US2477492A - Agglomerated water treating composition and method of producing same - Google Patents

Description

Patented July 26, 1949 ems-s "s rerss is arises HOD F 21 DDUC N "-i- 'santo Ghemic'al Company;- ai olorporation of i Delaware .i hlojbraa ing Application: e

islerial No. 512,1? i 14 Cigili'lfi. (013252 175) This invention; relates to a glomerated metaor polyph-osphates containing sodium carbonate and/or a wetting agent and to a process for making same.

An object of the invention-"is to provide a process for making an agglomerate of the above type in the form of a cube orother suitable configuration containing a predetermined number of Water softening units and having increased solution rate.

Another object of-theinvention is to provide a process for producing an agglomerated water treating compositionincluding a wetting agent, sodium hexametaph-osphate or a sodium poh phosphate and a sufiieientv amountof hydrated sodium; carbonate to furnish a :'-st1"'ong but readily soluble product which: will. furnish a hydrogen ion concentration in water'within the preferred range for efiicient detergency.

Another .objectis to making agglomerated .metaor 4 'polyphosp'hates containing a wetting agent; wherein an accurate control is maintained over the amount of water added toform the a-gglomerates;

A further object; is: to provide a process for making-agglomerated metaor polyphosphates containing a wetting agent and sodium carbonate wherein the rate at which the water is released during the. agglomerating operation is temperature controlled ation. Y

A still further object is to provide a process for making agglomerates or the above type wherein the distribution of water throughout the agglomerated mass is uniform.

An additional object is to provide aproc-ess "for making agglomerated rrieta or polyphos-phates containing-sodium: carbonate and a wetting agent,

ates containing only very-small quantities of fines and oversize.

Other objects will be-apparent-to those skilled in the art as thedescri'ption proceeds.

One'of the difficulties attendingthe solution in water of the alkali metal-meta or polyphosphates is the tendency 'ofsuch phosphates when added to water to-becomestickyand-guinmyand form a very viscous solution-immediately incontact with the surface ofsaid phosphates with the result that difiusionthrough the film is very La;

slow and the solution process is time consuming. It has already been- -propos ed to increase the solution ---rate or meta-phosphates by pressing them into thin fi-akes and coatine the flakeswith alkali metal salts. "'This treatment imp-roves the provide a process for togive more uniforinagglomerso1ution' 1rate;offthemetaphosphates over that of the originalmaterial but inmost instances the f rate is; still' so' slow' as toloe oblectionable for s d dn; tdtliefslo'wi solution rate, the flaked metaphosphates have -t-he objectionable property -of having a'tendency t tin t or cut the hands. Such a p oductialsc-n s h disadvantage that inuseit i 'difficulttoigauge the amount of mate which processt-yieldsuniformly sized agg1orneration, ohtai :size; chemical composition-and water content. productgialso ha's' a "relatively-high solution idamestiwi se; sin e thc'gcops rial necessary to soften'a given quantity of hard water with-the result that the consumer must resort to the wasteful practice of adding more than is necessary in order to be certain of obtaining the-desired result.

- Gne'qof the diiiiculties iin ag glomerat ing meta or polyphesphates is the; fact that such phos phates-,-"-=vvhenin con-tact' with water or I water vapor-tend to- -acquire"a{sticky orgum my consistencyfwhich adds to--"thedifficulties of me" -chan-ica1ly-=controlling nd'handling such moist products-"- Aiter -these phosphates become sticky and gummy there is-fgreat difiiculty in uniformly distributing-the?moisture throughout the agglomerates-and' also in uni-for nly proportioning i xtures containing such sticky phosloose salt phates- W ith -the result 'that g'r'anules tend; during manufacture-,; to become non-uniformp in compo- "SifiiOll. V

=I-have-"now-ouhd that if the moisture required for the agglomeration of; these phosphates or mixtures containing same-is incorporated in the .form,ofanefiiores'ce nt -=hydrated salt such as hydrated sold-111m ;carlcoifrate and if a Wetting agent is? ployedin the{-age10rnerati11e opern a-product'i which is uniform as to rate as-comparedwiththe products of the prior art and it non'e'o-fkthe-objectionable prop- -erties ofrsfiaked imetaphosphatesorthe other -for-rns .oit-metapl'rosphates' and polyphosphates.

Itis;; .elf;dissplving;a that is, :it requires no aeita- --t ion t dissolvje it. in Water :andwhen. made into various; shapes; as cubes, .it-ablets, etc. constam na a redetenn ned umber-of- Water softeninefunits, t

onvenientiorm for v umer-does not have wa er ss-at t unt'qf ,7 3d 1 home in bath tubs, laundry tubs, dish pans, wash pans and the like.

By water softening units I mean calcium and/ or magnesium repression values, which values will be controlled not only by the size of the cubes, tablets, etc, but also by the relative proportions of the phosphate and sodium carbonate contained therein.

I have discovered, for example, when producing agglomerates of sodium metaphosphate and sodium carbonate, that I may employ the sodium carbonate in whole or in part as a hydrate lower in water content than the-fully hydrated salt. For example, I have found thata mixture of hydrates of sodium carbonate containing say from 30% to 40% of Water of hydration may be intimately mixed with the ground hygroscopic metaphosphate and that then the rate of transfer of water from the hydrated salt to the metaphosphate is slow enough to permit intimate thorough mixing of the constituents before the development of a sticky condition takes place. The rate and the amount of water released from the hydrated salt employed for agglomeration can be controlled by varying the degreeof hydration of the hydrated salt and also by the temperature at which agglomeration is carried out and, therefore, the process may be adapted to straight line continuous agglomeration. Accordingly at no time is there sufiicient water vapor present in contact with the phosphate that serious reversion may take place.

In contrast to this method, the older methods usually provide for a spray of liquid water or exposure of the agglomerating constituents to humidified air under which conditions the more hygroscopic materials in the mixture have the tendency to acquire an excess of or more than their share of water. Since the hygroscopic constituent is the metaphosphate (or polyphosphate) there was danger that the moist metaphosphate containing an excess of water would, in part at least, revert to the orthophosphate. There was also, as a result of the older process, the tendency of certain parts of the agglomerating mixture to become too moist and consequently produce over-size material, while other parts of the mixture did not receive enough water to give satisfactory agglomeration and the development of suflicient strength to prevent shattering of the granule during handling.

The metaphosphates treated in accordance with are compositions which contain varying ratios of NazO and P205. They are ordinarily prepared by heating together either. the corresponding orthophosphates or by heating together orthophosphoric acid and a sodium salt such as soda ash, NazCOs. Such products are commonly termed molecularly dehydrated phosphates. The temperature to which the starting materials are heated is carried up to the sintering or reaction temperature and usually to the temperature at which complete fusion is obtained. When complete fusion is obtained, the melt is congealed by quickly cooling the molten mass. The character of the resulting solid depends somewhat upon the ratio of New to P205 employed in the starting products. Where the mol ratio of NazO to P205 is 1:2, (17.9% NazO and 82.1% P205 by weight) or even as high as 3:2, the product obtained is generally aclear, glassy, brittle, non-crystalline solid. When the product is as high in alkali as the 5:3 ratio, a crystalline phase manifests itand polyphosphates the present invention 4 self by the development of translucency in the glassy matrix.

When preparing Grahams salt, ordinarily designated as sodium hexametaphosphate, (NaPo c, or compositions containing the same, it is desir able to heat the ingredients entering into the reaction to the fusion temperature and then quickly cool the melt in order to obtain the metaphosphate not only in the water soluble form but.

also in a form in which it will most efficiently act as a water softening agent.

The metaphosphate containing compos1tion treated in accordance with this invention may have either a higher or a lower NazO content than that corresponding to NaPOa. Lower ratios may include the NazO to P205 ratio of 1 :2 (where the composition comprises sodium metaphosphate together with metaphosphoric acid, HPOs). These lower ratios are also glass-like, brittle solids and are somewhat more hygroscopic than the higher ratios. Other ratios include sodium metaphosphate itself (NaPOs) or (NaPO3)s,-i. e., where the ratios are 1:1 and range upwardly including the following additional specific compositions:

Mixtures of the above compounds may likewise be treated.

When the compositions are obtained as solid, glassy compositions, the brittle glass is readily ground to a fine powder, preferably of such a size as to pass through an '80 mesh screen. The powdered glass is then treated by the herein described process.

Broadly stated; my process comprises mixing together an efiiorescent salt hydrate, a wetting agent and a finely divided powder comprising a molecularly dehydrated alkali metal phosphate having an alkali metal oxide/P205 ratio substantially in the range of from 1:2 to 5:3 and agitating the mixture to form agglomer" ates.

More particularly, my process involves mixing together an alkylated aromatic sulfonate or sul fate, hydrated sodium carbonate and a finely divided molecularly dehydrated sodium phos' phate having a NazO/PzOs ratio of from 1:1 to 5:3 and agitating the mixtureto form agglomerates.

Still more particularly, my process involves mixing together hydrated sodium carbonate having between 30% and 40% water of crystalliza-. tion, sodium lauryl sulfate and a finely divided molecularly dehydrated sodium phosphate having a Nae P205 ratio from 1:2 to 1:1, agitating the mixture to form agglomerates, forming a layer of the agglomerates upon a suitable surface, sintering the layer of agglomerates to form a unitary sheet, subdividing the sheet by any suitable means into a plurality of detachable sections containing a predetermined number of Water s0ften ing units and drying the product.

My invention is illustrated but not limited by the following examples:

sodium hexametaphosphate (the preferred embodiment) I proceed in the following manner:

One part by weight of a wetting agent such as out.

tine remains dry 'for from- I satisfactorychain is dissolved in" parts of'watr. This solution is added to 9 parts of dry soda ash and stirred until the mix begins togranulate and dry This operation yields about 14 parts by weight of a hydrated soda ash containing about 1' bereft ""t'or-the above with where bywe eh i rg eshfsio m l di'um .i i' x eta hq heie. 'Tih ii i i i Im X- 1 "to "5 minutesatter mixing e i e t mre ti r is between C "The 'intimatemixture of "the phosphate,

wetting agent and 'carbonate isnow passed hrough. a rota in dmm ii .ir iie 1.3". 0' 5 minutes after mixing agglomeration will start due to the release of water from the hydrated "salt. The degree of agglomerationflcanbe' controlled by the length of time the'saltniixture is tumbled in the rotating drum, a longer time'of tumbling producing a larger agglomerate. If low bulk density,

softer agglomerates are desired, theagglomerating action is continued untilthe desired size range (usually -10-F80'm"e'sh)' is'obtained. If a hard dense product"isdesiredjthe salt mixture after mixing is allowed to *stand without agitation for from 5 to 10, minutes. The hydration of q the phosphate takes place in the quiescent mass. The somewhat sticky mass is then mechanically shredded and; passed. into a rotary agglomerator or revolving drum and .theparticles rounded by the tumbling action Within the drum.

,gThe agglomeratesmade by 'eithermethod are then removed from the agglomerator and dried by exposure to warm air. The products thus formed are very free-flowing; and-when dissolved in water to form a 1% solution, they given a pH of about 8.2 which is within the range (8.0-9.0) desired for domestic detergent purposes.

;The products produced b-ythe above process have substantiallythe following chemical com- Sodium salt of an alkylated aromatic sulionic acid containing 8 to -16 at'oms inthe alkyl While the above agglomerates constitute a very product, 'it' is-desirablefrom the standpoint of domestic use'to' prepare them in a form containing a predetermined number of water softening units. This may be 'ziccom plished bymolding or tableting the moist agglomerates discharged from the agglomerator and d i erm i- Another method of: accomplishing the same result consists in discharging the moist agglomerates onto a suitable snrfacein theiorm of a layer of substantially uniform-thickness, heating the layer to form a unitarysheen-subdividing the sheet into detachable section'slbyfforming groves into the surface tpijthfihethhd then "drying said sheet. As a modificationo'f this-procedure,

the sheet may be" cutinto cubes ortablets-and Considerablecare should be used in these operations to avoid either compressing-the agglomerates too strongly or forming a layer that is 'too 'lauryl sulfate is'p'repared "phate in a pug mill orrotating drum.

becomes tacky in one dried, reversion 'will take I place with-the result that its water softening capacity willb substantially reduced.

The agglomerate layer may "vary in thickness,

= 'water. This product is thoroughly mixed with 91 mesh ground sodiuin'hexanietaphos- 'Ihemix to three minutes and after continued stirring "or agitation, agglomeration of the hexametaphosphate takes place. The wet parts of 'agglomerates are removed and forcedthrough a 12 mesh screen. The" screened agglomerated are then dried in /4" deep-layers-forfio -40 min- "utes with circulating-air at"80- C to 90 0. -Ihe dried agglomerates are rescreened and a yield of 90-95%- of '-12+80m'e'sh' agglomerates'ds" thus obtained. I

Prior to drying, the-agglomerates' obtained-by the above process have the following -composition:

-'Percent Sodium hexameta'phos'phatm"has; ""8150 Sodium carbonate, hydrated r 12.02 Sodium lauryl sulfate u 0.48

After drying, the agglomerates' have-"the follow ing composition:

-Peicent Sodium hexametaphosphate a-91.0

- Sodium carbonate g 8.5 Sodium lauryl 'sulfate a es, I 10.5

If desired, the moist agglomeratesmay'betreat ed as in Example Ito rorm' cubes; tablets; etc, containing a predetermined-number of water-softening units.

Example 15 parts of hydratedsodium carbonate,

Na2COs.4U% H2O containing 2 parts by-weight, of dodecyl-benzene sodium sulfonate is prepared by dissolving 2 parts of said sulfonate in 6 parts-of Water, adding 'the solution thus formed to 9 parts by weight-ofdry soda ash and stirring iuntiL-the mix-beginsto granulate and dry out. The resulting product is intimately mixed with 89 parts'by weight-oi '80 mesh ground sodium hexametaphosphate in a pug mill, rotating drum orother suitable mixing or agitating device and is then treated as-in-EX- ample 2 above.

"Example 4 Approximately 0.6 part by Weight ofasodium alkyl benzene sul'fonate cori'sisting of a mixture of sulfonated compoundsderivedirom the alkylation of benzene by a' keroseneboilirig withiri the range "bf- 00-230 C. is dissolveu in EB'R 'parts 0f water and the resulting solution is stirred with 'duce a dry free flowin product having thefollowing composition:

Percent Phosphate composition 90.71 .Sodium carbonate 9.18 Sodium yl benzene sulfonate 0.10

' Example 1.2 parts by weight of sodium oleyl sulfate is dissolved in 29.0 parts of- Water and to this solu tion 54.00 parts of anhydrous sodium carbonate is added with stirring. The stirrin is continued until the carbonate begin to granulate and dry out and the product consisting of 83 parts of hydrated sodium carbonate (Na2CO3.S5% H) and 1.2 parts by Weight of the above wetting agent is intimately mixed with 5% parts of a 80 mesh phosphate powder having the same composition as that described in Example l. The mixture is then treated as in Example 1 to form a dry product having the following composition:

Per cent Phosphate composition 90.82 Sodium carbonate 8.97 Sodium oleyl sulfate 0.20

bon dioxide liberated circulates and floats them within the body of the liquid until they reach the top where the gas is released and then the cycle is repeated until solution takes place.

This behavior on the part of the agglomerates :is attributed to the presence therein of a small amount of a wetting agent which causes the carbon dioxide to be released slowly and uniformly. The slowly liberated CO2 floats the agglomerates and sets up convection currents which circulate them within the body of the liquid. This has the desirable effect of continuously exposing the agglomerates to the dissolving action of substantially pure water or water containing only relatively small concentrations of dissolved phosphates. As a result of this action, the agglomcrates dissolve very rapidly and completely and they do not form a viscous solution immediately adjacent their surfaces and thereby retard the solution rate of the undissolved material as is the case of prior art materials which do not contain a wetting agent.

The rate and amount of carbon dioxide developed by the agglomerates may be controlled to bonate with respect to each other.

.The chemical composition of the agglomerated product may vary considerably, but it is not desirable to use larger or smaller quantities than that indicated in the following formulation:

Per cent by weight Phosphate composition 86-91 Sodium carbonate 7-12 Wetting agent 0.1-2

If larger or smaller quantities than that indie cated above are employed, there is obtained either a product which furnishes a hydrogen ion concentration in water outside the preferred range for efiicient detergency or a product having a decreased water softening capacity due to the dilution effect.

By phosphate composition, I include alkali meta1 hexametaphosphates, alkali metal polyphosphates or any of the molecularly dehydrated alkali metal phosphates or phosphate mixtures described herein.

I obtain the most satisfactory results from the standpoint of detergent and water softening action by employing an agglomerated product having the following composition:

Per cent Sodium hexametaphosphate 89 Sodium carbonate i l Wetting agent 1 It will be noted that in describing my process I have pointed out that the wetting agent is dissolved in water, that the solution thus formed is added to anhydrous sodium carbonate and tha the hydrated salt thereby obtained is mixed with the meta or polyphosphate. This is the preferred method of carrying out my process as a more eifective distribution of the wetting agent is thus obtained with the result that the wetting agent'exercises a more effective control over the development of CO2 by the product. However, it should be understood that the wetting agent may be added to'the meta or polyphosphate and then mixed with the hydrated salt; it may be added to the hydrated salt and then combined with the metaor polyphosphates or it may be simultaneously mixed with the other two constituents. In fact, it may even be applied as a coating to the agglomerated product, but this method is objectionable because it requires large amounts of wetting agents (about 5% by weight) which dilute and thereby decrease the water softening capacity oi the product to an undesirable degree. 7

Water soluble alkali metal alkyl sulfates, alkylated aromatic sulfonates and alkali metal salts of the higher fatty acids generally aresuitable wetting agentsv The sodium salts of sulfonated or sulfated alcohols containing 12 or more carbon atoms give very satisfactory results, but I prefer to use the water soluble salts of alkylated aromatic hydrocarbon sulfonic acids, particularly the alkali metal salts of alkylated benzene sulfonic acids in which at least one alkyl group contains from 11 to 15 carbon atoms and mixtures thereof. Such salts of alkylated aromatic hydrocarbon sulfonic acids are described in Patent No. 2,161,174

7 to Kyrides. Alkali metal salts of sulfonic acids of of the preferred types of compounds and it should,

9 be understood that any suitable wetting agent may be employedm myprocess.

As indicated above, the wetting agent is preferably employed amounts ranging 0.1%

to 2% by Weight pimp-agglomerated produchbut -it is within the scope of any invention to employ larger or smailler amounts i-f desired.

While the use of the mixed hydrates of sodium carbonate containing about35% 'l-lzO is-preierrecl, other hydrates'either alone or mixed so as to an" proximatea water-contentofiromi'oo to 40% may be employed. For example, mixtures of the 1monohydrate and the deca'h-ydrate approximat- 'ing a water-contentof from 35% to 40% or =mix-- tures -of the -=arihydrous salt and the decahydrate mayalso be-used.

In general, in the agglomeration :of =metaand polyphosphates i-liaving a particle size of l ess than 80 mesh, the hydratedENazCQrshouldbe adjusted in amount and water =.conten'-t {so "as to furnish from to 6% by weight-ofwater the mixture to be agglomerated.

For the purpose of modifying somewhat the 'properties -of the agglomera'te "for treatin various waters, it is possible to incorporate other salts, or hydrates thereof, together with-the sodium carbonate hydrate. Should it; -'for example, be 'desired to supply :sulfate, 'orthophcsphate or =pyrophosphate-ion to'the treated water, it is possi ble to incorporate into the agglomerate, sodium sulfate, sodium orthophosphate or sodium pyroiphosphate as a "constituent thereof. "when hydrates of *these salts-fare employed-they one be employed in lieu of the hydrates of sodium can bonateorin combination with anhydrous-sodium carbonate.

"I'he-mechamsmby whichmyeagle-moraines are form-ed pomprisesfirstaloss-diwaterzof hydration or the hydrated salt, which water is then ab sorbed by the adjacent ?molecularly dehydrated phosphate:particleswith'the*formation,of :a sticky film-on such particles. "The agglomcrate isthen f-ormed -by the mechanical action of mixing or selling the particles of salts .over each otherin the-drum. Tl-hus itwvill befinoted that the moisture transference takes place 'at a uniform rate "and -to auniform degree "throughout the mass of particles.

The agglomeratedprodu'ctpreparedin accord-- ancewiththepresent invention comprises distinct highly porous granules composed of irregularly shaped powder particles of phosphate salts loose- :ly adhering to each other. -"These granules have intimately and uniformly interspersed therein a wetting agcntaandfazsodiumsaltselected from the phosphate and each granule is characterized-by -having:asubstantiallyhigherrateof solution than a physical mixture of its components.

application ,-is a continuation-impart or my copendingla-pplication,:Seria1 No. 497,141, filed March 13, 1943 now Patent No. 2,414,969 issued on January 28, 1947.

While Ihavespecificallydescribed the preferred posed of irregular powder particles :of said phosphate loosely adhering to each --other to .iorm said agglomerate and having intimat yand uniiormly interspersed therein from about 7% to about 12% by weight of sodium carbonate and from about 0.1% to;ab.outi2-% by'weight of a wator-soluble wetting .agentsclected-irom the group consisting of alkylated aromatic sul'fon-ates, alkyl sulfonates and a1ky1.su1fates,;said agglomerates being characterized by having a substantially higher rate of solution *thanrazmixtureiconsisting of said sodium phosphate and :said sodium carbonate, in bothrtheagglomerated and lunagglo-morated form.

-2. The-produotdefinedin claim .1 wherein :the water-soluble molecularly dehydrated sodium phosphate has :a .NazOfiPaQs imoleoular ratio of about 1:1.

3. A-watertreatingproductin th form ofdistinct highly porous zagglomerates-of sodium hexametaphosphate, eachagglomerate being composed of irregularpowder particles of said phosphate loosely adhering :to each :other 'to "form said .agglomerate and having intimately and uniformly interspersed thereinirom'il 170112 by weight of sodium carbonateand from-0.1% to 2% by weight of a sodium salt ,of an alkylated aromatic sulfonic acid having 81110 .16 .carbonratoms in :the alkyl chain, said agglomerates ibeing characterized by having a substantiallyrh-igher:rate of solution than a mixture consistin of said sodium "hexametaphosphate and said sodiumcarbonate, inboththe agglomerated and ;una'gglomerated form.

1. The product definediinclaim 3W1'1B-1'6ln dodecyl benzenel-sodiumrsulfonate is the sodium salt 'of an alkylated aromaiticsulfonio acidemployed.

5. A wateritreating produ'ct intheiorm of distinct highly porous :agglomerates consisting essentially of 90.82% by weight of sodium hexa- ;metaphosphate,r8.97% by weight of sodium carbonate and 0.2% by weight ofsodium oleyl sulfate, each agglomerate being composed of irregular powder particles =of said phosphate loosely adhering to each other "to- 'fo-rm-sai'd agglomerate and having-said carbonate and sulfate intimately and uniformly interspersed therein, said agglomera-te being characterized by having a substantially higher solution rate than:a=mixture consistingof said sodium hexametaphosphate and saidsodium carbonate, in'both the agglomerated and unasglomerated form.

6. A Water treating product-in-the form of distinct highly porous 'agglomerates containing 91% by Weight of sodium hexametaphosphate, 8.5 by Weight of sodium-'carbonateand 0.5% hyweight ,ofsodium laulfyl Sulfate, each agg1omerat e being composed of irregular powder particles .of said phosphate loosely -;adhering -to each other to .form said agglomerate and having-said carbonate and said sulfate intimateiyand'unifornily interspersed therein,said-agglomerate'being characterized by having a, substantiallyhigherrate ofsolution than a mixture consisting of said sodium 1hexameta- "phosphate and'so'diumoarbonatain both the agembodiments of -my inveritionfiitjs to'heunderf stood-that-the invention-isnotso' limited, but "may be otherwise embodied and practiced within the scope of the following claims.

What I claim is:

1. A water treating product in the form of distinct highly porous aggiomerates consisting essentially of a water-soluble molecularly dehydrated sodium phosphate having a Nam/P205 molecular ratio of from 1:2 to 5:3, each agglomerate being ,g'lomerated and unagglomerated form.

- 7. AsanarticleofQmanuiacturo, a ,self-dissolv ing water treat n lproduct'in the jforrn oiucubes,

tablets, and the like composed of highly porous agglomerates consisting essentially of a water soluole molecularly dehydrated sodium phosphate having a Nam P205 molecular ratio of from 1 :Z-to 5:3, said product having intimately and uniformly interspersed therein from 7 to 12 by weight of sodium carbonate and from about 0.1% to about 2% by weight of a wetting agent selected from the group consisting of alkylated aromatic sulfonates, alkyl sulfonates and alkyl sulfates, and said prodnot, when added to water, being characterized by the property of having a substantially higher solution rate than a mixture consisting of said sodium phosphate and said sodium carbonate, in both the agglomerated and unagglomerated form, and also by the property of slowly and uniformly liberating carbon dioxide, whereby convection currents are set up in the water which circulate and fioat said product until it is substantially completely dissolved therein.

8. As an article of manufacture, a self-dissolving water treating product in the form of cubes, tablets, and the like composed of highly porous agglomerates consisting essentially'ofa water soluble molecularly dehydrated sodium "phosphate having a Nam P205 molecular ratio of about 1:1, said product having intimately and uniformly interspersed therein from 7% to 12% by weight of sodium carbonate and from about0.l% to about 2% by weight of a wetting agent selected from the group consisting of alkylated aromatic sul fonates, alkyl sulfonates and alkyl sulfates, and said product, when added to water, being characterized by the propertyof having a substantially higher solution rate than a mixture consisting of said sodium phosphate and said sodium carbonate, in both the agglomerated and unagglomerated form, and also by the property of slowly and uniformly liberating carbon dioxide, whereby convection currents are set up in the water which circulate and floatsaid product until it is substantially completely dissolved.

9. The method of producing an agglomerated water treating product, which comprises preparing a substantially dry and homogeneous mixture consisting essentially of a water-soluble znolecularly dehydrated sodium phosphate having a particle size of less than 80 mesh'and a NazO/P2Os molecular ratio of from 1:2 to 5:3 together with from 0.1% to 2% by weight of'a water-soluble wetting agent selected from the group consisting of alkylated aromatic sulfonates, alkyl sulfomates, and alkyl sulfates and also a suflicient amount of hydrated sodium-carbonate having from about 30% to about 40% water of hydration to supply a water content of from 3% to 6% by weight of the substantially. dry mixture, thereupon subjecting said substantially dry mixture to an ag lomerating treatment which consists in agitating said mixture to liberate water of hydration from said hydrated salt whereby agglomerates are formed and thereafter drying said agglomerates to produce a product characterized by having a substantially higher solution rate than a mixture consisting of said sodium phosphate and said sodium carbonate, in both the agglomerated and unagglomerated form.

10. The method of producing an agglomerated water treating product, which comprises preparing a substantially dry and homogeneous mixture consisting essentially of a water-soluble molecularly dehydrated sodium phosphate having a particle size of less than 80 mesh and a Nero P205 molecular ratio of from 1:2 to 5:3 together with from 0.1% to 2% by weight of a water-soluble Wetting agent selected from the group consisting of alkylated aromatic sulfonates, alkyl sulfonates and alkyl sulfates and also a sulficient amount of hydrated sodium carbonate. having from 30% to 40% water of the hydration to supply a water content of from 3% to 6% by welght of the substantially dry mixture, subjecting said substantially dry mixture to an agglomerating treatment which consists in agitating said mixture to liberate water of hydration from said hydrated salt whereby agglomerates are produced, forming a layer of agglomerates, heating said layer to form a unitary sheet, subdividing said sheet into detachable sections and thereupon.

drying said subdivided sheet to yield a product characterized by having a substantially higher solution rate than a mixture consisting of said sodium phosphate and said sodiumcarbonate, in both the agglomerated and unagglomerated form.

11. The method defined in claim 10 in which the water soluble molecularly dehydrated sodium phosphate has a NazO/PzOs molecular ratio of about 1:1. i

12. The method defined in claim 10 in which the water soluble molecularly dehydrated sodium phosphate has a NazO/Pzos molecular ratio of about 6:5.

13. The method defined in claim 10 in which the water soluble molecularly dehydrated sodium phosphate has a NazO/PzOs molecular ratio of about 5 :3.

14. The method of producng an agglomerated water treating product, which comprises mixing together 9 parts by weight of dry soda ash and an aqueous solution of 2 parts of dodecylbenzene sodium sulfonate in 6 parts of water until the mixture begins to granulate and dry out, inti mately mixing 89 parts by weight of 80 mesh sodium hexametaphosphate with the resulting product to form agglomerates therewith, passing the agglomerates through a 12 mesh screen, drying the screened agglomerates in a 4 inch layer for 30 to 45 minutes with circulating air at 80 to 90 C. and then rescreening the dried material to yield from 90% to of 12 +80 mesh agglomerates which are characterized by having a substantially higher solution rate than a mixture consisting of said sodium hexametaphosphate and said sodium carbonate, in both the agglomerated and unagglomerated form.

JOE E. MOOSE.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Certificate of Correction Patent No. 2,477,492 July 26, 1949 JOE E. MOOSE It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 6, line 23, for 30 to 40 read 80 to 45 column 10, line 53, for the Word containing read consisting essentially of;

and that the said Letters Patent should be reed with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day of December, A. D. 1949.

Certificate of Correction Patent No. 2,477,492 July 26, 1949 JOE E. MOOSE It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 6, line 23, for 30 to 40 read 30 to 45 column 10, line 53, for the Word containing read consisting essentially of;

and that the SflJd Letters Patent should be reed With these corrections therein that the same may conform to the record of the case no the Patent Ofilce. Signed and sealed this 27th day of December, A. D. 1949.

THOMAS F. MURPHY,

Assistant Uommissz'oner of Patents.