| WO2020105055A1 | 2020-05-28 |
| US20200157014A1 | 2020-05-21 | |||
| US20060063674A1 | 2006-03-23 | |||
| US5174804A | 1992-12-29 |
| Claims 1. A fertilizer granule comprising Polyhalite, Dolomite and a binder, wherein said granule comprises a single strength of at least 3.2 KgF/granule. 2. The granule of claim 1, wherein said binder is selected from the group comprising Starch, molasse, Fly Ash, calcium oxide, bitumen, Portland cement, cellulose gum, sucrose, water glass, cements, Potassium Silicate and Sodium Silicate. 3. The granule of claim 2, wherein said binder is starch. 4. The granule of claim 3, wherein said starch is in a concentration of between 0.5- 5% w/w. 5. The granule of claim 4, wherein said starch is in a concentration of between 1- 3% w/w. 6. A process for the granulation of Polyhalite and Dolomite comprising mixing Polyhalite and Dolomite in a ratio of between 1 :2 to 2: 1 in rotating drum; adding binder to said rotating drum; adding water to said rotating drum; and transferring said granules to a dryer. 7. The process of claim 6, wherein said ratio is 1 : 1 6 |
Field of the Invention
The present invention relates to the field of composite fertilizers, specifically to production of a fertilizer containing polyhalite and dolomite.
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.
In some places there is necessary to add magnesium to the soil. One option to add extra dose of magnesium is by adding magnesium salts. The magnesium salts can be soluble like magnesium sulphate or insoluble kike magnesium carbonate or double salt like dolomite
Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula: K2Ca2Mg(SO4)42H2O. Polyhalite is used as a fertilizer since it contains four important nutrients and is low in chloride:
48% SO3 as sulfate,
14% K 2 O,
6% MgO,
17% CaO
Dolomite is a double salt containing Calcium Magnesium and carbonate
CaCO 3 MgCO 3
30% CaO,
22% MgO,
65% as CO 3 Summary of the invention
According to some demonstrative embodiments, there is provided herein a fertilizer granule comprising Polyhalite, Dolomite and a binder.
According to some embodiments, the granule may have a single strength of at least 3.2 KgF/granule.
According to some embodiments, the binder may be selected from the group comprising Starch, molasse, Fly Ash, calcium oxide, bitumen, Portland cement, cellulose gum, sucrose, water glass, cements, Potassium Silicate and Sodium Silicate. According to some embodiments, the binder may preferably be starch.
According to some embodiments, the starch may be in a concentration of between 0.5- 5% w/w, preferably, between 1-3% w/w.
According to some embodiments, there is provided herein a process for the granulation of Polyhalite and Dolomite comprising mixing Polyhalite and Dolomite in a ratio of between 1 :2 to 2: 1, preferably 1 : 1, in rotating drum; adding binder to said rotating drum; adding water to said rotating drum; and transferring said granules to a dryer.
Detailed Description of the Invention
According to some demonstrative embodiments, there is provided herein a granule comprising Polyhalite and Dolomite in a ratio of between 2: 1 to 1 :2, respectively, and a binder, in a concentration of 1-5% w/w, preferably, in a concentration of 1-2% w/w. According to some demonstrative embodiments, the ratio between Polyhalite and dolomite may be 1 : 1.
According to some demonstrative embodiments, standard granulation processes usually include some basic steps: creation of a nucleus, growth of the nucleus and consolidation followed by destruction of granules, for example, if the granules have a size which is bigger than the desired granule size.
It is therefore important to add water during a standard granulation process to create such a nucleus and start the granulation process.
According to some embodiments, the ordinary granulation process may not be suitable in the case of granulation of insoluble salts like Polyhalite, Ba, Ca, or Mg carbonate salts, Dolomite and the like. However, changing water content in a granule and deviating from the standard process known in the art may have substantial implications on the strength of the resulting granule.
In addition, according to some embodiments, Polyhalite and Dolomite have similar hardness qualities, which may cause difficulties in the granulation of these substances. According to some embodiments of the present invention, there is provided a granule of Polyhalite and Dolomite comprising at least one binder, e.g., suitable for creating an adhesion between the Polyhalite and Dolomite.
According to some embodiments, the binder may be selected from the group comprising of Starch, molasse, Fly Ash, calcium oxide, bitumen, Portland cement, cellulose gum, sucrose, water glass, cements, Potassium Silicate and Sodium Silicate. According to some preferable embodiments, the binder may be preferably starch.
According to some embodiments, the starch may increase the rate of nucleus growth and consolidation.
Since the binders of this application comprise both basic and acidic functional groups, they all have the ability to forms bonds in a wide pH range. These bonds may cause consolidation due to Van der Waals forces acting between nuclei or via hydrogen bonds. This is especially true in the case of Starch which has both Basic -OH groups and acidic -COOH groups.
According to some demonstrative embodiments, the binder may be at a concentration of between 0.5-5% w/w. more preferably between 1-3% w/w.
According to some embodiments, the PSD of the granule of the present invention may be between 0.5 mm to 3mm, preferably, 2 mm.
According to some embodiments, the strength of the granule of the present invention may be at least 3.2 KgF/granule.
According to some demonstrative embodiments, there is provided herein a process for the preparation of a fertilizer granule comprising
Mixing Polyhalite and Dolomite together with a binder in a rotating drum or pan granulator ,e.g., Eurich, for 1-4 minutes, preferably 2 minutes; Adding 5-15% w/w of water in the form of spray or steam to create a mixture; Mixing the mixture in a rotating drum, e.g., for 2 additional minutes to provide granules; Dry the granules in a dryer, e.g., at a temperature of around 150°C. According to some demonstrative embodiments, the granulation may take place using any suitable granulator or granulation method including, for example, Fluidized bed Granulation, Tumbling Granulation, Disc Granulation, Pan Granulation, Drum Granulation, Mixer-Granulation, Melt Granulation, Double shaft paddle Mixer- Granulation and the like.
Example -1
1500 gr of polyhalite, 1500 gr of dolomite PSD -0.5 mm and 2% of starch were mixed in a rotating drum.
10% water were added to create a mixture and the drum was operated for 2 more minutes to yield granules.
The granules were transferred to a dryer for 30 minutes at 150 C degrees.
Results
Granules abrasion -12 mesh 6.6%
Granule strength 3.5 KgF/granule
Eco dust 0.86%
Example -2
As example 1 but PSD of polyhalite and dolomite- 2mm
Results -
Granules abrasion - 12 mesh 3.6%
Granule strength 4.1 KgF/granule
Eco dust 0.39%
Example -3
As example 2 but with 8% water
Granules abrasion - 12 mesh 17.4%
Granul e strength 3.3 KgF / granul e
Eco dust 0.89%
Example 4
As Example 2 with 1% of starch
Granules abrasion - 12 mesh 9.4%
Granule strength 3.2 KgF/granule Eco dust 0.79%
While this invention has been described in terms of some specific examples, many modifications and variations are possible. It is therefore understood that within the scope of the appended claims, the invention may be realized otherwise than as specifically described.