U.S. patent application number 14/955354 was filed with the patent office on 2016-03-24 for fertilizer composition containing micronutrients and methods of making same.
The applicant listed for this patent is The Mosaic Company. Invention is credited to Michael McLaughlin, Lawrence Alan Peacock, Samuel Stacey.
Application Number | 20160083308 14/955354 |
Document ID | / |
Family ID | 44530139 |
Filed Date | 2016-03-24 |
United States Patent
Application |
20160083308 |
Kind Code |
A1 |
Peacock; Lawrence Alan ; et
al. |
March 24, 2016 |
FERTILIZER COMPOSITION CONTAINING MICRONUTRIENTS AND METHODS OF
MAKING SAME
Abstract
A fertilizer composition including a base fertilizer granule
with a barrier coating and one or more micronutrients. The base
fertilizer material is coated with a barrier coating, and then a
coating of one or more micronutrients. Alternatively, the base
fertilizer material is coated with a barrier coating having
discrete particles of micronutrients dispersed throughout. The
barrier coating acts to physically and chemically isolate the
micronutrient particles from the underlying fertilizer composition
such that more of the micronutrient is available to the soil
solution, and ultimately to the root zone of the plant.
Inventors: |
Peacock; Lawrence Alan;
(Riverview, FL) ; Stacey; Samuel; (Adelaide,
AU) ; McLaughlin; Michael; (Adelaide, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Mosaic Company |
Plymouth |
MN |
US |
|
|
Family ID: |
44530139 |
Appl. No.: |
14/955354 |
Filed: |
December 1, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13034781 |
Feb 25, 2011 |
9199883 |
|
|
14955354 |
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|
61309894 |
Mar 3, 2010 |
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61311011 |
Mar 5, 2010 |
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Current U.S.
Class: |
71/29 ; 71/27;
71/36 |
Current CPC
Class: |
C05G 5/30 20200201; C05B
7/00 20130101; C05G 5/37 20200201; C05B 1/04 20130101; C05B 1/04
20130101; C05B 7/00 20130101; C05C 9/00 20130101; C05D 9/00
20130101; C05D 9/02 20130101; C05G 5/37 20200201; C05G 5/30
20200201; C05G 5/37 20200201; C05G 5/30 20200201 |
International
Class: |
C05B 7/00 20060101
C05B007/00; C05G 3/00 20060101 C05G003/00 |
Claims
1. A fertilizer composition comprising: a base fertilizer granule;
a barrier coating covering at least a portion of an outer surface
of the base fertilizer granule; and one or more micronutrients
covering at least portion of the barrier coating such that the one
or more micronutrients are isolated from the base fertilizer
granule.
2. The fertilizer composition according to claim 1, wherein the
base fertilizer is a phosphate.
3. The fertilizer composition according to claim 2, wherein the
base fertilizer is selected from monoammonium phosphate, diammonium
phosphate, single superphosphate, triple superphosphate, and
combinations thereof.
4. The fertilizer composition according to claim 1, wherein the
barrier coating is a material that is non-reactive with the base
fertilizer and the one or more micronutrients.
5. The fertilizer composition according to claim 4, wherein the
barrier coating comprises a material including urea, langbeinite,
ammonium sulfate, potassium sulfate, magnesium sulfate, calcium
sulfate, elemental sulfur, silicates, respective hydrates, and
combinations thereof.
6. The fertilizer composition according to claim 1, wherein the one
or more micronutrients is selected from boron, copper, iron,
manganese, molybdenum, zinc, chlorine, cobalt, sodium, nickel,
selenium, and combinations thereof.
7. The fertilizer composition according to claim 1, further
comprising a polymer coating covering at least a portion of the
barrier coating, wherein the one or more micronutrients are adhered
to an outer surface of the polymer coating.
8. The fertilizer composition according to claim 7, wherein the
polymer coating comprises a polymer from a polyethyleneimine (PEI)
family of polymers.
9. A fertilizer composition comprising: a base fertilizer granule;
a barrier coating covering at least a portion of an outer surface
of the base fertilizer granule; and one or more micronutrients
dispersed within the barrier coating such that the one or more
micronutrients are isolated from the base fertilizer granule.
10. The fertilizer composition according to claim 9, wherein the
base fertilizer is a phosphate.
11. The fertilizer composition according to claim 10, wherein the
base fertilizer is selected from monoammonium phosphate, diammonium
phosphate, single superphosphate, triple superphosphate, and
combinations thereof.
12. The fertilizer composition according to claim 9, wherein the
barrier coating is a material that is non-reactive with the base
fertilizer and the one or more micronutrients.
13. The fertilizer composition according to claim 12, wherein the
barrier coating comprises a material including urea, langbeinite,
ammonium sulfate, potassium sulfate, magnesium sulfate, calcium
sulfate, elemental sulfur, silicates, respective hydrates, and
combinations thereof.
14. The fertilizer composition according to claim 9, wherein the
one or more micronutrients is selected from boron, copper, iron,
manganese, molybdenum, zinc, chlorine, cobalt, sodium, nickel,
selenium, and combinations thereof.
15. The fertilizer composition according to claim 10, further
comprising a polymer coating covering at least a portion of the
barrier coating, and one or more additional micronutrients covering
at least a portion of the outer surface of the polymer coating.
16. The fertilizer composition according to claim 15, wherein the
polymer coating comprises a polymer from a polyethyleneimine (PEI)
family of polymers.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 13/034,781 filed Feb. 25, 2011, which claims
the benefit of U.S. Provisional Application No. 61/309,894 filed
Mar. 3, 2010, and U.S. Provisional Application No. 61/311,011 filed
Mar. 5, 2010, each of which is hereby incorporated herein in their
entirety by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to fertilizer composition,
and more particularly to fertilizer compositions containing
micronutrients for subsequent introduction into soil solution and
eventually into the root zone of a plant.
BACKGROUND OF THE INVENTION
[0003] In addition to primary nutrients, such as carbon, hydrogen,
oxygen, nitrogen, phosphorous, and potash, micronutrients and
secondary nutrients are elements which are also essential for plant
growth, but are required in much smaller amounts than those of the
primary nutrients. Secondary nutrients can include, for example,
calcium (Ca), sulfur (S), and magnesium (Mg). Micronutrients can
include, for example, boron (B), copper (Cu), iron (Fe), manganese
(Mn), molybdenum (Mo), zinc (Zn), chlorine (Cl), cobalt (Co),
sodium (Na), and combinations thereof.
[0004] Micronutrient sources vary considerably in their physical
state, chemical reactivity, cost, and availability to plants. Four
main classes of micronutrient sources include: (1) inorganic
products such as oxides, carbonates, and metallic salts such as
sulfates, chlorides, and nitrates; (2) synthetic chelates formed by
combining a chelating agent with a metal through coordinate
bonding; (3) natural organic complexes including lignosulfonates,
polyflavonoids, and phenols, made by reacting metallic salts with
certain organic by-products of the wood pulp industry or related
industries; and (4) frits, or fritted glassy products, containing a
concentration of micronutrient from about 2 to 25 percent.
[0005] The most common method of micronutrient application for
crops is soil application. Recommended application rates usually
are less than 10 lb/acre on an elemental basis so uniform
application of micronutrient sources separately in the field can be
difficult. Including micronutrients with mixed fertilizers is a
convenient method of application and allows more uniform
distribution with conventional application equipment. Costs also
are reduced by eliminating a separate application step. Four
methods of applying micronutrients with mixed fertilizers can
include incorporation during manufacture, bulk blending with
granular fertilizers, coating onto granular fertilizers, and mixing
with fluid fertilizers.
[0006] Incorporation during manufacture is the incorporation of one
or more micronutrients directly in fertilizers granules, such as
NPK or phosphate fertilizer, as they are being produced. This
practice allows each granule of phosphate fertilizer to have a
consistent concentration of the desired micronutrient(s) and
uniform distribution of the micronutrient(s) throughout the
granular fertilizers. Because the phosphate granules are evenly
dispersed over the growing area, the contained micronutrient(s) are
as well. However, because the micronutrient source is in contact
with the mixed fertilizer components under conditions of high
temperature and moisture during manufacture, the rate of chemical
reactions with the phosphates is increased which can reduce the
plant availability of some micronutrients because the
micronutrient(s) remain in the phosphate granule.
[0007] Bulk blending with granular fertilizers is the practice of
bulk blending separately granulated micronutrient compounds with
granular phosphate fertilizers and granular potash fertilizers. The
main advantage to this practice is that fertilizer grades can be
produced which will provide the recommended micronutrient rates for
a given field at the usual fertilizer application rates. The main
disadvantage is that segregation of nutrients can occur during the
blending operation and with subsequent handling. In order to reduce
or prevent size segregation during handling and transport, the
micronutrient granules must be close to the same size as the
phosphate and potash granules. Because the micronutrients are
required in very small amounts for plant nutrition, this practice
has resulted in granules of micronutrients unevenly distributed and
generally too far from most of the plants to be of immediate
benefit as most migrate in soil solution only a few millimeters
during an entire growing season.
[0008] Coating of granular fertilizers decreases the possibility of
segregation. However, some binding materials are unsatisfactory
because they do not maintain the micronutrient coatings during
bagging, storage, and handling, which results in segregation of the
micronutrient sources from the granular fertilizer components.
Steps have been taken to reduce the segregation problem in the case
secondary nutrients and micronutrients, for example as in the case
of sulfur or sulfur platelets in the fertilizer portion as
described in U.S. Pat. No. 6,544,313 entitled "Sulfur-Containing
Fertilizer Composition and Method for Preparing Same" and in the
case of micronutrients as described in U.S. Pat. No. 7,497,891
entitled, "Method for Producing a Fertilizer with Micronutrients,"
both of which are incorporated herein by reference in their
entireties.
[0009] Similar to incorporation of micronutrients during
manufacture described above, the micronutrient source is in contact
with the fertilizer components in a coated product and the
micronutrients can undergo chemical reactions with the phosphates,
thereby reducing the plant availability of some micronutrients
because the micronutrient(s) remain in the phosphate granule.
[0010] There remains a need for a fertilizer product that contains
one or more micronutrients that maximizes the introduction of the
micronutrient(s) into soil solution and ultimately to the root zone
of plants.
SUMMARY OF THE INVENTION
[0011] Embodiments of the invention are directed to the
incorporation of desired micronutrient(s) into granular fertilizer
formulations for subsequent introduction of the micronutrients into
soil solution and eventually into the root zone of the plant. A
coating over the base fertilizer is used as a barrier coating or
separator to prevent or reduce chemical/physical interactions
between the micronutrient(s) and the base fertilizer.
[0012] In one embodiment of the invention, a barrier coating
material is in a liquid or molten state. One or more micronutrients
are then incorporated into the melt of the barrier coating
material. The barrier coating material is spray coated on an
appropriate fertilizer granule, such as an ammonium phosphate,
calcium phosphate, or potassium phosphate fertilizer. The
micronutrient particles are retained within the barrier coating
material, separated from chemical and physical interaction with the
underlying fertilizer material.
[0013] In another embodiment of the invention, an appropriate
fertilizer granule, such as an ammonium phosphate, calcium
phosphate, or potassium phosphate is coated by conventional methods
such as spray coating with a barrier coating material. One or more
micronutrients are then added in either a continuous or
discontinuous coating around the barrier coated fertilizer granules
such that the micronutrient particles are chemically and physically
separated or isolated from the underlying fertilizer material.
[0014] The above summary of the invention is not intended to
describe each illustrated embodiment or every implementation of the
present invention. The detailed description that follows more
particularly exemplifies these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a fertilizer granule containing micronutrients
according to one embodiment of the invention;
[0016] FIG. 2 is a fertilizer granule containing micronutrients
according to another embodiment of the invention;
[0017] FIG. 3 is a graph comparing micronutrient dissolution over
time for various barrier coating materials; and
[0018] FIG. 4 is a graph depicting the effect of water solubility
on plant uptake of zinc.
DETAILED DESCRIPTION OF THE DRAWINGS
[0019] According to one embodiment of the invention illustrated in
FIG. 1, a fertilizer granule containing micronutrients 100 can
comprise a core fertilizer portion 102, a barrier coating material
104 coated or otherwise applied over at least a portion of
fertilizer portion 102, and a micronutrient coating 106 containing
one or more micronutrients covering at least a portion of barrier
coating material 104.
[0020] In this embodiment, barrier coating material 104 can be a
liquid, solid or molten form, and can be sprayed, curtain coated,
or any of a number of suitable coating techniques to form a
continuous or discontinuous coating over fertilizer portion 102. In
one particular embodiment, a barrier coating material is combined
with water to form a slurry that is sprayed onto fertilizer
granules in a granulator. The granules are then dried. The barrier
coated granules are then subsequently coated with an appropriate
micronutrient, such as a complex of micronutrient, for example,
ZnSO.sub.4.H.sub.2O, by any of a number of suitable coating
techniques, such as spray coating.
[0021] Optionally, a hot coating of polymer can be added to the
barrier coated granules before addition of the micronutrient to
provide a tacky surface for adherence of the micronutrients to the
granules, and further to improve the water solubility of
micronutrients. Such polymers can comprise, for example,
polyethyleneimine (PEI).
[0022] According to an alternative embodiment of the invention
illustrated in FIG. 2, a fertilizer granule containing
micronutrients 200 can comprise a core fertilizer portion 202, a
barrier coating material 204 coated or otherwise applied over at
least a portion of fertilizer portion 202, and one or more
micronutrients 206 dispersed within barrier coating material
204.
[0023] Fertilizer portion 102, 202 can comprise any suitable
fertilizer, such as, for example, nitrates, ureas, potashes,
phosphate fertilizers such as mono-ammonium phosphate (MAP),
diammonium phosphate (DAP), single superphosphate, triple
superphosphate, potassium phosphates, calcium phosphates and
combinations thereof.
[0024] Barrier coating material 104, 204 can comprise one or more
materials that isolate the micronutrient(s) from the fertilizer
composition to reduce or eliminate chemical reactions and/or other
interactions between the micronutrient(s) and the underlying
fertilizer composition. For example, if the underlying fertilizer
composition is a phosphate, barrier coating material 104 can
comprise urea, langbeinite (otherwise known as K-Mag or
K.sub.2Mg.sub.2(SO.sub.4).sub.3), ammonium sulfate
((NH.sub.4).sub.2SO.sub.4), potassium sulfate (K.sub.2SO.sub.4),
magnesium sulfate (MgSO.sub.4), calcium sulfate (CaSO.sub.4),
elemental sulfur (S), silicates, their respective hydrate (salt
with associated water of hydration [.xH.sub.2O]), and combinations
thereof.
[0025] Micronutrients 106, 206 can comprise boron (B), copper (Cu),
iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), chlorine
(Cl), cobalt (Co), sodium (Na), nickel (Ni), selenium (Se), and
combinations thereof. Micronutrients 106, 206 can be in the form of
discrete particles or platelets, and can optionally be incorporated
into a PEI matrix.
[0026] The following examples discuss particular embodiments of the
invention. The equipment used in preparation of each of the
examples was a four-foot diameter pan granulator (13 inches wide
with a 5 inch bed depth), equipped with a variable-frequency drive
(VFD) and mounted vertically. The drum was not flighted; it was
equipped only with slip rods to keep the bed moving.
[0027] Example materials were prepared in batch mode by first
charging the granulated with uncoated MAP, followed by the addition
of the appropriate barrier material to evenly coat the MAP
particles. The appropriate micronutrient(s) were then added to
these coated granules, together with a polymer that is effective at
improving the water solubility of micronutrients.
Example 1
Urea Barrier Coating
[0028] Uncoated MAP was completely coated with molten urea
(approximately 10%) and allowed to cool. The coated granules were
spray-coated with hot PEI and subsequently coated with zinc in the
form of ZnSO.sub.4.H.sub.2O or copper in the form of Cu
SO.sub.4.5H.sub.2O. The complex was then formed by spraying with a
small amount (approximately 0.25%) of acidic water (pH adjusted to
approximately 2). Talc (approximately 1%) was added to yield
free-flowing granules.
Example 2
K-Mag (K.sub.2Mg.sub.2(SO.sub.4).sub.3) Coating
[0029] Uncoated MAP was completely coated with powdered K-Mag
blended with half its weight of diluted calcium lignosulfonate
solution (diluted to 70/30 w/w CLS/H.sub.2O with CLS comprising 58%
solids). The slurry was evenly spread over the tumbling bed of MAP
granules and heated to dryness. The coated granules were
spray-coated with hot PEI (99%) and subsequently coated with zinc
in the form of ZnSO.sub.4.H.sub.2O. The complex was then formed by
spraying with a small amount (approximately 0.25%) of acidic water
(pH adjusted to approximately 2 with citric acid). The coated
granules were then air-dried. Talc (approximately 1%) was added to
yield free-flowing granules.
Example 3
Ammonium Sulfate ((NH.sub.4).sub.2SO.sub.4) Coating
[0030] Uncoated MAP was completely coated with powdered ammonium
sulfate blend with an equal weight of diluted calcium
lignosulfonate solution (diluted to 70/30 w/w CLS/H.sub.2O with CLS
comprising 58% solids) to form a flowable slurry. The slurry was
evenly spread over the tumbling bed of MAP granules and heated to
dryness. The coated granules were spray-coated with hot PEI (99%)
and subsequently coated with zinc in the form of
ZnSO.sub.4.H.sub.2O. The complex was then formed by spraying with a
small amount (approximately 0.25%) of acidic water (pH adjusted to
approximately 2 with citric acid). The coated granules were then
air-dried. Talc (approximately 1%) was added to yield free-flowing
granules.
Example 4
Potassium Sulfate (K.sub.2SO.sub.4) Coating
[0031] Uncoated MAP was completely coated with powdered ammonium
sulfate blend with half its weight of diluted calcium
lignosulfonate solution (diluted to 70/30 w/w CLS/H.sub.2O with CLS
comprising 58% solids) to form a flowable slurry. The slurry was
evenly spread over the tumbling bed of MAP granules and heated to
dryness. The coated granules were spray-coated with hot PEI (99%)
and subsequently coated with zinc in the form of
ZnSO.sub.4.H.sub.2O. The complex was then formed by spraying with a
small amount (approximately 0.25%) of acidic water (pH adjusted to
approximately 2 with citric acid). The coated granules were then
air-dried. Talc (approximately 1%) was added to yield free-flowing
granules.
[0032] As shown in the graph in FIG. 3, the coated fertilizer
composition using K-Mag as the barrier coat material (Example 2)
resulted in the highest % dissolution of the micronutrient after
eight hours. All the proposed examples resulted in significantly
higher % dissolution than a product wherein the micronutrient is
incorporated in the phosphate fertilizer.
[0033] As shown in the graph in FIG. 4, the coated fertilizer
composition using K-Mag as the barrier coat material (Example 2)
also performed the best in terms of effect of water solubility on
plant uptake of Zinc.
[0034] The invention may be embodied in other specific forms
without departing from the essential attributes thereof; therefore,
the illustrated embodiments should be considered in all respects as
illustrative and not restrictive.
* * * * *