LV13570B - Porous granular clay material with large specific surface of granules and method of its preparation - Google Patents

Abstract

The method offered is predicted for production of activated regular-shaped porous clay ceramic granules/grains having macro-, micro- and nanopores therein. The diameters of grains can be controlled during the process of granulation. Preserving the crystalline structure of the clay minerals after influence/action of onium salts, the grains exhibit excellent filtering and sorption properties having the granule size over the range from 1 to 10 mm, a bulk density from 300 to 900 g/l, a porosity from 50 to 80% v/v, and a liquid absorbency, expressed as ratio of liquid to the solid phase of granular material, from 40 to 260%, and specific surface from 40 to 400 m2/g. The method is characterized by heating granules, comprising a mixture of clay and a combustible organic filler, and by interaction of clay in wet phase with positive onium ions, containing one or more hydrocarbon side chains consisting of 5 to 24 carbon atoms. The pores are formed by voids derived from the combustion of organic filler previously mixed in, ratio of which is from 1:2,5 to 2,5:1. The temperature and time of heating ensure that a substantial amount of the clay remains un-vitrified, the organic filler is substantially completely burnt out, and the weight loss of the mixture is between 30 and 70% based on the weight of the dried granules. The grains obtained are suitable for use as an industrial absorbent for liquids and soluble solids and ions, as carrier for liquid fertilizers, inorganic and organic salts, catalysts and complex mixtures, as filler for compounding the thermoplastic materials, as modifier of polymerization processes and as carrier for micro-organisms growth.

Description

Porous granular clay material with large specific surface of granules and method of its preparation.

BACKGROUND INFORMATION 001. The present invention relates to porous clay ceramie materiāls and to methods for their produetion. In particular, the present invention provides a porous clay ceramie material having absorbent properties which, at least when in a granular form, make it suitable for such end uses as industrial absorbent.

It also relates to regular-shaped pārticies of activated clay, to a method of producing the same and to use thereof. More particularly, the invention relates to regular-shaped clay pārticies of activated clay comprising an ammonium salt-treated product of a clay minerāls having maero, micro and nano pores in the pārticies, having excellent adsorbing property and filtering property in combination, and exhibiting excellent decolorizing performance and catalytic performance, to a method of producing the same and to use thereof. 002. It has been known from the old times that clay minerāls exhibit adsorbing property and decolorizing property. In Great Britain these minerāls have also been called fuller's earth or bleaching earth. 003. It has also been known that the so-called activated clay having inereased specific surface areas by treating clay minerāls with an acid. For example, Japanese Examined Patent Publication (Kokoku) No. 335/1948 discloses a method of producing activated clay by kneading and moulding acidic clay or a similar clay in vvater into a size of from 0,5 to 30 mm not to collapse, introducing resulting clay into an acid-resistant Container, and heating and circulating an inorganic acid therein to activate the clay. 004. Japanese Examined Patent Publication (Kokoku) No. 2960/1957 discloses a method of producing granular activated clay by adding sulphuric acid to acidic clay to shape it and, then, drying until it can be milled, followed by milling, sieving to trap the pārticies of predetermined sizes and activating the pārticies in a customary manner. 005. Japanese Examined Patent Publication (Kokoku) No. 11209/1970 discloses a method of treating alumina silicate clay to producē activated clay or fīne powdery silica by treating alumina silicate clay containing acid-soluble basie components with an acid, vvherein the alumina silicate clay is added an acidic aqueous solution in an amount of not larger than the amount of an acidic aqueous solution with which clay pārticies in a dispersion starts precipitating, the clay pārticies being formed in the dispersion due to the addition of an acid, or an acid in an amount of from 1,0 to 1,5 equivalents with respect to the basie mētai components that are to be removed, the basie mētai components in the clay are reacted with the acid in the dispersion and, then, the reaction product is isolated from the dispersion solution, the pārticies of the reaction product are treated in an aqueous medium at a pH of not larger than 1, and the basie mētai components are pieked up from the product. -2- 006. According to the conventional production of activated clay by the treatment with an acid, the treatment conditions are adjusted such as adjusting the acid concentration, temperature, treating time, etc. so that the acid-soluble basie components in the clay minerāls are at least partly eluted to improve decolorizing performance and to inerease the specific surface area. 007. Among the uses of activated clay, the use as a refining aģent for oils and fats requires a strong property for adsorbing colouring matters such as chlorophyll and the like contained in fats or oils, as well as good filtering property for separating the refined fats and oils from the waste clay from the standpoint of production. 008. In the conventional activated clay, hovvever, the property for adsorbing coloring matters is not compatible with the filtering property, and no clay has yet been known satisfying both of these properties to a sufficient degree. 009. That is, property for adsorbing colouring matters is improved as the particle diameter of the activated clay becomes more fine. On the other hand, the filtering property decreases to a conspicuous degree as the particle diameter becomes fine. 010. The clay used as a starting material for preparing an organo-clay is usually selected to provide a high degree of absorbency, and clays of the smectite class, such as montmorillonite, bentonite, heetorite and saponite are most suitable for this purpose. The material used to treat the surface of the clay generally comprises molecules which have both polar or hydrophilic, groups for effective bonding with the hydrophilic clay surface and non-polar or oleophilic groups, which wiil form bonds with the organic impurities which are to be removed. Material which have been found to be particularly suitable for this purpose inelude primary, secondary and tertiary amines and quaternary ammonium compounds, which contain a hydrocarbon radical having at least 8, and, preferably from about 10 to about 24, carbon atoms.

DISCLOSURE OF THE INVENTION 011. The present inventors have succeeded in producing regular-shaped pārticies of activated clay forming maero, micro and nano pores therein, preserving fine strueture of the clay minerāls, and having particle diameters controlled to lie within a range in which they exhibit excellent filtering property and have discovered the fact that the activated regular-shaped clay pārticies exhibit excellent adsorbing property and filtering property in combination. 012. The object of the present invention, therefore, is to provide activated regular-shaped clay pārticies obtained by treating a clay minerāls with a positive onium ions, containing one or more hydrocarbon side chains, consisting from 5 to 24 C atoms and combustible filler in a weight ratio of 1:2,5 to 2,5:1, the temperature and time of heating being such that a substantial amount of the c!ay remains un-vitrified and the organic filler is substantially completely burnt off and the vveight loss of the mixture is betvveen 30 and 70% based on the vveight of the dried mixture. -3- -3- LV 13570 013. The pores in said porous material being constituted by voids derived from the combustion of organic filler, previously contained therein and influence of onium salts to crystalline structure of clay mineral, said method comprising heating granules comprising a mixture of particulate clay, thus, having macro, micro and nano pores in the pārticies, having excellent adsorbing property and filtering property in combination, and exhibiting excellent decolorizing performance and catalytic performance, and a method of producing the same. 014. According to the present invention, there are provided activated regular-shaped clay pārticies obtained by treating clay minerāls with an positive onium ions, containing one or more hydrocarbon side chains, consisting from 5 to 24 C atoms and combustible filler in a vveight ratio of 1:2,5 to 2,5:1, wherein the regular-shaped pārticies have a volume-based median diameter of from 1,0 to 10,0 mm. 015. As found by a laser diffraction method, have a porous volume of porous radii of 1000 to 70,000 angstroms of from 0,30 to 0,90 cc/g as measured by a mercury intrusion porosity method, and have a granules specific surface area from 40 to 400 m2 /g . 016. Another object of the present invention is to provide a method of easily and efficiently producing the activated regular-shaped clay pārticies having the above-mentioned properties vvithout using any particular apparatus or means.

DESCRffTION 017. The clay used as a starting material for preparing extended clay is usually selected to provide a high degree of absorbency, and clays of the smectite class, such as montmorillonite, bentonite, hectorite and saponite are most suitable for this purpose. The material used to treat the surface of the clay generally comprises molecules which have both, polar or hydrophilic groups for effective bonding with the hydrophilic clay surface and non-polar or oleophilic groups. 018. In the method of the invention the liquid medium will in most cases be water. The organic onium compounds may be soluble in vvater and organic filler can be soluble in water or may be insoluble in vvater in which case they will be present in the form of a povvder, suspension or an emulsion, containing from 10% to 65% by vveight consists of composite granules. 019. Organic filler comprise from any combustible organic material or carbon in form of the pārticies less then 1,5 mm, better less then 0,5 mm, preferably derivatives of the cellulose, lignin or lignite groups of compounds or the carbon povvders. The extended clay are prepared by suspending the clay minerāls in solvent together with selected onium ion compound by steering until forms the stabile suspension in temperature interval from 5 to 85 °C. 020. This invention is illustrated by the follovving examples vvhich are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or -4- the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight. EXAMPLE 1. 021. 10 kg of the extended clay (moisture content 22% wet basīs), 18 kg milled peat (moisture content 27% wet basis) and 3,7 litres of vvater are placed in an mixer and mixed for 5 minūtes. The resulting agglomerative mixture is feed into a granulator, which compresses the mixture in the form of a mixed size granules which are passed through a drier at 100 °C until the moisture content is reduced to not more than 5% wet basis. This hardens the granules so that they may be sieved to recover granules of a size range of 1-10 mm. The selected granules are finally heated by passage through a kiln at 900 °C until substantially ali the peat is bumed off. 022. The product of this process is a porous granular ceramie material of circular shape, with a granule size within the range of from 1 to 10 mm. A bulk product density of 470 g/l is aehieved by this process. The product is of substantially neutral pH and is capable of absorbing 126% of its own vveight of vvater or 30% urea solution. The porosity of the product is vvithin the range of from 72 to 78% v/v. The product has high intrinsic strength and is very resistant to attrition and dust formation, both dry and in use. Discoloration of the product in use is minimal. 023. The bulk density of the product is calculated by determining the vveight of a given volume (not less than 1000 cm3) of material. The liquid absorption is determined by covering the material vvith liquid, mixing, and leaving to stand for 5 minūtes, the residual liquid then being removed. The absorption in % is calculated from the material vveight (Wm) and liquid vveight absorbed (W,) according to the equation: (W|.times.100)/ Wm The porosity is determined using the same method, except that the porosity is calculated from the material volume Vm and the volume of liquid absorbed Vt according to the equation: (V, ,times.100)/Vm. The volume Vm is the volume of the material per se, that is, excluding the volume betvveen pārticies. The pH of the material is determined by dispersing pārticies of the material of size less than 2,0 mm in deionised vvater and after mixing allowing to stand for at least 12 hours, the sample then being stirred for one minūte priorto measuring the pH of the solution. 024. The extended clay are prepared by suspending the100 parts of clay in 100 parts of vvater together vvith 10 parts of selected onium ion compound - cetil-tri-methyl ammonium bromide in this particular case, steering until forms the stabile suspension in temperature interval from 5 to 85 °C. -5- -5- LV 13570 COMPARATIVE EXAMPLES 1-5 025. In this series of experiments, the general procedure utilized in Exampie 1 was repeated. Other parameters are changed according to values given in table 1.

Table 1.

Nr. Clay/ Moisture % Peat/ Moisture Time min % Water I Density Absorbency g/i % Porosity %v/v Onium/clay p/p-°c Weight loss % 1 10/22 18/27 5 3.7 470 126 72-78 10/100-20 65 2 8/43 20/30 5 2.5 300 220 78-80 30/100-5 70 3 10/13 22/30 5 4.5 550 180 68-70 20/100-35 68 4 20/21 8/25 5 5.5 900 40 50-52 5/100-85 30 5 15/8 22/15 5 7.5 560 187 69-72 15/100-40 53 COMPARATIVE EXAMPLES 6-10 026. In this series of experiments, the general procedure utilized in Example 1 was repeated except, that the extended clay are prepared by suspending the100 parts of clay in 100 parts of water together with 10 parts of selected onium ion compound - heksa-methyl-di-ammonium acetate in this particular case, steering until forms the stabile suspension in temperature interval from 5 to 85 °C.

Other parameters are changed according to values given in table 2.

Table 2.

Nr. Clay/ Moisture % Peat/ Moisture Time min % VVater I Density Absorbency g/i % Porosity %v/v Onium/clay p/p-°c VVeight loss % 6 10/24 18/27 5 3.7 430 131 70-72 10/100-20 60 7 8/40 20/30 5 2.5 300 220 76-78 30/100-5 71 8 10/20 22/30 5 4.5 510 180 68-70 20/100-35 68 9 20/19 8/25 5 5.5 880 40 50-52 5/100-85 30 10 15/11 22/15 5 7.3 600 187 68-70 15/100-40 53 COMPARATIVE EXAMPLES 11-15 027. In this series of experiments, the general procedure utilized in Example 1 was repeated except , that the extended clay are prepared by suspending the100 parts of clay in 100 parts of water together with 10 parts of selected onium ion compound - -6- N-methyl-N-di-hidrogenated-tallow-ammonium sulphate in this particular case, steering until forms the stabile suspension in temperatūra interval from 5 to 85 °C.

Other parameters ara changed according to values given in table 3.

Table 3.

Nr. Clay/ Moisture % Peat/ Moisture Time min % Water I Density Absorbency g/i % Porosity %v/v Onium/clay p/p-°c VVeight loss % 11 10/25 18/27 5 3.7 420 156 78-80 10/100-20 61 12 8/48 20/28 5 2.5 280 260 80-88 30/100-5 73 13 10/12 22/26 5 4.5 450 180 68-70 20/100-35 69 14 20/18 8/25 5 5.5 800 90 56-59 5/100-85 29 15 15/5 22/15 5 7.8 460 227 71-75 15/100-40 59 028. The properties of the product depend upon a variety of factors, which may be adjusted in order to obtain a product of particular desired characteristics. These factors include, for example: the type of clay employed, which affects the colour and strength of the product; the particle sizes of the clay and combustible material, which determine the pore size and the absorption properties; the onium salt, which Controls the absorbency and specific surface: the ratio of clay to combustible material, which Controls the density and hence the porosity and strength; the drying time and temperatūra, which may affect the particle shape and also the strength; and the kiln environment (that is, the temperatūra, firing profilē and atmosphere), which can affect the colour, density, strength and absorption properties. For example, an increased strength may be obtained in a material according to the invention by using a higher drying temperatūra or a higher kiln temperatūra. 029. The product usually has a substantially neutral pH and is usually strong enough to rasist attrition and dust formation in use. The material has an open-pore structure, the matrix of which is permeable. That is, the material contains a netvvork of relatively large poras that are interconnected by relatively small poras, which makes it suitable for use as an industrial absorbent for liquids and soluble solīds and ions, as carrier for liquid fertilizers, inorganic and organic salts, catalysts and complex mixtures, as carrier for micro-organisms growth, as filler for compounding the thermoplastic materiāls and as filler and/or for polymerisation process modification and for other purposes. 030. Variations in the present invention are possible in light of the description of it provided herein whole certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described vvhich will be within the full intended scope of the invention as defined by the follovving appended claims.

Claims 1. Activated regular-shaped clay ceramie pārticies forming maero, micro and nano pores therein, preserving fine strueture of the clay minerāls after influence of onium salts to crystalline strueture of clay mineral, and having particle diameters controlled to lie within a range in vvhich they exhibit excellent filtering and sorption property, has a granule size of from 1 to 10 mm, a bulk density of from 300 to 900 g/l, a porosity of from 50 to 80% v/v, and a liquid absorbency of from 40 to 260% of water based on the weight of the granular material and specific surface from 40 m2/g to 400m2/g by heating a mixture of clay and a particulate combustible material and by interaction of clay in wet phase with positive onium ions, containing one or more hydrocarbon side chains, consisting from 5 to 24 C atoms and the pores in said porous material being constituted by voids derived from the combustion of organic filler, previously contained therein, said method comprising heating granules comprising a mixture of particulate clay and combustible filler in a vveight ratio of 1:2,5 to 2,5:1, the temperature and time of heating being such that a substantial amount of the clay remains un-vitrified and the organic filler is substantially completely burnt off and the vveight loss of the mixture is betvveen 30 and 70% based on the vveight of the dried mixture. 2. A method according to elaim 1, vvherein the heating temperature is up to 1050 °C, preferably up to 900 °C., belovv the clay vitrified temperature. 3. A method according to elaim 1, vvherein the mixture of clay and organic filler is obtained by mixing clay, the organic filler and vvater to obtain a moist agglomerate mixture and to svvell it in Ι-ΙΟ mm granules, drying granules to a moisture content of not more than 5%. 4. A method according to elaim 3, vvherein the mixture in granules form is dried at a temperature not exceeding 200 °C. 5. A method according to elaim 1, vvherein the mixture is first shaped into granules and then dried and heated. 6. A method according to elaim 5, vvherein the mixture is shaped by granulation and the granules are dried and screened to recover granules vvithin a pre selected size range for heating. 7. A method according to elaim 1, vvherein the particle sizes of clay and the organic filler in the starting mixture are each not greaterthan 1,5 mm. 8. A clay ceramie granules, forming maero, micro and nano pores therein, having a granule size predominately vvithin the range of from 1 to 10 mm; a bulk density of from 300 to 900 g/l, a porosity of from 50 to 80% v/v, and a liquid absorbency of from 40 to 260%, of vvater based on the vveight of the granular material and specific surface from 40 m2/g to 400m2/g and comprising an intimate mixture of particulate clay and particulate organic filler in a vveight ratio of from 1:2,5 to 2,5:1 before heating, vvherein they are suitable for use as an industrial absorbents for liquids and soluble solīds and ions, as carrier for liquid fertīlizers, inorganic and organic salts, catalysts and complex mixtures, as carrier for micro-organisms grovvth, as filler for compounding the thermoplastic materiāls and as filler . for polymerisation process modification and prepared according to the process of any claims from 1 to 7. -8- -8- LV 13570

Abstract

Activated regular-shaped clay ceramie pārticies forming maero, micro and nano pores therein, after influence of onium salts to crystalline strueture of clay mineral, preserving fine strueture of the clay minerāls, and having particle diameters controlled to lie within a range in which they exhibit excellent filtering and sorption property, has a granule size of from 1 to 10 mm, a bulk density of from 300 to 900 g/l, a porosity from 50 to 80% v/v, and a liquid absorbency from 40 to 260%, of water based on the vveight of the granular material and specific surface from 40 m2/g to 400m2/g .

The invention further provides method of producing the material by heating a mixture of clay and a particulate combustible material and by interaction of clay in wet phase with positive onium ions, containing one or more hydrocarbon side chains, consisting from 5 to 24 C atoms, and forming in the granular form before drying and heating. The material is suitable for use or as an industrial absorbent for liquids and soluble solids and ions, as carrier for liquid fertilizers, inorganic and organic salts, catalysts and complex mixtures, as carrier for micro-organisms growth, as filler for compounding the thermoplastic materiāls, as filler and/or for polymerisation process modifīcation and for other purposes.

Claims (8)

Claims 1. A method of producing a regular form of activated ceramic granules on a clay basis, wherein the granules have macro-, micro-, and nanopores, whereby in the process of obtaining them, the fine grain structure of the clay is maintained after exposure to the onyon ions on the crystalline structure of the clay; the process is regulated so that they are within a range of granules of 1 to 10 mm in diameter showing good filtration and sorption properties, with a bulk density of 300 to 900 g / l, a porosity of 50 to 80% by volume, and the absorbency of liquids ranges from 40 to 260% by weight of water against the solid phase of the granular material, and the specific surface area of the granules ranges from 40 to 400 m2 / g, characterized in that a mixture of clay and combustible organic material is heated to clay in the wet phase before mixing with this material is treated with positive onion ions containing one v a number of hydrocarbon side chains having 5 to 24 carbon atoms, wherein the pores in said porous material form voids which result from burning the previously blended organic filler, said method comprising pellet heating containing a mixture of clay particles and a mixture of combustible filler in relation to 1: 2.5 to 2.5: 1, the heating temperature and heating time are selected such that the largest amount of clay is not subjected to the glazing process, the organic filler essentially burns out completely and the weight loss of the mixture ranges from 30 to 70%, based on the ratio of the dried mixture. mass. Method according to claim 1, characterized in that the heating temperature is up to 1050 ° C, preferably up to 900 ° C, without exceeding the glass transition temperature of the clay. 3. A method according to claim 1, characterized in that the mixture of clay and filler is obtained by mixing clay, filler and water to form a wet agglomerate blend and granulated from 1 mm to 10 mm granules, followed by granules. dried to a moisture not exceeding 5%. Method according to claim 3, characterized in that the mixture in the form of pellets is dried at a temperature not exceeding 200 ° C. Method according to claim 1, characterized in that the mixture is first formed in the form of pellets, then dried and heated. Method according to claim 5, characterized in that the mixture is formed in the form of pellets, the pellets are dried and sieved to separate the pellets of the size selected in the pre-selected range for heating. Method according to claim 1, characterized in that both the clay and the organic filler particles have a particle size of not more than 1.5 mm in the initial mixture. 8. Clay ceramic granules, where the granules contain macro-, micro-, and nanopores and the granules have a size of between 1 mm and 10 mm, have a bulk density of between 300 and 900 g / l, while the porosity, calculated as volume ratio, is from The absorption capacity of 50 to 80% as well as granular fluids is from 40 to 260%, calculated as the ratio of absorbed liquid to solid phase, and the specific surface area of the granules ranges from 40 to 400 m2 / g, with granules consisting of clay particles and filler. a homogeneous mixture of particles in which the weight of the components prior to heating is from 1: 2.5 to 2.5: 1, characterized in that the granules are made according to a method as defined in any one of claims 1 to 7, and suitable for liquid, soluble solids and ionic industrial sorbents, as well as for carriers of liquid fertilizers, inorganic and organic salts, catalysts and complex mixtures, are usable as carriers for microbes for cultivation of pasturage as well as for use as a filler for the formation of thermoplastic material compounds and for the modification of polymerization processes as filler.