CA1176942A - Method for retarding gelation of bicarbonate - carbonate - zeolite - silicate crutcher slurries - Google Patents
Method for retarding gelation of bicarbonate - carbonate - zeolite - silicate crutcher slurriesInfo
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Abstract
METHOD FOR RETARDING GELATION OF BICARBONATE-CARBONATE-ZEOLITE-SILICATE CRUTCHER SLURRIES
ABSTRACT OF THE DISCLOSURE:
Gelation and setting of desirably miscible and pumpable crutcher slurries comprising sodium carbonate, sodium bicarbonate, zeolite 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.
ABSTRACT OF THE DISCLOSURE:
Gelation and setting of desirably miscible and pumpable crutcher slurries comprising sodium carbonate, sodium bicarbonate, zeolite 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.
Description
The present invention relates to non-gelling aqueous slurries of inorganic salt mixtures and to methods for their manufacture. ~ore particularly, it relates to the utilization of certain materials whicll, in combination, develop an exceptionally good and im.roved anti-gelling action, preventing gelation, excess thickenin~ and settin~
up o~ bicarbonate - carbonate - zeolite - silicate slurries from which particulate heavy duty synthetic organic deteroent co-npositions may be made, as by spray drying such slurries and post-spraying the resulting dried beads with a synthctic nonionic deter~ent.
Aqueous crutcher mix~es containin~ substantial propor-tions o~ bicarbonate, carbonate, zeolite and silicate tend to ~el or set prematurely, sometimes be~ore they can bc tllor~u~rhly 11'7694Z
mixed and pumped out of a crutcher to spray towers. 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. Citric acid or water soluble citrate incorporated in the crutcher mix delay or pre-vent gelation and setting of bicarbonate - carbonate - silicate mixes and allow commercial spray drying thereof, following normal procedures for pump-ing out the crutcher contents to the spray nozzles. However, while such in-vented process was and is successful, it has been supplanted by the present process when zeolite is present in the crutcher and the anti-gelling effect obtained is greater. In addition to improving the anti-gelling activity and increasing the length of time in which a crutcher mix would be workable with-out 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 com-position 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, could interfere with the absorption of liquid non-ionic detergent sprayed onto such 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 anti-gelling com-pounds can ionize and therefore it may be considered that in the cnltcller mix there~re present m.lgnesium, citrate and sulfate ions. Accordingly, crutcher mixes having charged thereto mi:;tures o~ compounds tll~t result in thc ~esired ionic composition are also useful for retarding and preventin~
gelations of inorganic crutcher mixes. Thus, magnesium citrate or magnesium acid citrate coul~ be employed, prefer-ably with sodium sulfate, but also without the sulfate being present, because it is considered that the ma~nesium and citrate ions are the most effective in inhi~iting gelation.
lo Citric acid and the various citrates may be referred to herein as "citric material".
In accordance with the present invention, a rniscible and pumpable crutcher slurry which does not prematurely gel or set and which is capable of being mixed and pumped for a period of at least an hour 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 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na20:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio OL sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sadium carbonate: sodium silicate being within the range o about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of about 1:1 to 8:1, and the ratio of zeolite : silicate being within the ran~e of about 1:2 to 10:1, and wl1ich solids content includes, on a slurry basis, a gelation retarding proportion of a com~ination ~7~i~42 of 0.1 to 2% of a citric material selected from the group consisting of citric acid, water soluble citrate(s) and mixtures thereof, and from 0.1 to 1.4% of magnesium sulfate, with the total of such citric material and magne-sium sulfate being at least 0.4% of the slurry. The invention also relates to a method for retarding or preventing the gelation of a miscible and pump-able crutcher slurry of the general bicarbonate - carbonate - zeolite - sili-cate type described, by addition thereto of a citric material and magnesium sulfate, in the described small quantities. The invention is also of similar slurries and methods wherein magnesium citrate is present or is utilized as an anti-gelling material.
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, zeolite, silicate and water, such as those not including the zeolite, very significant anti-gelling effects are noted when the zeolite-containing crutcher mixes are treated by the method of this invention, i.e., addition of citric material and magnesium sulfate (or magnesium citrate). It is significant that the zeolite, although hydrated, does not tend to dissolve in the crutcher, and consequently, its presence can cause significant thickening of the mix. Also, the finely ` 1~7G94~Z
divided zeolite particles can serve as nuclei for gel formation and for pre-cipitation.
The slurries or crutcher mixes treated in accord with this inven-tion comprise about 40 to about 70% of solids and are about 60 to about 30%
of water. The solids contentJ on a 100% solids basis, is about 20 to about 45% of sodium bicarbonate, about 10 to about 30% of sodium carbonate, about 10 to about 65% of zeolite and about 5 to about 25% of sodium silicate, of Na20:SiO2 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 1 or 1.2:1 to about 4:1, the ratio of sodium carbonate : sodium silicate is within the range of about 1:2.5 to about 5:1, the ratio of sodium bicarbon-ate : sodium silicate is within the range of about 1:1 to about 8:1 and the ratio of zeolite : silicate is within the range of about 1:2 to about 10:1.
The percentage of citric material, which is citric acid, water soluble citrate, a mixture of such citrates or a mixture of citric acid and such citrate(s), will be from about 0.1 to about 2% and the percentage of magne-sium sulfate will be from 0.1 to 1.4%, on a slurry basis. The total of citric material and magnesium sulfate will be at least 0.4% and will usually not exceed 2.5 to 3%, with the percentages mentioned being on a total crutcher mix or slurry basis, such slurry 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, 1 to 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%, preferably 0.5 to 2%, of magnesium acid citrate ~MgHC6H5O7 5H20) or equivalent proportion of equivalent magnesium citrate.
Preferably, the crutcher slurry contains from 50 to 65% of solids, with the balance being water, and of the solids content, 25 to 40% is sodium bicarbonate, 13 to 25% is sodium carbonate, 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.6 to 1:2.6, and 35 to 65% lS
hydrated, water softening zeolite, with the ratio of sodium bicarbonate :
sodium carbonate being within the range of 1.5:1 to 3:1, the ratio of sodium carbonate : sodium silicate being within the range of 1:2 to 2:1, the ratio of sodium bicarbonate : sodium silicate being within the range of 2:1 to 5:1, and the ratio of hydrated, water softening zeolite : sodium silicate being within the range of 2:1 to 7:1. In such a slurry the percentages of citric material and magnesium sulfate are 0.1 to 0.8 and 0.1 to 1.2, respectively, with a minimum total of 0.4%. More preferably, the crutcher slurry contains from 55 to 65% of solids and 45 to 35% of water, of which solids content 25 to 35% is sodium bicarbonate, 13 to 20% is sodium carbonate, 8 to 15% is sodium silicate of Na20:SiO2 ratio in the range of 1:2 to 1:2.4, and 35 to ~176942 50% is hydrated, water softening zeolite. In such more preferred composi-tions the ratio of sodium bicarbonate : sodium carbonate is within the range of 1.5:1 to 2.5:1, the ratio of sodium carbonate : sodium silicate is within the range of 1:1 to 2:1, the ratio of sodium bicarbonate : sodium silicate is within the range of 2:1 to 4:1, and the ratio of hydrated, water soften-ing zeolite : sodium silicate is within the range of 3:1 to 5:1. In such cases the percentages of gelation preventing citric material and magnesium sulfate are in the ranges of 0.2 to 0.6% and 0.4 to 1.1%, respectively. The materials described herein, except for water, are all normally solid and the percentages and ratios are on an anhydrous basis, although the various mate-rials 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 hydrate(s), such as the mono-hydrate, 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 usually be of Na20:SiO2 ratio within the range of 1:1.6 to 1:2.6, preferably 1:1.6 to 1:2.4 and more preferably 1:2 to 1:2.4.
The zeolites employed include crystalline, amorphous and mixed cry-stalline-amorphous zeolites of both natural and synthetic origins which are of satisfactorily quick and sufficiently effective activities in counteract-ing calcium hardness ions in wash waters. Preferably, such materials are capable of reacting sufficiently rapidly with the calcium ions so that, alone or in conjunction with other water softening compounds in the deter-gent, they soften the wash water before adverse reactions of such ions with other components of the synthetic organic detergent composition occur. The zeolites employed may be characterized as having a high exchange capacity for calcium ion, which is normally from about 200 to 400 or more milligram equivalents of calcium carbonate hardness per gram of the aluminosilicate, preferably 250 to 350 mg. eq./g. Also they preferably have a hardness deple-tion rate residual hardness of 0.02 to 0.05 mg. CaCO3/liter in one minute, preferably 0.02 to 0.03 mg./l., and less than 0.01 mg./l. in 10 minutes, all on an anhydrous zeolite basis.
Although other ion exchanging zeolites may also be utilized, nor-mally the finely divided synthetic zeolite builder particles employed in the practice of this invention will be of the formula (Na20) x' (A1203) y~ (SiO2) Z W H20 :~, 117G9a~Z
wherein x is 1J Y is from 0.8 to 1.2, preferably about 1, z is from 1.5 to 3.5, preferably 2 to 3 or about 2 and w is from 0 to 9, preferably 2.5 to 6.
The zeolite should be a univalent cation-exchanging zeolite, i.e., it should be an aluminosilicate of a univalent cation such as sodium, potas-sium, lithium (when practicable) or other alkali metal, ammonium or hydrogen ~sometimes). Preferably the univalent cation of the zeolite molecular sieve is an alkali metal cation, especially sodium or potassium, and most prefer-ably is sodium.
Crystalline types of zeolites utilizable as good ion exchangers in the invention, at least in part, include zeolites of the following crystal structure groups: A, X, Y, L, mordenite and erionite, of which types A, X
and Y are preferred. Mixtures of such molecular sieve zeolites can also be useful, especially when type A zeolite is present. These crystalline types of zeolites are well known in the art and are more particularly described in the text Zeolite Molecular Sieves by Donald W. Breck, published in 1974 by John Wiley ~ Sons. A1SOJ suitable zeolites have been described in many patents in recent years for use as detergent composition builders.
11"~69~Z
The 3eolite used in the invention is usually synthetic and it is often characterized by having a network of substantially uniformly sized pores in the range of about 3 to 10 Angstroms, often being about 4 A (normal), such size being uniquely determined by the unit structure of the zeolite cry-stal. Preferably it is of type A or similar structure, particularly des-cribed at page 133 of the aforementioned text. Good results have been ob-tained when a Type 4A molecular sieve zeolite is employed, wherein the univa-lent cation of the zeolite is sodium and the pore size of the zeolite is about 4 Angstroms. Such zeolite molecular sieves are described in U.S.
patent 2,882,243, which refers to them as Zeolite A.
Molecular sieve zeolites can be prepared in either a dehydrated or calcined form which contains from about 0 or about 1.5% to about 3% of mois-ture or in a hydrated or water loaded form which contains additional bound water in an amount from about 4% up to about 36% of the zeolite total weight, depending on the type of zeolite used. The water-containing hydrated form of the molecular sieve zeolite (preferably about 15 to 70% hydrated) is pre-ferred in the practice of this invention when such crystalline product is used. The manufacture of such crystals is well known in the art. For example, in the preparation of Zeolite A, referred to above, the hydrated zeolite crystals that are formed in the crystallization medium (such as a hydrous amorphous sodium aluminosilicate gel) are used without the high ii'7694Z
temperature dehydration ~calcining to 3% or less water content) that is nor-mally practiced in preparing such crystals for use as catalysts, e.g., crack-ing catalysts. The crystalline zeolite, in either completely hydrated or partially hydrated form, can be recovered by filtering off the crystals from the crystallization medium and drying them in air at ambient temperature so that their water contents are in the range of about S to 30% moisture, pre-ferably about 10 to 25%, such as 17 to 22%. However, the moisture content of the molecular sieve zeolite being employed may be much lower, as was pre-viously described, in which case the zeolite will usually be hydrated during crutching and other processing.
Preferably the zeolite should be in a finely divided state with the ultimate particle diameters being up to 20 microns, e.g., 0.005 or 0.01 to 20 microns, preferably being from 0.01 to 15 microns and especially pre-ferably of 0.01 to 8 microns mean particle size, e.g., 3 to 7 or 12 microns, if crystalline, and 0.01 to 0.1 micron, e.g., 0.01 to 0.05 micron, if amor- ;
phous. Although the ultimate particle sizes are much lower, usually the zeo-lite particles will be of sizes within the range of 100 to 400 mesh, prefer-ably 140 to 325 mesh. Zeolites of smaller sizes will often become objection-ably dusty and those of larger sizes may not sufficiently and satisfactorily cover the carbonate-bicarbonate base particles.
~k 1~7694Z
It is highly preferred to make the crutcher slurry and the base bead product of this invention (from which a heavy duty built nonionic syn-thetic organic detergent composition can be produced) of essentially in-organic salts, some water soluble and some water insoluble, 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. There-fore, adjuvants, such as perfumes, colorants, en~ymes, bleaches and flow pro-moting agents, are often sprayed onto the beads with the nonionic detergent or are post-added, so that their presence in spray dried beads does not inhibit absorption of the detergent. However, for stable and normally solid adjuvants, mixing in with the inorganic salt slurry in the crutcher can also 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
up o~ bicarbonate - carbonate - zeolite - silicate slurries from which particulate heavy duty synthetic organic deteroent co-npositions may be made, as by spray drying such slurries and post-spraying the resulting dried beads with a synthctic nonionic deter~ent.
Aqueous crutcher mix~es containin~ substantial propor-tions o~ bicarbonate, carbonate, zeolite and silicate tend to ~el or set prematurely, sometimes be~ore they can bc tllor~u~rhly 11'7694Z
mixed and pumped out of a crutcher to spray towers. 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. Citric acid or water soluble citrate incorporated in the crutcher mix delay or pre-vent gelation and setting of bicarbonate - carbonate - silicate mixes and allow commercial spray drying thereof, following normal procedures for pump-ing out the crutcher contents to the spray nozzles. However, while such in-vented process was and is successful, it has been supplanted by the present process when zeolite is present in the crutcher and the anti-gelling effect obtained is greater. In addition to improving the anti-gelling activity and increasing the length of time in which a crutcher mix would be workable with-out 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 com-position 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, could interfere with the absorption of liquid non-ionic detergent sprayed onto such 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 anti-gelling com-pounds can ionize and therefore it may be considered that in the cnltcller mix there~re present m.lgnesium, citrate and sulfate ions. Accordingly, crutcher mixes having charged thereto mi:;tures o~ compounds tll~t result in thc ~esired ionic composition are also useful for retarding and preventin~
gelations of inorganic crutcher mixes. Thus, magnesium citrate or magnesium acid citrate coul~ be employed, prefer-ably with sodium sulfate, but also without the sulfate being present, because it is considered that the ma~nesium and citrate ions are the most effective in inhi~iting gelation.
lo Citric acid and the various citrates may be referred to herein as "citric material".
In accordance with the present invention, a rniscible and pumpable crutcher slurry which does not prematurely gel or set and which is capable of being mixed and pumped for a period of at least an hour 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 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na20:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio OL sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sadium carbonate: sodium silicate being within the range o about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of about 1:1 to 8:1, and the ratio of zeolite : silicate being within the ran~e of about 1:2 to 10:1, and wl1ich solids content includes, on a slurry basis, a gelation retarding proportion of a com~ination ~7~i~42 of 0.1 to 2% of a citric material selected from the group consisting of citric acid, water soluble citrate(s) and mixtures thereof, and from 0.1 to 1.4% of magnesium sulfate, with the total of such citric material and magne-sium sulfate being at least 0.4% of the slurry. The invention also relates to a method for retarding or preventing the gelation of a miscible and pump-able crutcher slurry of the general bicarbonate - carbonate - zeolite - sili-cate type described, by addition thereto of a citric material and magnesium sulfate, in the described small quantities. The invention is also of similar slurries and methods wherein magnesium citrate is present or is utilized as an anti-gelling material.
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, zeolite, silicate and water, such as those not including the zeolite, very significant anti-gelling effects are noted when the zeolite-containing crutcher mixes are treated by the method of this invention, i.e., addition of citric material and magnesium sulfate (or magnesium citrate). It is significant that the zeolite, although hydrated, does not tend to dissolve in the crutcher, and consequently, its presence can cause significant thickening of the mix. Also, the finely ` 1~7G94~Z
divided zeolite particles can serve as nuclei for gel formation and for pre-cipitation.
The slurries or crutcher mixes treated in accord with this inven-tion comprise about 40 to about 70% of solids and are about 60 to about 30%
of water. The solids contentJ on a 100% solids basis, is about 20 to about 45% of sodium bicarbonate, about 10 to about 30% of sodium carbonate, about 10 to about 65% of zeolite and about 5 to about 25% of sodium silicate, of Na20:SiO2 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 1 or 1.2:1 to about 4:1, the ratio of sodium carbonate : sodium silicate is within the range of about 1:2.5 to about 5:1, the ratio of sodium bicarbon-ate : sodium silicate is within the range of about 1:1 to about 8:1 and the ratio of zeolite : silicate is within the range of about 1:2 to about 10:1.
The percentage of citric material, which is citric acid, water soluble citrate, a mixture of such citrates or a mixture of citric acid and such citrate(s), will be from about 0.1 to about 2% and the percentage of magne-sium sulfate will be from 0.1 to 1.4%, on a slurry basis. The total of citric material and magnesium sulfate will be at least 0.4% and will usually not exceed 2.5 to 3%, with the percentages mentioned being on a total crutcher mix or slurry basis, such slurry 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, 1 to 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%, preferably 0.5 to 2%, of magnesium acid citrate ~MgHC6H5O7 5H20) or equivalent proportion of equivalent magnesium citrate.
Preferably, the crutcher slurry contains from 50 to 65% of solids, with the balance being water, and of the solids content, 25 to 40% is sodium bicarbonate, 13 to 25% is sodium carbonate, 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.6 to 1:2.6, and 35 to 65% lS
hydrated, water softening zeolite, with the ratio of sodium bicarbonate :
sodium carbonate being within the range of 1.5:1 to 3:1, the ratio of sodium carbonate : sodium silicate being within the range of 1:2 to 2:1, the ratio of sodium bicarbonate : sodium silicate being within the range of 2:1 to 5:1, and the ratio of hydrated, water softening zeolite : sodium silicate being within the range of 2:1 to 7:1. In such a slurry the percentages of citric material and magnesium sulfate are 0.1 to 0.8 and 0.1 to 1.2, respectively, with a minimum total of 0.4%. More preferably, the crutcher slurry contains from 55 to 65% of solids and 45 to 35% of water, of which solids content 25 to 35% is sodium bicarbonate, 13 to 20% is sodium carbonate, 8 to 15% is sodium silicate of Na20:SiO2 ratio in the range of 1:2 to 1:2.4, and 35 to ~176942 50% is hydrated, water softening zeolite. In such more preferred composi-tions the ratio of sodium bicarbonate : sodium carbonate is within the range of 1.5:1 to 2.5:1, the ratio of sodium carbonate : sodium silicate is within the range of 1:1 to 2:1, the ratio of sodium bicarbonate : sodium silicate is within the range of 2:1 to 4:1, and the ratio of hydrated, water soften-ing zeolite : sodium silicate is within the range of 3:1 to 5:1. In such cases the percentages of gelation preventing citric material and magnesium sulfate are in the ranges of 0.2 to 0.6% and 0.4 to 1.1%, respectively. The materials described herein, except for water, are all normally solid and the percentages and ratios are on an anhydrous basis, although the various mate-rials 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 hydrate(s), such as the mono-hydrate, 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 usually be of Na20:SiO2 ratio within the range of 1:1.6 to 1:2.6, preferably 1:1.6 to 1:2.4 and more preferably 1:2 to 1:2.4.
The zeolites employed include crystalline, amorphous and mixed cry-stalline-amorphous zeolites of both natural and synthetic origins which are of satisfactorily quick and sufficiently effective activities in counteract-ing calcium hardness ions in wash waters. Preferably, such materials are capable of reacting sufficiently rapidly with the calcium ions so that, alone or in conjunction with other water softening compounds in the deter-gent, they soften the wash water before adverse reactions of such ions with other components of the synthetic organic detergent composition occur. The zeolites employed may be characterized as having a high exchange capacity for calcium ion, which is normally from about 200 to 400 or more milligram equivalents of calcium carbonate hardness per gram of the aluminosilicate, preferably 250 to 350 mg. eq./g. Also they preferably have a hardness deple-tion rate residual hardness of 0.02 to 0.05 mg. CaCO3/liter in one minute, preferably 0.02 to 0.03 mg./l., and less than 0.01 mg./l. in 10 minutes, all on an anhydrous zeolite basis.
Although other ion exchanging zeolites may also be utilized, nor-mally the finely divided synthetic zeolite builder particles employed in the practice of this invention will be of the formula (Na20) x' (A1203) y~ (SiO2) Z W H20 :~, 117G9a~Z
wherein x is 1J Y is from 0.8 to 1.2, preferably about 1, z is from 1.5 to 3.5, preferably 2 to 3 or about 2 and w is from 0 to 9, preferably 2.5 to 6.
The zeolite should be a univalent cation-exchanging zeolite, i.e., it should be an aluminosilicate of a univalent cation such as sodium, potas-sium, lithium (when practicable) or other alkali metal, ammonium or hydrogen ~sometimes). Preferably the univalent cation of the zeolite molecular sieve is an alkali metal cation, especially sodium or potassium, and most prefer-ably is sodium.
Crystalline types of zeolites utilizable as good ion exchangers in the invention, at least in part, include zeolites of the following crystal structure groups: A, X, Y, L, mordenite and erionite, of which types A, X
and Y are preferred. Mixtures of such molecular sieve zeolites can also be useful, especially when type A zeolite is present. These crystalline types of zeolites are well known in the art and are more particularly described in the text Zeolite Molecular Sieves by Donald W. Breck, published in 1974 by John Wiley ~ Sons. A1SOJ suitable zeolites have been described in many patents in recent years for use as detergent composition builders.
11"~69~Z
The 3eolite used in the invention is usually synthetic and it is often characterized by having a network of substantially uniformly sized pores in the range of about 3 to 10 Angstroms, often being about 4 A (normal), such size being uniquely determined by the unit structure of the zeolite cry-stal. Preferably it is of type A or similar structure, particularly des-cribed at page 133 of the aforementioned text. Good results have been ob-tained when a Type 4A molecular sieve zeolite is employed, wherein the univa-lent cation of the zeolite is sodium and the pore size of the zeolite is about 4 Angstroms. Such zeolite molecular sieves are described in U.S.
patent 2,882,243, which refers to them as Zeolite A.
Molecular sieve zeolites can be prepared in either a dehydrated or calcined form which contains from about 0 or about 1.5% to about 3% of mois-ture or in a hydrated or water loaded form which contains additional bound water in an amount from about 4% up to about 36% of the zeolite total weight, depending on the type of zeolite used. The water-containing hydrated form of the molecular sieve zeolite (preferably about 15 to 70% hydrated) is pre-ferred in the practice of this invention when such crystalline product is used. The manufacture of such crystals is well known in the art. For example, in the preparation of Zeolite A, referred to above, the hydrated zeolite crystals that are formed in the crystallization medium (such as a hydrous amorphous sodium aluminosilicate gel) are used without the high ii'7694Z
temperature dehydration ~calcining to 3% or less water content) that is nor-mally practiced in preparing such crystals for use as catalysts, e.g., crack-ing catalysts. The crystalline zeolite, in either completely hydrated or partially hydrated form, can be recovered by filtering off the crystals from the crystallization medium and drying them in air at ambient temperature so that their water contents are in the range of about S to 30% moisture, pre-ferably about 10 to 25%, such as 17 to 22%. However, the moisture content of the molecular sieve zeolite being employed may be much lower, as was pre-viously described, in which case the zeolite will usually be hydrated during crutching and other processing.
Preferably the zeolite should be in a finely divided state with the ultimate particle diameters being up to 20 microns, e.g., 0.005 or 0.01 to 20 microns, preferably being from 0.01 to 15 microns and especially pre-ferably of 0.01 to 8 microns mean particle size, e.g., 3 to 7 or 12 microns, if crystalline, and 0.01 to 0.1 micron, e.g., 0.01 to 0.05 micron, if amor- ;
phous. Although the ultimate particle sizes are much lower, usually the zeo-lite particles will be of sizes within the range of 100 to 400 mesh, prefer-ably 140 to 325 mesh. Zeolites of smaller sizes will often become objection-ably dusty and those of larger sizes may not sufficiently and satisfactorily cover the carbonate-bicarbonate base particles.
~k 1~7694Z
It is highly preferred to make the crutcher slurry and the base bead product of this invention (from which a heavy duty built nonionic syn-thetic organic detergent composition can be produced) of essentially in-organic salts, some water soluble and some water insoluble, 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. There-fore, adjuvants, such as perfumes, colorants, en~ymes, bleaches and flow pro-moting agents, are often sprayed onto the beads with the nonionic detergent or are post-added, so that their presence in spray dried beads does not inhibit absorption of the detergent. However, for stable and normally solid adjuvants, mixing in with the inorganic salt slurry in the crutcher can also 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, 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 sul-fate is inorganic and appears to be useful in aiding absorption of nonionic 1 ~ '769~2 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 pro-motes the production of a more desirable base bead, lower in organic content.
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 inor-ganic salts, is normally alkaline, usually being of a pH in the range of 9 to12, 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 con-sidered to be superior. Instead of adding citrate, a mixture of the acid and a neutralizing agent, e.g., NaOH, KOH, Mg(OH)2, may be used and instead of the acid form, a citrate plus an acid can be substituted, if desired (al-though this latter course of action will rarely be followed). The proportion X
` 1~'7694Z
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 magne-sium 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 2.5% will suffice, preferably from 0.5 to 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 com-pound, 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, usually in proportion from 0.3 to 3%, preferably 0.5 to 2%, on a slurry basis.
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 foam-11769~Z
ing accompanies the following of a specific order. However, such problems have not been found to be serious. In some instances it is possible to pre-mix 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.
Preferably, for the manufacture of the crutcher mix, water will be added to the crutcher initially, followed by magnesium sulfate, part of the citric material, part of the zeolite, bicarbonate, carbonate, the balance of the citric material, the balance of the zeolite, part of the silicate, and the balance of the silicate. Normally, mixer speed and power will be in-creased as the materials are added. For example, low speeds may be used until after admixing in of the last of the zeolite, when the speed may be in-creased to medium, and then to high before addition of the second portion of silicate solution. 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 prefer-able 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 at about room temperature or elevated, normally in the 20 to 70C. range and preferably will often be from 25 to 40C. Heating the crutcher medium may promote solution of the water soluble salts of the mix and thereby in-crease mix mobility. However, the heating operation can slow production rates and therefore an advantage of the present invention is that lower temperature non-gelling slurries are obtainable. Temperatures higher than 70 C. will usually be avoided because of the possibility of decomposition of one or more crutcher mix components, e.g., sodium bicarbonate. Also, in some cases lower crutcher temperatures increase the upper limits of crutcher solids contents, probably due to insolubilizing normally gelling components.
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 `--`` 117~94Z
medium may be ~s little as five minutes but in some cases, can take up to an hour, although 30 minutes is a preferabIe upper limit. Counting any such initial admixing times, normal crutching periods will be from 15 minute~ t~ two hours, e.g., 20 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., lO to 30 hours (before pump-out to the spray tower).
The arutched slurry, with the various salts and any other components thereof, 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, iB 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 absorp-tive bead form. During the drying, part of the bicarbonate may be converted to carbonate, with the release of carbon dioxide, which appears to improve the physical characleristics of the beads made so that they become more absoprtive of liquids, such as liquid nonionic detergent, which may be post-_ 17 -. ~ l 11';'69~Z
sprayed onto them subsca~uently. ~lowevcr, the ~eoli~e componen~ of the base beads made also favors absorptiol- of liquid so less d~composition of bicarbonate still results in a highly absorptive product.
After drying, the product is screened to desired size, e.g., 10 to 100 mesh, U.S. Standard Sieve Serles, and is ready for application of nonionic detergent spray there-to, with the beads being either in warm or cooled (to room temperature) condition. However, the nonionic detergellt 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.
Even i at room temperature the detergent is somewhat tacky this characteristic does not make the final composition poorly flowing because the detergent penetrates to below the bead surface. The nonionic detergent, applied to the tumbling beads in known manner, as a spray or as droplets, is preferably a condensation product of etllylene oxide and higher fatty alcohol, with the hiyher fatty alcohol being of 10 to 20 carbon atoms, preferably of 12 to 16 carbon atoms, and more preferably averaging 12 to 13 carbon a~oms, and with the nonionic detergent containing from 3 to 20 ethylene oxide groups per mole, preferably from 5 to 12, more prefer-ably 6 to 8. Instead of the ethylene oxide being aondensed ~ith higher fatty alcohol the lipophilic por~ion of ~ e detergent may be aromatic, e.g., nonylphenyl, isoctylphenyl - 18 - j or similar alkylphenyls, obtainable from corresponding phenols. The prc{~ortion of nonionic detergent in the Einal 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 and without thezeolite, the liquid absorption rate of the base beads would be good, with some base bead compositions and nonionic detergents it could be difficult to have more than 20% of the nonionic detergent sufficiently quickly and satisfactorily absorbed by the base beads. It has been found that the present anti-gelling treatment, applied to a zeolite containing formula and utilizing a mixture of citric materi~l and magnesium sulfate, e.g., citric acid and magnesium sulfate, and often with less citric acid beinc3 used to produae the same workability of the crutcher mix,can result in beads of better absorption pro~erties, in which, for example, as much as 22~ or even 25~ of nonionic detergent may be abs~rbed in a reasonable time, with the production of a free flowing product.
-A preferred finished formulation made from the presently described base beads contains from 15 to 25~, preferably 20 to 25% of the nonionic detergent, e.g., Neodol 23-6.5, made by Shell Chemical Company, 15 to 25%
of sodium bicarbonate, 5 to 15% of sodium carbonate, 25 to 35~ of zeolite, 5 to 15~ of sodium silicate, e.g., of Na20:SiO2 ratio of about 1:2.4, 1 to 3~ of fluorescent brightener, 0.5 to 2~ of proteolytic cnzyme, sufficient bluing to color the product and whitcn tllc wash, as desired, 3 or 5 to 10~ of moisture, 0.25 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 presen~ from 0.3 to 3~ of magnesium citrate, preferably 0.5 to 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 20 to 35~ of sodium bicarbonate, 10 to 20% of sodium carbonate, 30 to 45% of zeolite, 10 to 20% of sodium silicate, 0.3 to 2% of sodium citrate and 1 to 2~ of magnesium sulfate (or 0.~ ~o 4'~ of magnesium citrate), 0 to 10~ of adjuvant(s) and/or diluent(s) and 3 to 10~ of moisture. In such products the proportion of sodium bicarbonate in the s~rayed beads will normally be within the range of 1.2 to 4 times tha~ of sodium carbonate, e.g., l.S to 3 times.
~rhe higllly bencficial 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, yelation and setting of the crutcher mix in the vessel before com~lete discharge thereof is prevented,and additionally, higher solids content crutcher slurrio3 may be made. l'hus, down 1176g42 times and cleanouts are eliminated. Although many bicarbonate - carbonate -zeolite - silicate mixtures desirably employed in crutcher mixes for making base beads for built particulate nonionic detergent compositions would nor-mally gel and set up in the crutcher, with the present invention, at little expense and without any detrimental effects on the product, the desired pro-portions of such builder salts can be employed and variations in such propor-tions can be made, as desired, without fear of freeze-ups in 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, can 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 sometimes present, such as proteolytic enzymes and protein-aceous materials. The presence of the citric materials and the magnesium sul-fate in the base beads also has the desirable effect of having the gelation preventing material present in any base beads or detergent beads being re-worked, so that such material, if off-specification (as for being undersize or 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 mixin~ with water is easier than would be the case were the an~i-gelling comuosition not present in the base beads to prevent or retard gelation or excessive thickening.
The following exampl~s illustra~e but do not limit the invention. Unless otherwise indicated all temperatures are in C. and all parts are by weight in the ex~mples and throuyhout the specification. Also, when weights and propor-tions of zeolite are given these are intended to be for the normal hydrate heing used,because it i5 considered that the zeolite water of hydration does not leave the zeolite and does not become part of the aqueous solvent medium in the present crutching operations.
A 10,000 pound t4536 k~.) crutcher mix batch is made by mixing in water at a temperatvre of about 27C.
(80F.), with low speed crutcher mixing, and sequentially, 216 parts of ~psom salts, 25 parts of citric acid, 1,264 parts of Linde hydrated zeolite 4A (20~ water of crystalliza-20 tion), 1,634 parts of sodium bicarbonate, 821 parts of soda ash, 25 more parts of citric acid and 1,264 more parts of the mentioned zeolite, after which the mixer speed is increased to medium and 814 parts of a 47.5% aqueous 301ution of sodium 3ilicate ~Na20:SiO2 ratio of 1:2.4) are admixed, after which the agitator speed is increased to high, and after another 20 seconds an additional 814 parts of the silicate 11';'~942 solution are admixed in. Mixing of the entire batch then continues for at least an hour (and in some cases for as many as four hours~, during which time about 500 parts of water are lost. During the mixing time the crutcher slurry is continuously mobile and does not gel or cake.
Starting about five minutes after all the components of the crutcher mix are present, the mix is dropped from the crutcher to a pump which pumps it at a pressure of about 300 p.s.i. ~about 21 kg./sq. cm.) into the top of a countercurrent spray tower wherein the initial temperature is about 800F. (430C.) and the final temperature is about 220 F. ~105C.).
The essentially inorganic base beads resulting are of a bulk density of about 0.7 g./ml., an initial adhesion of about 40%, a particle size range substant-ially between lO and 100 mesh, U.S. sieve series, and a fines characteristic ~through U.S. Sieve No. 50~ of about 15%. The moisture content of the pro-duct is about 7%. The base beads are found to be free flowing, non-tacky, porous, yet firm on the surfaces thereof, and capable of readily absorbing significant proportions of liquid nonionic detergent without becoming object-ionably tacky. Detergent products are made with them by spraying a normally waxy nonionic detergent, either Neodol 23-6.5 or Neodol 45-11, in heated liquid state, onto the tumbling bead surfaces so as to make a product contain-ing 20% or 22% of the nonionic detergent ~1 or 2% of proteolytic enzyme, e.g., Maxatase6~, and 0.2 or 0.3% of perfume may also be applied to X
11'7694Z
;
the tumbling beads). Tbe resulting dctergcnt products are excellent heavy duty laundry detergents, especially useful for washing househqld laundry in automatic washing machines.
In addi.ion to their desirable washin~ properties they are physically and aesthetically advantageous because they are non-dusting and extremely freely flowing, allowing them to be packaged in narrow necked glass and plastic bottles, and to flow readily from these.
Although normally crutcher mixes will be made quickly and may be emptied from the crutcher equally fast, sometimes being made within a period of as little as five minutes and being pumped out of the crutcher in as little as five or ten minutes, it is important that the present mixes be able to withstand at least an hour in the crutcher without gelling or solidifying because so~etimes holdups o such times are encountered in commercial production. The described crutcher mix is found to be capable of being held for as long as four hours and often longer, without gelling or solidifying.
In variations of the present experiment the tempera-ture is elevated to 125F. (52C.) and the desired crutcher mix may be made and the base beads may be spray dried there-from without untoward incident. In other variations of the experiment the proportions of the various components may be varied plus or minus 10%, plus or minus 20~ and plus or minus 30~, maintaining them within the ranges previously '694Z
given, and workable crutcher mixes that do not gel and do not solidify for periods of at least an hour'are obtainable.
When either the citric acid or magnesium sulfate is omitted from'the mix or when sucl~isadded after the silicate (usually about five minutes thereafter) objectionable gelation often results. It is also noted that the presence of the zeolite also tends to promote~gelation so the use of the combination of magneslum sulfate and citric material is esuecially important with respect to the described crutcher mix formulas.
Instead of using Epsom salts and citric acid, equivalent compounds that also result in the same type of anti-gelling action n-ay be employed. Thus, magnesium citrate, anhydrous magnesium sulfate, sodium citrate and various combinations thereof may be employed. Similarly, other zeolites, such as zeolites X and Y may be used and the zeolites may be oE various degrees of hydration. Other orders of addition of the various components of the crutcher mix may be followed but it will usually be desirab1e to have at least some of the source of magnesium ion and the source 20 of citric ion present in the aqueous medium as early in the '' manufacturing process as is feasible.
When the citric material and magnesium salt are added as described above the solids content of the crutcher mix may exceed 55~ and often may be 65 or 70~ without undesired gelation taking place within an hour of the completion of the making of the crutcher mix ~and often after four hours or - 25 - ' 11'76~Z
more). However, when either the citric material or the magnesium salt or both are omitted from the mix, premature gelation, thickening and precipita-tion occur, especially at elevated temperatures within the 20 to 70C. range and at the higher solids content. In computing the solids contents the water of hydration in the zeolite is considered as a part of the zeolite solid and not as a part of the water content of the crutcher mix. This is because such water of hydration behaves like a solid and is not released into the aqueous medium, being "insoluble" therein during crutching. For the lower solids content crutcher mixes, those of 50-60%, the citric acid content has been reduced to 0.25% in the first working example given supra, with the magnesium sulfate content remaining at 1%, and the mix resulting is still satisfactorily non-gelling. Still, use of the larger proportion is desirable for higher solids content mixes and as a safety measure.
In a comparative example the formulation and processing described for the first formulation and processing described for the first formula of Example 1 are followed except that the solids content of the crutcher mix, including the water of hydration of the zeolite, is 59.6%, the citric acid content is 0.25% and the proportions of sodium bicarbonate and sodium carbon-ate are changed. In one such experiment, designated 2A, the sodium bicarbon-ate content is maintained at 16.3% of the crutcher mix ~as is basis) and the sodium carbonate content is 7.6%. In Experiment 2B such proportions are changed to 13.1% and 10.7%, respectively and in Experiment 2C they are further modified to 10.0% and 13.8%, respectively. Thus, the ratios of sodium bicarbonate to sodium carbonate in the crutcher mixes are 2.1, 1.2 and 0.7, respectively, instead of 2.0, as in Example 1. It is noted that the crutcher mix of Experiment 2B has a higher initial viscosity than that of Experiment 2A, but it is still workable and does not gel over a four-hour holding period. However, the mix of Experiment 2C solidifies during silicate addition, showing the importance of maintaining the proportion of sodium )-~
- ~'7~i94Z
bicarbonate to sodium carbonate in the present compositions within the ranges herein described.
The following formulas are made according to the general method described in the first working experiment of Example 1, with the batch temperatures being within the range of 43 to 46C. Numerals given in the chart are parts by weight except for the percentage of solids, which is a weight percentage.
Component 3A 3B 3C 3D 3F 3G
Tap water 38.9 37.6 35.1 32.7 33.7 33.0 Citric Acid - 0.25 0.25 0.25 0.25 MgS04, anhydrous - 1.0 1.0 1.0 - 1.0 Zeolite 4A (20% hydrated) 22.9 22.9 23.8 24.8 24.8 24.8 Sodium bicarbonate 15.6 15.6 16.3 16.9 16.9 16.9 Soda Ash 7.9 7.9 8.2 8.5 8.5 8.5 Sodium silicate ~47.5%14.7 14.7 15.4 15.9 15.9 15.9 solids; Na2O:SiO2 = 1:2.4) % Solids (including zeolite53.4 54.7 56.8 59.0 58.0 58.7 water of hydration) The mix of Experiment 3A solidifies in the crutcher during silicate addition. The mixes of Experiments 3B, 3C and 3D are satisfactory and form no gel during silicate additions. Initial vicosities of such mixes are about the same despite the increase in solids content from 3B to 3D but such viscos-ities for the mix of Experiment 3D are measurably greater than those for the mixes of Experiment 3B and 3C. With the magnesium sulfate being omitted from the formula, the mix of Experiment 3F solidifies during silicate addition.
The Experiment 3G crutcher mix does not solidify during silicate addition but does solidify thirty minutes thereafter. Thus, the products of experiments 3A, 3F and 3G are unsatisfactory.
..,.: ~
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 inor-ganic salts, is normally alkaline, usually being of a pH in the range of 9 to12, 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 con-sidered to be superior. Instead of adding citrate, a mixture of the acid and a neutralizing agent, e.g., NaOH, KOH, Mg(OH)2, may be used and instead of the acid form, a citrate plus an acid can be substituted, if desired (al-though this latter course of action will rarely be followed). The proportion X
` 1~'7694Z
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 magne-sium 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 2.5% will suffice, preferably from 0.5 to 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 com-pound, 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, usually in proportion from 0.3 to 3%, preferably 0.5 to 2%, on a slurry basis.
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 foam-11769~Z
ing accompanies the following of a specific order. However, such problems have not been found to be serious. In some instances it is possible to pre-mix 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.
Preferably, for the manufacture of the crutcher mix, water will be added to the crutcher initially, followed by magnesium sulfate, part of the citric material, part of the zeolite, bicarbonate, carbonate, the balance of the citric material, the balance of the zeolite, part of the silicate, and the balance of the silicate. Normally, mixer speed and power will be in-creased as the materials are added. For example, low speeds may be used until after admixing in of the last of the zeolite, when the speed may be in-creased to medium, and then to high before addition of the second portion of silicate solution. 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 prefer-able 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 at about room temperature or elevated, normally in the 20 to 70C. range and preferably will often be from 25 to 40C. Heating the crutcher medium may promote solution of the water soluble salts of the mix and thereby in-crease mix mobility. However, the heating operation can slow production rates and therefore an advantage of the present invention is that lower temperature non-gelling slurries are obtainable. Temperatures higher than 70 C. will usually be avoided because of the possibility of decomposition of one or more crutcher mix components, e.g., sodium bicarbonate. Also, in some cases lower crutcher temperatures increase the upper limits of crutcher solids contents, probably due to insolubilizing normally gelling components.
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 `--`` 117~94Z
medium may be ~s little as five minutes but in some cases, can take up to an hour, although 30 minutes is a preferabIe upper limit. Counting any such initial admixing times, normal crutching periods will be from 15 minute~ t~ two hours, e.g., 20 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., lO to 30 hours (before pump-out to the spray tower).
The arutched slurry, with the various salts and any other components thereof, 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, iB 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 absorp-tive bead form. During the drying, part of the bicarbonate may be converted to carbonate, with the release of carbon dioxide, which appears to improve the physical characleristics of the beads made so that they become more absoprtive of liquids, such as liquid nonionic detergent, which may be post-_ 17 -. ~ l 11';'69~Z
sprayed onto them subsca~uently. ~lowevcr, the ~eoli~e componen~ of the base beads made also favors absorptiol- of liquid so less d~composition of bicarbonate still results in a highly absorptive product.
After drying, the product is screened to desired size, e.g., 10 to 100 mesh, U.S. Standard Sieve Serles, and is ready for application of nonionic detergent spray there-to, with the beads being either in warm or cooled (to room temperature) condition. However, the nonionic detergellt 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.
Even i at room temperature the detergent is somewhat tacky this characteristic does not make the final composition poorly flowing because the detergent penetrates to below the bead surface. The nonionic detergent, applied to the tumbling beads in known manner, as a spray or as droplets, is preferably a condensation product of etllylene oxide and higher fatty alcohol, with the hiyher fatty alcohol being of 10 to 20 carbon atoms, preferably of 12 to 16 carbon atoms, and more preferably averaging 12 to 13 carbon a~oms, and with the nonionic detergent containing from 3 to 20 ethylene oxide groups per mole, preferably from 5 to 12, more prefer-ably 6 to 8. Instead of the ethylene oxide being aondensed ~ith higher fatty alcohol the lipophilic por~ion of ~ e detergent may be aromatic, e.g., nonylphenyl, isoctylphenyl - 18 - j or similar alkylphenyls, obtainable from corresponding phenols. The prc{~ortion of nonionic detergent in the Einal 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 and without thezeolite, the liquid absorption rate of the base beads would be good, with some base bead compositions and nonionic detergents it could be difficult to have more than 20% of the nonionic detergent sufficiently quickly and satisfactorily absorbed by the base beads. It has been found that the present anti-gelling treatment, applied to a zeolite containing formula and utilizing a mixture of citric materi~l and magnesium sulfate, e.g., citric acid and magnesium sulfate, and often with less citric acid beinc3 used to produae the same workability of the crutcher mix,can result in beads of better absorption pro~erties, in which, for example, as much as 22~ or even 25~ of nonionic detergent may be abs~rbed in a reasonable time, with the production of a free flowing product.
-A preferred finished formulation made from the presently described base beads contains from 15 to 25~, preferably 20 to 25% of the nonionic detergent, e.g., Neodol 23-6.5, made by Shell Chemical Company, 15 to 25%
of sodium bicarbonate, 5 to 15% of sodium carbonate, 25 to 35~ of zeolite, 5 to 15~ of sodium silicate, e.g., of Na20:SiO2 ratio of about 1:2.4, 1 to 3~ of fluorescent brightener, 0.5 to 2~ of proteolytic cnzyme, sufficient bluing to color the product and whitcn tllc wash, as desired, 3 or 5 to 10~ of moisture, 0.25 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 presen~ from 0.3 to 3~ of magnesium citrate, preferably 0.5 to 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 20 to 35~ of sodium bicarbonate, 10 to 20% of sodium carbonate, 30 to 45% of zeolite, 10 to 20% of sodium silicate, 0.3 to 2% of sodium citrate and 1 to 2~ of magnesium sulfate (or 0.~ ~o 4'~ of magnesium citrate), 0 to 10~ of adjuvant(s) and/or diluent(s) and 3 to 10~ of moisture. In such products the proportion of sodium bicarbonate in the s~rayed beads will normally be within the range of 1.2 to 4 times tha~ of sodium carbonate, e.g., l.S to 3 times.
~rhe higllly bencficial 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, yelation and setting of the crutcher mix in the vessel before com~lete discharge thereof is prevented,and additionally, higher solids content crutcher slurrio3 may be made. l'hus, down 1176g42 times and cleanouts are eliminated. Although many bicarbonate - carbonate -zeolite - silicate mixtures desirably employed in crutcher mixes for making base beads for built particulate nonionic detergent compositions would nor-mally gel and set up in the crutcher, with the present invention, at little expense and without any detrimental effects on the product, the desired pro-portions of such builder salts can be employed and variations in such propor-tions can be made, as desired, without fear of freeze-ups in 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, can 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 sometimes present, such as proteolytic enzymes and protein-aceous materials. The presence of the citric materials and the magnesium sul-fate in the base beads also has the desirable effect of having the gelation preventing material present in any base beads or detergent beads being re-worked, so that such material, if off-specification (as for being undersize or 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 mixin~ with water is easier than would be the case were the an~i-gelling comuosition not present in the base beads to prevent or retard gelation or excessive thickening.
The following exampl~s illustra~e but do not limit the invention. Unless otherwise indicated all temperatures are in C. and all parts are by weight in the ex~mples and throuyhout the specification. Also, when weights and propor-tions of zeolite are given these are intended to be for the normal hydrate heing used,because it i5 considered that the zeolite water of hydration does not leave the zeolite and does not become part of the aqueous solvent medium in the present crutching operations.
A 10,000 pound t4536 k~.) crutcher mix batch is made by mixing in water at a temperatvre of about 27C.
(80F.), with low speed crutcher mixing, and sequentially, 216 parts of ~psom salts, 25 parts of citric acid, 1,264 parts of Linde hydrated zeolite 4A (20~ water of crystalliza-20 tion), 1,634 parts of sodium bicarbonate, 821 parts of soda ash, 25 more parts of citric acid and 1,264 more parts of the mentioned zeolite, after which the mixer speed is increased to medium and 814 parts of a 47.5% aqueous 301ution of sodium 3ilicate ~Na20:SiO2 ratio of 1:2.4) are admixed, after which the agitator speed is increased to high, and after another 20 seconds an additional 814 parts of the silicate 11';'~942 solution are admixed in. Mixing of the entire batch then continues for at least an hour (and in some cases for as many as four hours~, during which time about 500 parts of water are lost. During the mixing time the crutcher slurry is continuously mobile and does not gel or cake.
Starting about five minutes after all the components of the crutcher mix are present, the mix is dropped from the crutcher to a pump which pumps it at a pressure of about 300 p.s.i. ~about 21 kg./sq. cm.) into the top of a countercurrent spray tower wherein the initial temperature is about 800F. (430C.) and the final temperature is about 220 F. ~105C.).
The essentially inorganic base beads resulting are of a bulk density of about 0.7 g./ml., an initial adhesion of about 40%, a particle size range substant-ially between lO and 100 mesh, U.S. sieve series, and a fines characteristic ~through U.S. Sieve No. 50~ of about 15%. The moisture content of the pro-duct is about 7%. The base beads are found to be free flowing, non-tacky, porous, yet firm on the surfaces thereof, and capable of readily absorbing significant proportions of liquid nonionic detergent without becoming object-ionably tacky. Detergent products are made with them by spraying a normally waxy nonionic detergent, either Neodol 23-6.5 or Neodol 45-11, in heated liquid state, onto the tumbling bead surfaces so as to make a product contain-ing 20% or 22% of the nonionic detergent ~1 or 2% of proteolytic enzyme, e.g., Maxatase6~, and 0.2 or 0.3% of perfume may also be applied to X
11'7694Z
;
the tumbling beads). Tbe resulting dctergcnt products are excellent heavy duty laundry detergents, especially useful for washing househqld laundry in automatic washing machines.
In addi.ion to their desirable washin~ properties they are physically and aesthetically advantageous because they are non-dusting and extremely freely flowing, allowing them to be packaged in narrow necked glass and plastic bottles, and to flow readily from these.
Although normally crutcher mixes will be made quickly and may be emptied from the crutcher equally fast, sometimes being made within a period of as little as five minutes and being pumped out of the crutcher in as little as five or ten minutes, it is important that the present mixes be able to withstand at least an hour in the crutcher without gelling or solidifying because so~etimes holdups o such times are encountered in commercial production. The described crutcher mix is found to be capable of being held for as long as four hours and often longer, without gelling or solidifying.
In variations of the present experiment the tempera-ture is elevated to 125F. (52C.) and the desired crutcher mix may be made and the base beads may be spray dried there-from without untoward incident. In other variations of the experiment the proportions of the various components may be varied plus or minus 10%, plus or minus 20~ and plus or minus 30~, maintaining them within the ranges previously '694Z
given, and workable crutcher mixes that do not gel and do not solidify for periods of at least an hour'are obtainable.
When either the citric acid or magnesium sulfate is omitted from'the mix or when sucl~isadded after the silicate (usually about five minutes thereafter) objectionable gelation often results. It is also noted that the presence of the zeolite also tends to promote~gelation so the use of the combination of magneslum sulfate and citric material is esuecially important with respect to the described crutcher mix formulas.
Instead of using Epsom salts and citric acid, equivalent compounds that also result in the same type of anti-gelling action n-ay be employed. Thus, magnesium citrate, anhydrous magnesium sulfate, sodium citrate and various combinations thereof may be employed. Similarly, other zeolites, such as zeolites X and Y may be used and the zeolites may be oE various degrees of hydration. Other orders of addition of the various components of the crutcher mix may be followed but it will usually be desirab1e to have at least some of the source of magnesium ion and the source 20 of citric ion present in the aqueous medium as early in the '' manufacturing process as is feasible.
When the citric material and magnesium salt are added as described above the solids content of the crutcher mix may exceed 55~ and often may be 65 or 70~ without undesired gelation taking place within an hour of the completion of the making of the crutcher mix ~and often after four hours or - 25 - ' 11'76~Z
more). However, when either the citric material or the magnesium salt or both are omitted from the mix, premature gelation, thickening and precipita-tion occur, especially at elevated temperatures within the 20 to 70C. range and at the higher solids content. In computing the solids contents the water of hydration in the zeolite is considered as a part of the zeolite solid and not as a part of the water content of the crutcher mix. This is because such water of hydration behaves like a solid and is not released into the aqueous medium, being "insoluble" therein during crutching. For the lower solids content crutcher mixes, those of 50-60%, the citric acid content has been reduced to 0.25% in the first working example given supra, with the magnesium sulfate content remaining at 1%, and the mix resulting is still satisfactorily non-gelling. Still, use of the larger proportion is desirable for higher solids content mixes and as a safety measure.
In a comparative example the formulation and processing described for the first formulation and processing described for the first formula of Example 1 are followed except that the solids content of the crutcher mix, including the water of hydration of the zeolite, is 59.6%, the citric acid content is 0.25% and the proportions of sodium bicarbonate and sodium carbon-ate are changed. In one such experiment, designated 2A, the sodium bicarbon-ate content is maintained at 16.3% of the crutcher mix ~as is basis) and the sodium carbonate content is 7.6%. In Experiment 2B such proportions are changed to 13.1% and 10.7%, respectively and in Experiment 2C they are further modified to 10.0% and 13.8%, respectively. Thus, the ratios of sodium bicarbonate to sodium carbonate in the crutcher mixes are 2.1, 1.2 and 0.7, respectively, instead of 2.0, as in Example 1. It is noted that the crutcher mix of Experiment 2B has a higher initial viscosity than that of Experiment 2A, but it is still workable and does not gel over a four-hour holding period. However, the mix of Experiment 2C solidifies during silicate addition, showing the importance of maintaining the proportion of sodium )-~
- ~'7~i94Z
bicarbonate to sodium carbonate in the present compositions within the ranges herein described.
The following formulas are made according to the general method described in the first working experiment of Example 1, with the batch temperatures being within the range of 43 to 46C. Numerals given in the chart are parts by weight except for the percentage of solids, which is a weight percentage.
Component 3A 3B 3C 3D 3F 3G
Tap water 38.9 37.6 35.1 32.7 33.7 33.0 Citric Acid - 0.25 0.25 0.25 0.25 MgS04, anhydrous - 1.0 1.0 1.0 - 1.0 Zeolite 4A (20% hydrated) 22.9 22.9 23.8 24.8 24.8 24.8 Sodium bicarbonate 15.6 15.6 16.3 16.9 16.9 16.9 Soda Ash 7.9 7.9 8.2 8.5 8.5 8.5 Sodium silicate ~47.5%14.7 14.7 15.4 15.9 15.9 15.9 solids; Na2O:SiO2 = 1:2.4) % Solids (including zeolite53.4 54.7 56.8 59.0 58.0 58.7 water of hydration) The mix of Experiment 3A solidifies in the crutcher during silicate addition. The mixes of Experiments 3B, 3C and 3D are satisfactory and form no gel during silicate additions. Initial vicosities of such mixes are about the same despite the increase in solids content from 3B to 3D but such viscos-ities for the mix of Experiment 3D are measurably greater than those for the mixes of Experiment 3B and 3C. With the magnesium sulfate being omitted from the formula, the mix of Experiment 3F solidifies during silicate addition.
The Experiment 3G crutcher mix does not solidify during silicate addition but does solidify thirty minutes thereafter. Thus, the products of experiments 3A, 3F and 3G are unsatisfactory.
..,.: ~
Claims (16)
1. A method of retarding or preventing gelation of a miscible and pumpable crutcher slurry containing from about 40 to 70% of solids and 60 to 30% of water, of which solids content, on a 100% solids basis, about 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio of sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sodium carbonate : sodium silicate being within the range of about 1:2.5 to 5:1, the ratio of sodium bicarbonate :
sodium silicate being within the range of about 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, which comprises preparing a crutcher slurry of the described composition containing, on a slurry basis, from 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, and mixing such composition in a crutcher during preparation thereof.
sodium silicate being within the range of about 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, which comprises preparing a crutcher slurry of the described composition containing, on a slurry basis, from 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, and mixing such composition in a crutcher during preparation thereof.
2. A method according to claim 1 wherein the crutcher slurry contains from 50 to 65% of solids and 50 to 35% of water, of which solids content 25 to 40% is sodium bicarbonate, 13 to 25% is sodium carbonate, 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.6 to 1:2.6 and 35 to 65% is hydrated, water softening zeolite, the ratio of sodium bicarbonate : sodium carbonate is within the range of 1.5:1 to 3:1, the ratio of sodium carbonate :
sodium silicate is within the range of 1:2 to 2:1, the ratio of sodium bicarbonate : sodium silicate is within the range of 2:1 to 5:1 and the ratio of hydrated, water softening zeolite : sodium silicate is within the range of 2:1 to 7:1, and wherein the percentages of gelation preventing citric material and magnesium sulfate are in the ranges of 0.1 to 0.8 and 0.1 to 1.2, respectively.
sodium silicate is within the range of 1:2 to 2:1, the ratio of sodium bicarbonate : sodium silicate is within the range of 2:1 to 5:1 and the ratio of hydrated, water softening zeolite : sodium silicate is within the range of 2:1 to 7:1, and wherein the percentages of gelation preventing citric material and magnesium sulfate are in the ranges of 0.1 to 0.8 and 0.1 to 1.2, respectively.
3. A method according to claim 2 wherein the crutcher slurry is of a temperature in the range of 20 to 70°C., at atmospheric pressure, and the citric material and magnesium sulfate are incorporated in the slurry before addition thereto of at least some of the sodium silicate.
4. A method according to claim 3 wherein the crutcher slurry contains from 55 to 65% of solids and 45 to 35% of water, of which solids content 25 to 35% is sodium bicarbonate, 13 to 20% is sodium carbonate, 8 to 15% is sodium silicate of Na2O:SiO2 ratio of 1:2 to 1:2.4, and 35 to 50% is hydrated, water softening zeolite, the ratio of sodium bicarbonate : sodium carbonate is within the range of 1.5:1 to 2.5:1, the ratio of sodium carbon-ate : sodium silicate is within the range of 1:1 to 2:1, the ratio of sodium bicarbonate : sodium silicate is within the range of 2:1 to 4:1 and the ratio of hydrated, water softening zeolite : sodium silicate is within the range of 3:1 to 5:1, and wherein the percentages of gelation preventing citric material and magnesium sulfate are in the ranges of 0.2 to 0.6 and 0.4 to 1.1, respectively.
5. A method according to claim 1 wherein mixing is at a temperature in the range of 20 to 70°C., the citric material and magnesium sulfate are incorporated in the slurry before the sodium silicate, and mixing is con-tinued for at least one hour after completion of the making of the crutcher slurry.
6. A method according to claim 4 wherein the crutcher slurry tempera-ture is from 25 to 40°C., mixing is effected for at least two hours after completion of the making of the crutcher slurry, and at least a part of the crutcher mix is pumped out of the crutcher to a spray drying tower and is spray dried therein after said mixing.
7. A method according to claim 1 wherein citric acid is the gelation preventing citric material in the crutcher slurry.
8. A method according to claim 1 wherein the magnesium sulfate is added to the slurry as epsom salts.
9. A method according to claim 6 wherein citric acid is the gelation preventing citric material in the crutcher slurry.
10. A method according to claim 6 wherein the magnesium sulfate is added to the slurry as epsom salts.
11. A method according to claim 1 wherein from 0.1 to 10% of the crutcher slurry is of adjuvant(s) and/or diluent(s).
12. A miscible and pumpable crutcher slurry comprising from 40 to 70% of solids and 60 to 30% of water, of which solids content, on a 100% solids basis, about 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio of sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sodium carbonate : sodium silicate being within the range of about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of about 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, and which solids content includes, on a slurry basis, a gelation re-tarding proportion of a combination of 0.1 to 2% of a citric material selected from the group consisting of citric acid, water soluble citrates and mixtures thereof, and from 0.1 to 1.4% of magnesium sulfate, with the total of such citric material and magnesium sulfate being at least 0.4% of the slurry.
13. A method of making a particulate base material in bead form, suit-able for absorbing nonionic detergent to make a built heavy duty synthetic organic detergent composition, which comprises making a miscible and pump-able slurry in a crutcher by the method of claim 1, pumping the slurry out of the crutcher in ungelled and readily pumpable state and spray drying the slurry to particulate bead form.
14. A product of the process of claim 13.
15. A method of retarding or preventing the gelation of a miscible and pumpable crutcher or slurry containing from about 40 to 70% of solids and 60 to 30% of water, of which solids content, on a 100% solids basis, about 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na2:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio of sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sodium carbonate : sodium silicate being within the range of about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of about 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, which comprises preparing a crutcher slurry of the des-cribed composition in which there is admixed from 0.3 to 3% of magnesium citrate or magnesium acid citrate, on a slurry basis, and mixing such composi-tion in a crutcher during preparation thereof.
16. A miscible and pumpable crutcher slurry comprising from 40 to 70%
of solids and 60 to 30% of water, of which solids content, on a 100% solids basis, about 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio of sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sodium carbonate : sodium silicate being within the range of about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, and which solids content in-cludes, on a slurry basis, a gelation retarding proportion of magnesium citrate, from 0.3 to 3% of the slurry.
of solids and 60 to 30% of water, of which solids content, on a 100% solids basis, about 20 to 45% is sodium bicarbonate, about 10 to 30% is sodium carbonate, about 5 to 25% is sodium silicate of Na2O:SiO2 ratio within the range of 1:1.4 to 1:3, and about 10 to 65% is zeolite, with the ratio of sodium bicarbonate : sodium carbonate being within the range of about 1:1 to 4:1, the ratio of sodium carbonate : sodium silicate being within the range of about 1:2.5 to 5:1, the ratio of sodium bicarbonate : sodium silicate being within the range of 1:1 to 8:1 and the ratio of zeolite : silicate being within the range of about 1:2 to 10:1, and which solids content in-cludes, on a slurry basis, a gelation retarding proportion of magnesium citrate, from 0.3 to 3% of the slurry.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000386562A CA1176942A (en) | 1981-09-24 | 1981-09-24 | Method for retarding gelation of bicarbonate - carbonate - zeolite - silicate crutcher slurries |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000386562A CA1176942A (en) | 1981-09-24 | 1981-09-24 | Method for retarding gelation of bicarbonate - carbonate - zeolite - silicate crutcher slurries |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1176942A true CA1176942A (en) | 1984-10-30 |
Family
ID=4121017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000386562A Expired CA1176942A (en) | 1981-09-24 | 1981-09-24 | Method for retarding gelation of bicarbonate - carbonate - zeolite - silicate crutcher slurries |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1176942A (en) |
-
1981
- 1981-09-24 CA CA000386562A patent/CA1176942A/en not_active Expired
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