A delayed release fertilizer composition consisting essentially of a mixture of a urea-formaldehyde resin and a lignosulfonate prepared by spray-drying an aqueous mixture of a urea-formaldehyde resin and a lignosulfonate. The composition of this invention, is also use as a fertilizer carrier as a replacement for expanded vermiculite fertilizers.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates in general to a spray-dried composition prepared by 
spray drying a mixture of a urea-formaldehyde resin and a lignosulfonate, 
to the method of preparing the composition, to fertilizers containing the 
compositions and to the method of preparing such fertilizers. The 
composition of this invention is useful as a delayed release fertilizer 
and is also useful as a fertilizer carrier, as a replacement for expanded 
vermiculite-based fertilizers. 
2. Description of Related Art 
Slow release nitrogen fertilizers based on urea-formaldehyde resins are 
known in the art. For example, Darden, U.S. Pat. No. 2,766,283 describes 
fertilizer compositions based on urea-formaldehyde resins. The urea and 
formaldehyde are reacted in the presence of water, and at the conclusion 
of the reaction, the product is neutralized and separated by filtration, 
by centrifuging, or by another suitable method. Darden does not disclose 
spray-drying the urea-formaldehyde resin fertilizer composition and does 
not disclose the use of a lignosulfonate in the composition. 
It is also known that lignosulfonate and urea-formaldehyde compositions can 
be used to improve the wet-strength of paper. Keim, U.S. Pat. No. 
2,622,979 disclose lignin sulfonate-modified urea-formaldehyde resins 
prepared by reacting urea-formaldehyde and a lignin sulfonate under 
controlled conditions. This modified resin then is incorporated into a 
paper stock and improves the wet-strength properties of the subsequently 
produced paper. The lignin sulfonate-modified urea-formaldehyde resin of 
Keim is not spray-dried and is not disclosed to be useful as a fertilizer 
or fertilizer carrier. 
Mills, U.S. Pat. No. 2,845,397, teaches that when Kraft lignin is treated 
with urea, or derivatives of urea, and formaldehyde prior to mixing with a 
rubber latex and coagulating, rubber products having improved abrasion 
resistance are produced. The so-modified lignin composition is mixed with 
an alkaline rubber latex and the treated lignin and rubber coagulate is 
recovered by spray-drying or coprecipitating. Mills does not disclose 
preparing a spray-dried mixture of a lignosulfonate and a 
urea-formaldehyde resin for use as a fertilizer or fertilizer carrier. 
Christ, U.S. Pat. No. 3,076,772, discloses an alkaline resinous adhesive 
comprised of urea, phenol and formaldehyde reacted in the presence of an 
alkali metal base catalyst such as sodium hydroxide. The 
phenol-urea-formaldehyde resin then is reacted with a sulfite waste 
liquor, such as lignosulfonate, and the resulting composition is used in 
making particleboard. 
Bornstein, U.S. Pat. No. 4,130,515, discloses a process for preparing a 
thermosetting resin composition which comprises copolymerizing a 
lignosulfonate salt, melamine, and an aldehyde. The resin prepared by 
Bornstein is useful in binding consolidated cellulosic particles to form a 
board-like product. Edler, in U.S. Pat. Nos. 4,194,997 and 4,244,846, 
discloses adhesive compositions comprising mixtures of urea-formaldehyde 
resins and lignosulfonate useful in the production of particleboard. 
Finally, Detroit, in U.S. Pat. Nos. 4,752,317, 4,756,738 and 4,789,391, 
discloses lignosulfonate-acrylonitrile graft copolymers which provide slow 
release of urea fertilizers. The patents to Detroit disclose that the 
fertilizer may be modified to provide controlled nutrient release by 
controlling the solubility of the fertilizer. 
An article by Vorob'eva titled "The Effect of Salt Media on the 
Lignosulfonate Urea Formaldehyde Resin Polycomplex" describes experiments 
demonstrating the use of a urea-formaldehyde resin, and its mixture with 
lignosulfonate, to produce granulated potassium chloride fertilizers. Use 
of the resin provides improved granule strength and slow release 
properties. The lignosulfonate and urea-formaldehyde compositions in the 
Russian paper are dried either at room temperature, or in an oven at 
110.degree. C. The Russian article does not disclose a spray-dried 
lignosulfonate and urea-formaldehyde composition.

DESCRIPTION OF THE INVENTION 
The invention comprises an insoluble urea-formaldehyde resin and 
lignosulfonate composition prepared by spray-drying an aqueous mixture of 
lignosulfonate and a water-soluble, or at least a stable 
water-dispersible, urea-formaldehyde resin. The composition of this 
invention is useful as a fertilizer per se, having delayed release 
characteristics, or as a fertilizer carrier, serving as a replacement, for 
example, for expanded vermiculite fertilizers. Insoluble, spray dried 
compositions of the invention containing a urea-formaldehyde resin and a 
lignosulfonate have the ability to absorb a significant amount of water 
without degrading the flowability of the composition, i.e. without caking. 
Compositions of this invention also have desirable dry bulk and wet bulk 
densities, particularly as compared to dry compositions containing a 
mixture of a lignosulfonate and urea-formaldehyde resin which were not 
prepared by spray-drying techniques. 
The present invention is based on the discovery that upon spray-drying, 
aqueous compositions consisting essentially of a mixture of a 
lignosulfonate and a water-soluble urea-formaldehyde resin, or at least a 
water-dispersible urea-formaldehyde resin, become water insoluble and 
useful as a slow-release fertilizer. The particles of the spray-dried 
composition have a porosity sufficient to absorb a significant amount of 
water without caking, which makes the material useful as a fertilizer 
carrier. 
Fertilizers according to the present invention can be made using one of two 
alternative embodiments. In a first approach, fertilizer compounds, 
particularly fertilizer nutrients, and other desired adjuvants can be 
incorporated into an aqueous mixture of a urea-formaldehyde resin and a 
lignosulfonate before spray drying to make a slow-release fertilizer 
product having the desired ultimate fertilizer composition. Upon 
spray-drying, the water-soluble mixture of urea-formaldehyde resin, a 
lignosulfonate, and other materials becomes a water-insoluble powder, thus 
giving the composition delayed release characteristics. The spray-dried 
product of this invention not only is a free-flowing powder, but also is 
able to absorb up to 50% by weight water without losing its free-flowing 
characteristics, i.e. without caking. 
In an alternative approach, fertilizer nutrients can be incorporated into a 
previously spray-dried composition of the present invention by absorption 
of an aqueous solution of such nutrients on the spray-dried powder. In 
this way, the spray-dried composition of the invention functions much like 
expanded vermiculite carriers of the prior art. 
The spray-dried powder of this invention produced via either approach can 
also be pelletized or granulated using known techniques. Granulation of 
the spray dried powders produces strong beads. 
Lignin is recovered in the paper industry as a by-product from waste 
pulping liquors obtained by processing cellulosic materials such as wood, 
straw, corn stalks, baggasse, and the like. Lignin is a polymeric 
substance of substituted aromatics which is the essential binder in trees, 
and vegetable tissue associated with cellulose and other plant 
constituents. While there is some variation in the chemical structure and 
in the nature of other constituents found in the plant depending on the 
type of plant, place where the plant is grown, and also upon the method 
used to recover or isolate the particular constituents from the plant 
tissue, the basic structure and properties of these materials are similar 
and upon sulfonation form a well-known group of water-soluble materials 
known as lignosulfonates or sulfonated lignin. The lignosulfonate used in 
the present invention can be either a sulfonated lignin made by 
sulfonating alkali lignin made by an alkaline pulping process such as the 
Kraft process or more preferably is a water-soluble sulfonated lignin 
recovered directly from the spent pulping liquor of the sulfite pulp 
process. The reactions and properties of lignosulfonates and lignin are 
covered in the text, The Chemistry of Lignin, by F. E. Brauns et al., 
Academic Press, New York, N.Y. (1960). 
One of the main sources of sulfonated lignin is the residual pulping 
liquors obtained in the pulp and paper industry using the sulfite pulping 
process. In the sulfite pulping process, lignocellulosic material is 
digested with a sulfite or bisulfite to sulfonate (solubilize) the lignin 
and obtain a residual product commonly referred to as "spent sulfite 
liquor" containing the water-soluble sulfonated lignin. In other alkaline 
paper-making processes, the residual pulping liquor or lignin as obtained 
from the process may not be a water-soluble sulfonated product. However, 
the residual liquors or products containing the lignin portion may be 
sulfonated by the various known methods to the degree needed to produce a 
water soluble sulfonated lignin material. 
Spent sulfite liquor or other sulfonated lignin products obtained upon 
sulfonation of residual pulping liquors generally contain other 
constituents beside sulfonated lignin or lignosulfonates. Such lignin 
products may contain carbohydrates, degradation products of carbohydrates, 
and resinous materials as well as other organic and inorganic 
constituents. Although these non-lignin constituents may be removed, in 
the context of the present invention it is not necessary to do so. In this 
regard, the lignosulfonates or products containing the lignosulfonates may 
be subjected to different treatments such as acid treatment, alkaline or 
heat treatment, oxidation or fermentation to remove or modify some of the 
non-lignin constituents or for other purposes. Generally, the basic 
phenolpropane polymeric structure of the lignin constituents and 
properties and characteristics of these products are not destroyed unless 
the treatment is unusually severe. The treated or nontreated lignin 
products also may be fractionated to obtain a particular lignosulfonated 
fraction or polymerized to increase its molecular weight. 
In the present application, the lignin source for obtaining the 
lignosulfonate may be any common cellulosic material including hardwoods 
and softwoods and may be either crude or pure. Lignin recovered from the 
preparation of paper grade quality pulp is suitable. The lignosulfonate 
employed according to the present invention is usually in a salt form 
generally based on an alkali metal or alkaline earth metal such as sodium, 
potassium, calcium, magnesium or ammonium. Preferred lignosulfonate salts 
are the calcium and ammonium lignosulfonate salts. 
In accordance with the invention, the water-soluble lignosulfonate is mixed 
with an aqueous urea-formaldehyde resin (the resin is at least water 
dispersible but preferably is itself water-soluble) to form a uniform 
(homogeneous) mixture before spray drying. Urea-formaldehyde resins used 
in the present inventions are characterized by a particular formaldehyde 
to urea mole ratio (F/U) and solids content. In the broad practice of the 
present invention, any urea-formaldehyde composition containing adducts of 
urea and formaldehyde and only a small amount of unreacted urea species, 
typically less than 5 weight % urea monomer, and having a formaldehyde to 
urea mole ratio of from about 1:1 to about 6:1 can be used in the present 
invention. The solids content of suitable urea-formaldehyde generally is 
at least about 30 weight %. More specifically, to minimize the level of 
water removal required during the spray dry process, the solids content is 
preferably about 40 weight % or higher, and usually about 60 weight %. The 
upper limit for the solids content of the urea-formaldehyde resin before 
spray-drying depends on the nature of the resin itself, including its mole 
ratio and molecular weight. The solids content cannot be so high that the 
solution cannot be pumped through the spray dryer equipment. 
The formaldehyde to urea mole ratio and the solids content of the resin 
must be such that the resultant spray-dried product of the aqueous mixture 
of urea-formaldehyde resin and lignosulfonate produces a water insoluble 
powder. Typically, the F/U mole ratio of the urea-formaldehyde resin used 
to prepare compositions of the present invention is within the range of 
from about 1:1 to about 4:1. More specifically, the F/U mole ratio of the 
urea-formaldehyde resin preferably is within the range of from about 1:1 
to about 3:1. 
The urea-formaldehyde resin itself can be prepared using any of the known 
procedures for making such resin compositions. Generally, an aqueous, 
water-soluble urea-formaldehyde resin is prepared under mildly alkaline 
reaction conditions. 
The relative amount of lignosulfonate solids to urea-formaldehyde resin 
solids used to form the homogenous aqueous mixture for spray drying also 
can be varied to a certain extent provided that, upon spray-drying, the 
mixture produces an insoluble, freely flowing powder. Typically, the 
urea-formaldehyde resin solids and lignosulfonate solids are supplied in 
at least about a 1:1 weight ratio. The desirable water absorption property 
of the insoluble spray dried powder generally tends to increase as the 
weight ratio of urea-formaldehyde resin solids to lignosulfonate solids is 
increased. The weight ratio of urea-formaldehyde resin solids to 
lignosulfonate solids can vary from about 1:1 to about 15:1, and more 
particularly varies between about 1:1 to about 10:1. 
As noted above, in one preferred approach, other fertilizer constituents 
also are included in the aqueous solution of the urea-formaldehyde resin 
and lignosulfonate before spray drying. Fertilizer constituents which can 
be added to the aqueous mixture of urea-formaldehyde resins and 
lignosulfonate include, for example, water-soluble potassium sources, such 
as potassium hydroxide, potassium chloride and potassium sulfate and 
water-soluble phosphates, such as phosphoric acid, diammonium phosphate, 
superphosphate and the like. Trace minerals such as boron, manganese, 
copper, zinc, molybdenum and iron salts also can be added. 
The spray-dried powder then can be used as is or often it is more desirable 
to pelletize or granulate the powder to provide an ultimate slow-release 
fertilizer product. Skilled practitioners in the art will recognize how to 
pelletize and granulate the spray-dried powder of the present invention as 
these operations are well known in the art. For example, the spray dry 
powder can be compacted, pelletized (California pellet mill), drum 
granulated, pan granulated or put through a pug mill, using a known 
binder. 
As previously noted, spray dried urea-formaldehyde and lignosulfonate 
compositions of the present invention also are useful as a fertilizer 
carrier, for example serving as a replacement for expanded vermiculite. In 
such instances, an aqueous solution containing the proper amount of 
fertilizer nutrients can be prepared and then is applied to the 
spray-dried powder of the subject invention. The fertilizer solution can 
be applied to the powder by spraying it onto the powder, or by adding the 
spray-dried powder to an aqueous bath of the fertilizer solution. 
As indicated above, the spray-dried powder of the present invention possess 
a high water absorption characteristic yet retains excellent flowability 
(resists caking). Typically, the spray-dried powder of the present 
invention can absorb at least about 50% of its weight in water without 
degrading the flowability of the powder. The powder also exhibits 
desirable dry and wet bulk densities. Dry bulk densities of the 
spray-dried compositions of the present invention typically range from 
about 2.5 ml/g to about 6.0 ml/g, while wet bulk densities of the 
spray-dried powders may typically range from about 4.7 ml/g to about 8.6 
ml/g. The procedures for determining these properties are described in the 
Examples. 
Spray drying in accordance with the present invention is typically carried 
out with pressure nozzles or centrifugal atomizers operating at speeds of 
up to 10,000 to 16,000 RPM or more. Commercial sources of such spray 
drying equipment are well known to those skilled in the art. At these 
speeds, one milliliter of liquid feed can be converted to over 100 million 
fine droplets. Despite this high velocity generation of droplets, the 
spray dryer preferably is designed so that the droplets do not contact the 
spray dryer wall under proper operating procedures. This effect is 
achieved by a precise balance of atomizer velocity, air flow, spray dryer 
dimensions of height and diameter, and inlet and outlet means to produce a 
cyclonic flow of air in the chamber. This highly specialized art is 
clearly to be distinguished from the random and promiscuous spraying of 
liquid droplets such as one might do with a garden hose. The process of 
spray drying is well known to those skilled in the art. 
A spray dryer for use in connection with the present invention preferably 
is operated at a dryer air inlet temperature of about 230.degree. C. and 
an outlet temperature of about 110.degree. C. The atomizer is typically 
set to operate at a flow ratio of the aqueous mixture flow rate to dryer 
and collection air flow rate of about 10.sup.-5 to 1. More specifically, 
the inlet temperature of the dryer air feed to the spray dryer can vary in 
the range from about 220.degree. C. to about 250.degree. C., and 
preferably from about 225.degree. C. to about 235.degree. C. The outlet 
temperature generally varies from about 100.degree. C. to about 
110.degree. C. 
The following examples further illustrate the practice of the subject 
invention and are not intended as a limitation on the claims thereof. 
EXAMPLES 
In all the following examples, spray dried compositions were prepared using 
a Yamato spray dryer Model DL-41. 
Example 1 
In this example an aqueous mixture of 130 grams of a 50 weight % aqueous 
solution of calcium lignosulfonate (LIGNOSITE.RTM.50, available from G-P), 
and 100 grams of an aqueous urea-formaldehyde (UF) resin was prepared. The 
UF resin had been prepared at a 2.35 F/U mole ratio by first reacting 
about 44 parts of a commercially available UFC concentrate 
(STAFORM.RTM.60) with about 22 parts of a 50% by weight aqueous 
formaldehyde solution in the presence of about 10 parts aqua-ammonia (28% 
ammonium hydroxide), followed by further reaction at an alkaline pH with 
sufficient urea to provide the final F/U mole ratio. The UF resin had a 
final solids concentration of about 60% by weight. The resin contained 
less than about 2.0 weight % unreacted urea monomer. To this mixture sixty 
grams of water were added in which 13 grams of ammonium sulfate had been 
dissolved. 
The mixture was then spray dried to produce a fertilizer carrier 
composition. The spray dryer was operated at an inlet gas temperature of 
250.degree. C., and a gas outlet temperature of 105.degree. C. The flow 
rate of aqueous mixture contain UF resin and lignosulfonate and having a 
solids content of about 46 weight per cent was maintained at about 10 
ml/min and the atomizer pressure was set at 3 kg/cm.sup.2. The flow rate 
of dryer collection air was set at 0.7 m.sup.3 /min. The mixture sprayed 
with some difficulty as it tended to collect on the spray nozzle. 
Example 2 
Example 1 was repeated except that the solution was spray dried at a lower 
solids content and in the presence of a lower amount of ammonium sulfate. 
To prepare the mixture for spray drying an aqueous solution containing 6 
grams of ammonium sulfate in 120 grams of water was used. The solids 
content of the mixture flowed to the spray drier was 36.8% by weight. The 
mixture sprayed with much less difficulty than the aqueous mixture of 
Example 1. 
Example 3 
Example 2 was repeated except that no ammonium sulfate was added to the 
aqueous mixture before spray drying. The total solids content of the 
mixture flowed to the spray drier was 35.7% by weight. 
All three spray-dried products were insoluble in water, and were able to 
absorb over 50% of their weight in water. The dry bulk densities of the 
spray-dried powders are reported below in Table 1. 
TABLE 1 
______________________________________ 
Example Density (lb/ft.sup.3) 
______________________________________ 
1 15 
2 10.2 
3 10 
______________________________________ 
Example 4 
A fertilizer composition was prepared by spray drying an aqueous mixture of 
13.3 grams of LIGNOSITE.RTM. 17 (a 47.6% by weight aqueous solution of 
ammonium lignosulfonate), 158.4 grams of an aqueous urea/formaldehyde 
resin containing about 55% by weight resin solids and less than 5% by 
weight urea monomer, about 5 grams of a 85% by weight phosphoric acid 
solution, about 4 grams of potassium hydroxide and 72 grams of water. The 
potassium hydroxide was added as pellets to the 72 grams of water to which 
the phosphoric acid was added. The aqueous solution for spray drying had a 
solids content of about 40 weight % and a pH of 5.9, which was adjusted to 
5.0 with dilute phosphoric acid. The UF resin was prepared by first 
reacting, in the presence of ammonium hydroxide, a UFC concentrate 
(STAFORM.RTM. 60) with sufficient formaldehyde to provide a F/U mole ratio 
of about 3.2, and thereafter adding sufficient urea to reduce the F/U mole 
ratio to about 1.6 and completing the reaction at an alkaline pH. The 
aqueous solution spray-dried very well and the resulting powder was 
insoluble in water. The powder contained about 6% lignosulfonate and had a 
bulk density about 30-35 lb/ft.sup.3. 
Example 5 
The procedure of Example 4 was repeated except that the aqueous solution 
which was spray dried contained 29 grams of LIGNOSITE.RTM. 17, 122 grams 
of an aqueous UF resin having a solids content of about 65 weight % and 
less than about 1 weight % free urea monomer, about 5 grams of a 85% by 
weight phosphoric acid solution, about 4 grams of potassium hydroxide and 
91 grams of water. The aqueous solution for spray drying had a solids 
content of about 40% by weight and a pH about 6.0. The UF resin was 
prepared by first reacting formaldehyde with sufficient urea to provide a 
F/U role ratio of about 2.5 under an acidic pH, followed by reaction at a 
slightly alkaline pH with sufficient additional urea to lower the F/U role 
ratio to about 1.1. Spray drying the aqueous solution proceeded similarly 
to Example 4. The recovered powder contained about 14% by weight 
lignosulfonate and had a similar bulk density to the product of Example 4. 
Example 6 
Example 5 was repeated except the pH of the aqueous solution to be spray 
dried was adjusted from 6.0 to 4.8 with dilute phosphoric acid. Results 
were similar to Example 5. 
In the following examples, compositions containing a mixture of a 
urea-formaldehyde resin and a lignosulfonate were made in accordance with 
the previously identified Vorob'eva article. 
Example 7 (Comparative) 
Fifty grams of a calcium spent sulfite liquor containing about 50% by 
weight solids was mixed with 50 grams of the same UF resin used to prepare 
the product of Examples 1 to 3. The solution was heated in an oven at 
110.degree. C. for 18 hours and a solid product was recovered. 
Example 8 (Comparative) 
Comparative Example 7 was repeated except that 275 ml of a 2.5M potassium 
chloride solution was added to the aqueous mixture of lignosulfonate and 
UF resin before drying. About 25 grams of insoluble precipitate formed 
separate from a clear supernatant. The insoluble material was split into 
two parts. One part was dried at room temperature (Example 8A), and the 
other part was dried at 110.degree. C. (Example 8B). The insoluble 
material first melted on heating, and then separated into what appeared to 
be white gels about 3-5 mm in diameter and a dark liquid. The clear 
supernatant solution also was divided into two equal portions of about 175 
ml each. One part was dried at room temperature, yielding a very 
non-uniform solid product which contained KCl crystals (Example 8C). The 
solids content of the other fraction was recovered by drying at 
110.degree. C. (Example 8D). 
Example 9 (Comparative) 
A solution prepared by blending ten grams of calcium spent sulfite liquor 
containing 50% by weight solids, 10 grams of the UF resin of Examples 1-3 
and 10 ml of a 2.5M KCl solution was oven-dried at 110.degree. C. The 
mixture separated into light and dark layers of dried product. 
Example 10 (Comparative) 
A solution prepared by blending 25 grams of calcium spent sulfite liquor 
having 50% by weight solids and 25 grams of the UF resin used in Examples 
1-3 was dried at room temperature and a solid product was recovered. 
In the following Examples 11-13 the spray dryer was operated under the 
following conditions: atomizing air pressure at 1.2 kg/cm.sup.2, drying 
flow air at 0.8 m.sup.3 /min., an inlet air temperature of about 
210.degree. C., and an outlet temperature of about 110.degree. C. The 
solution was spray dried at a rate of about 5 ml/min. 
Example 11 
Using the spray drying conditions noted above, a 50:50 weight mixture of UF 
resin and lignosulfonate as used in Comparative Example 1 was spray dried 
at an initial solids concentration of 55% to yield a solid product. 
Example 12 
An aqueous solution containing 75 grams of the UF resin of Example 1 to 3, 
75 grams of a 50 weight % calcium spent sulfite liquor and 75 grams of a 
2.5M KCl solution was spray-dried as above. A solid product was recovered. 
Example 13 
An aqueous solution containing 30 grams of the UF resin of Examples 1-3, 60 
grams of a 50% by weight calcium spent sulfite liquor and 40 grams of 
water was spray-dried as above except that the flow rate of solution to 
the spray dryer was reduced to 3 ml/min. A solid product was recovered. 
Determination of Dry and Wet Volumes 
All of the room temperature and oven-dried samples of Examples 8-10 were 
ground with a coffee mill before testing. Samples were put into a 10 ml 
graduated cylinder with light tamping to three milliliters volume, and the 
weight of the material was recorded as the dry bulk density (ml/g). The 
spray-dried products were oven-dried before testing their dry bulk 
density. Once the dry bulk density was measured, water was added to the 
graduated cylinders to the 10 ml mark, and the wet volume measured after 
sitting overnight. The samples were stirred once after one-half hour, and 
the results are shown in Table II. 
Water Absorption Properties 
Water was added to 3 grams of each of the product samples in one-half gram 
increments with good mixing until the samples reached a sticky paste 
consistency or until free water was evident. The absorption characteristic 
is reported as the volume of water (ml) needed to reach such condition. 
The data is reported in Table II. 
TABLE II 
______________________________________ 
Dry and Wet Volumes and Water Absorption Properties 
of UF Resin/Calcium Lignosulfonate Insoluble Products 
Bulk Density 
Drying (ml/g) Absorb. 
Example KCl Conditions Dry Wet (ml/3 g) 
______________________________________ 
7 No 110.degree. C. 
1.1 1.6 1-1.5 
8 Yes RT 1.2 1.7 1-1.5 
8B Yes 110.degree. C. 
1.4 3.4 1-1.5 
8C Yes RT 1.1 1.5 0.5-1 
8D Yes 110.degree. C. 
0.9 0.9 1-1.5 
9 Yes 110.degree. C. 
1.2 1.2 1-1.5 
10 No RT 1.4 2.2 0.5-1 
11 No Spray-Dry 3.1 4.7 4-4.5 
12 Yes Spray-Dry 2.5 5.6 7-7.5 
13 No Spray-Dry 6.0 8.3 7-7.5 
3 No Spray-Dry 6.0 8.6 8.5-9 
______________________________________ 
As seen from Table II, samples made by the procedures described in the 
Vorob'eva article yield materials that clearly differ from those made by 
spray-drying. Importantly, the spray-dried compositions of the present 
invention exhibited absorption characteristics 4 to 8 times greater than 
the room or oven dried products. Additionally, the dry bulk density of 
spray-dried composition was 2 to 5 times greater, and the wet bulk density 
was 5-9 times greater than the compositions dried at room temperature or 
in an oven. 
The following examples further illustrate the superiority of spray-dried 
urea-formaldehyde and lignosulfonate compositions as compared to those 
prepared by room temperature or oven drying over a range of 
urea-formaldehyde to lignosulfonate weight ratios. 
Example 14 (Comparative) 
Calcium spent sulfite liquor (5 g) and 50 grams of the UF resin of Example 
1 were heated in an oven at 110.degree. C. for 18 hours until dry. 
Example 15 (Comparative) 
Calcium spent sulfite liquor (5 g) and 50 grams of the UF resin of Example 
1 were dried at room temperature. 
Example 16 (Comparative) 
Calcium spent sulfite liquor (6 g) and 30 grams of the UF resin of Example 
1 were heated in an oven at 110.degree. C. for 18 hours. 
Example 17 (Comparative) 
Calcium spent sulfite liquor (6 g) and 30 grams of the UF resin of Example 
1 were dried at room temperature. 
Example 18 (Comparative) 
Calcium spent sulfite liquor (10 g) and 100 grams of the UF resin of 
Example 1 were mixed and 300 ml of 2.5M KCl solution were added which 
resulted in the formation of a precipitate and a clear supernatant. About 
3.9 grams of insoluble material were recovered on drying at 110.degree. C. 
Example 19 (Comparative) 
The clear supernatant of Comparative Example 18 was divided. One part was 
dried at 110.degree. C. (Sample 19A), and the other part was dried at room 
temperature (Sample 19B). As Sample 19B was dried, KCl crystal growth was 
observed and a very non-uniform product was recovered. 
The spray dryer conditions for the following Examples 20 and 21 were as 
follows: atomizing air pressures 1.2 kg/cm.sup.2 ; drying air flow 0.8 
m.sup.3 /min; air heater setting at 230.degree. C.; inlet drying air 
temperature at 210.degree. C.; outlet gas temperature was about 
110.degree. C.; and flow rate of the aqueous mixture was about 4 ml/min. 
Example 20 
The urea-formaldehyde resin of Example 1 (50 g), 5 grams of calcium spent 
sulfite liquor and 25 gms of water were spray-dried at the noted 
conditions and free flowing powder was recovered. 
Example 21 
The UF resin of Example 1 (50 g), 10 grams of calcium spent sulfite liquor 
and 25 grams of water were spray-dried at the noted conditions and a 
powder was recovered. 
Determination Of Dry and Wet Volumes 
All of the room temperature and oven-dried samples were ground with a 
coffee mill before testing. Samples were put into graduated cylinders with 
light tamping to three milliliters volume, and the weight of the material 
(dry bulk density) was recorded as dry (ml/g) in Table III. The 
spray-dried products were oven-dried before testing their dry bulk 
density. Once the dry bulk density had been measured, water was added to 
the graduated cylinders, and the contents of the graduated cylinders were 
stirred after two hours. The wet volume was measured after sitting 
overnight. The results are shown in Table III as Wet (ml/g). 
Water Absorption Properties 
Water was added to 3 grams of the comparative samples and fully cured 
spray-dried products in one-half gram increments with good mixing until 
the samples reached a sticky paste consistency or until free water was 
evident. The amount of water added to obtain that condition was recorded. 
The data is shown in Table III and is listed as Absorbency, ml/3 grams. 
TABLE III 
______________________________________ 
Dry and Wet Volumes and Water Absorption Properties 
of UF Resin Calcium Lignosulfonate Insoluble Products 
Sample 
Ratio Drying ml/g Absorb. 
No. UF/Lig KCl Conditions 
Dry Wet ml/3 g 
______________________________________ 
Comparative Examples 
14 10/1 No 110.degree. C. 
1.3 2.1 1.5-2 
15 10/1 No RT 1.2 3.0 3.5-4 
16 5/1 No 110.degree. C. 
1.1 1.8 1-1.5 
17 5/1 No RT 1.2 2.7 2.5-3 
19B 10/1 Yes RT 1.0 1.4 1-1.5 
19A 10/1 Yes 110.degree. C. 
1.6 2.0 2-2.5 
18 10/1 Yes 110.degree. C. 
1.2 1.6 2-2.5 
Inventive Examples 
20 10/1 No Spray-Dry 
3.2 9.0 7.5-8 
21 5/1 No Spray-Dry 
5.0 12.5 9.5-10 
______________________________________ 
As seen from Table III, even at the higher UF resin to lignosulfonate 
weight ratios the spray-dried products of the present invention were 
superior to the comparative samples. The spray-dried products differed 
from the comparative samples in several ways. 
Dry bulk densities were 2 to 5 times greater. 
Wet bulk densities were 5-9 times greater. 
Uniformity was observed to be better. 
Water absorption capacities were 2-8 times greater. 
The foregoing examples are for illustrative purposes only and are not 
intended to limit the scope of the present invention. Those skilled in the 
arts will recognize that various modifications may be made without 
departing from the spirit or scope of the invention, and it is understood 
that the invention is defined in the appended claims.