BE676913A - - Google Patents

Description

       

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  "REFRACTORY COATING COMPOTTIONS.



   The present intention relates to new and improved compositions of refractory coatings, as well as to a method of propagating such compositions. The invention more particularly relates to compositions suitable for application to ingot source casting plates.



   Recently, research has been undertaken to find a way to provide and apply a slurry or dispersion of a refractory material based on finely divided silica powder in colloidal silica. in order to improve the useful life of the source casting plates of the ingot molds, The slurry or dispersion is applied to the source casting plate, the mold is placed on the latter and the

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 hot metal is poured into the mold,

       When the simple combination of the aqueous celiac sillica and the silica powder is applied to the coarse spray * casting plates *, on the source casting plate a hard coating is obtained. , compact and adherent reducing erosion of the source-cast plate by hot metal, which extends the life of this plate. the siliceous coating also prevents the ingot from sticking to the source casting plate,
With this simple combination of colloidal silica.

   water and silica powder, it is necessary to continuously stir the slurry * or dispersion in order to prevent the suspended silica powder from settling. If silica powder settles in spray tanks or lines, the equipment should be disassembled and cleaned,
Anyway, these compositions can be applied to the sprue plates by means of brushes or rollers, thus avoiding the clogging and clean-up problems associated with spray applications.

     However, this system has obvious limitations for both efficient and economical application. Although it is more efficient, the spray equipment, in which a pressure tank fitted with an agitator is used, requires all the spray lines ** to be swept immediately after use, i.e. to the waste. or back into the pressure tank, in order to prevent obstruction of the lines. This system is complicated in casting operations, in which are applied to the source casting plates, frequenta coatings of short duration.



   Much effort has been made to find a suspending agent to maintain the silica powder in a relatively stable suspension in aqueous colloidal silica. In several cases, we have found

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 EMI3.1
 up, suspending agent giving a stable suspension, but the siliceous slurry containing the suspending agent did not give satisfactory results, since the composition obtained did not adhere well to the source casting plate, in particular when the application was carried out on a source casting plate
 EMI3.2
 or.t''1 ';!. satmmant hot so that the liquid phase of the composition evaporates almost instantly upon application.



   This problem is caused by the fact that the suspending agent is also a thickening agent. The slurry in suspension is much more viscous than the simple com-
 EMI3.3
 i..di1aiaon montioUi1ée above, Accordingly, although it was liable to force the material through a pipe and UM f.:X'(JU10 nozzle using the system of a pxeusicn tank described above , the greatest thickness of the dream.



   The emont came out such that the steam, produced when the coating bond heats up the source casting plate, would lift the layer: pocket the coating from adhering to the plate. nuin does not adhere re.1, "however to the sr: 9 casting plate, the latter is in no way w cs: gaim. The same problems arise when applying, to the source casting plate, a coating of the slurry in suspension by means of a brush.



     Following the present invention, it has been found that by using a particular type of suspending agent
 EMI3.4
 In a refractory lining consisting of a slurry of refractory particles in a liquid containing a binder, a used stable slurry which could be sprayed mechanically and which, applied in spray form to a solid surface such as a plate, could be prepared. flow into a hot spring, formed a hard, compact and adherent layer.

   The quantity of the mixture and the surface of the coating are easily and precisely controlled,

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 resulting in economical application speeds *
The suspended mine agent employed for the object
 EMI4.1
 of the invention is a hydrophilic Xanthomonaat colloid This colloid is a polymer containing mannose, glucose, potassium gluouronate and acetyl in the ratio
 EMI4.2
 approximate molar of gililil In this colloid, the potassium fraction can be replaced by different other * cations without causing significant changes in the pro-
 EMI4.3
 priety of this material for the purpose of "X" invention.

   This colloid, which is a high molecular weight exocellular material, can be prepared using the bacterium "Xanthomonro camnentris NRRL B-14'9", by complete fermentation of a medium containing Z-5% of. Commercial glucose, a source of organic nitrogen, potassium dihydrophorphate and suitable trace elements. The incubation period is approximately 96 hours at 28 ° C under arabic conditions.



   When preparing the colloid as described above, male maceration liquor or * dry soluble distillery product * should be used as the source of organic nitrogen. In order to promote vigorous growth of bacteria, it is appropriate to grow the culture in two intermediate stages before the final inoculation. These intermediate stages can take place in media having a pH of about 7 * In a first stage, one can carry out a transfer of a slant culture of agar in a dilute glucose broth and the bacteria can be carried out. cultured for 24 hours, while shaking vigorously
 EMI4.4
 well and ventilating at a temperature of about 30 ° C.

   The culture thus obtained can then be used, in a second intermediate stage, in order to inoculate a larger volume of a broth having a higher glucose content (3%). During this stage, the reaction can be allowed to proceed for 24 hours under the same conditions as

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 The culture thus acclimatized for use with the glucose during the first and second stages above is then added to the final glucose medium.

   In the above process of preparing the hydrophilic Xanthomonas colloid, a loop of the organism of the agar-agar slant culture is suitable for the first stage comprising 200 ml of this glucose medium,
In the second stage, the material from the first can be used with a 3% glucose medium in an amount equal to 9 times its volume. During the final stage, the material obtained during the second stage can be mixed with the final medium in an amount equal to its volume.

   A good final medium may contain 3% glue, 0.5% soluble dry distillery product, 0.5% dipotassium phosphate, 0.1% magnesium sulphate containing 7 molecules of water of crystallization and the water. The final stage reaction can advantageously be carried out for 96 hours at 30 C, while vigorous stirring and aeration. The resulting colloidal material can be recovered! by precipitating, in methanol, the mixture clarified prove. laughing; of fermentation.

   The above suspending agent gives much more stable slurries than those obtained with other suspending agents such as a caustified mixture of polyacrylic acid, caustified polyacrylic acid, carboxy-methyl-cellulose, methyl-cellulose and the like * The above-mentioned problems relating to blockage of the equipment by the siliceous slurry are avoided when a hydrophilic colloid of Xanthonas is employed as the release agent. suspended mine *
A typical slurry obtained according to the present invention has the following general composition:

   

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 Ingredients 96 by weight Finely divided refractory material 10-70
 EMI6.1
 Liquid containing a binder 0-.90 Xanthomonas colloid up to about 2 The total being 100 and the viscosity being 1500 to 4500, preferably 1800 to 2500 oentipoiaea to 70 * y (2191 * 0) 0
A specific example of a slurry of this type will be given below:

   
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 Ingredients * & by weight Finely divided fused silica 50 (325 links)
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 Silica sol containing bzz, sio2 in water 43.2 Ethylene glycol 6.5 Hydrophilic colloid of Xanthomonas 0.3
 EMI6.4
 1., Preferred method of preparation consists of, "mixing sodium hydroxide diluted in water with silica sol to adjust the pH to 10.9, followed by addition of ethyl.
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 Lene-glycol. Next, the Xanthomonae colloid is mixed and this composite product is added to the liquid, with rapid stirring. Rapid stirring is continued for at least 10 minutes and preferably for more than an hour.

     The initial viscosity is determined after letting it stand. slurry obtained for a few minutes * A viscosity
 EMI6.6
 preferred initial is 2,000 to 2,300 contipoids at 70T (21.1nC).



     The finely divided refractories * suspended or dispersed in the slurries of the invention preferably consist of at least one siliceous refractory material, for example vitreous silica, crystalline silica or metal silicates. insoluble in water such as magnesium silicate, silicate
 EMI6.7
 aluminum, zirconium silicate or 8ilioeu- clays

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 EMI7.1
 3ce, However, non-siliceous materials such as alumina and graphite can be employed.



   These materials are all well known and commercially available substances. Aluminum silicate
 EMI7.2
 Typical may include: ', for example mica, an etratim type spun from (aluminum mullito silicate # an orthorhombic aluminum silicate, orthorhombic utinlutu obtainable in the Il. of Mull or which can be artificially made from heating of
 EMI7.3
 .andalourite, sillimanifte u 06 kyanites Excellent magnesium silicate * is toret-rite or talc, while a useful zirconium silicate is ziroon. A*
 EMI7.4
 A typical crystalline product is quartz. The preferred rearrangement material and hereinafter described in more detail.
 EMI7.5
 16 have the Glassy Militia.



   The binder employed in the slurries of the present invention. is preferably a colloidal silica sol.
 EMI7.6
 However, aqueous dispersions of aluminum phosphate, ethyl silicate, sodium silicate or mixtures thereof with a colloidal silica sol can be employed, such as.
 EMI7.7
 binder for the slurries of the present invention.



  The preferred binder, used to form porridge
 EMI7.8
 do of the present invention is an allie * collotdalo sol. ! if these are well known materials of which there are several commercial sources ... A typical group of silica sols available commercially and which may be used in the practice of the invention are that of sols.
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 do silica sold us the name of "Nalcoag".

   Silica sols of this type are described in Table I below.

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 EMI8.1
 Silica sol 1 II III IV V ¯ ,, .. yi Colloidal silica knotted form of Sio2t% 15 30 35-36 31-22 49-50 35 pH 8.6 10.2 8.6 3 # 7 90ô 3.5 Vioooaite at 77 * t less less less less (25 * 0), ope of 5 of of of 10 20-30 605 Weight specific to 686P (2060) 1.09 1.205 1.255 ', 06 1 # C $ 5 it255 Average area 330- 190- 135- 1'- 120- 135- m2 per S of sio2 43o 270 190 igo 150 190
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<tb> Average <SEP> size
<tb>
<tb> of the <SEP> particle *.

   <SEP> 7.9 <SEP> 11-16 <SEP> 16-22 <SEP> 16-22 <SEP> 20-25 <SEP> 16-22
<tb>
 
 EMI8.3
 millimicrons
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<tb> Density <SEP> to <SEP> 68 F
<tb>
 
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 (2000 hrs lbs / US gallon 961 10.0 10.5 8.8 '11.6 10.5 g / cm3 igob3 1, 1.25 1.047 1.38 1.25 Na209% 0.04 0.40 0, 10 0.05 0.30 0.01 Other silica sols which may be used in
 EMI8.6
 more than those indicated below) can be prepared by adopting a variety of well-known customary techniques.

   A suitable method of preparing aqueous salts of colloidal militia
 EMI8.7
 is described by Bird in US Pat. No. 2,224,355, in which a dilute solution of an alkali metal silicate is passed in contact with a cation exchange resin to form hydrogen, so as to transform the silicate into a dilute aqueous soil of colloidal militia. Diluted soil can be concentrated to more economically usable solids concentrations from a shipping spawning and end-use perspective by employing the techniques described in U.S. Patent No. 2,574,902.
 EMI8.8
 to the names of Beohtold et al., U.S. Patent No. 2,680,721 to the names of Broge et al.

   or US Patent No. x.601.29x in the names of Alexauder et al. Another type of silica sol which can be employed in practicing the invention is described in the specification of US Pat. No. 2,856,302 in the name of Reuter, although it is possible to employ

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 aqueous soles of colloidal silica, it is understood that other forms of colloidal silica can be used, for example sols mainly containing polar organic solvents. These soils can be defined by the generic term "organo-soils" and examples of such sole described in US Pat. No. 2,386,247 in the name of Marshall.

   It suffices that the silica particles used can be dispersed in a colloidal manner in a hydrophilic substance, for example water or lower alkyl alcohols and other organic compounds having relatively high dielectric constants *
In some cases, as the suspending media for the colloidal silica particles, water and organic substances compatible with water can be employed. Particularly preferred organic substances are those which lower the freezing point of pure aqueous sols by mixing them with such aqueous silica sols.



    These final salts are particularly useful shad during the coldest month of the year. should be stored and / or used at relatively low temperatures *, The amines. such as morphoiline, diethylamine, etc., as well as polyhdroxyl-crganiques compounds such as ethylene-glycol, propylene-glycc1-1,2, propylene. glycol-1, ', glycerin $ etc. are preferred materials for the preparation of silica hearths containing substances as the sole silica suspending medium or as a fraction of a mixture additionally containing water.

   A preferred soil. freeze-protected contains 5-50 parts by weight of a polyhydroxy compound such as ethylene glycol, 20-85 parts by weight of water and 10-60 parts by weight of silica. In carrying out the present invention, the glycol added to the composition is also employed in an amount sufficient to inhibit the baotecomposition.

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   nothing of the hydrophilic Xanthomonas colloid. For this purpose, the amount of glycol should be at least 0.5% and, preferably, at least 1% by weight of the composition.



   Regardless of the process employed to form the colloidal silica sol containing water, polar erganic liquids or mixtures of these substances under a continuous phase of suspension, it is desirable that these sols contain dense, amorphous silica particles having particles with an average diameter not exceeding 150 millimicrons. As can be seen from Table I, all the silica sols considered as starting materials have particles with an average diameter well below 150 millimicrons. Preferably, the starting silica sols have particles of a average diameter of 10 to 50 microns.

   The silica concentration of the sols can be between 0.1 and 60% by weight of silica, as SiO2. Preferred sols contain 3.0 to 60% by weight of silica and more preferably 10 to 60% by weight of silica. weight*
Other sols which may be employed as binders for the silica refractory are those known as "salt-free silica sols". These sols are particularly preferred when the medium for suspending the silica particles of the binder itself is only a polar organic liquid or a mixture of water and a polar organic liquid.

     Since most of the hearths described above usually contain alkali metal compounds as stabilizers, they are generally not compatible with organic systems, since salts in aqueous soil cause gelation or precipitation. silica particles when the aqueous phases are exchanged for polar organic solvents. This drawback can be avoided by using "salt-free" aqueous silica hearths as materials.

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 raw materials in the preparation of pure organoils or mixtures of water and an organic material as a silica carrier.

   In order to avoid this gelation effect, it is necessary
 EMI11.1
 oeeeaire to remove the causative cations from the surface of the silica particles dispersed in a colloidal manner, as well as from the liquid phase of the sol. This removal can be easily overcome by treating silica hearths of the type described in U.S. Patent No. 2,574,902 to Bechtold et al. With a cation exchange resin in the form of Hydrogen, as well as a strongly basic D-exchange resin. anions in hydroxide form. This treatment tends to result in a finished aqueous sol in which the continuous aqueous phase of the sol and the silica particles are both considered to be "free of salts."



   Among the silica sols available in the com-
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 merce and which can be deioninated to form 8el.- free silica soils, there are those described in Table 1 above. These aqueous silica% soles free of sole "may
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 be used in any combination with one of the aforementioned refractories to form a slurry coating material or they may be modified so that the aqueous phase is exchanged completely or by - only against a hydrophilic polar liquid such as an alcohol; alcohol can also be mixed with the salt
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 aqueous in desired proportions.

   The alcoholic alcohols of silica -eMpb8 of 86: .- p6u., Can then be easily combined with a refractory material.
 EMI11.5
 re and the slurry obtained can be used to coat the source casting plates.



   When the particle sizes of the silica sols described above are within the specified ranges, the silica particles present in the starting aqueous or organic sol have specific surface areas of at least

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 EMI12.1
 20 m2 / g and usually more than 100 m2 / g. In 0; } t when deionized soles are used as binders, they are hampered *. usually a salt content (expressed as Na2S04) of t'.na of 0.01.



  As mentioned above, the m8. Preferred refractories are those generally known as "vitreous silicas". It acts here of vitreous modi) ation8 of silica, obtained by the fusion of crystalline imes. chosen at low temperature and they are usually designated by the terms "verro de quart ** or
 EMI12.2
 "Silica glass" Specific vitreous silicas comprise particles obtained from fused quartz glasses, silicate glasses, silica glasses as the materials. Well known "Vyoor" and silica locks
 EMI12.3
 fondue.

   With regard to all these matters, the coefficients. of thermal expansion are relatively small compared to other refractories, for example those of the soda lime and lead glass types. They generally have lower thermal expansion coefficients.
 EMI12.4
 Likewise, the silica content of these granular siliceous refractories is generally greater than 9 <5/6 # expressed as syrup and can reach 9998% SiO2o. , by the term -vitreous silica 'is meant a refractory material comprising a silica glass having a coefficient of thermal expansion and a temperature.
 EMI12.5
 neur in S1.0v, axis lying in the above interval.



   The preferred refractories are those having the highest purities with a minimum coefficient of thermal expansion. These properties are found particularly in vitreous silica and more particularly in types of fused silica. These latter materials have
 EMI12.6
 a silica content greater than 97 ;, expressed as SiO, 0 as well as a thermal expansion coefficient not exceeding

 <Desc / Clms Page number 13>

 
 EMI13.1
 not about 6 x 10 cm / em / eo,
 EMI13.2
 A typical fused silica of the type described above and extremely useful for the practice of the invention, while having a coefficient of thermal expansion of approx.
 EMI13.3
 ron 5 s 10 * "'cm / em / o and responds to the following typical analysis Table TI
 EMI13.4
 Ingredient:

  & .l! 1n weight sio2 97.3 AI 201 1.7 Soua-oxyd * 1 of 811 108 160
 EMI13.5
 The * product * of ailioe of the type \ <,; 'l: ï, \ "i; J .... cleddu8 is easily prepared by grinding very fine glass of molten s11ioe * .J.'i1 !. De oxi can also grind boroai glasses and "Vyoo '" silica boars to form extremely useful refractory material. The size of the refractory material can also be crushed. However, it is preferable to read the refractories so that they are small enough to obtain a uniform dispersion of the air and the binder. particle size distribution, plus a slurry formed from the binder and the material r-Jt''L \ (rt. \ 'to..tA'3 restar ",' long time in the homogeneous state. ! 1in.j that 3.

    one could use particles of a large-
 EMI13.6
 nuuil us lIitm..l1t anbra 125 meshes and a fraction of a micron.



  The preferred rf.ro.cstt.ixee materials have a trie moyenno granuloma, ranging between 20 and 00 microns, the particles
 EMI13.7
 corresponding to the lower limits of the interval being much preferred. The specific substances of silica vi-
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 treuse referred to as "NALCASTp fall into the uterval- uterval- the above-uttered granuloma sorts and they have been used
 EMI13.9
 with great success to prevent the erosion of the base parts from the molds, as well as the adhesion of the ingots formed

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 to these mussels. The binder that is part of the roe porridge. This must be present in an amount sufficient to bind the particles of the refractory material together, thereby forming a continuous coating,

   firmly adhering to the surface of the hotplate. Without a quantity
 EMI14.1
 binder property with respect to the refractory material, after application and drying of the slurry, the coating obtained rnui93t. a "wafer" effect does not include numerous holes in one, thereby exposing parts of the source casting plate or the base surface of the mold.
 EMI14.2
 determined that the slurry should consist of 10 to 70% by weight of the refractory and 30 to 901% of the binder by weight. Medium to *, again, the slurry contains 30% 70% by weight <16 refractory material and 70% by weight <0%. 'in poîdF3 o-t - 1fni ;.



  L88 cleaving examples illustrate embodiments of the invention. These examples are given merely by way of illustration and the invention is in no way limited thereto.
 EMI14.3
 KXMMPLK. ,, 1
A porridge * is prepared by mixing, in a Lightinin blender, approximately equal parts by weight of crushed molten militia $ * a ream of a fine pou-
 EMI14.4
 dre and free flowing (14 & 1.cote 8? O-PIt). as well as an aqueous sol of colloidal garlic protects against freezing at 1.0 "yen ethylene glycol, 27% by weight of militia and 0.35% if the weight of the hydrophilic colloid of! .2J:

  i.tl1omonas described above from 18, the latter percentage being calculated on the weight of the b 1 il- lie. The slurry has an initial viscosity of 2,600 centip -
 EMI14.5
 his. By letting it stand for 8 to 12 hours, the vincos drops to around 2,400 oentipoiaee and it pays off at this level.
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  At oe45% and 0.50% by weight of the hydrophilic colloid of Xanthonionaej the viscosities: final. porridge his

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 EMI15.1
 respectively of 3,300 and 4,000 centipoisea,
EXAMPLE II A solid mixture of fused silica is mixed.
 EMI15.2
 When crushed, we form a fine, free-flowing powder (wnalcote 870-P ") and 0.8% by weight of the hydrophilic XanthomoRajt colloid described oi-deaauat. The dry mixture is packaged for shipment. This dry mixture can be packed. be used to arm the porridge of the invention by adding and
 EMI15.3
 dispensing, with stirring, a colloidal silica eoi of the type described above, for example, a 30% by weight aqueous colloidal silica sol.



   In the aforementioned proportions, the hydro- colloid
 EMI15.4
 Xanthomonas philius forms slurries of the refractory material in the colloidal alloyed sol binder of the type required for a suitable application by spraying, in particular a spray we form atomized * Other nht8 thickeners such that carboxy-methyl-.cellulose, 1 ,,;:, <tlgine, to. ethyl-ûeUMiotSe, aorylamide and acid Üt: "..- y llqu .. cauntlî'î, 6 and 1. ' ... ,, 1uo acrylic caustified and analogous ;;: x <-. & U d (hm, U11i pAl! Dow result * similar from the point of view of properties of the slurry.

   Although they form a bouile 1- j Initial:! U1ti: -: sfl \ î1'Snnt. 1o't: '8 which they have used in conducibleis aVrri6o., Thickening agents give .u left to stand, z an increase in the viscosity of the buil1ia to the point where a solidification occurs. d.:t'ioati()n we form a phase ball or in the phase in "when the slurry is not * spared * in an upper aqueous component and a lower component based on slurry solids. characteristics are partial
 EMI15.5
 Harmful effects during spray application, where solidification results in clogging of spray lines and equipment.



   As mentioned, the other agents * thick

 <Desc / Clms Page number 16>

 
 EMI16.1
 siesantx do not provide the same degree of dispersion as a Xanthomonau colloid at a given viscosity. In other. In other words, Xanthomonaa colloid possesses the ability to suspend particles of fused silica for a period of time.
 EMI16.2
 longer time than other agent. teatés at dosages ensuring the same viscosity or an equivalent viscosity.



   With the slurry of the invention, one can optionally-
 EMI16.3
 ment add a miorobiocide such as r6¯dehyd. aqueous,
EXAMPLE III
A slurry of the type described in Example 1 was sprayed under high pressure onto a hot spring casting plate to form a mold. The temperature of the
 EMI16.4
 hot plate of spring casting is about 5000F (260 * C) <By e .. y # nd daw.rp: l., a * .tionr the slurry breaks into fine. particles drying almost instantly on contact with the hot spring casting plate. The spray coating *% binds together into a hard, compact and adherent layer.
 EMI16.5
 annuity with a thickness of the order of 1/64 to 1 / 8w (0.397 to 3.175 night).

   Certain * zones of the source casting plate may receive a thicker coating than the other zones, in order to confer additional protection at the place where the impact of the hot metal is the most severe,
The spray equipment is preferably high pressure foam spray equipment, capable of providing at least about 200 gauge pei (14 kg / square meter).
 EMI16.6
 there the pump outlet. With the refractory structures of the invention, high pressures of this order ensure proper flows with good spray from a nozzle.



   The present invention does not relate to the process
 EMI16.7
 particular application of the composition: refractory to the solid surface, The mechanical spraying process. OR.
 EMI16.8
 high pressure described in Example III is very effective. Gold

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 process is described and claimed in another US patent application by the Applicant,
EXAMPLE IV
In order to evaluate the stabilizing effect of a hydrophilic colloid of Xanthomonaa, compared to other thickening agents or other suspending agents, we have
 EMI17.1
 e;

  During the following tests, To 100 g of a 325 mesh vitrousa silica ("Nal- cote 87O-P"), the required amount of each suspending agent was added to obtain a viscosity of the order of 1,500 to 2,500 centîpoieeo $ this viscosity being determined by preliminary tent; then, one mixed suitably,
This mixture was then added to a solution of
 EMI17.2
 gd g of a silica sol containing 30% 6i02 ("Nalooag 1030,) e adjusted to pH 10.9 with dilute sodium hydroxide and water, as well as 1 ig of ethylene glycol The amount of nut sol * is adjusted to compensate for different% amounts of suspended nias agents, in order to maintain a load of 200 g.
 EMI17.3
 



  The viscosities were measured with a broar'e3.ci model LV viaootiter at 60 revolutions / minute using a non-approximately 7Q * F (21 t 1 lc) biloolie. The mining agents in suspension were evaluated below. !
 EMI17.4
 Hydrophilic colloid of Ca.nthomanae ("Kelzan") ar'boxypmthylae3, .ulase 68% ("CMCT-.13D") HydroxY-6thyl-cellulo .. (MN.tro8ol 250 MR ") Purified carboxy-methyl-cellulose (" Carboxel Mu45 ") Hydroxy-propyl-methyl-oellulo8e (" Methooel of HG-2 ") Ammonium alginate (" Superloid ") Alginic acid (" Kelco801 ").
 EMI17.5
 



  In test # 1, samples were placed in closed glass jars, and subjected to

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 vibrations for four hours in a shaker
 EMI18.1
 dl * Eberbacb * jerks per minute.



  In test # 2, samples were stored in
 EMI18.2
 hermetically sealed glass jars, under static conditions at room temperature.
 EMI18.3
 



  In test No. 3, samples were stored in hal'1 'formed glass boxes! Uh ::! qJlnt.ut. , - r: 1! do * oandi ... tione static * and at temperature (l.t1 v atubia.n! 'ët Periodically), each sample was re-mixed and subjected to viscosity tests *
 EMI18.4
 In the nO lef test, samples were stored in hermetically sealed glass jars under static conditions at 120 ° P (48.89 0). for 24 hours and allowed to cool to room temperature.



  At, test n8 5 # Samples were sealed in glass jars, under static conditions, below 10 F (-12 * 0) for 24 hours and allowed to thaw at room temperature. result link * of these tests are included in the
 EMI18.5
 tables follow s

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TEST N 1
 EMI19.1
 ntine in mine in Sïï & ïî SEPARATION DIC PHASES suspension suspension after After After After,,; i. , ..., #, ..-. - .. 1 h. 2 hrs. 3h # 4hd.
 EMI19.2
 
<tb>



  Kelzan <SEP> 0.22 <SEP> 1500 <SEP> none <SEP> none <SEP> none <SEP> none
<tb>
<tb> Kelzan <SEP> 0.31 <SEP> 2550 <SEP> none <SEP> none <SEP> none <SEP> none
<tb>
<tb> CMC <SEP> T13D <SEP> 0.7 <SEP> 1660 <SEP> none <SEP> none <SEP> none <SEP> none
<tb>
 
 EMI19.3
 ONC T13D 0.76 2600 none none none none Natrosol MR250 0.3 1600 30% 80% full *
 EMI19.4
 
<tb> Natroaol
<tb>
 
 EMI19.5
 IM250 0.375 2650 20% 70% complete
 EMI19.6
 
<tb> Carboxel
<tb> M-245 <SEP> 0.57 <SEP> 1500 <SEP> complete
<tb>
<tb> Carboxel
<tb> M-245 <SEP> 0.60 <SEP> 2400 <SEP> complete
<tb>
<tb> Mothocel
<tb>
 
 EMI19.7
 65HG-2 0.3 1600 complete Methocal
 EMI19.8
 
<tb> 65HG-2 <SEP> 0.34 <SEP> 2400 <SEP> complete
<tb>
<tb> Suporloid <SEP> 0.26 <SEP> 1400 <SEP> complete <SEP> j
<tb>
 
 EMI19.9
 Suparloid 0,

  00 2450 25% complete Kelceaal ot22 1550 25% complete Kelconoi 0.25 2500 25% vso # 80% oeatplfct *
 EMI19.10
 Compositions prepared with "Kelzan" and "CMC T-13D" did not separate into two phases All other samples;
 EMI19.11
 ae are separated.

   Samples prepared with "CMC T-13D" had asst sa 't;, QSLR

 <Desc / Clms Page number 20>

 TEST N 2
 EMI20.1
 Agent Viscosity Agent Phase separation as 2) 8
 EMI20.2
 
<tb> put <SEP> in <SEP> put <SEP> in <SEP> Centipoi- <SEP> 18 <SEP> hours
<tb> suspension <SEP> suspension <SEP> ses
<tb>
 
 EMI20.3
 ¯¯¯¯¯¯¯¯ 96 111.-,. # ,,,, ,,,
 EMI20.4
 
<tb> Kelzan <SEP> 0.22 <SEP> 1500 <SEP> None
<tb>
 
 EMI20.5
 Kelzan 0,, 31 2600 None
 EMI20.6
 
<tb> CMC <SEP> T13D <SEP> 0.7 <SEP> 1600 <SEP> None
<tb>
<tb> CMC <SEP> T13-D <SEP> 0.76 <SEP> 2600 <SEP> None
<tb>
<tb> Natrosol
<tb>
 
 EMI20.7
 MR25 0.3 1550 Natro8ol hem
 EMI20.8
 
<tb> MR250 <SEP> 0.375 <SEP> 2500 <SEP> Complete *
<tb>
<tb> Carboxel
<tb>
 
 EMI20.9
 M-245 0.57 1400 25 after 1/4 hour.

   complete
 EMI20.10
 
<tb> after <SEP> 18 <SEP> clash)
<tb>
<tb> Carboxel
<tb>
 
 EMI20.11
 M-245 0.60 S430 25% after 1/4 hour, complete
 EMI20.12
 
<tb> after <SEP> 18 <SEP> hours
<tb>
<tb> Methocel
<tb>
 
 EMI20.13
 65HG-2 0, '0 "' 0 5O5 & after 2 hours .., complete
 EMI20.14
 
<tb> after <SEP> 18 <SEP> hours
<tb>
<tb> Methocel
<tb> 65HG-2 <SEP> 0.34 <SEP> 2500 <SEP> 30% <SEP> after <SEP> 2 <SEP> hour., <SEP> full
<tb> after <SEP> 18 <SEP> hours
<tb>
<tb> Superloid <SEP> 0.26 <SEP> 1500 <SEP> 25% <SEP> after <SEP> 1/2 <SEP> hour, <SEP> full
<tb> after <SEP> 18 <SEP> hours
<tb>
 
 EMI20.15
 Superloid 0.30 2500 25% after 1/2 hour, full
 EMI20.16
 
<tb> after <SEP> 18 <SEP> hour
<tb>
 
 EMI20.17
 Kilo0801 0.22 1400 2596 after 1/2 hour, complete
 EMI20.18
 
<tb> after <SEP> 18 <SEP> hours
<tb>
<tb> Kelcosol <SEP> 0,

  25 <SEP> 2700 <SEP> 25% "after <SEP> 1/2 <SEP> hour, <SEP> complete
<tb> after <SEP> 18 <SEP> hour
<tb>
 
 EMI20.19
 The compositions prepared with "Kelzan" and ECHO T15D and did not separate into two phases after 18 years. All other samples separated. The sample. prepared with "CMC T-13D" / solidified.

 <Desc / Clms Page number 21>

 



   TEST N 3
 EMI21.1
 
<tb> Agent.de <SEP> Agent <SEP> of <SEP> Viscosity <SEP> Viscosity <SEP> Viscosity <SEP> Remarks <SEP>. <SEP> '<SEP>
<tb>
<tb> put <SEP> in <SEP> put <SEP> in <SEP> initial <SEP> after <SEP> 3 <SEP> after <SEP> 18
<tb>
<tb> suspension <SEP> suspension <SEP> cps. <SEP> hours <SEP> hours
<tb>
 
 EMI21.2
 ¯¯¯¯., ¯¯¯¯ ¯ ¯¯ ¯¯ # -. # Epse, Cpa - ## .. ## .. ###.
 EMI21.3
 
<tb>



  Kelzan <SEP> 0.22 <SEP> 1600 <SEP> 1500 <SEP> 1400 <SEP> none <SEP> separa-
<tb>
 
 EMI21.4
 tïongmouifaci.
 EMI21.5
 
<tb> the <SEP> to <SEP> mix
<tb>
 
 EMI21.6
 Ksisan 0.31 2600 2500 2400 no separation, slack, faoi
 EMI21.7
 
<tb> the <SEP> to <SEP> mix
<tb>
<tb> CMC <SEP> T13D <SEP> 0.7 <SEP> 1600 <SEP> 15500 <SEP> infinite <SEP> solid
<tb>
<tb> CMC <SEP> T13D <SEP> 0.76 <SEP> 2600 <SEP> infinite <SEP> infinite <SEP> solid
<tb>
<tb> Natrosol
<tb> MR250 <SEP> 0.3 <SEP> 1700 <SEP> 1550 <SEP> 1700 <SEP> separation <SEP> com
<tb>
 
 EMI21.8
 plete, diffioile
 EMI21.9
 
<tb> to <SEP> remix
<tb>
 
 EMI21.10
 Naëresel 0.375 2600 2500 2550 separation nom- 'LE "250 piety, difficult
 EMI21.11
 
<tb> to <SEP> remix
<tb>
 
 EMI21.12
 4th. Rbaxca.

   1. '' 2 0 1600 1470 1500 oom- separation
 EMI21.13
 
<tb> full, <SEP> soft, <SEP> easy
<tb>
<tb> the <SEP> to <SEP> mix
<tb>
 
 EMI21.14
 Oarlo: s 1? -845 Oo6o 2SSÓ 2450 2200 complete separation.mou.raoi-
 EMI21.15
 
<tb> the <SEP> to <SEP> mix
<tb>
<tb> Methocel
<tb>
 
 EMI21.16
 6 10 = 2 6.30 1600 1250 850 complete separation, hard tawwâ
 EMI21.17
 
<tb> @ethcesl
<tb>
 
 EMI21.18
 10 oo34 2500 1750 100 complete separation. your ... hard:

  .2solea.d 0.26 1620 1500 1250 complete separation, fao.le to
 EMI21.19
 
<tb> mix
<tb>
<tb> superleid <SEP> 0.30 <SEP> 2600 <SEP> 2550 <SEP> 2500 <SEP> full <SEP> separation, soft, <SEP> easy <SEP>
<tb> the <SEP> to <SEP> mix
<tb>
<tb> lelcesol <SEP> 0.22 <SEP> 1550 <SEP> 1450 <SEP> 1200 <SEP> separation <SEP> oom-
<tb>
 
 EMI21.20
 plite roou faai-
 EMI21.21
 
<tb> the <SEP> to <SEP> mix
<tb>
<tb> olcosol <SEP> 0.25 <SEP> 2600 <SEP> 2480 <SEP> 2300 <SEP> separation <SEP> com
<tb>
 
 EMI21.22
 plete, mouttaoi ..

   
 EMI21.23
 
<tb> the <SEP> to <SEP> mix
<tb>
 
 EMI21.24
 The compositions prepared from "Kelzan", "Natro801M," MR-250 ", Carboxl M-25%" Superloid * "and" Kelcoeol "do not pre-

 <Desc / Clms Page number 22>

 not feel much change in viscosity after 18 beur .., The
 EMI22.1
 viscosities of all * other * samples have undergone significant changes a,
TEST N 4
 EMI22.2
 
<tb> Agent <SEP> of <SEP> Agent <SEP> of <SEP> Viscosity <SEP> Observations
<tb>
 
 EMI22.3
 misa in misa in initial Aspect after Remêlang4evinconit4
 EMI22.4
 
<tb> suspension <SEP> suspension <SEP> cpa. <SEP> 24 <SEP> hours <SEP> after <SEP> a <SEP> will keep.
<tb>
<tb>% <SEP> tion <SEP> of <SEP> 24 <SEP> hours
<tb>
 
 EMI22.5
 - - ¯ # - #. , .UI. ,,., .. # #v ....

   T,., -,., # ... # -, - m .-., .. #### cjM..t¯¯¯¯¯¯ Kelssai * 1,), 22 1700 mine. plush 1300
 EMI22.6
 
<tb> of water <SEP> of <SEP> 1/8 "
<tb>
 
 EMI22.7
 (3 e 175 Mm) Zelsaan 0.31 2600 thin layer 2000
 EMI22.8
 
<tb> of water <SEP> of <SEP> 1/16 "
<tb>
 
 EMI22.9
 (1, .587 Ma) Omo 13D Oe7 1600 infinite solid ('1'JO T13D 0.7é 2400 infinite solid N & trsao 0.3., 160 separation 800 MSSO c & utplete Ilateusol 0.375 2650 separation 1200
 EMI22.10
 
<tb> MR230 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Carboxel <SEP> 0.57 <SEP> 1400 <SEP> separation <SEP> 4200
<tb>
<tb>
<tb>
<tb>
<tb> M-245 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Carboxel <SEP> 0,

  60 <SEP> 2550 <SEP> separation <SEP> paste <SEP> thick
<tb>
<tb>
<tb>
<tb>
<tb> M-245 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Methooel <SEP> 0.3 <SEP> 1750 <SEP> separation <SEP> 1200
<tb>
<tb>
<tb>
<tb>
<tb> 65HG-2 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Methocel <SEP> 0.34 <SEP> 2400 <SEP> separation <SEP> 1200
<tb>
<tb>
<tb>
<tb>
<tb> 65HG-2 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Superloid <SEP> 0.26 <SEP> 1500 <SEP> separation <SEP> 1850
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Superloid <SEP> 0.3 <SEP> 2500 <SEP> Separation <SEP> 2900
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Kelcosol <SEP> 0,

  22 <SEP> 1500 <SEP> separation <SEP> 1400
<tb>
<tb>
<tb>
<tb>
<tb> complete
<tb>
 
 EMI22.11
 Kalconol 0.25 2500 separation 2200
 EMI22.12
 
<tb> complete
<tb>
 
 EMI22.13
 The compositions prepared from -Kelzan 'and' OMO T-13D "did not separate into two phases. All other samples did separate. The compositions prepared from" Kelzan "and
 EMI22.14
 "KolconolO showed little change in viscosity, but all other compositions showed a clear change in viscosity *

 <Desc / Clms Page number 23>

 . TEST N 5.
 EMI23.1
 
<tb>



  .Agent <SEP> of <SEP> Agent <SEP> of <SEP> Viscosity <SEP> Observation <SEP> ions <SEP>
<tb>
 
 EMI23.2
 miss in mine in initial, Aspect after Remixed, visoosit4 suspension suspension opne thaw after conservation,, ¯¯ ¯¯ ¯¯ # '10 "¯¯¯¯ ¯¯ # ¯¯ ¯¯¯¯ op ..
 EMI23.3
 
<tb>



  Kelzan <SEP> 0.22 <SEP> 1700 <SEP> thin <SEP> layer <SEP> 1500
<tb>
<tb> of water <SEP> of <SEP> 1/16 "
<tb>
 
 EMI23.4
 (1,587 Il1m) "
 EMI23.5
 
<tb> Kelzan <SEP> 0.31 <SEP> 2600 <SEP> none <SEP> separa- <SEP> 2100
<tb>
<tb>
<tb>
<tb>
<tb> tion
<tb>
 
 EMI23.6
 CI.t) 'r 1 D 0.7 1600 no separa- infinite
 EMI23.7
 
<tb> tion, <SEP> solid
<tb>
<tb>
<tb>
<tb>
<tb> CMC <SEP> T13D <SEP> 0.76 <SEP> 2400 <SEP> none <SEP> separa- <SEP> infinite
<tb>
<tb>
<tb>
<tb> tion, <SEP> solid
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Natrosol <SEP> 0.3 <SEP> 1650 <SEP> separation <SEP> 1400
<tb>
<tb>
<tb> MR250 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Natrosol <SEP> 0.375 <SEP> 2650 <SEP> separation <SEP> 2250
<tb>
<tb>
<tb> MR250 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Carboxel <SEP> 0,

  57 <SEP> 1400 <SEP> separation <SEP> paste <SEP> thick *
<tb>
<tb>
<tb>
<tb> M-245 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb> Carboxel <SEP> 0.60 <SEP> 2550 <SEP> separation <SEP> paste <SEP> thick
<tb>
<tb>
<tb> M-245 <SEP> complete
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Moethocel <SEP> 0.3 <SEP> 1750 <SEP> separation <SEP> 1300
<tb>
<tb>
<tb> 65HG-2 <SEP> complete
<tb>
 
 EMI23.8
 Metbooel ove, 34 2400 separation 1700
 EMI23.9
 
<tb> 65HG-2 <SEP> complete
<tb>
<tb> Superloid <SEP> 0.26 <SEP> 1300 <SEP> separation <SEP> 1600
<tb> complete
<tb>
 
 EMI23.10
 81, Pbrloîd 0.30 2500 separation 3500
 EMI23.11
 
<tb> complete
<tb>
 
 EMI23.12
 Kel9 '<! L oe22 1500 separation 1500 complete Kelc-i.

   if 0925 2500 separation 2350
 EMI23.13
 
<tb> complete
<tb>
 
 EMI23.14
 Impositions prepared with wkelzan "and .OMO T13D * do not go separated into two phases after thawing. Samples prepared with" Kolban "," Natrogol R-2U "and Koloosolu have au- hi J} U da change in viscosity Samples prepared with * C *, 'r1, DM solidified.



  From the above results, it was found that the hydrophilic Xanthomonas colloid was the only suspending agent.

 <Desc / Clms Page number 24>

 board stabilizing the suspension of refractory material enough to withstand all tests.



   It is understood that in its broader aspects, the invention is not limited to the coating of the source casting plates, but that it can be applied to other uses, in which it is desired to apply a coating. refractory, for example a coating applied to a refractory brick roof of a siemens-Martin fuir.



   The present invention is particularly useful when the surface to be coated is at a temperature above the boiling point of water,
In the preferred method, the coating slurry is applied to dry surfaces, particularly metal surfaces having a temperature between the boiling point of water and 1000 F (538 C), preferably. Between
212 and 800 F (100 and 427 C). The best adhesion of the solid coating to the source casting plates is obtained by applying the slurries to these plates at a temperature between 200 and 500 F (93 and 260 C). ).

   In order to obtain the best results, it has been found that the films should have a thickness of 0.01 inch (0.254 mm) to 3 inches (76.2 mm) and preferably 0.01 inch ( 0.254 mm) to
1/8 inch (3.175 mm). A thickness of about 1/16 inch (1.587 mm) is most practical.



   It is assumed that the success of excellent coatings. obtained by using the refractory compositions defined above lies in the ability of these compositions to remain stable, to form particles having the physical characteristics suitable for application to solid surfaces, as well as their ability. to form a strong ceramic coating. The present invention also provides for obtaining acid resistant coatings 1, for example, when the coated surfaces are put in, intact.

 <Desc / Clms Page number 25>

 with vapors, gases and acidic liquids.



   CLAIMS
1. A coating composition comprising finely divided macroscopic refractory solids. suspended in an aqueous liquid containing a binder, this suspension being stabilized by an intimate dispersion of a stabilizing amount of a hydrophilic Xanthomans colloid.


    

Claims (1)

2, A coating composition comprising finely divided macroscopic refractory solid particles suspended in an aqueous medium containing a binder, said suspension being stabilized by an intimate dispersion of a stabilizing amount of a hydrophilic Xanthomonas colloid, these refractory solid particles. having a particle size not exceeding 125 mesh (series of standard sieves). this composition having a viscosity of 1500 to 4500 units at 70 F (21 C), 3. A composition according to claim 1, characterized in that it also contains a sufficient amount of an alkylene glycol to inhibit the bacterial action exerted on this hydrophilic Xanthomonas colloid. 4. Composition according to claim 1, characterized in that this liquid comprises an alkylene glycol in an amount sufficient to lower the freezing temperature of this composition. 5. A composition according to claim 1, araracterized in that it also contains an alkali in an amount sufficient to render it alkaline at a pH not exceeding about 10.5%. 6. Coating composition comprising finely divided macroscopic vitreous silica in dispersion. <Desc / Clms Page number 26> in an aqueous silica sol, in which is also dispersed about 0.2 to 1.0% by weight (calculated on this composition) of a suspending agent based on a hydrophilic Xanthomonas colloid , 7. A coating composition useful for coating source casting plates of iron molds, characterized in that it comprises finely divided macroscopic vitreous militia dispersed in an aqueous silica sol having also dispersed about. 0.2 to 1% by weight (calculated on this composition) of a mixing agent in suspension in bine of a hydrophilic colloid of Xanthomonaa, this composition having a viscosity of about 1500 to 2500 centipoise at 20 F (-6 , 67 C). 8. A stable coating composition comprising 10 to 70% polus of a fine macroscopic refractory material. This is divided into a dispersion in 30 to 90% by weight of an aqueous liquid containing a binder and in which are also dispersed. about 0.2 to 2.0% by weight (calculated on the total weight of this composition) of a suspending agent based on a hydrophilic Xanthomenas colloid. 9. A stable coating composition used * for the coating of source casting slabs of cast iron molds, characterized in that it comprises 10 to 70% by weight of finely divided macroscopic vitreous silica in 30 to 90% dispersion. by weight of an aqueous silica sol, in which is also dispersed about 0.2 to 1.0% by weight (calculated on this composition) of a suspending agent based on a hydrophilic colloid of Xanthomonas. 10. Composition consisting essentially of about 50% by weight of finely divided macroscopic vitreous silica having a particle size of not more than about 125 mesh, about 43.2% of a silica sol containing 30% of SiO2 in water, about 6.5% ethylene glycol and about <Desc / Clms Page number 27> 3 $ 4 'a hydrophilic Xanthomonas colloid. 11. A solid composition comprising a body of finely divided refractory particles * containing dispersed 0.4 to 2.0% by weight (calculated on these refractory particles%) of a hydrophilic colloid of Xanthomonas, said The composition being intended to form, when added to and stirred with colloidal silica sol in proportions of 30.70 to 70:30, a stable suspension of the particles of silica in the silica sol.