperature of less than 45°C.
5. The method according to any one of claims 1 to 4, wherein the moistened granules are dehydrated with an air flow rate of at least 300 m3, e.g., at least 600 m3 per metric ton of granules.
6. The method according to any one of claims 1 to 5, wherein the moistened granules are dehydrated with air at an air temperature of less than 35°C.
7. The method according to any one of claims 1 to 6, wherein the moistened granules are exposed to air and/or dehydrated in a fluidized bed system.
8. The method according to any one of claims 1 to 7, wherein the moistened granules in a dehydration zone of the fluidized bed device are exposed to an air stream without an upstream hot air drying zone.
9. The method according to any one of claims 1 to 8, wherein the moistened granules are moistened with water in a mixer, for example, a shaft mixer.
10. The method for producing fertilizer granules, for example, potassium sulfate fertilizer granules, wherein - starting material, for example, fine-grained potassium salt is moistened with the addition of water for example, - the moistened starting material is compacted in a roller press to form a slab, - the slab is pulverized to form granules and optionally classified, and wherein the granules are then conditioned by a method according to any one of claims 2 to 9.
11. The method according to claim 10, wherein the starting material is not heated before being compacted.
12. The method according to claim 10 or 11, wherein the slab is pulverized in a moist condition without being dried first and is optionally classified.
13. The method according to any one of claims 10 to 12, wherein the conditioned granules are stored in air in a storage device.
14. A device for conditioning fertilizer granules, in particular potassium chloride fertilizer granules or potassium sulfate fertilizer granules by a method according to any one of claims 1 to 9, comprising:
- a mixing device for moistening the granules, and - a dehydration device in which the moistened granules are exposed to a stream of air of at least 100 m3 per metric ton of granules and an air temperature of less than 45°C.
- a mixing device for moistening the granules, and - a dehydration device in which the moistened granules are exposed to a stream of air of at least 100 m3 per metric ton of granules and an air temperature of less than 45°C.
15. The device according to claim 14, characterized in that the dehydration device is designed as a fluidized bed system.
16. The device according to claim 14 or 15, characterized in that the mixing device is designed as shaft mixer, for example, as a dual-shaft mixer or as a mixing drum.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102015101199.9A DE102015101199A1 (en) | 2015-01-28 | 2015-01-28 | Process for conditioning fertilizer granules |
| DE102015101199.9 | 2015-01-28 | ||
| DE102015115468.4 | 2015-09-14 | ||
| DE102015115468.4A DE102015115468A1 (en) | 2015-09-14 | 2015-09-14 | Process for conditioning fertilizer granules |
| PCT/EP2016/051686 WO2016120317A1 (en) | 2015-01-28 | 2016-01-27 | Method for conditioning granular fertilizer material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2975179A1 true CA2975179A1 (en) | 2016-08-04 |
Family
ID=55353173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2975179A Abandoned CA2975179A1 (en) | 2015-01-28 | 2016-01-27 | Method for conditioning fertilizer granules |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP3250314A1 (en) |
| BR (1) | BR112017015339A2 (en) |
| CA (1) | CA2975179A1 (en) |
| RU (1) | RU2674974C1 (en) |
| WO (1) | WO2016120317A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102017007716A1 (en) * | 2017-08-16 | 2019-02-21 | K+S Aktiengesellschaft | Process for reducing the tendency to caking of potassium chloride |
| CN108715558A (en) * | 2018-06-07 | 2018-10-30 | 国投新疆罗布泊钾盐有限责任公司 | A kind of method that potassium sulfate ball-type is granulated |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2810640C2 (en) | 1978-03-11 | 1983-03-17 | Kali Und Salz Ag, 3500 Kassel | Process for the manufacture of granular products |
| DD136956B1 (en) | 1978-06-01 | 1981-09-30 | Wolfgang Tittel | METHOD FOR PRODUCING NON-DUSTING ABRASIVE CALIDUIN AGENT GRANULES |
| SU986478A1 (en) * | 1980-08-11 | 1983-01-07 | Пермский политехнический институт | Method of producing granulated mineral fertilizers |
| DE3918523A1 (en) | 1989-06-07 | 1990-12-13 | Kali & Salz Ag | METHOD FOR BINDING DUST IN DUENGER GRANULES |
| IT1243397B (en) * | 1990-11-27 | 1994-06-10 | Agrimont Spa | PROCESS FOR THE GRANULATION OF POTASSIC SALTS |
| DE10252848B3 (en) * | 2002-11-13 | 2004-03-25 | Kali-Umwelttechnik Sondershausen Gmbh | Preparing potassium fertilizer granules comprises treating crude granulate with silicate or carbonate solution, then vibrating mixture |
-
2016
- 2016-01-27 WO PCT/EP2016/051686 patent/WO2016120317A1/en active Application Filing
- 2016-01-27 EP EP16704139.1A patent/EP3250314A1/en not_active Withdrawn
- 2016-01-27 RU RU2017129806A patent/RU2674974C1/en active
- 2016-01-27 BR BR112017015339A patent/BR112017015339A2/en not_active Application Discontinuation
- 2016-01-27 CA CA2975179A patent/CA2975179A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| RU2674974C1 (en) | 2018-12-13 |
| WO2016120317A1 (en) | 2016-08-04 |
| EP3250314A1 (en) | 2017-12-06 |
| BR112017015339A2 (en) | 2018-01-09 |
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