Gelation and setting of desirably miscible and pumpable crutcher slurries comprising sodium carbonate, sodium bicarbonate and sodium silicate in an aqueous medium are retarded and often prevented by the addition to such medium of a citric material, such as citric acid and/or water soluble citrate, and magnesium sulfate. Alternatively, magnesium citrate may be employed. The addition of the citric material and magnesium sulfate (or magnesium citrate) lengthens appreciably the workable crutcher time before setting, increasing it over such working time for similar crutcher mixes containing the citric material but not containing magnesium sulfate. The improved workability of the crutcher mix permits the making of higher solids content crutcher slurries, thereby resulting in significant energy savings and increases in production rates when the crutcher slurries are subsequently spray dried to free flowing inorganic salt base bead form, from which detergent compositions may be made by post-spraying with nonionic synthetic organic detergent in liquid state.

The present invention relates to non-gelling aqueous slurries of inorganic 
salt mixtures and to methods for their manufacture. More particularly, it 
relates to the utilization of certain materials, which, in combination, 
exert an exceptionally good and improved anti-gelling action, preventing 
gelation, excess thickening and setting up of 
bicarbonate-carbonate-silicate slurries, from which particulate heavy duty 
synthetic organic detergent compositions may be made, as by spray drying 
and post-spraying. 
Built synthetic organic detergent compositions in free flowing particulate 
bead form have been well known heavy duty laundry products for years. 
Recently, limitations have been placed on the use of polyphosphate builder 
salts, such as pentasodium tripolyphosphate, due to alleged detrimental 
ecological effects thereof, and nonionic synthetic organic detergents of 
improved detergency and other desirable properties have been made and have 
partially replaced the previously dominant anionic detergents in household 
washing products. Nonionic detergents are often adversely affected by 
spray drying temperatures and the "pluming" of drying towers in which they 
are being processed is environmentally objectionable. Accordingly, some 
household laundry detergent compositions are now made by spray drying 
inorganic builder salt mixtures, devoid of organic detergent, and 
subsequently spraying onto the surfaces of the resulting spray dried beads 
a nonionic detergent in liquid state so that it is absorbed by the beads. 
It has been found that base beads which are satisfactorily absorptive of 
liquid nonionic detergent can be made from mixtures of alkali metal 
bicarbonate, alkali metal carbonate and alkali metal silicate, which 
apparently owe at least some of their absorbency to the nature of the bead 
made, which in turn, appears to be due to the partial decomposition of 
bicarbonate to carbonate during the spray drying operation. The silicate 
in such base beads helps make the bead firmer and more resistant to 
powdering and crushing, helps prevent corrosion of aluminum parts and 
contributes detergent building properties to the composition. However, it 
has been found that aqueous crutcher mixes containing substantial 
proportions of bicarbonate, carbonate and silicate tend to gel or set 
prematurely, sometimes before they can be thoroughly mixed and pumped out 
of a crutcher to spray towers, and consequently, extensive experimentation 
has been undertaken in an effort to find ways to diminish the tendencies 
of such systems to solidify or gel in the crutcher. 
While various ways may be employed to diminish gelation, the most dramatic 
successes have been found to result from the use of small quantities of 
particular additives, which are surprisingly effective in preventing or 
retarding gelation. Thus, prior to the present invention it had been 
discovered by a fellow researcher of the present inventor that small 
quantities of citric acid or water soluble citrate incorporated in the 
crutcher mix could delay or prevent gelation and setting of 
bicarbonate-carbonate-silicate mixes and would allow commercial spray 
drying thereof, following normal procedures for pumping out the crutcher 
contents to the spray nozzles. However, while such invented process was 
and is successful, it has been supplanted by the present one, which 
represents a significant improvement over it because the anti-gelling 
effect is greater with the present combination of citric material and 
magnesium sulfate than it is with the citric material alone. (The term 
"citric material" includes citric acid and water soluble derivatives 
thereof, e.g., water soluble salts). In addition to improving the 
anti-gelling activity and increasing the length of time in which a 
crutcher mix will be workable without the need for significantly larger 
proportions of anti-gelling agent being incorporated, the present 
invention allows the use of a lesser proportion of organic material, 
thereby decreasing the likelihood of the spray dried composition 
deteriorating in the heat of the dryer and improving the absorbency and 
flowability of the product. Also, whereas the citric acid component, if 
used in larger quantity, might interfere with the absorption of liquid 
nonionic detergent sprayed onto the spray dried base beads, magnesium 
sulfate appears to be desirably absorbent, thereby helping to make the 
product free flowing. 
In the aqueous crutcher mix the various dissolved compounds can ionize and 
therefore it may be considered that in the crutcher mix there are present 
magnesium, citrate and sulfate ions. Accordingly, crutcher mixes having 
charged thereto mixtures of compounds that result in the same ionic 
composition are also useful for retarding and preventing gelations of 
inorganic crutcher mixes. Thus, magnesium citrate or magnesium acid 
citrate could be employed, preferably with sodium sulfate, but also 
without the sulfate being present. 
In accordance with the present invention, a miscible and pumpable crutcher 
slurry which does not prematurely set and which is capable of being mixed 
and pumped for a period of at least one or two hours after making, 
comprises from 40 to 70% of solids and 60 to 30% of water, of which solids 
content, on a 100% solids basis, about 55 to 85% is sodium bicarbonate, 
about 5 to 25% is sodium carbonate and about 5 to 25% is sodium silicate 
of Na.sub.2 O:SiO.sub.2 ratio within the range of 1:1.4 to 1:3, with the 
ratio of sodium bicarbonate:sodium carbonate being within the range of 
about 2:1 to 8:1, the ratio of sodium carbonate:sodium silicate being 
within the range of about 1:3 to 3:1, and the ratio of sodium 
bicarbonate:sodium silicate being within the range of about 3:1 to 10:1, 
and a gelation retarding proportion of a combination of 0.1 to 2% of a 
citric material selected from the group consisting of citric acid, water 
soluble citrate and mixtures thereof, and from 0.1 to 1.4% of magnesium 
sulfate, with the total of such citric material and magnesium sulfate, in 
combination, being gelation retarding and at least 0.4% of the slurry. The 
invention also relates to a method for retarding or preventing the 
gelation of a miscible and pumpable crutcher slurry of the general 
bicarbonate-carbonate-silicate type described, by addition thereto of a 
citric material and magnesium sulfate, in the described small quantities. 
The invention is also of similar products and methods wherein magnesium 
citrate is present as an anti-gelling material. 
Without admitting that for the purpose of the Patent Law it is applicable 
prior art, it is recognized by the present inventor that prior to his 
invention the most preferred way of retarding gelation of 
bicarbonate-carbonate-silicate crutcher mixes in aqueous media was by the 
addition of small proportions of citric materials, as is described in U.S. 
patent application Ser. No. 81,799, filed Oct. 4, 1979 by Ronald S. 
Schreiber. Prior to Schreiber's work citric acid had been a known water 
softening or organic builder constituent of synthetic organic detergent 
compositions. Also, it had been suggested that magnesium salts might be 
added to synthetic detergent compositions or to wash waters containing 
them so as to increase foaming of anionic syndets in such media, and it 
was known that magnesium salts of some anionic detergents are water 
soluble. The problem of soluble silicates forming insoluble products in 
detergent compositions and in wash waters had been recognized and efforts 
had been made to prevent objectionable deposits of silicates on laundered 
articles. In some cases particular polyvalent metals had been utilized to 
"cap" alkali metal silicates to reduce polymerization thereof. Thus, for 
example, in recent U.S. Pat. No. 4,157,978, it is taught that a sodium or 
potassium silicate having an alkali metal oxide:silica ratio greater than 
2 may be reacted with a water soluble salt of aluminum, titanium, zinc, 
zirconium, tin, vanadium, molybdenum, tungsten, selenium or germanium and 
the capped alkali metal silicate made may then be reacted with a water 
soluble material that will provide a carboxylate ion in aqueous solution. 
Among the various compounds of the mentioned metals that were suggested 
for reaction with the silicate there were included citrates. The mentioned 
patent does not suggest magnesium citrate nor does it suggest the 
combination of magnesium sulfate and citric acid or magnesium compound and 
water soluble citrate, e.g., sodium citrate or other alkali metal citrate. 
The crutcher mixes that are spray dried according to the teaching of the 
patent all include significant proportions of synthetic organic detergent; 
they are not builder salt crutcher mixes intended for later absorption of 
detergent. Thus, it appears that although the problem of gelling inorganic 
salt crutcher mixes has been recognized and the use of citric acid to 
ameliorate this condition was discovered by Schreiber, and although 
certain polyvalent metal salts were employed to cap silicates intended for 
use in detergent composition crutcher mixes to be spray dried, the art 
does not suggest or describe the use of a combination of citric material 
and magnesium sulfate (or magnesium citrate) in an inorganic salt base 
bead crutcher mix to prevent or retard gelation thereof. Neither does the 
art suggest the exceptionally good and unexpectedly beneficial 
anti-gelling effect of the combination of such materials of this 
invention, with the savings obtained in avoiding crutcher freezes and line 
blockages and in permitting the processing of higher solids content base 
bead crutcher mixes, with resulting energy savings and production capacity 
increases. 
Although the anti-gelling features of the present invention may also be 
obtained with other inorganic builder base compositions than those which 
are primarily of bicarbonate, carbonate, silicate and water, the most 
significant anti-gelling effects are noted when crutcher mixes based 
substantially (preferably essentially) on such materials and water are 
treated by the method of this invention, i.e., addition of citric material 
and magnesium sulfate (or magnesium citrate). The compositions so treated 
comprise about 40 to about 70% of solids and are about 60 to about 30% of 
water. The solids contents, on a 100% solids bases, is about 55 to about 
85% of sodium bicarbonate, about 5 to about 25% of sodium carbonate and 
about 5 to about 25% of sodium silicate, of Na.sub.2 O:SiO.sub.2 ratio 
within the range of 1:1.4 to 1:3. In such compositions the ratio of sodium 
bicarbonate:sodium carbonate is within the range of about 2:1 to about 
8:1, the ratio of sodium carbonate:sodium silicate is within the range of 
about 1:3 to about 3:1, and the ratio of sodium bicarbonate:sodium 
silicate is within the range of about 2:1 to about 10:1. The proportion of 
citric material, which is citric acid, water soluble citrate, mixture of 
such citrates or mixture of citric acid and such citrate(s), will be from 
about 0.1 to about 2% and the percentage of magnesium sulfate will be from 
0.1 to 1.4%. The total of citric material and magnesium sulfate will be at 
least 0.4% and will usually not exceed 2.5 or 3%, with the percentages 
mentioned being on a total crutcher mix or slurry basis, including the 
mentioned salts, water and any adjuvants which may be present. A preferred 
range of such total is 0.5 to 3%, more preferably 0.6 to 2% and most 
preferably, usually, 0.7 to 1.2%. Although the employment of a combination 
of citric material, such as citric acid, and magnesium sulfate is 
preferable, there may be used in substitution for it from 0.3 to 3% of 
magnesium acid citrate (M.sub.g HC.sub.6 H.sub.5 O.sub.7.5H.sub.2 O) or 
equivalent proportion of equivalent magnesium citrate. 
Preferably, the cruther slurry contains from 50 to 65% of solids, with the 
balance being water, and of the solids content, 55 to 80% is sodium 
bicarbonate, 10 to 25% is sodium carbonate and 10 to 25% is sodium 
silicate, with the ratio of sodium bicarbonate:sodium carbonate being in 
the range of 3:1 to 6:1, the ratio of sodium carbonate:sodium silicate 
being within the range of 2:5 to 5:2 and the ratio of sodium 
bicarbonate:sodium silicate being within the range of 4:1 to 8:1. More 
preferably, the crutcher slurry contains from 58 to 64% of solids and 42 
to 36% of water, of which solids content 70 to 75% is sodium bicarbonate, 
13 to 19% is sodium carbonate and 8 to 15% is sodium silicate. In such 
more preferred compositions the ratio of sodium bicarbonate:sodium 
carbonate is within the range of 4:1 to 5:1, the ratio of sodium 
carbonate:sodium silicate is within the range of 1:1 to 3:2 and the ratio 
of sodium bicarbonate:sodium silicate is within the range of 5:1 to 7:1. 
The materials described herein, except for water, are all normally solid 
and the percentages and ratios are on an anhydrous basis, although the 
various materials may be added to the crutcher as hydrates, or dissolved 
or dispersed in water. Normally, however, the sodium bicarbonate is 
anhydrous and the sodium carbonate is soda ash. Yet, the carbonate 
monohydrate may also be employed. The silicate is usually added to the 
crutcher slurry as an aqueous solution, normally of 40 to 50% solids 
content, e.g., 47.5%, and is preferably added near the end of the mixing 
process and after previous addings and dispersings and dissolvings of the 
citric material and magnesium sulfate (or magnesium citrate). The silicate 
employed will preferably be of Na.sub.2 O:SiO.sub.2 ratio within the range 
of 1:1.6 to 1:2.6, more preferably 1:1.6 to 1:2.4 and most preferably 
1:2.0 to 1:2.4. 
Although it is highly preferred to make the crutcher slurry and the base 
bead product of this invention (from which a heavy duty built nonionic 
synthetic organic detergent composition can be produced) of essentially 
inorganic salts, in such manner that they will be of bead properties that 
promote absorption through the bead surfaces of nonionic detergent sprayed 
thereon in liquid form, and although often the adjuvants, such as 
perfumes, colorants, enzymes, bleaches and flow promoting agents, may be 
sprayed onto the beads with the nonionic detergent or may be post-added, 
for stable and normally solid adjuvants, mixing in with the inorganic salt 
slurry in the crutcher may be feasible. Thus, it is contemplated that from 
0 to as much as 20% of the crutcher slurry may be of suitable adjuvants or 
diluents (diluents include inorganic salts, such as sodium sulfate and 
sodium chloride). However, if such adjuvants are present, normally the 
proportion thereof will be from 0.1 to 10% and often their content will be 
limited to 5%, and sometimes to 1 or 2%. Normally the organic material 
content of the crutcher slurry will be limited to about 5% maximum, 
preferably 3% maximum and most preferably 1 or 1.5% maximum, so as to 
avoid any problems of tackiness of the base beads after spray drying and 
to avoid any adverse effects on absorption of synthetic nonionic organic 
detergent by the beads. Because magnesium sulfate is inorganic and appears 
to be useful in aiding absorption of nonionic by the base beads and 
because it improves the anti-gelling activity of the citric material it 
allows the use of less citric material and thereby promotes the production 
of a more desirable final product. 
The preferred combination gelation preventing materials employed, which 
have been found to be startlingly successful in preventing gelation, 
thickening, setting and freezing up of the crutcher slurry before it can 
be emptied from the crutcher and spray dried, using normal crutching, 
pumping and spray drying equipment, are citric material and magnesium 
sulfate. Because the crutcher slurry, including both dissolved and 
dispersed inorganic salts, is normally alkaline, usually being of a pH in 
the range of 9 to 12, preferably 10 to 11, when the citric material 
employed is citric acid it is considered to be ionized and converted to 
the corresponding citrate or brought into equilibrium with citrate ions. 
Thus, other soluble citrates may be employed instead of citric acid, 
including sodium citrate, potassium citrate and magnesium citrate, 
although for many applications the acid is considered to be superior. 
Instead of adding citrate, a mixture of the acid and a neutralizing agent, 
e.g., NaOH, KOH, Mg(OH).sub.2, may be used, and instead of the acid form, 
a citrate plus an acid can be substituted, if desired (although this 
latter course of action will rarely be followed). The proportion of citric 
material, in combination with magnesium sulfate will normally be only 
sufficient to accomplish the gelation preventing task in the particular 
crutcher slurry to be treated. However, for safety's sake an excess, e.g., 
5 to 20% more than the sufficient quantities of citric material and 
magnesium sulfate, may be employed. While it is possible to use as much as 
3.4% of the combination of citric material and magnesium sulfate, on a 
crutcher contents weight basis, to retard or prevent gelation, usually 
from 0.4 to 1.5% will suffice, preferably from 0.5 to 1.2%. When employing 
a citrate, such as an alkali metal citrate, one may wish to increase the 
percentage of the additive slightly to compensate for the presence of the 
heavier cation but for simplicity's sake the range of proportions of 
additives given will apply to both the acid and salt forms. With respect 
to the magnesium compound, the sulfate is highly preferred but this may be 
replaced by other sources of magnesium as by the magnesium ion in 
magnesium citrate, when that compound is used, preferably in proportion 
from 0.4 to 1.2% or 0.5 to 0.8%. 
The order of addition of the various components to the crutcher is not 
considered to be critical, except that it is highly desirable to add the 
silicate solution last, and if not last, at least after the addition of 
the gel preventive combination of materials. Also, minor variations in 
orders of addition may be made under certain circumstances, as when 
objectionable foaming accompanies the following of a specific order. 
However, such problems have not been found to be serious. In some 
instances it is possible to premix the magnesium sulfate and citric 
material and to add the mixture thereof to the crutcher. In other cases 
the citric material is added first, followed by the magnesium sulfate, or 
vice versa. If desired, one or both of the citric material and magnesium 
sulfate may be premixed with another material or with other materials. In 
such instances it will be preferred for the anti-gelling additive 
components to be mixed in with other crutcher mix materials before 
addition of the silicate to the crutcher. However, in some instances one 
can add the anti-gelling materials after addition of the silicate, but 
preferably very promptly thereafter. 
Usually, during the manufacture of the crutcher mix some water will be 
added to the crutcher initially, followed by some inorganic salt, either 
carbonate or bicarbonate, more water and more salt, and then, gel 
preventive materials and silicate, but dispersion-solutions of the 
individual components may be made beforehand, if feasible. The water 
employed may be city water of ordinary hardness. In theory, it is 
preferable to utilize deionized water or distilled water, if available, 
because some metallic impurities in the water may have a triggering action 
on gel formation, but that is not considered to be necessary. 
The temperature of the aqueous medium in the crutcher will usually be 
elevated, normally to the 40.degree. to 70.degree. C. range and preferably 
will be from 50.degree. to 60.degree. C. Heating the crutcher medium 
promotes solution of the water soluble salts of the mix and thereby 
increases mix mobility. However, temperatures higher than 70.degree. C. 
will usually be avoided because of the possibility of decomposition of one 
or more crutcher mix components, e.g., sodium bicarbonate. Heating of the 
crutcher mix, which may be effected by utilizing hot aqueous medium 
charged and by heating the crutcher contents by means of a heating jacket 
or heating coils, also helps to increase drying tower throughput because 
less energy has to be transferred to the sprayed droplets of crutcher mix 
in the tower. Using higher solids mixes also increases production. 
Crutcher mixing times to obtain good slurries can vary widely, from as 
little as ten minutes for small crutchers and for slurries of higher 
moisture contents, to as much as four hours, in some cases. The mixing 
times needed to bring all the crutcher mix components together in one 
medium may be as little as five minutes but in some cases, can take up to 
an hour, although 30 minutes is a preferable upper limit. Counting any 
such initial admixing times, normal crutching periods will be from 20 
minutes to two hours, e.g., 30 minutes to one hour, but the crutcher mix 
will be such as to be mobile, not gelled or set, for at least one hour, 
preferably for two hours and more preferably for four hours or so after 
completion of the making of the mix, e.g., 10 to 30 hrs. 
The crutched slurry, with the various salts, dissolved or in particulate 
form, uniformly distributed therein, in part due to the desirable 
anti-gelling effects of the citric compound and the magnesium sulfate, is 
transferred in usual manner to a spray drying tower, which is located near 
the crutcher. The slurry is normally dropped from the bottom of the 
crutcher to a positive displacement pump, which forces it at high pressure 
through spray nozzles at the top of a conventional spray tower 
(countercurrent or concurrent), wherein the droplets of the slurry fall 
through a hot drying gas, which is usually composed of fuel oil or natural 
gas combustion products, in which the droplets are dried to desired 
absorptive bead form. During the drying, part of the bicarbonate is 
converted to carbonate, with the release of carbon dioxide, which appears 
to improve the physical characteristics of the beads made so that they 
become more absorptive of liquids, such as liquid nonionic detergent, 
which may be post sprayed onto them subsequently. 
After drying, the product is screened to desired size, e.g., 10 to 100 
mesh, U.S. Standard Sieve Series, and is ready for application of nonionic 
detergent spray thereto, with the beads being either in warm or cooled (to 
room temperature condition). However, the nonionic detergent will usually 
be at an elevated temperature to assure that it will be liquid; yet, upon 
cooling to room temperature, desirably it will be a solid, often 
resembling a waxy solid. The nonionic detergent, applied to the tumbling 
beads in known manner, as a spray or as droplets, is preferably a 
condensation product of ethylene oxide and higher fatty alcohol, with the 
higher fatty alcohol being of 10 to 20 carbon atoms, preferably of 12 to 
16 carbon atoms, and more preferably averaging 12 to 13 carbon atoms, and 
with the nonionic detergent containing from 3 to 20 ethylene oxide groups 
per mole, preferably from 5 to 12, more preferably 6 to 8. The proportion 
of nonionic detergent in the final product will usually be from 10 to 25%, 
such as from 20 to 25%. Whereas when using citric acid alone as the 
anti-gelling agent, without the magnesium sulfate, the absorbency of the 
base beads would be good, with some base bead compositions and nonionic 
detergents it would be difficult to have more than 20% of the nonionic 
detergents satisfactorily absorbed by the base beads. It has been found 
that the present anti-gelling treatment, utilizing a mixture of citric 
material and magnesium sulfate, e.g., citric acid and magnesium sulfate, 
can result in beads of significantly greater absorbency, allowing 
absorption of 22% of nonionic detergent, with the production of a free 
flowing product and sometimes allowing absorption of as much as 25% of the 
nonionic detergent. In comparative tests against beads made using citric 
compound alone (citric acid) as the anti-gelling agent in the base bead 
crutcher mix, compositions of the present invention, made by the methods 
thereof, are more absorptive, as a general rule. 
A preferred finished formulation made from base beads of this invention 
contains from 15 to 25%, preferably 20 to 25% of the nonionic detergent, 
e.g., Neodol 23-6.5, made by Shell Chemical Company, 30 to 40% of sodium 
bicarbonate, 20 to 30% of sodium carbonate, 5 to 15% of sodium silicate of 
Na.sub.2 O:SiO.sub.2 ratio of 1:2.4, 1 to 3% of fluorescent brightener, 
0.5 to 2% of proteolytic enzyme, sufficient bluing to color the product 
and whiten the wash, as desired, 0.5 to 3% of moisture, 0.5 to 1.2% of 
citric material, preferably sodium citrate and 0.8 to 2% of magnesium 
sulfate. Instead of the mixture of citric material and magnesium sulfate 
there may be present from 0.3 to 3% of magnesium citrate, preferably 0.4 
to 1.2%. Optionally, sodium sulfate may be present, as a diluent, but the 
amounts thereof will normally be restricted to 20% preferably to 10% and 
most preferably to less than 5%, if it is present at all. The base beads 
made, devoid of nonionic detergent and adjuvants, will preferably comprise 
from 35 or 40 to 60% of sodium bicarbonate, 15, 20 or 25 to 45% of sodium 
carbonate, 10 to 20% of sodium silicate, 0.1 to 3% of sodium citrate +0.1 
to 2% of magnesium sulfate (or 0.5 to 5% of magnesium citrate), 0 to 10% 
of adjuvant(s) and/or diluent(s) and 1 to 10% of moisture. In such 
products the proportion of sodium bicarbonate in the sprayed beads will 
normally be within the range of 1.2 to 4 times that of sodium carbonate, 
e.g., 1.5 to 3 times. 
The highly beneficial result of incorporating the mentioned small 
percentages of citric compound and magnesium sulfate or magnesium citrate 
in the crutcher slurry in accordance with this invention is two-fold, 
gelation and setting of the crutcher mix in the vessel before complete 
discharge thereof is prevented and additionally, higher solids content 
crutcher slurries may be made. Thus, down times and cleanouts are 
eliminated and energy savings are achieved due to less water having to be 
evaporated from the crutcher droplets in the spray dryer. Although many 
bicarbonate-carbonate-silicate mixtures desirably employed in crutcher 
mixes for making base beads for built particulate nonionic detergent 
compositions would normally gel and set up in the crutcher, with the 
present invention, at little expense and without any detrimental effects 
on the product, the desired proportions of such builder salts can be 
employed and variations in such proportions can be made, as desired, 
without fear of freeze-ups of the crutcher. Tests of the final product 
show no adverse effects due to the presence of the citric material and 
magnesium sulfate therein. In fact, some positive results, due to metal 
ion sequestration and improved absorption of nonionic detergent, may 
result. The presence of the citric material is thought to promote 
maintenance of the stability of perfumes and colors present and it may 
help to prevent development of malodors from deteriorations of other 
organic additives, such as proteolytic enzymes and proteinaceous 
materials. The presence of the citric materials and the magnesium sulfate 
in the base beads also has the desirable effect of having the gelation 
preventing material present in any base beads or detergent beads being 
reworked, so that such material, if off-specification (as for being 
undersize of for being tower wall buildup), may be mixed with water and 
made into a more concentrated rework mix for subsequent blending back with 
the regular crutcher mix. Such mixing with water is easier than would be 
the case were the anti-gelling composition not present in the base beads 
to prevent or retard gelation or excessive thickening.

The following examples illustrate but do not limit the invention. Unless 
otherwise indicated all temperatures are by .degree.C. and all parts are 
by weight in the examples and throughout the specification. 
EXAMPLE 1 
______________________________________ 
Final Product Component Percent 
______________________________________ 
Nonionic Detergent (Neodol 23-6.5) 
18.6 
Proteolytic enzyme 1.4 
Moisture 1.5 
NaHCO.sub.3 46.0 
Na.sub.2 CO.sub.3 19.0 
Sodium silicate (Na.sub.2 O:SiO.sub.2 = 1:2.4) 
10.9 
Sodium citrate 0.9 
Magnesiun sulfate (as Epsom salt) 
0.8 
Adjuvants (fluorescent brightener, bluing, perfume) 
0.9 
100.0 
______________________________________ 
A product of the above formula is made by spray drying a crutcher mix 
comprising sodium bicarbonate, sodium carbonate, sodium silicate, citric 
acid, magnesium sulfate, fluorescent brightener and water in a spray tower 
to produce essentially inorganic base beads, after which there is sprayed 
onto the surfaces of such beads a nonionic detergent in liquid state, 
solidifiable at room temperature, the beads and detergent are cooled and 
proteolytic enzyme powder and perfume are applied to them. The product 
made, of the formula given, is of a bulk density of 0.8 g./ml. and an 
initial adhesion of 40% and exhibits a fines characteristic (through U.S. 
Standard Sieve No. 50) of 15%. 
The base beads are made by adding to the crutcher 308 parts of water, 15 
parts of fluorescent brightener, 1.5 parts of blue pigment, 4.5 parts of 
anhydrous citric acid, 10 parts of magnesium sulfate (Epsom salt), 403 
parts of sodium bicarbonate (anhydrous), 87.5 parts of soda ash, and 170 
parts of a 47.5% solids content aqueous sodium silicate solution, the 
sodium silicate of which is of Na.sub.2 O:SiO.sub.2 ratio of 1:2.4. During 
the mixing of this base builder composition the temperature in the 
crutcher is maintained at about 38.degree. C. It takes about 20 minutes 
for the various materials to be mixed together in the order given (except 
that the brightener, pigment and citric acid are added in two parts, with 
the second halves being added after the soda ash), and after completion of 
addition of the last component the mixing is continued for about another 
20 minutes, after which spray drying of the product is begun. Some of the 
crutcher mix is not sent to the spray dryer so that the time for gelation 
thereof may be measured. It is found that the crutcher mix remains 
miscible and pumpable, ungelled and uncongealed for 30 hours. The crutcher 
mix, which is pumped to the spray tower, using a Triplex positive 
displacement pump generating a pressure of about 30 kg./sq. cm., is dried 
in drying air, which is the combustion products of an oil burner, at a 
temperature ranging from a high of 400.degree. to 600.degree. C. to a low 
of about 100.degree. to 200.degree. C. and drying is to a moisture content 
of about 1.9%. The base beads resulting are screened so as to be within 
the 10 to 100 mesh U.S. Sieve Series range and are free flowing, non-tacky 
and of a bulk density of about 0.7 g./ml. They are porous, yet firm on 
the surfaces thereof and are capable of readily absorbing significant 
proportions of liquid nonionic detergent without becoming objectionably 
tacky. The detergent products made, including absorbed nonionic detergent, 
are excellent heavy duty laundry detergents, useful in washing household 
laundry in automatic washing machines and in cleaning textile materials by 
other methods, too. 
In variations of this experiment, using the same proportions of all 
components except for water, citric acid and magnesium sulfate, when the 
amounts of such components are changed to 322, 3.5 and 10, respectively, 
the gelation time at 37.8.degree. C. is found to be ten hours; when 
changed to 313, 4.5 and 5, respectively, it is eight hours; when changed 
to 307, 4.5 and 11.3, respectively, it is 7.5 hours; when changed to 314, 
3.5 and 5, respectively, it is five hours; and when changed to 311, 2.5 
and 10, respectively, it is four hours. Such crutcher mix compositions are 
of excellent stability and are very useful in commercial production of the 
present detergent base beads because they allow extra time before 
gelation, so that any "normal" problems associated with crutching and 
spray drying may usually be overcome before gelation or setting up in the 
crutcher could become a problem. When the mentioned proportions are 30.9, 
2.5 and 11.3 or 317, 4.5 and 1, respectively, the crutching time, at 
37.8.degree. C., before gelation will be 3.5 hours and when the 
proportions are 316, 1.5 and 5 it will be 1.5 hours. Such formulations are 
also acceptable, especially the first two, because usually the contents of 
the crutcher can be completely sprayed out within 1.5 hours and almost 
always within 3.5 hours. However, it will usually be desirable to utilize 
more citric acid or magnesium sulfate or equivalent materials than the 1.5 
and 5 parts mentioned, just to provide extra time against untoward 
incidents. 
When the proportions of citric acid and/or magnesium sulfate and/or the sum 
thereof are outside the ranges given in the specification, premature 
gelation occurs or a satisfactory dispersion is not made. For example, 
when 30.2 parts of water, 2.5 parts of citric acid and 19 parts of 
magnesium sulfate are employed the product gels immediately, which also 
occurs when 304 parts of water, 0.5 part of citric acid and 19 parts of 
magnesium sulfate are utilized, or when such proportions are 304, 3.5 and 
15 or 306, 1.5 and 15. Gelation occurs within about 25 minutes when the 
proportions are 321, 0.5 and 1 and within about 20 minutes when they are 
313, 0.5 and 10. Thus, it can be seen that the compositions of the present 
invention, made by the described methods, are especially useful in the 
preparation of spray dried base builder beads for heavy duty laundry 
detergents, without the danger of premature gelation of the crutcher mix. 
When sodium citrate is substituted for citric acid in the formulas given 
above, with the magnesium sulfate being either anhydrous or in Epsom salt, 
similar results are obtained. Also, when equivalent proportions of 
magnesium citrate are employed, whether Mg.sub.2 (citrate).sub.3 or 
MgHC.sub.6 H.sub.5 O.sub.7.5H.sub.2 O, e.g., 1.5% good anti-gelling 
effects are obtained, although they are not as good as those for the 
combination of citric acid (or sodium citrate) and magnesium sulfate. 
The crutcher mixes of this invention may be of greater solids contents than 
those for similar compositions in which a sufficient quantity of citric 
acid is employed (without the magnesium sulfate) to obtain the same (or 
somewhat inferior) anti-gelling effects. Thus, the presence of the 
magnesium sulfate with the citric acid appears to improve the anti-gelling 
effects so that even higher contents of solids may be present in the 
crutcher slurries without gelation. In the past it has been found that 
solids content and gelation tendencies were directly proportional and this 
is also the case when combinations of citric acid and magnesium sulfate 
are employed. Still, one can utilize higher solids content crutcher mixes 
without objectionable gelling, whereas similar mixes, when treated with 
citric acid alone, could gel prematurely. Also, when the citric 
acid-magnesium sulfate mixture is employed the content of organic material 
in the product may be minimized, while still maintaining the crutcher 
slurry miscible for sufficiently long periods of time to avoid crutcher 
set-ups or line blockages. 
EXAMPLE 2 
In comparative experiments a crutcher mix formulation is made essentially 
like that of the crutcher mix which results in a base bead for making a 
detergent composition of the formula first given in Example 1, but with 
the solids content of the crutcher mix being kept at 56.5%. The mix is 
made in the same manner and the crutching times up to objectionable 
gelation are measured when various materials are added with the citric 
acid as anti-gelling agents, in replacement of the magnesium sulfate. 
Using 0.25% of citric acid and 1% of each of such other anti-gelling 
"salt" additives, on an anhydrous basis, the slurry fluidity is maintained 
for only about 20 minutes when either sodium chloride or calcium chloride 
is the salt employed, which is about the same time for which fluidity is 
maintained when the citric acid is used alone. With sodium sulfate as the 
salt added the slurry life is extended to 1.5 hours and calcium sulfate 
allows mixing for up to five hours. Magnesium silicate results in an 
initially thin slurry, which solidifies in about five hours. Calcium oxide 
and magnesium oxide make very highly viscous slurries which solidify in a 
few hours. Magnesium chloride extends the slurry life to ten hours and 
magnesium sulfate extends it to more than 32 hours. However, when various 
heat stable adjuvants are present in the crutcher mix, such as bluing, 
fluorescent brightener and other normal detergent adjuvants for crutcher 
mixes, it has been found that gelation is accelerated, sometimes occurring 
in one-tenth to one-half the time normally taken. Thus, since it is 
desirable that at least an hour be provided before gelation and 
preferably, that more time should be available, none of the anti-gelling 
salts except the magnesium chloride and magnesium sulfate is considered to 
be useful and of these two the magnesium sulfate is clearly superior. On 
the basis of above experiments it is within the invention to utilize 
magnesium chloride with citric acid or to employ a mixture of magnesium 
chloride and magnesium sulfate with citric acid. 
EXAMPLE 3 
The experiment of Example 2 is repeated but the order of addition of the 
detergent builder salt components to the crutcher is altered so that the 
bicarbonate, carbonate and silicate are mixed together in the aqueous 
medium before addition thereto of the magnesium sulfate and citric acid. 
In such case, after a few minutes the mix becomes objectionably thick and 
solidifies in an irreversible manner. However, if as it is noted that the 
mix is thickening, the magnesium sulfate component or the magnesium 
sulfate-citric acid anti-gelling composition is quickly added at that 
time, before solidification, it will thin the mix to a workable state. 
This is another advantage of the present invention because, in addition to 
extending the crutching time, it allows control of the fluidity of the 
crutcher mix in response to indications of gelation, as they appear. Thus, 
the crutcher operator has improved processing control during the period in 
which the mix is held in the crutcher before spray drying. Should there be 
some interruption of spray tower operation, neccesitating holding the mix 
longer in the crutcher than planned, he can extend the period of 
miscibility of the crutcher mix by further addition of magnesium sulfate 
and citric acid or equivalent anti-gelling agent(s) of this invention or 
magnesium sulfate alone, in many instances. For example, it has been found 
that often as little as 0.3% of MgSO.sub.4 or 0.6% of Epsom salt will 
reverse gelation, providing that the mix it still fluid enough to permit 
mixing in of the magnesium salts. Normally, from 0.3 to 1% of MgSO.sub.4 
will be added. This feature of the invention allows minimizing of the 
magnesium sulfate and citric acid contents of the product, so that product 
characteristics will not be changed noticeably, and yet assures the 
operator that he will not have to dig solidified crutcher mix out of the 
crutcher, with the waste of material and loss of production time that 
would be involved. This improvement in the manufacturing process is 
important because if the crutcher mix solidifies, spray tower operation 
can be halted, essentially shutting down the detergent manufacturing 
operation. When operations are restarted even when that is done reasonably 
promptly after gelling first occurs, the spray tower will have to be 
brought to equilibrium, and during the first part of such resumed 
manufacturing some unacceptable product can result. Sometimes gelation in 
the crutcher is not so extensive as to solidify the mass of mix but still 
the production of some gel can block spray nozzles and cause interruption 
of production. Such adverse effects are avoided by use of the present 
process, as herein described. 
EXAMPLE 4 
An attempt is made to make a crutcher mix of the type described in Example 
2, utilizing 0.25% of citric acid and 1% of magnesium sulfate (anhydrous), 
with the order of addition of the various components being changed so that 
the water, silicate, magnesium sulfate and citric acid are first mixed 
together, after which the bicarbonate and carbonate are added, plus the 
fluorescent dye and pigment. However, such crutcher mixes gel prematurely 
and for that reason the mentioned order of addition is unsatisfactory. The 
experiment was repeated several times but in all cases the crutcher mix 
froze so that it could not be stirred, pumped and spray dried. 
EXAMPLE 5 
Attempts were made to manufacture in laboratory equipment crutcher mixes 
containing high solids contents. Thus using the basic formulas previously 
given, with 0.25% of citric acid and 1% of magnesium sulfate, and adding 
the components in the operative order described in Examples 1 and 2, the 
builder salt composition was 70% of sodium bicarbonate, 20% of soda ash 
and 10% of sodium silicate in one instance, 77%, 13% and 10% in the second 
and 67%, 23% and 10% in the third, so that the bicarbonate;carbonate 
ratios were 3.5:1, 6:1 and 3:1, respectively. Such products could not be 
made in laboratory equipment but are makable, especially with additional 
magnesium sulfate and citric acid, up to twice as much as being employed 
initially, when heavy duty plant equipment is utilized. 
In a similar manner three other formulations were made, lower in solids 
content, comprising 56%, 19% and 25% in the one case, 60%, 15% and 25% in 
the second case and 60%, 20% and 20% in the third case, of sodium 
bicarbonate, soda ash and sodium silicate, so that the bicarbonate: 
carbonate ratios are 3:1, 4:1 and 3:1, respectively. Such products are 
very easily manufactured, even in laboratory equipment, but because of the 
need to evaporate more water during the spray drying process they are not 
as economically feasible as higher solids content crutcher mixes. In the 
described experiments the silicate is that of Example 1. 
From the above experiments it is seen that the present invention is an 
important one. The anti-gelling materials being employed allow the use of 
higher solids content crutcher mixes and thereby conserve energy (less 
drying air needed) and increase throughputs. The invention also ensures 
the crutcher mix freeze-ups do not occur, with the loss of time and 
materials that would otherwise result. Operations at higher crutcher 
temperatures are permissible despite the fact that increasing such 
temperatures would otherwise increase the probability of gelation of the 
crutcher mix. The magnesium salt anti-gelling agents improve product 
characteristics to a significant extent and although one will usually 
attempt to minimize the citric acid or other citric material content, the 
presences of such materials have good effects, too. It appears from the 
experimental results that the solids content of the crutcher mix may be as 
high as 70% in some circumstances and good mixing and sufficiently delayed 
gelation are obtainable by means of the present invention, despite such 
high solids contents. Also, the crutcher mix temperature may go as high as 
70.degree. C. Of course, at such higher solids contents and temperatures 
stronger mixing would usually be used and often more anti-gelling agent 
will be present. 
The invention has been described with respect to various illustrations and 
embodiments thereof but is not to be limited to these because it is 
evident that one of skill in the art, with the present specification 
before him, will be able to utilize equivalents and substitutes without 
departing from the invention.