WO2023067591A1

WO2023067591A1 - A granule of kieserite and a process for the production thereof

Info

Publication number: WO2023067591A1
Application number: PCT/IL2022/051094
Authority: WO
Inventors: Khalil Abu-Rabeah
Original assignee: Icl Europe Cooperatief U.A.
Priority date: 2021-10-22
Filing date: 2022-10-17
Publication date: 2023-04-27

Abstract

According to some embodiments, there is provided herein a granule comprising Kieserite and one or more additives selected from the group including phosphate rock, Ammonium sulphate and Ammonium Nitrate, in a ratio of between 30:70 to 70:30, respectively.

Description

A GRANULE OF KIESERITE AND A PROCESS FOR THE PRODUCTION THEREOF

Field of the Invention

The present invention relates to the field of fertilizers, specifically to production of kieserite granules.

Background of the Invention

To grow properly, plants need nutrients (nitrogen, potassium, calcium, zinc, magnesium, iron, manganese, etc.) which normally can be found in the soil. Sometimes fertilizers are needed to achieve a desired plant growth as these can enhance the growth of plants.

This growth of plants is met in two ways, the traditional one being additives that provide nutrients. The second mode by which some fertilizers act is to enhance the effectiveness of the soil by modifying its water retention and aeration. Fertilizers typically provide, in varying proportions, three main macronutrients:

Nitrogen (N): leaf growth;

Phosphorus (P): Development of roots, flowers, seeds, fruit;

Potassium (K): Strong stem growth, movement of water in plants, promotion of flowering and fruiting; three secondary macronutrients: calcium (Ca), magnesium (Mg), and

Sulphur (S); micronutrients: copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), boron (B), and of occasional significance there are silicon (Si), cobalt (Co), and vanadium (V) plus rare mineral catalysts.

The most reliable and effective way to make the availability of nutrients coincide with plant requirements is by controlling their release into the soil solution, using slow release or controlled release fertilizers.

Solid fertilizers include granules, prills, crystals and powders. A prilled fertilizer is a type of granular fertilizer that is nearly spherical made by solidifying free-falling droplets in air or a fluid medium. Most controlled- release fertilizers (CRFs) used in commercial nurseries are prilled fertilizers that have been coated with sulfur or a polymer. These products have been developed to allow a slow release of nutrients into the root zone throughout crop development.

Kieserite is the magnesium sulfate mineral (MgSCh H2O).

Kieserite (26% MgO, 50% SO3) is quick acting and is particularly useful on severely magnesium-deficient soils where a magnesium-responsive crop such as sugar beet is to be grown.

Summary of the Invention

According to some embodiments, there is provided herein a granule comprising Kieserite and phosphate rock, in a ratio of between 30:70 to 70:30, respectively, preferably between 60:40-40:60.

According to some embodiments, the strength of the granule may be at least 0.8 Kg/Granule without drying, preferably at least 1 Kg/Granule without drying. Kieserite is quick acting and is particularly useful on severely magnesium- deficient soils where a magnesium-responsive crop such as sugar beet is to be grown.

According to some embodiments, the granule may further include a binder selected from the group of starch, molasses, manure bentonite, sodium silicate, lignosulfonates, vinasses, hydrated lime, bitumen, Portland cement, clay, cellulose gum, sucrose, water, water glass, cements, Fly Ash, Potassium and Sodium Silicate, MgO, CaO, Geo-polymers, oils and waxes and the like, or a combination thereof.

According to some embodiments, the binder may preferably be starch, lignosulphonate, Molasses, Manure and/or Vinasses.

According to some embodiments, there is provided herein a process for the compaction of Kieserite with Phosphate rock comprising:

Crushing or screening or both of the Kieserite to PSD lower than 2mm; crushing or screening of the phosphate rock to PSD lower than 2 mm; mixing said Kieserite with said Phosphate rock in a mixer to yield a mixture; compacting said mixture in a compactor to yield flakes; crushing said flakes in a crusher to yield particles; and screening said particles in a screener to yield different particles in three different sizes: oversized particles which undergo a second crushing process and are retuned to screener for screening; undersized particles which are transferred to mixer for further mixing with the feed; and desired size granular particles which are transferred to a polish screener.

According to some embodiments, the process may further include adding a binder to the mixture prior to compacting the mixture.

According to some embodiments, the ratio between of Kieserite and phosphate rock may be 58:38, respectively.

Detailed Description of the Invention

According to some demonstrative embodiments, there is provided herein a fertilizer granule including Kieserite and one or more additives selected from the group including phosphate rock, Ammonium sulphate and Ammonium Nitrate., in a ratio of between 30:70 to 70:30, respectively.

According to some embodiments, the granule of the present invention may contain K2O, P, SO4, Mg and ,Ca, yet the unique combination of Kieserite and phosphate rock may supply the plants with essential macro-elements such as K, P Ca, Mg and S via a single granule.

According to some embodiments, both the Kieserite and the Phosphate rock are both used naturally in the granule without the need to undergo any chemical modification, for example, this allows for better plant growth and obviates the need for further industrial processing.

According to some embodiments, the specific use of phosphate rock together with Kieserite enables, e.g., due to the existence of carbonate, the effective use of the granule of the present invention in acidic soils.

However, although both Kieserite and Phosphate rock may useful for the proper growth of a plant, they are practically un-mixable due to the fact that each one or both of them have to be crushed or enlarged to the same range of particles sizes, e.g., to enable homogenous properties and/or prevent electrical repelling forces to take place when particle sizes differ.

According to some embodiments, the granule may contain K2O, P, SO4, Mg and Ca.

According to some embodiments, there is provided herein a fertilizer granule comprising Kieserite and Phosphate rock and optionally a binder; wherein the ratio between Kieserite and Phosphate rock may be 30:70 to 70:30, respectively.

According to some embodiments, there is provided herein a process for the compaction of Kieserite with a Phosphate rock which may include: crushing or screening (or both) of the Kieserite to PSD lower than < 2mm. crushing or screening (or both) of the phosphate rock to PSD lower than 2 mm. Mixing the Kieserite with a Phosphate rock and optionally a binder in a mixer to yield a mixture. Compacting the mixture in a compactor to yield flakes; crushing the flakes in a crusher to yield particles; and screening the particles in a screener to yield different particles in three different sizes: oversized particles which undergo a second crushing process and are retuned to screener for screening, undersized particles which are transferred to mixer for further mixing with the feed, and desired size granular particles which are transferred to a polish screener.

The mixture for the compactor contains 40-60% to 60-40 % of Kieserite and phosphate rock, respectively.

According to some embodiments, the mixing may be performed in a blade blender and/or any other suitable devise capable of having a s mixing that creates a swirling motion for a perfect homogenization and a high blending precision, e.g., a Ploughshare ® Mixer.

According to some embodiments, the compaction be a wet compaction.

According to some embodiments, the compaction process may include the addition of a dry or wet binder 1-5% w/w.

According to some embodiments, the binder may include but not limited: for example, organic or inorganic binders, such as, starch, molasses, manure bentonite, sodium silicate, lignosulfonates, , hydrated lime, bitumen, Portland cement, clay, cellulose gum, sucrose, water, water glass, cements, Fly Ash, Potassium and Sodium Silicate, MgO, CaO ,Geo-polymers, oils and waxes and the like, or a combination thereof.

According to some demonstrative embodiments, the compaction process may include the following steps:

Mixing Kieserite with phosphate rock at a ratio between 30:70 to 70:30 w/w, respectively, to yield a mixture. According to some embodiments, micronutrients may be added to the mixture, and water may be added between 0.5 - 4% w/w, preferably 3% w/w.

According to some embodiments, the process may include adding organic or inorganic binder between 1-5% w/w, preferable between 2-4% w/w.

According to some embodiments, the mixture may be heated to a temperature between 80-180 °C, preferably 160°C.

Feeding the mixture into a compactor to provide compacted flakes;

Grinding of the flakes;

Sieving of the grinded flakes; and

After sieving there are three types of yield: 1. Desired sized flakes between 12- 33 mm thickness, S.G. between 1.9 to 2.4 g/cm³. According to some embodiments, the desired size of the flakes (also referred to herein as “particles” or “granules” or "the final product") is between 1-6 mm, most preferably between 2-4.75 mm.

2. Oversized (OS) flakes - are returned to the grinding stage, e.g., between 4-25% w/w of the total resulting flakes.

3. Undersized (US) flakes - are recycled to the mixture for compaction, e.g., between 10 to 80% w/w of the total flakes.

In the dry process, optionally a binder may be added in a concentration of between 0.01-7% w/w, preferably between 1-5% w/w, most preferably between 2-4% w/w.

According to some embodiments, the final product may submitted to posttreatment, including, for example, oil or derivatives or inorganic materials that may be added to the resulting granules, e.g., to improve the rheology, protect the granules against weather or abrasion of the product and diminish dust formation. Polishing the granules or Coating. The resulting flakes/granules may be glazed and further coated with a suitable coating. For example, the coatings may include biodegradable coatings, sustained release coatings, controlled release coatings, oily coatings, wax coatings.

The compacting process may include the following steps:

1. Mixing materials - Kieserite, Phosphate Rock in 200 lit mixer

2. Adding binder

3. Adding water 4. Compacting using a compactor diameter 600 mm, width 145 mm.

Working force llOKN/cm. Roll velocity 6 rpm.

5. Crushing using hammer mill.

6. Screening

7. Drying the granule between 2-5 mm

8. Recycling of U.S. and O.S.-80%

9. Analysis. All analysis conducted according to the standard procedure

Example 1

60% Kieserite + 40% phosphate rock

This combination was tested 3 times.

Resulting strength of granule immediately after production without drying was between 0.9- 1.2 Kg/ granule.

Example 2

59% Kieserite + 40% phosphate rock +1% water

This combination was tested 4 times.

Resulting strength of granule immediately after production without drying was between 1.4- 1.7 Kg granule

Example 3

58% Kieserite + 39% phosphate +3% water.

Strength of granule immediately after production after drying at 150- degrees 1.3 Kg granule.

Abrasion test -12mesh after production without drying 73%. Eco dust after production without drying 1.5%.

Strength of granule after 45 days without drying 1.2 Kg granule.

Strength of granule after 45 days and drying at 150-degrees 2.6 Kg granule.

Abrasion test -12mesh after 45 days and drying at 150 degrees 27%.

Eco dust after 45 days and drying at 150 degree 2.6%

Example 4

57% Kieserite + 37% phosphate rock + 3% starch +3% water

This combination was tested twice.

Strength of granule immediately after production without drying 1.3- 1.4 Kg/granule.

Strength of granule after 45 days 1.3- 1.4 Kg/granule without drying.

Strength of granule after 45 days and drying at 150-degree 2.5-2.6 Kg/ granule.

Example 5

57% Kieserite + 38% phosphate rock + 3 % lignosulphonate +2% water.

Strength of granule immediately after production without drying 1.5Kg/ granule.

Strength of granule after 45 days 1.2Kg without drying. Strength of granule after 45 days and drying at 150-degree 1.9 Kg/granule.

Example 6

58% Kieserite + 38% phosphate rock + 3 % Molasses +1% water.

This combination was tested 4 times. Resulting strength of granule immediately after production without drying was 1.1- 1.6 Kg/ granule.

Example 7

57% Kieserite + 37% phosphate rock + 2-4 % Lignosulphonate +2-4% water.

Strength of granule immediately after production without drying was 1.2- 1.4Kg/ granule.

Strength of granule after 45 days without drying IKg granule.

Strength of granule after 45 days and drying at 150 degrees was 2.3 Kg granule.

Example 8

58% Kieserite + 37% phosphate rock + 3 % Manure +2% water.

This combination was tested 4 times.

Resulting strength of granule after 45 days without drying 1.1- 1.4 Kg/granule

Resulting strength of granule after 45 days and drying at 150-degree was 1.8- 1.9 Kg/granule.

Example 9

58% phosphate rock +38 Kieserite+1 % Vinasses+3% water.

Strength of granule after 45 days without drying 0.8Kg. granule

Strength of granule after 45 days and drying at 150 -degrees 1.7 Kg/gran

Example 10 68% phosphate rock +28 Kieserite+1 % Vinasses+3% water.

Strength of granule after 45 days without drying IKg/granule

Strength of granule after 45 days and drying at 150-degree 1.9 Kg/granule.

Example 11

50% Kieserite + 50% phosphate rock

This combination was tested 3 times.

Resulting strength of granule immediately after production without drying was 0.8 - 1.2 Kg/granule.

Kieserite and Ammonium Sulphate

According to some demonstrative embodiments, there is provided herein a fertilizer granule comprising Kieserite and Ammonium Sulphate and optionally a binder.

According to some demonstrative embodiments, the granule may comprise a concentration of 40-60% w/w Kieserite and 60-40% w/w of Ammonium Sulphate.

According to some demonstrative embodiments, there is provided herein a process for the compaction of Kieserite with Ammonium Sulphate, the process comprising: mixing a feed of Kieserite with a feed of said Potassium salt and binder in a mixer to yield a mixture; compacting in a compactor to yield masses; crushing said masses in a crusher to yield particles; and screening said particles in a screener to yield different particles in three different sizes: oversized particles which undergo a second crushing process and are retuned to said screener for screening, undersized particles which are transferred to said mixer for further mixing, and desired size granular particles which are transferred to a pohsh screener.

The mixture for the compactor contains 40-60% Kieserite, 60-40 % of Ammonium Sulphate and binder.

The mixing is performed in a blade blender and/or any other suitable devise capable of having a rotation speed that creates a swirling motion for a perfect homogenization and a high blending precision, e.g., a Ploughshare® Mixer. The compaction may be a wet compaction.

The compaction process may include the addition of 1-5% binder.

The binder may include but not limited : for example, organic or inorganic binders, such as, starch, bentonite, sodium silicate, lignosulfonates, molasses, hydrated lime, bitumen, Portland cement, clay, , cellulose gum, sucrose, water, water glass, cements, Fly Ash, Potassium and

SodiumSilicate, MgO, CaO, Alganite, Molasses, Vinasses, Geo-polymers, oils and waxes and the like, or a combination thereof.

The dry compaction process may include the following steps:

Mixing Potash with Ammonium Sulphate according to the formula. Adding micronutrients.

Adding organic or inorganic binder between 1-5% preferably between 2-4%,

1-2%

Adding water between 0.5-2%, preferably 0.5-1%.

The mixture may be heated to a temperature between 80-180 °C, preferably 160°C.

Feeding the mixture into a compactor to provide compacted flakes;

Grinding of the flakes;

Sieving of the grinded flakes; and after sieving there are three types of yield:

1. Desired sized flakes - between 14 - 33 mm thickness, S.G. between

1.9 to 2.4 g/cm³. According to some embodiments, the desired size of

the flakes (also referred to herein as “particles” or “granules”) is between 1-6 mm, most preferably between 2-4.75 mm.

2. Oversized (OS) flakes (above 4.75 mm) - are returned to the grinding stage, e.g., between 4-20% w/w of the total resulting flakes. 3. Undersized (US) flakes and crushed OS (below 2 mm) - are recycled to the mixture for compaction, e.g., between 10 to 80% w/w of the total resulting flakes.

According to some embodiments, in the dry process, optionally a binder may be added in a concentration of between 0.01-7% w/w, preferably between 1- 5% w/w, most preferably between 2-4% w/w.

The final product may submit to post-treatment. Oil may be added to the resulting granules, e.g., to improve the rheology of the product and diminish dust formation. Polishing the granules or Coating. The resulting flakes/granules may be glazed and further coated with a suitable coating.

For example, the coatings may include biodegradable coatings, sustained release coatings, controlled release coatings, oily coatings, wax coatings.

The dry compaction process may include the following steps:

1. Mixing materials - Kieserite, ammonium in 200 liter mixer

2. Adding binder and mixing

3. Adding water and mixing

4. Compacting- Diameter 600 mm, width 145 mm. working force 90KN/cm. roll velocity 6 rpm.

5. Crushing using hammer mill

6. Screening

7. Drying the granules between 2-4.75 mm

8. Recycling-80 %

9. Analysis. All analyses conducted according to the standard procedure

Example 13

40% Kieserite + 59.2% ammonium sulphate +0.8 % water

Abrasion in - 12 mesh 17%, 21% after 24 hours

Eco dust 1.6%, 1.3% after 24 hours

Strength of granule immediately after production 2.3 Kg granule

Strength of granule after 24 hours 2.0 Kg granule

Strength of granule after 1 month 3.2 Kg granule Example 14

38% Kieserite + 60% ammonium sulphate +2% vinasse

Abrasion in - 12 mesh 17% , 15% after 24 hours

Eco dust 1.1%, 1% after 24 hours

Strength of granule immediately after production 1.5 Kg granule

Strength of granule after 24 hours 1.6 Kg/granule

Strength of granule after 1 month 1.7 Kg granule

Kieserite and Ammonium Nitrate

According to some demonstrative embodiments, there is provided herein a fertilizer granule including Kieserite and ammonium nitrate, in a ratio of between 30:70 to 70:30, respectively.

The kinetic solubility of N fertilizers is high. According to some embodiments, the granule of the present invention may have a controlled solubility, either by coating a Kieserite granule with an N fertilizer or via formation of a Kieserite granule containing an N fertilizer in a slow soluble matrix.

According to some embodiments, there is provided herein a process for the granulation of Kieserite with ammonium nitrate (AN), comprising: mixing a feed of Kieserite with a feed of AN as solid or as a melt, to yield a mixture;

Carbonate salts, sulphate salts Potassium salts, magnesium salts, micronutrients, and/or bentonite may be added to the mixture;

Granulating the mixture in a drum granulator to yield particle masses; Screening the particle masses in a screener to yield different fractions in three different sizes: Oversized particles which undergo a crushing process and are returned to the granulator as recycle, desired size granular particles which are transferred to coating and fine particle which are transferred back to the granulator.

Granulation of Kieserite

According to some demonstrative embodiments, there is provided a process for the granulation of Kieserite.

According to some demonstrative embodiments, granules of Kieserite may provide superior characteristics, including for example, a sustained and/or controlled released of the fertilizer to the ground, for example, due to the substantially similar size and/or diameter of the granules.

According to some demonstrative embodiments, the term “fertilizer” may include any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants, including, for example, Single nutrient ("straight") fertilizers such as Ammonium nitrate, Urea, calcium ammonium nitrate, superphosphate, e.g., "Single superphosphate" (SSP), phosphogypsum, Triple superphosphate (TSP) or a mixture thereof; Multinutrient fertilizers such as Binary (NP, NK, PK) fertilizers, e.g., monoammonium phosphate (MAP) and/or diammonium phosphate (DAP), NPK fertilizers which are three-component fertilizers providing nitrogen, phosphorus, and potassium; fertilizers which include one or more of the main micronutrients sources of iron, manganese, boron, molybdenum, zinc, and copper and the like; Compound fertilizers, e.g., which contain N, P, and K; Organic fertilizers such as peat, animal wastes, plant wastes from agriculture, and sewage sludge; and/or Other elements such as calcium, magnesium, and sulfur.

According to some embodiments, use of Kieserite in granules is also beneficial to prevent the segregation of the Kieserite in a powder mix. Segregation often occurs due to differences in the size or density of the component of the mix. Normally, the smaller and/or denser particles tend to concentrate at the base of the container with the larger and/or less dense ones on the top. An ideal granulation will contain all the Kieserite of the mix in a correct proportion in each granule and segregation of granules will not occur.

According to some demonstrative embodiments, the Kieserite granules are produced from fine material, e.g., powder, having a Particle Size Distribution (PSD) which is too small to be used by other conventional methods, e.g., bulk blending.

According to some embodiments, the fine material (also referred to herein as fine dry Kieserite powder has a PSD of between 0.01mm- 1mm, preferably between 0.03mm-0.08mm.

According to some embodiments, the Kieserite granules of the present invention may have a spherical shape and accordingly blending with other nutrients (via for example bulk blending) may provide a more homogenous composition, the granules may also possess a low tendency of segregation, the granules may also exhibit low brake tendency to into small particles, the granules may also exhibit easy dissolution velocity, the granules may be easily coated and exhibit a low tendency to produce dust, thus diminishing environmental pollution (no dust liberation).

The process can be changed according with the market needs and development, new line of products with different chemically and physically behaviors can be produced.

According to some embodiments, the granules of the present invention may be coated with various coating materials, e.g., for anti-dusting and anticaking purposes, slow release and for the addition of microelements and/or macro-elements.

According to some demonstrative embodiments, the granules of the present invention may also include one or more binders which include any suitable material or compound that may mechanically and/or chemically hold or draw other materials together to form a cohesive whole including, for example, organic or inorganic binders, such as, sodium silicate, potassium silicate, fly ash, geopolymers, starch, bentonite, lignosulfonates, molasses, hydrated lime, bitumen, Portland cement, clay, acids (nitric, hydrochloric, phosphoric, sulphuric), cellulose gum, sucrose, water, water glass, cements, or combinations thereof.

According to some embodiments, preferably, the binders are sodium silicate, potassium silicate and/or fly ash.

According to some demonstrative embodiments, there is provided a process for the production of Kieserite granules which includes:

Filling a mixer with dry Kieserite and mixing for one minute

Mixing a binder, for example, in a concentration of between 2.5-10% of the feed weight, preferably 5%, with water for example, in a concentration of between 3-9% of the feed weight, preferably 6%, in a separate vessel, to provide for a binder-water mix;

Adding the binder-water mix to the mixer including the Kieserite and mixing for 5 - 15 minutes;

Adding 0.5% water without stopping the mixer and mixing for at least two more minutes;

Discharging the material from the mixer and introducing the material into fluid bed for one minute at 20 Celsius degrees;

Drying the material at 150 degrees Celsius in fluid bed or drum dryer; and Screening the material to receive granules ranging in size between 1.4 mm to 4.75 mm

There is provided herein a process for the granulation of Kieserite with a Sulphate of Potash (SOP) also referred to as Potassium Sulphate.

According to some demonstrative embodiments, the process may comprise: mixing a feed of Kieserite with a feed of said Potassium Sulphate salt and binder in a mixer to yield a mixture; granulating the mixture in a granulator to yield masses; crushing the masses in a crusher to yield particles; and screening the particles in a screener to yield different particles in three different sizes: oversized particles which undergo a second crushing process and are retuned to said screener for screening, undersized particles which are transferred to said mixer for further mixing, and desired size granular particles which are transferred to a polish screener.

According to some embodiments, the final product may contain: N, K2O,

SO4, MgO, CaO According to some embodiments there is provided herein a granule comprising a mixture of Kieserite, for example, 40-60% w/w and SOP, for example, in a concentration of 40-60% and optionally a binder.

According to some embodiments, the granule may comprise superior properties, in comparison to a granule comprising only Kieserite or only SOP.

According to some embodiments, Potassium sulfate (in British English potassium sulphate (SOP), also called sulphate of potash, arcanite, or archaically known as potash of sulfur) is the inorganic compound with formula K2SO4.

Kieserite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula: K2Ca2Mg(SO4)4 2H2O.

According to some embodiments, it has been surprisingly found that although both Kieserite and SOP are both sulphate salts, the resulting granule exhibits superior strength properties.

According to some demonstrative embodiments, adding SOP to a Kieserite granule elevates the concentrations of Potassium and sulphate in the granule, while maintaining the granule as chloride free.

According to some demonstrative embodiments, a number of cash crops, such as vegetables, fruits, nuts and field crops, are known for their sensitivity to chloride. Chloride toxicity is expressed in the affected plants as leaf scorching. When the chloride concentration in the soil solution increases, plants take up chloride on the account of essential anionic nutrients, and this may result in reduced crop yield and quality. Traditional preparation processes of chloride-free potash fertilizers (KNO3, K2CO3 and K2SO4) have certain limitations, such as complicated operation and existing potential pollution.

According to some demonstrative embodiments, the combination of SOP and Kieserite in a single granule possess numerous surprising advantages. According to some embodiments, the granule of the present invention comprises two different sources for providing the plant with Potassium and Sulphate. According to some embodiments, the first source may be Kieserite, and the second source may be SOP. According to some embodiments, SOP and Kieserite comprise different dissolution rates, and according to some embodiments enable a plant exposed to the granule of the present invention to absorb vital nutrients such as Potassium and Sulphate in quick rate and in a controlled, e.g., slower, rate.

According to some embodiments, the dissolution quantity of SOP is 120 g L- 1 at 25°C.

According to some embodiments, the dissolution of SOP can further be enhanced by adding one or more additives which ameliorate the diffusion coefficient (D) and the diffusion layer thickness (h), such as sodium tripolyphosphate (STPP) and/or urea phosphate (UP).

According to some embodiments, the granule of the present invention may further include one or more additional fertilizers, for example, selected from the group including any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants, including, for example, Single nutrient ("straight") fertilizers such as Ammonium nitrate, Urea, calcium ammonium nitrate, superphosphate, e.g., "Single superphosphate" (SSP), phosphogypsum, Triple superphosphate (TSP) or a mixture thereof; Multinutrient fertilizers such as Binary (NP, NK, PK) fertilizers, e.g., monoammonium phosphate (MAP) and/or diammonium phosphate (DAP), NPK fertilizers which are three -component fertilizers providing nitrogen, phosphorus, and potassium; fertilizers which include one or more of the main micronutrients sources of iron, manganese, boron, molybdenum, zinc, and copper and the like; Compound fertilizers, e.g., which contain N, P, and K; Organic fertilizers such as peat, animal wastes, plant wastes from agriculture, and sewage sludge; and/or Other elements such as calcium, magnesium, and sulfur.

According to some demonstrative embodiments, the granule of the present invention may also include one or more binders, e.g., selected from the group including any suitable material or compound that may mechanically and/or chemically hold or draw other materials together to form a cohesive whole including, for example, organic or inorganic binders, such as, starch, bentonite, sodium silicate, lignosulfonates, molasses, hydrated lime, bitumen, Portland cement, clay, acids (nitric, hydrochloric, phosphoric, sulphuric), cellulose gum, sucrose, water, water glass, cements, or combinations thereof.

According to some demonstrative embodiments, the binder may preferably be selected from the group including: Starch, most preferably, activated starch, whether alone or in combination with potassium silicate; meta kaolin; potassium silicate; sodium silicate or a combination thereof. According to some preferable embodiments, the binder is activated starch. According to some embodiments, the granule of the present invention may comprise a binder in a concentration of between 0.1-5% w/w, preferably 0.5- 3% w/w, most preferably 1-2% w/w.

According to some embodiments, the ratio between Kieserite and SOP in the granule may be 1.1:0.9 to 0.9: 1.1.

According to some embodiments, the granule may be prepared by mixing the Kieserite and SOP in a drum and/or any other suitable machine capable of having a rotation speed of 20-30 rpm.

Adding water 4-10% preferably 7% as spray. According to some embodiments, the mixing may take place at 40-60 C preferably at 45 C degrees for 3-5 minutes preferably 3.5 minutes.

After achieving good mixing the mixture may be transferred to a fluidized bed dryer at 100-140 C, preferably 120 C for 30-60 minutes preferably 40 minutes.

The granulation process may include the addition of a binder 1-5% binder. The binder may include but not limited, for example, organic or inorganic binders, such as, starch, bentonite, sodium silicate, lignosulfonates, molasses, hydrated lime, bitumen, Portland cement, clay, cellulose gum, sucrose, water, water glass, cements, Fly Ash, Potassium and Sodium Silicate, MgO, CaO, Alganite, Geo-polymers, oils and waxes and the like, or a combination thereof.

The dry process may include the following steps:

Mixing Kieserite with Potassium Sulphate according to the formula. Adding micronutrients . Sieving of the granules

After sieving there are three types of yield:

1. Desired sized granules “between 1-6 mm, most preferably between 2-

4 mm. Around 70% of the granules were between 2-4.75 mm.

2. Oversized (OS) granules - are returned to the grinding stage,

3. Undersized (US) granules - are recycled to the mixture for granulation.

According to some embodiments, samples may be taken for analysis.

Examples

The sequence of the process:

1- Fill the mixer with the components and mix one minute and stop.

2- Mix the binder (5% of the feed weight) with the water (6% of the feed weight) in a small vessel (the mix).

3- Add the mix (binder + water) to the mixer and start it and the chopper during 5 minutes.

Mixer velocity: 350 rpm (7.3 M/sec linear velocity)

Chopper velocity: 1500 rpm

Residence time 7 - 10 min,

4- Add water to the mixer in an amount equal to 0.5 % of the feed weight without stopping and after the water addition stop the chopper.

5-Continue to mix two additional minutes

6-Discharge the material 7- Introduce the material into fluid bed for one minute at 20 degrees

8- Dry the material at 150 degrees five minutes.

9- Screen the material 1.4 mm to 4.75 mm

Drum trials were conducted in drum that have 80 cm diameter. Kieserite and phosphate rock in proportion of 60:40 , Water were added by spray by nozzle at 4 atm and binder added .The mixture mixed for 1 minute at 300 rpm. Water was added on the materials and rotated rpm for additional time at velocity 20 rpm. The granules were dried at 150 degrees for 20 minutes. The yield is approximately 50-70%.

Example- 15

A mixture of Kieserite and phosphate rock in proportion of 60:40, and 3.5% of fly ash was added together with 5-7.5% of water. Granulation time was 7-8 minutes.

The granules' strength before humidity chamber was 1.7-2.9 Kg I granule and after humidity at 77% for 24 hours 0.7-1.6 Kg/granule, the yields were 60-67 %.

Example 16

As example 15 with 4% of fly ash + 1% of Calcium Hydroxide. Granulation time 7 minutes. Strength of granule before humidity 2.6-3.5 Kg/granule and 1.6-1.8 Kg/granule after humidity, the yields were between 52-74%. Example 17

As example 15 with 2% of fly ash+1% of Calcium Hydroxide. Strength of granule before humidity 2.6 Kg/granule and 1.5 Kg/granule after humidity. The yield was 43%.

Plow Share Trials

The plow share has volume of 100 Lit. Filling materials at 15%. The Velocity was 300 rpm and Chopper velocity was 1500 rpm.

10-15 Kg of Kieserite mixed with weighted binders for 1 minute at 300 rpm. Water were added and continue to mixed for additional time, then the granules were dried at 150 degrees for 20 minutes.

Example 18

10 kg of Kieserite , was mixed with 7% of fly ash+5% of Calcium Hydroxide for 1 minute Water was added and mixed 5 minutes. The product was dried. This combination was tested 4 times.

The resulting strength of the granules before humidity was 3.8- 4.1 Kg/granule. and 1.8-2.1 after humidity at 77% for 24 hours and 1.7-1.9 Kg/granule after 72 hours at 77% humidity.

Example 19

15 kg of Kieserite was mixed with 6.5% of fly ash+ 2-4% of Calcium Hydroxide for 1 minute, and then water was added and mixed for 5 minutes. The product was dried. The Strength of the granules before humidity 2.2- 2.9 Kg/granule. and 0.4-0.8 after humidity at 77% for 24 hours and 1.7

Kg/granule after 72 hours at 77% humidity.

Example 20

Using 100 Liter volume plow share. Filling with materials to 40%. velocity was set to 300 rpm. Chopper velocity 1500 rpm. The Kieserite was mixed with weighted binders - 4% fly ash and 1% Calcium hydroxide for 1 minute at 300 rpm. Water was added and mixed for 5 minutes. The product was dried for 10 minutes at 140 degrees and screened.

The average PSD was 1.4-4.75 mm. The single strength of the granules were 3.6-4.3 Kg /granules before humidity and 1.4- 1.5 KG/granule after humidity at 77and 86% for 24 hours. Collective strength 77-78%. Caking 0.3 Kg, and the yield 62-73%. After 180 days the single strength of the granules was 2.8- 2.9 Kg /granules collective 68-71%, and caking 2.7Kg.

Example 21

Experiment- compacting of polyhalite and Kieserite

A mixture of 85% Kiesereite and 15% Polyhalite was compacted.

Granule strength- 1.6 kg/ granule.

Dust 2.5 %

Abrasion -32 mesh 13 %

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. It will be appreciated that various features of the invention which are, for clarity, described in the contexts of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination. It will also be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove.

Claims

1. A granule comprising Kieserite and one or more additives selected from the group including phosphate rock, Ammonium sulphate and Ammonium Nitrate in a ratio of between 30:70 to 70:30, respectively.

2. The granule of claim 1, wherein the strength of the granule is at least 0.8 Kg/Granule without drying.

3. The granule of claim 1, wherein the strength of the granule is at least 1 Kg/Granule without drying.

4. The granule of claim 1, further comprising a binder selected from the group of starch, molasses, manure bentonite, sodium silicate, lignosulfonates, vinasses, hydrated lime, bitumen, Portland cement, clay, cellulose gum, sucrose, water, water glass, cements, Fly Ash, Potassium and Sodium Silicate, MgO, CaO, Geo-polymers, oils and waxes and the like, or a combination thereof.

5. The granule of claim 4, wherein said binder is starch, lignosulphonate, Molasses, Manure and/or Vinasses.

6. A process for the compaction of Kieserite one or more additives selected from the group including phosphate rock, Ammonium sulphate and Ammonium Nitrate comprising: crushing or screening of the Kieserite to less than 2mm; crushing or screening of said one or more additives to less than 2 mm; mixing said Kieserite with said one or more additives in a mixer to yield a mixture; compacting said mixture in a compactor to yield flacks; crushing said masses in a crusher to yield particles; and screening said particles in a screener to yield different particles in three different sizes: oversized particles which undergo a second crushing process and are retuned to screener for screening; undersized particles which are transferred to mixer for further mixing with the feed; and desired size granular particles which are transferred to a polish screener. The process of claim 6, further comprising adding a binder to said mixture prior to compacting said mixture. The process of claim 6, wherein the ratio between of Kieserite and said one or more additives is 58:38, respectively. A process for production of Kieserite granules from fine dry Kieserite powder comprising: preparing a binder-water mix and mixing the binder-water mix with the Kieserite powder in a mixer; continuously adding water to the mixer to provide a Kieserite material;

Discharging the Kieserite material from the mixer and introducing the material into a fluid bed;

Drying the material; and

Screening the material to receive granules ranging in size between

1.4 mm to 4.75 mm. The process of claim 1, wherein preparing a binder-water mix comprises mixing a binder in a concentration of between 2.5-10% of the feed weight with water in a concentration of between 3-9% of the feed weight. The process of claim 1, wherein continuously adding water to the mixer to provide a Kieserite material comprises continuously adding water for at least two more minutes. The process of claim 1, wherein discharging the material from the mixer and introducing the material into a fluid bed is performed for one minute at 20 degrees. The process of claim 1, wherein drying the material is performed at 150 degrees. The process of claim 6, wherein said drying is performed in a fluid bed or drum dryer. A process for the production of Kieserite granules comprising:

Filling a mixer with dry Kieserite and mixing for one minute Mixing a binder with water in a separate vessel to provide for a binder-water mix;

Discharging the material from the mixer and introducing the material into fluid bed for one minute at 20 Celsius degrees; Drying the material at 150 degrees Celsius in fluid bed or drum dryer; and

Screening the material to receive granules ranging in size between 1.4 mm to 4.75 mm