Fertilizer chip and process for making same

This invention pertains to a fertilizer and a process for producing the same which incorporates flyash, which is a by-product from the coal fired utility industry, with an organic fertilizing component comprising manure. The flyash and manure are mixed with the resulting mixture compressed by passing the mixture through a roller press thereby forming a sheet and then fracturing the sheet into chips or other particulate form. The water content of the mixture is controlled in an effort to produce particulates having high dry strength.

FIELD OF THE INVENTION 
This invention relates to agricultural fertilizers In chip form and to a 
process for producing such fertilizers. 
BACKGROUND OF THE INVENTION 
The use of various inorganic and organic components which are rich in 
phosphorus, potassium and nitrogen as agricultural fertilizers is well 
known. Often these components or materials are combined with a binder and 
pelletized to facilitate handling, storage and application to agricultural 
fields. 
It has been common practice in the manufacture of fertilizer compositions 
to incorporate materials which are by-products from various processes as a 
way of converting materials of little commercial value into fertilizer 
compositions. Such utilization of by-products not only solves a disposal 
problem associated with such by-products, but converts these generally low 
value products into products of value. Often there are associated 
difficulties in such conversions in that products are not storage stable, 
are difficult to handle, or may not be applied to the crops with 
conventional equipment. 
With respect to the agricultural fertilizer of the present invention, the 
following patents have relevancy to the extent that they deal with many of 
the components comprised in the agricultural fertilizer. These patents 
include the following: 
U.S. Pat. No. 242,777 discloses a process for preserving and disinfecting 
animal and vegetable substances derived from rendering establishments, 
sewers, manure, etc. while at the same time converting the manure and 
animal substances into fertilizers which are effective as stimulus to the 
growth of vegetation and which are effective as active insecticides. The 
process contemplates forming a solution or magma of lava rich in potash by 
contacting a lava containing silica, alumina, lime, iron, magnesium and a 
small phosphorus with sulfuric acid or hydrochloric acid. The solution is 
filtered and the solid residue remaining is removed therefrom. The 
solution then is mixed with fecal matter at a maximum of 5 kg filtrate per 
kg of fecal matter and then mixed with empyreumatic lime. This material is 
mixed and then dried for conversion into a fertilizer. 
U.S. Pat. No. 19,974 discloses a process for condensing and fixing ammonia 
in fertilizers for use in the soil. In that process, an aluminous earth 
consisting of various silicates of alumina mixed with other silicates; 
e.g., silicate of potash, sodium or silicate of iron, is powdered and made 
into a porous bed having access to the free action of air. 
U.S. Pat. No. 144,877 discloses methods for producing fertilizers from the 
carcasses of tallow-rendering animals. A supernatant liquid obtained from 
a tallow-rendering vat is withdrawn from the vat and the water evaporated 
therefrom to produce a solution. This liquid then is mixed with Plaster of 
Paris for the purpose of combining with the remaining moisture in the 
syrupy residue. When allowed to dry, the mixture of Plaster of Paris and 
tallow residue is converted into a friable mass which then can be ground 
to a fine powder for fertilizer application. Dried clay, chalk and marl 
are suggested as possible replacement candidates for the Plaster of Paris. 
U.S. Pat. No. 17,237 discloses a process for preparing green-sand-marl 
fertilizers. The marl is washed to separate a large amount of alumina and 
useless earthy components, leaving the green-sand which then is dried, 
pulverized and disintegrated. The green-sand then is mixed with about 600 
lbs. of night soil per 1000 lbs. of green-sand and 100 lbs. of sulfate of 
lime. 
SUMMARY OF THE INVENTION 
This invention pertains to a fertilizer and a process for producing the 
same which incorporates flyash, which is a by-product from the coal fired 
utility industry, with an organic fertilizing component comprising manure. 
The flyash and manure are mixed with the resulting mixture compressed into 
a sheet and then the resulting sheet fractured into chips. 
The invention has significant advantages and these include: 
the development of an agricultural fertilizer having excellent storage 
stability and handling characteristics; 
the utilization of a by-product of the coal-fired electric power industry 
into a useful product; 
an ability to formulate an agricultural fertilizer in "chip" form which has 
excellent strength in dry condition, but is readily friable under moist 
conditions allowing for dispersion into the soil and utilization of the 
nutrients contained therein by crops; 
a process which is simple to perform in non sophisticated equipment. 
DETAILED DESCRIPTION OF THE INVENTION 
The agricultural fertilizer contemplated here comprises flyash as one of 
the components. Flyash is generated in coal-fired power plants, primarily 
where the coal is combusted in finely divided form and the flyash 
precipitated from the flue gases. The particle size of such flyash is 
generally between about 100 to 325 mesh U.S. standard sieve. Flyash is 
predominantly silica and alumina with large amounts of iron oxides. As 
might be expected from a silica containing product, flyash is somewhat 
glassy in appearance because of the high temperatures reached in the 
combustion process. 
The other primary component of the agricultural fertilizer is manure, and 
that term requires little description. Virtually any manure may be used 
for combination with the flyash, although it is preferred that the manure 
be essentially free of extraneous fibrous material such as straw, chaff, 
and the like. Manure from chickens, sheep and other ruminants is desirable 
for preparing the agricultural fertilizer. 
Other additives conventionally used in fertilizers may be incorporated into 
the agricultural fertilizer, and these include nitrogen, phosphorus, 
potash providing components, as well as insecticides and specialty 
herbicides. Examples of fertilizer components include ammonium nitrate, 
ammonium phosphate, ammonium sulfate, pH adjustment additives such as 
calcium carbonate, etc. Insecticides include thiocarbamates, an example 
being sold under the trademark, Sevin; chlorinated organics, and 
diazinone. Virtually any of the specialty herbicides may be combined with 
the fertilizer batch in amounts as desired. 
In formulating the fertilizer, a master formulation is prepared by mixing 
the flyash with the manure and other preselected fertilizer components 
thereby creating a blend. The liquid, primarily water, concentration of 
the blend should be controlled such that from about 5% to 28% by weight of 
the batch is liquid or water. Such liquid or water content will leave the 
resulting blend in the form of a thick paste having a consistency similar 
to peanut butter. If too much water is present in the resulting blend, 
problems are associated with the sheet-forming step with residual water 
being squeezed from the resulting mixture during pressing and sheet 
forming. Too little water results in a paste having insufficient binding 
attraction for enhanced sheet formation. 
In the processing of the blend to form a storage-stable, high strength 
chip, which is easily handled during storage and easily handled for 
application to crops, the blend is formed into a sheet and the resulting 
sheet fractured into small chips. One method of sheet formation is 
accomplished by passing the blend through a roll press under a compression 
load of from 4 to 20 tons force per linear inch of sheet width. Typically 
a roll speed of 1 to 10 linear feet per second is made during compaction, 
thus providing a residence time of from about 0.1 to 0.5 seconds. 
Generally, the roll faces are maintained at elevated temperature; e.g., 
from 25.degree. C. to 135.degree. C. High temperature generally ought to 
be avoided since the high temperature also results in the liberation of 
ammonia from the blend, thereby decreasing its nitrogen imparting 
characteristics. To facilitate compaction and compression in the roll 
press, the blend may be conveyed to the roll press via a screw-type 
conveyor which delivers the blend in relatively compact form to the 
compression rolls. As the blend of flyash and manure, optionally including 
other fertilizer components, is fed to the compression roll, the blend is 
formed into a thin sheet; e.g., from about 0.08 to 0.54 inches in 
thickness. Because of the high compression pressures, the manure and 
flyash bond through physical attraction for providing chip form product 
having excellent dry strength. 
The sheet can be fractured into chip utilizing a wide variety of mechanical 
apparatus or chips can be ground or fractured allowing the sheet from the 
compression rolls to fall onto a conveyor, with the falling onto the belt 
causing the sheet to fracture. Supplemental crushing can be conducted, if 
required. The resulting chips have a size of from about 1/4 to 1 inch on a 
side when dried and have excellent strength for promoting storage 
stability and handling.

The following examples are provided to illustrate various embodiments of 
the invention and are not intended to restrict the scope thereof. 
EXAMPLE 1 
Trial Procedure for producing Chip Form Fertilizer 
A series of tests were carried out in order to produce "chip" form 
agricultural fertilizers from flyash and a straw free cow manure. The roll 
press used in the process was a Komarek lab compactor; a granulating unit 
having a 3/8" open screen was also used. 
In general a blend was prepared by mixing a flyash with manure with the 
weight percent of flyash being about 70% and the manure being about 30% 
These materials were blended in a Beardsley and Piper Speed Mullor Mixer, 
Model 45B having an 18-inch drive with 10-inch straight side with a 
scraper and muller operating at 400 rpm. The blend was densified via a 
densifying screw press and then introduced to a variable speed vertical 
double roll compactor, said compactor having smooth roll surfaces. The 
rolls were 2 inches wide and had a 5 inch diameter. The roll separating 
force ranged from about 4 to 9 tons per linear inch of roll face with the 
roll speed ranging from 6 to 11 rpm. The temperature of the roller face 
approached 135.degree. F. causing an evolution of ammonia and urea. A 
sheet having a thickness of about 0.25 inches was generated and was 
comminuted into chip form product using a Model DAS 06 Knife Comminutor. 
The chips were about 1/8 inch in thickness and had irregular planar 
dimensions of about 1/2 to 1 inch. The chips then were ground in the 
comminutor to produce a product having a mesh size of 4 to 30 US mesh. 
More specifically, the feed was prepared in an amount of 280 lbs flyash and 
120 lbs of cow manure. The manure was placed in the mixer and initially 
mixed for 5 min. After that, the fly ash was added and mixing was 
continued for an additional 5 min. Then water in preselected amounts was 
added and the blend mixed for an additional 10 min. The blend was the 
compacted and processed as described above. Table 1 below set forth the 
general processing conditions and results. 
TABLE 1 
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Blend 
Roll 
Sheet Roll 
Flyash 
Manure 
Moisture 
Density 
Speed 
Thickness 
Force 
Run 
% % % g/cc RPM mm MN/m 
Description of Chips 
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1 70 30 14.1 0.89 6 3.5 1.39 
Strong, stable 
2 50 50 14.1 0.94 10.8 
1.3 1.39 
Weak, friable 
3 80 20 15.1 0.8 10.8 
2.9 1.39 
Medium strong, easily broken 
4 100 -- 5.0 0.68 6 2.7 1.39 
Poor chips 
5 80 CaSO.sub.4 
9.4 0.6 6 2.9 1.39 
Strong, stable 
6 100 12.0 0.87 6 3.3 1.39 
Poor strength 
7 100 6 Brewex* 
7.2 0.64 6 2.9 1.39 
Medium strong 
8 100 9 Brewex 
10.1 0.8 8.2 2.9 1.39 
Very strong and stable 
9 70 30 25.8 0.87 0.87 
2.9 1.39 
Strong and stable 
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*Brewex is a trademark for a modified starch containing 47% malto 
dextrins, 33% maltose, 10% glucose, 6% protein and 4% ash.