Note: Descriptions are shown in the official language in which they were submitted.
1333224
~ hIzER IHPREGNATED WIl~I
LIQUID AGRICULl~RAL T~F.Al~T CO~POSITIONS,
AND ~ETHOD OF IMPREGNATION
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to processes for
impregnating a fertilizer with liquid agricultural treatment
compositions, and to fertilizers impregnated with liquid
agricultural treatment compositions. More specifically, the
present invention relates to the impregnation of a
fertilizer with previously unat~ainable amounts of a liquid
agricultural treatment compositions, such as an herbicides,
the resulting herbicide-impregnated fertilizer.
2. Description of Background and Material Inf~rmation
The concept of impregnating dry bulk fertilizers with
herbicides has been known for a number of years. The use of
impregnated fertilizers is popular with farmers because it
permits the application of both nutrients and herbicides in
~ one application, commonly referred to as "weed and feed"
applications. Although urea, crystalline byproduct of
ammonium sulfate and NPK blends have been impregnated with a
variety of different herbicides, with varying degrees of
success, the present invention is based on the discovery
that granular ammonium sulfate is particularly amenable to
impregnation with herbicides and the like in amounts in
excess of what has heretofore been possible with the
previously mentioned impregnated-fertilizers, and yet
remains free-flowing.
By way of background, ammonium sulfate has a number of
important applications, with perhaps the chief among these
being agricultural fertilization. In this capacity ammonium
sulfate provides a ready source of nitrogen and sulfur,
13~322~
P5947S01
which are critical crop nutrient6.
Ammonium 6ulfate may be produced in a number of ways,
including as a by-product of other industries. For example,
ammonium sulfate is commonly crystallized from solutions
produced as a by-product from coke ovens and caprolactum
plants. The production of ammonium sulfate per se, rather
than as an incidental by-product, generally involves
combining ammonia with sulfuric acid, which results in
ammonium 6ulfate having a crystalline structure.
Ammonium sulfate is often not used as a fertilizer by
itself, but rather in combination with other vital plant
nutrients. Therefore, in commercial use ammonium sulfate
must often be blended with granular fertilizers to produce a
balanced fertilizer blend.
There i6 a long history of processes for the production
of ammonium sulfate, and of attempts to improve on the
shape, 6ize, uniformity, and storage characteristics of
ammonium sulfate either by modification of crystallization
procedures or by the use of granulating techniques.
A representative example of a conventional method of
granulation, is to use a rotary ammoniator granulator.
Another common method is to use a pugmill to contact recycle
fines with varying proportions of ammonia and sulphuric
acid, using granulation aids such as phosphates, ammonium
nitrate, urea, or lignosulfates.
More recently, a process for the production of granular
ammonium sulfate has been developed in which ammonium
sulfate is granulated in the presence of a granulation aid
which i8 an aluminum salt or a ferric salt. In this
process, ammonia and sulfuric acid are first mixed in a pipe
reactor to form a slurry. The slurry is distributed onto a
bed of ammonium sulfate fines, where further ammoniation
occurs, and is then granulated in the presence of the
aluminum salt or the ferric salt. The resulting product is
free-flowing and non-caking; has a pH of about 4.0 to 4.5,
measured in a 10% 601ution (by weight in water); and has an
1333221
P5947S01
average Pfizer hardness (as defined below) of about 5.0
pounds. The granulation may be carried out in a
conventional apparatus, ~uch a6 a rotary granulator or a
pugmill.
It ha6 been found, however, that ammonium sulfate
granules, produced to have a Pfizer hardness of greater than
about 5.0 pounds, and preferably greater than about 6.8
pounds, and more preferably at least about 9.8 pounds, with
a usual hardness range of between about 9.8 ~nd 12.7 pounds,
and having a pH of less than about 4.0, preferably a pH of
between about 2.5 and 4.0, and more preferably a pH between
about 2.5 and 2.9, with a most preferred average pH of about
2.7, have a 6uperior capacity for the absorption of
agricultural treatment composition, 6uch as herbicides and
the like, and yet maintain their free-flowing, non-caking
characteri6tics rendering such impregnated-fertilizers
particularly suitable for use in agricultural "weed and
feed" applications.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that
granular ammonium sulfate produced by a process which result
with free-flowing granules having minimal tendencies to
become wet or glisten and cake possess superior absorptive
properties when compared to granular urea or conventional
crystalline ammonium sulfate. This is particularly true for
ammonium sulfate granules produced to have a Pfizer hardness
of greater than about 5.0 pounds, and preferably greater
than about 6.8 pounds, and most preferably at least about
9.8 pounds, with a usual hardness range of between about 9.8
and 12.7 pounds, as well as for ammonium sulfate granules
produce to have a pH of less than about 4.0, and preferably
between about 2.5 and 4.0, and most preferably between about
2.5 and 2.9, with an average pH of about 2.7.
It has been unexpectedly discovered that granular
ammonium sulfate exhibiting the previously mentioned
characteristics remains substantially dry and free-flowing
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P5947S01
when impregnated with ~mount~ of herbicide which would tend
to cause urea granule6, crystalline byproduct ammonlum
sulfate, and other fertilizers, to become wet, i.e., or
gli~ten, and viscous, and tend to agglomerate into ~mall
groups that which tend not to be readily flowable.
Herbicide~ which may be u6ed for purposes of the
present invention may be eelected from the group consi~ting
of Avadex BW (triallate) Edge EC~ (ethafluralin), EPTC,* EPTC
plu6 R-2S788 plu~ R-33865, Butylate*, Butylate plus R-25788,
cyanazine, trifluralin, pendimethalin, metribuzin, 2,4-D,
atrazine, triallate, trifluralin, glysophate, glysophate
+2,4-D, sethoxydim, metolachlor, metolachlor + atrazine; S-
propyl dipropylthiocarbamate, alpha, alpha, alpha-trifluoro-
2,6-dinitro-N,N-dipropyl-p-toluidine; S-ethyl
lS diisobutylthiocarbamate; 2,6-dichlorobenzonitrile; 1,1'-
dimethyl-4-4'-bipyridinium dichloride; 2,4-dichlorophenoxy
acetic acid; sodium 2,4-dichlorophenoxy acetate; 3-amino-
2,5-dichlorobenzoate; s-ethyl dipropylthiocarbamate; S-ethyl
hexahydro-lH-azepine-l-carbothioate; S-ethyl cyclohexyl
ethyl thiocarbamate: 2,4,5-trichlorophenoxyacetic acid; 2-
methyl-4-chlorophenoxy acetic ac$d; 2,4-bis(3-
methoxypropylamino)-6-methylthio-s-triazine; 2-chloro-4-
ethylamino-6-isopropylamino-6-triazine; 2-ethylamino-4-
i~opropylamino-6-methylmercapto-6-triazine; 3-(3,4-dichloro-
phyenyl)-l,l-dimethylurea; N,N-diallyl-alphachloroacetamide;
N-(alpha-chloroacetyl)hexamethyleneimine; N,N-diethyl-alpha-
bromoacetamide; 3-amino-2,5-dichloro-benzoic acid and
mixtures thereof. Of the previously listed herbicides,
liquid fertilizers and emul~ifiable herbicide concentrates
selected from the group consisting of Avadex BW (triallate)
Edge EC (ethafluralin), EPTC, EPTC plus R-25788 plus R-
33865, Butylate, Butylate plus R-25788, cyanazine,
trifluralin, pendimethalin, metribuzin, atrazine and 2,4,-D,
are preferred, with Avadex BW and Edge EC being more
preferred.
A preferred fertilizer for purposes of impregnation
*trade-mark
' ';
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P5947SOl
with herbicides in accordance with the present invention iB
free-flowing granular ammonium sulfate. AB used herein
granular ammonium sulfate or ammonium sulfate granule6 means
particles formed from agglomerated microscopic cry6tals of
ammonium sulfate, a6 distinguished from the macroscopic
crystals of conventional crystalline ammonium sulfate which
are discrete forms vi6ible to the naked eye. Ammonium
sulfate granules suitable for purpose6 of the pre6ent
invention are produced by a process which involves the steps
of adding a granulating aid selected from the group
~ consi6ting of a metal salt, a metal oxide, and a salt of a
metal hydroxide, to a slurry of ammonia and sulfuric acid
and granulating the slurry to produce ammonium sulfate
granules under 6ufficiently acidic conditions that the
ammonium sulfate granules have a pH of less than about 4.0,
e.g., between about 2.5 and 4Ø
Another free-flowing granular ammonium sulfate
preferred for being impregnating with herbicides in
accordance with the present invention is produced by a
process which involves the 6teps of adding a granulating aid
6elected from the group con6isting of a metal salt, a metal
oxide, and a salt of a metal hydroxide, to a slurry of
ammonia and sulfuric acid, in an amount sufficient to yield
ammonium sulfate granules comprising more than about 0.05
percent by weight of the metal; and granulating the slurry
to produce ammonium sulfate granules under sufficiently
acidic conditions that the ammonium sulfate granules have a
pH of les6 than about 4Ø
Granular ammonium 6ulfate or ammonium sulfate granules
preferred for impregnation with herbicides in accordance
with the present invention may also be produced by a process
which involves the 6teps of adding a granulating aid
selected from the group con6i6ting of a metal 6alt, a metal
oxide, and a salt of a metal hydroxide, to a slurry of
ammonia and sulfuric acid, in an amount 6ufficient to yield
ammonium 6ulfate granules compri6ing more than about 0.0
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P5947S01
percent by weight of the metal; granulating the 61urry to
produce ammonium sulfate granules under sufficiently acidic
conditions that the ammonium sulfate granules have a pH of
le6s than about 4.0; followed by cooling the ammonium
sulfate granules to a temperature of less than about 150 F
at a cooling rate of greater than about 7.5 F/minute,
whereby more than about 85.7% of the ammonium 6ulfate
granules have a particle 6ize which equals or exceeds +10
Tyler mesh screen size and the ammonium sulfate granules
have a Pfizer hardness of greater than about 5.0 pounds.
An object of the present invention is the production of
substantially dry, free-flowing, non-caking ammonium sulfate
granules impregnated with herbicides in amounts up to about
60 liters/tonne and preferably greater than about 23.5
liters/tonne, such as amounts greater than about 28.5
liters/tonne, i.e., greater than about 30 liters/tonne, and
even greater than about 40 liters/tonne, e.g., greater than
about 50 liters/tonne.
Another still further object of the present invention
is the production of free-flowing, non-caking ammonium
sulfate granules having a pH of between about 2.S and 4.0,
including a metal selected from the group consi6ting of
aluminum and iron which are impregnated with herbicides in
amounts up to about 60 liters/tonne and preferably greater
than about 23.5 liters/tonne, such as amounts greater than
about 28.5 liters/tonne, i.e., greater than about 30
liters/tonne, and even greater than about 40 liters/tonne,
e.g., greater than about 50 liters/tonne.
Another further object of the present invention i8 the
production of ammonium sulfate granules having a pH of less
than about 4.0, containing more than about 0.05% by weight
of a metal selected from the group consi6ting of aluminum
and iron which ~re impregnated with herbicides in amount6 up
to about 60 liter6/tonne and preferably greater than about
23.5 liters/tonne, 6uch as amounts greater than about 28.5
liters/tonne, i.e., greater than about 30 liters/tonne, and
13~3224
P5947S01
even greater than about 40 liters/tonne, e.g., greater than
about 50 liters/tonne.
Another still further ob~ect of the present invention
i8 the production of ammonium ~ulfate granule6 having a
Pfizer hardnes6 of greater than about 6.8 pounds which are
impregnated with herbicides in amounts up to about 60
liters/tonne and preferably greater than about 23.5
liters/tonne, 6uch as amounts greater than about 28.5
liters/tonne, i.e., greater than about 30 liters/tonne, and
even greater than about 40 liters/tonne, e.g., greater than
about 50 liters/tonne.
Another yet still further object of the present
invention i6 the production of ammonium sulfate granules,
the production of and wherein more than about 85.7% of the
granules are equal to or larger than +10 Tyler mesh 6creen
size, which are impregnated with herbicides in amounts up
to about 60 liters/tonne and preferably greater than about
23.5 liters/tonne, such a6 amounts greater than about 28.5
liters/tonne, i.e., greater than about 30 liters/tonne, and
even greater than about 40 liters/tonne, e.g., greater than
about 50 liters/tonne.
It i8 another ob;ect of the present invention to
provide a method for impregnating a fertilizer with a
liquid agricultural treatment composition selected from the
group consisting of herbicides, pesticides, insecticides,
fungicides, 6poricides, hematocides, bacteriocides,
larvacides and mixtures thereof, which involves
impregnating the fertilizer with the liquid agricultural
treatment composition in amounts up to about 60 liter6/tonne
and preferably greater than about 23.5 liters/tonne, 6uch
as amounts greater than about 28.5 liters/tonne, i.e.,
greater than about 30 liters/tonne, and even greater than
about 40 liters/tonne, e.g., greater than about 50
liters/tonne, wherein the fertilizer remains sufficiently
dry and free-flowing for application by conventional
fertilizer application means.
1~33224
P5947SOl
DESCRIPTION OF PREFERRED EMBODIMENTS
For purposes of the pre6ent invention, the process will
be de6cribed with re6pect to the granular ~mmonium sulfate
a6 the preferred fertilizer and Avadex BW or Edge EC a8 the
herbicide.
The proces6 ~ccording to the present invention
initially involve6 the provi6ion of ammonium 6ulfate
granules. Granular ammonium sulfate which has been
discovered to be suitable for impregnation with herbicides,
such as Avadex BW and Edge EC, in accordance with the
present invention are produced by a process which involves
first forming an ammonium sulfate slurry by mixing ammonia
and sulfuric acid in a pipe reactor. The ammonium sulfate
61urry i6 introduced onto a bed of recycled ammonium sulfate
fines, where further ammoniation takes place. Granulation
is then carried out in the presence of a granulating aid,
and the resulting product is dried, 6creened, and cooled.
Any conventional granulating 6ystem may be used, including
rotary granulators and pugmills.
The granulating aid may be a metal oxide, preferably
hydrated, such as aluminum oxide; a salt of a metal
hydroxide, 6uch as 60dium aluminate; an aluminum salt; or a
ferric salt. Aluminum salts are preferred, with aluminum
sulfate being most preferred. Where the granulating aid
contain6 aluminum, the aluminum should be present in a
601uble form.
The aluminum oxide granulating aid i6 preferably u6ed
in the form of a 61urry, while the aluminum or ferric salt
may conveniently be introduced to the ammonium sulfate
slurry in the form of an aqueous solution. Generally, the
aqueous solution is introduced into the slurry in the pipe
reactor. However, the aqueous solution may be metered into
the granulation apparatus at any convenient location, 6uch
as adjacent the inlet thereof. Alternatively, the aluminum
or ferric salt may be added to the granulator or to the
recycle in 601id form, by means of a feeding apparatus.
133322~
P5947S01
Where an aluminum salt iB used, it is generally used in
an amount sufficient to give ~ final product containing
more than about 0.05% by weight of aluminum. Preferably the
product contains between about 0.05 and 1.06% by weight of
aluminum, even more preferably between about 0.15 and 1.06%,
and most preferably the aluminum content is between about
0.25 ~nd 0.40% by weight.
The product may contain phosphate derived from the
starting materials or phosphate may be deliberately added.
The presence of phosphate may favorably affect the
granulation of the ammonium sulfate.
The process according to the present invention i6
conducted at a pH sufficient to yield ammonium sulfate
granules with a pH of less than about 4.0, measured in a 10%
solution, and the pH may be as low a~ about 2.5.
Granules produced according to the present invention
and exhibiting a pH of between about 2.5 and 4.0 show no
caking during storage, as initially indicated by performing
accelerated caking tests on such granules. 100 gram samples
of granular ammonium sulfate were placed in a stainless
steel tube with an outer diameter of 2.0 inches. The
samples were pressurized to 35 psi, using a pneumatic
piston, and stored for one week at a temperature of 85F.
The amples were then removed from the stainless steel tube
and examined for caking; no caking was observed.
The accelerated caking tests were confirmed by a series
of full-scale production runs producing ammonium sulfate
granules having ph values of from 2.5-4Ø The granules
were cooled in accordance with the present invention and
stored in commercial-sized storage piles of 400-10,000 tons.
After several weeks of ~torage, the product remained free-
flowing and free from caking.
After leaving the drying step the granules are screened
and cooled prior to storage. Without being bound by this
theory, it is thought that the non-caking properties of the
low pH granules result from the rapid cooling of the
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P5947S01
granules, ~uch as in a rotary cooler, generally from an
lnitial temperature of about 225F to a pre-storage
temperature of about 120F.
The rate of cooling i8 generally greater than about
7.5 F/minute, preferably between about 9.5 and 16.5
F/minute, and most preferably between about 9.5 and 11.5
F/minute.
While the cooling should be rapid, any suitable means
may be employed, including but not limited to a rotary
cooler or a fluidized bed cooler. The critical factor i6
not how the granules are cooled, but rather that they be
cooled to a pre-storage temperature of less than about 150
F and preferably of between about 60 and 130 F, with a pre-
storage temperature of between about 110 and 130 F being
most preferred.
Granulated ammonium 6ulfate produced according to this
process remains free-flowing and doe6 not consolidate or 6et
to a hard mass upon being allowed to stand in large piles
during storage. In addition, the resulting ammonium 6ulfate
granules are 6ubstantially harder than granular ammonium
sulfate known to the prior art.
The hardnes6 of the granules is mea6ured with a
commercial compression tester, such as a Chatillon
compression tester. At least 25 granules within the Tyler
mesh size range of -7 +8 from a given product run are tested
individually, and the average of these mea6urements is taken
a6 the Pfizer hardnes6 of the product run from which the
tested granules were taken. The granules are placed, one at
a time, on a flat surface provided on the compression
tester. Pressure iB applied to each granule using a flat-
end rod attached to the compression tester, and a gauge
mounted in the compression te6ter measures the pressure
reguired to fracture the granule. Ammonium sulfate granules
produced according to the process of the present invention
generally po6se6s a Pfizer hardne6s in the range of from 9.8
to 12.7 pounds, while prior art granular ammonium sulfate
-- 10 --
1333224
PS947S01
has typical Pfizer hardness values of 5 pounds or less.
Due to the superior 6ize and hardness of the granule6,
ammonium ~ulfate produced according to the present invention
experiences minimal breakdown into undesirably 6mall
fragments during cooling, storage, handling, blending,
shipping, and 6preading.
Moreover, use of granular ammonium 6ulfate produced
according to the present invention, either as a fertilizer
per ~e or as an ingredient in fertilizer blends, produces
exceptionally uniform results. This follows from the fact
that the mechanics of spreading fertilizer are improved by
use of a physically more uniform product, resulting in more
uniform spreading. In addition, when fertilizer blends are
used, blends using granular ammonium ~ulfate produced
according to the present invention will remain uniformly
blended, rather than tending to layer out by component by
the time the end user is reached as is often the case with
prior art blends.
It should be noted that in the process according to the
present invention, ammonium sulfate fines produced therein
are recycled through the granulation apparatus, where they
are formed into the bed onto which the slurry containing
ammonium sulfate is distributed. While the recycle ratio
generally ranges from about 7:1 to 20:1, ratios as low as
about 2.5:1 have been achieved.
In accordance with the best mode for practicing the
present invention, the granular ammonium sulfate, exhibiting
one or more of the previously discussed characteristics,
produced in accordance with the procedures described above,
is then impregnated with a herbicide. In this regard, any
conventional procedure for impregnating fertilizers with
adjuvants, additives and the like, such as agricultural
treatment compositions, i.e., herbicides, pesticides,
insecticides, fungicides, bacteriocides, sporicides,
larvacides, hematocides and mixtures thereof, may be used
for purposes of the present invention.
- al -
P5947S01 1 3 3 3 2 2 4
For example, fertilizer, ~uch a6 granular ammonium
sulfate may be introduced batchwise into a rotary drum
mixer, having a capacity of about 2 to 8 tonne6. The
herbicide, 6uch a6 Avadex BW or Edge EC, is then 6prayed
slowly into the rotating drum via a metering pump and a
6pray nozzle or nozzle6 until the de6ired ratio of herbicide
to fertilizer is reached. In this regard, it has been
unexpectedly discovered that granular ammonium sulfate,
exhibiting the characteri6tic6 described above, and produced
in accordance with the previously described procedure,
absorb greater amount6 of herbicide than conventional
fertilizer6, such as granular urea or crystalline by product
of ammonium sulfate, i.e., amounts up to about 60
liters/tonne and preferably greater than about 23.5
liters/tonne, e.g., amounts greater than about 28.5
liters/tonne, including amount6 greater than about 30
liter6/tonne, as well a6 ~mount6 greater than about 40
liter6/tonne. Even more unexpected i6 that granular
ammonium 6ulfate can absorb amount6 greater than about 50
liters/tonne, i.e., an amount of about 60 liters/tonne,
without experiencing the adverse effects normally resulting
from impregnation of fertilizer6 with herbicide6. Once the
amount of herbicide has been introduced, the herbicide flow
i6 then 6topped, and the drum i6 rotated for a few more
minutes to ensure that all the herbicide has been absorbed.
The impregnated fertilizer is then discharged from the drum.
Of the previously identified agricultural treatment
compositions which may be suitable for purposes of the
present invention, herbicides have been found to be
preferred for purposes of impregnating granular ammonium
sulfate in accordance with the present invention. Such
herbicides include those selected from the group consisting
of Avadex BW, Edge EC, EPTC, EPTC plus R-25788 plus R-33865,
Butylate, Butylate plus R-25788, cyanazine, trifluralin,
pendimethalin, metribuzin, 2,4-D, atrazine, triallate,
trifluralin, glysophate, glysophate +2,4-D, 6ethoxydim,
- 12 -
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P5947S01
metolachlor, metolachlor + atrazine; S-propyl
dipropylthiocarbamate, alpha, alpha, alpha-trifluoro-2,6-
dinitro-N,N-dipropyl-p-toluidine: S-ethyl
diisobutylthiocarbamate; 2,6-dichlorobenzonitrile; 1,1'-
dimethyl-4-4'-bipyridinium dichloride; 2,4-dichlorophenoxy
acetic acid; sodium 2,4-dichlorophenoxy acetate; 3-amino-
2,5-dichlorobenzoate; s-ethyl dipropylthiocarbamate; S-ethyl
hexahydro-lH-azepine-l-carbothioate; S-ethyl cyclohexyl
ethyl thiocarbamate; 2,4,5-trichlorophenoxyacetic acid; 2-
methyl-4-chlorophenoxy acetic acid; 2,4-bis(3-
methoxypropylamino)-6-methylthio-s-triazine; 2-chloro-4-
ethylamino-6-isopropylamino-s-triazine; 2-ethylamino-4-
isopropylamino-6-methylmercapto-s-triazine; 3-(3,4-
dichlorophyenyl)-l,l-dimethylurea; N,N-diallyl-alpha-
chloroacetamide; N-(alpha-chloroacetyl)hexamethyleneimine;
N,N-diethyl-alpha-bromoacetamide; 3-amino-2,5-dichloro-
benzoic acid and mixtures thereof. Of the previously
li6ted herbicides, liquid herbicides and emulsifiable
herbicide concentrates, such as those selected from the
group consi6ting of Avadex BW (triallate) Edge EC
(ethafluralin), EPTC, EPTC plUB R-25788 plus R-33865,
Butylate, Butylate plus R-25788, cyanazine, trifluralin,
pendimethalin, metribuzin, atrazine and 2,4,-D, are
preferred, with Avadex BW and Edge EC being more preferred.
The present invention may be further appreciated by
reference to the following Examples. It is to be understood
that these Examples are merely illustrative and in no way
define or limit the scope of the present invention, which
extends to any and all composition6, means, and methods
suited for practice of the process according to the present
invention, as well as to any and all products made thereby.
EXAMPLE I
Approximately four hundred grams of fertilizer was
placed in a one liter polyethylene sample bottle.
Approximately one third of the appropriate amount of
emulsifiable herbicide, i.e., Avadex BW, was added to the
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fertilizer and the sample bottle wa~ agitated by hand forapproximately one minute. Then, the next third of the
appropriate volume of herbicide was added, followed by about
one minute of agitation: prior to finally adding the last
third of the herbicide followed by about one to two minutes
of agitation. The reFulting mixture was then transferred to
125 ml glass sample bottles.
After all the 6amples were prepared, each sample was
compared qualitatively. The samples sat in the bottles for-
about one to two hours before the comparisons took place.
(Avadex ~.W. is a registered trademark of Monsanto
Company).
The test results are shown in Tables 1 and 2 appearing
below:
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TABLE 1
APPEARANCE OF GRANULAR FERTILIZERS AFTER
IMPREGNATION WITH HERBICIDE
Granular Ammonium Sulphate
20.5-0-0-24
IMPREGNATION RATE
(LITERS HERBICIDE/TONNE FERTILIZER) OBSERVATIONS
23.5 Granules are dry with no visible
moisture on 6urface. Granules
are free flowing.
28.5 Granules are dry with no visible
moisture on 6urface. Granules
are free flowing.
36.9 Surface of some granules
slightly moist. Granules do not
stick together and remain free
flowing.
47.0 Surface of all granules are wet.
Granules begin to adhere to each
other. Still relatively free
flowing.
58.7 Surfaces of all granules
are wet. Granules adhere
together in small clu~ters
of 3 or more. Flow becomes
vi6cous, but still
- 15 -
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relatlvely froe flowing.
TABLE ~
SAPPEARANCE OF GRANULAR FERTILIZERS AFTER
IMPREGNATION WITH AVADES (REGISTERED) BW HERBICIDE
Urea 46-0-0
IMPREGNATION RATE OBSERVATIONS
(LITERS HERBICIDE/TONNE FERTILIZER) ONE HOUR AFTER BLENDING
23.5 Surfaces of all granules are
wet. Granules adhere together
in small clusters of 3 or more.
Flow is viscous, but 8till
relatively free flowing.
Similar in appearance to
granular ammonium sulphate with
58.7 liters herbicide/tonne
fertilizer.
36.9 Surfaces of all granules are
very wet. Granules adhere
together in clusters. Flow is
more viscous than urea with 23.5
l/tne.
- 16 -
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P5947S01
Byproduct Crystalline Ammonium Sulphate
23.5 Surfaces of all granules
are very wet. Granules
adhere together in
cluster6. Flow is viscou6.
36.9 Surfaces of all granules
are wetter than crystalline
with 23.5 l/tne. Granules
adhere together in
clusters. Flow is more
viscou6 than crystalline
with 23.5 l/tne.
As shown, the granular ammonium sulphate impregnated
with Avadex in accordance with the present invention was
found to remain dry and flowable at impregnation rates up to
about 37 liters of herbicide per tonne of fertilizer. At
rates above this, the surface of the granules began to
become wet, granules began to agglomerate and the mixture
became viscous, and yet the granules still remain
substantially free-flowing.
In contrast, the urea mixture was wet at impregnation
rates as low as 23.5 liters of herbicide per tonne of urea
with some agglomeration and increase in viscosity. The
agglomeration and viscosity was more pronounced at 37
liters/tonne impregnation rate. The crystalline byproduct
ammonium 6ulphate was very wet and vi6cou6 with a high
degree of agglomeration at both tested impregnation rates.
Thus, the granular ammonium sulphate impregnated with
Avadex herbicide in accordance with the present invention
exhibited a a much greater capacity for absorbing herbicide
than did urea or crystalline byproduct ammonium 6ulphate.
At about 23.5 l/tne, to ~u6t under 36.9 l/tne, the granular
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ammonium ~ulphate impregnated with the herbicide inaccordance with the pre6ent invention was relatively dry,
versus urea and crystalline ammonium, both of which
exhibited excessive moi6ture at impregnation rates as low as
23.5 l/tne. At impregnation rates of about 58.7 l/tne, the
granular ammonium sulpl.ate impregnated with the herbicide in
accordance with the present invention exhibited properties
similar to those of urea impregnated with ~ust 23.5 l/tne.
EXAMPLE II
Using a procedure 6imilar to the one described above
with respect to Example I, a similar test wa6 conducted
wherein Edge EC, which i8 ethafluralin dissolved in an
organic solvent, was used as the herbicide for purpo6es of
impregnating the fertilizer.
Approximately 400 grams of fertilizer was placed in a
one liter polyethylene 6ample bottle. Approximately one
third of the appropriate amount of liquid herbicide, in this
case Edge EC, was added to the fertillzer and the sample
bottle was agitated by hand for approximately one minute.
Afterwards, the next third of the appropriate volume of
herbicide was added to the bottle followed by agitating the
bottle containing the fertilizer and herbicide mixture for
about one minute. Finally, the last third of the
appropriate volume of herbicide was added to the bottle
which was then agitated between about one-two minutes.
Afterwards, the resulting mixture was transferred to 125 ml.
glass sample bottles, which were permitted to sit for about
one-two hours. Subsequently, the samples were compared
qualitatively, the test results being shown in Table 3
appearing below.
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TABLE 3
GRANULAR AMMONIUM SULPHATE
S EDGE ABSORPTION CAPACITY
ABSORPTION CAPACITY
(LITERS OF EDGE/TONNE FERTILIZER) OBSERVATIONS AFTER 1-2 HOURS
10 GRANULAR
AMMONIUM SULPHATE UREA
20-0-24 46-0-0
15 15.7 DRY, FREE FLOWING
23.6DRY, FREE FLOWING
31.4 10.0 SLIGHT MOISTURE, FREE FLOWING
39.3 15.7 WET, STICKY, FREE FLOWING
50.0 23.6 WET, CLUSTERS, VISCOUS FLOW
31.4 VERY WET, CLUSTERS, VISCOUS FLOW
As indicated above, granular ammonium 6ulfate can be
impregnated with Edge EC with similar re6ults to that
achieved when granular ammonium sulfate i6 impregnated with
Avadex BW. In this regard, granular ammonium sulfate
ab60rbed Edge EC in the amount of 23.6 liters/tonne of
fertilizer, and yet the impregnated granular ammonium
sulfate remained dry and free-flowing. In contrast,
granulated urea formed clusters, glistened or appeared wet
and exhibited a viscous flow when impregnated with 23.6
liters of Edge EC/tonne of fertilizer. This condition did
not begin to appear in granular ammonium sulphate until
impregnated with 50 liter6 of Edge EC/tonne of fertilizer.
As used herein, dry or substantially dry refer6 to the
appearance of fertilizer, such a6 granular ammonium 6ulfate,
which is different from fertilizers which appear wet or
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glisten upon impregnation with an amount of herbicide. The
term dry, therefore, is not used in the strict sense of
being bone dry, nor is the term meant to be limited to a
prescribed moisture or liquid content. A simple
determination of whether a fertilizer i6 wet or dry can be
made by placing a quantity of impregnated ammonium sulfate
granules in a glass-sided vessel and observing whether the
particles glisten and the sides of the glass become wet.
Although the invention has been described with respect
to the preferred embodiments di~cussed above, it is clearly
understood that this is by way of example only, and that the
invention is not limited to the particulars disclosed but
extends to all eguivalents within the scope of the claims.
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