Abstract: The invention is directed to an nanocomposite material and products produced from the nanocomposite material. This invention is also directed to a process for preparing a polymer-clay nanocomposite comprising the steps of (i) forming a concetrate comprising a layered clay material with a matrix polymer-compatible functionalized oligomer or polymer, and (ii) melt compounding the concentrate with a melt-processible matrix polymer to produce a polymer-clay nanocomposite.

Abstract: An improved method for purifying titania contaminated kaolin clay by froth flotation which features the use an hydroxamate flotation collector at a neutral or mildly alkaline pH wherein a slurry of the impure clay is conditioned for the flotation step in a baffled conditioning apparatus provided with mean for imparting sufficient mechanical energy to heat a dispersed slurry of the impure clay before flotation.

Abstract: This invention is directed to a polyamide-clay nanocomposite, products produced from the nanocomposite, and a process for preparing a polyamide-clay nanocomposite. The polyamide-clay nanocomposite comprises (a) an amorphous matrix polyamide comprising (i) a residue of a dicarboxylic acid component comprising at least two diacids and (ii) a residue of a diamine component, and (b) a layered clay material, wherein the layered clay material is dispersed in the matrix polyamide.

Abstract: In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymer-containing plasticizer, or EO/PO comb polymer-containing plasticizer, and further containing clay, such as a smectite clay, which expands when in contact with water, the step of providing an agent operative to modify the clay whereby the plasticizer absorbing capability of the clay is reduced. In exemplary methods of the invention, the plasticizer is an EO/PO (e.g., oxyalkylene) plasticizer and preferably an EO/PO comb polymer, and the clay-activity-modifying agent may comprise an inorganic cation, an organic cation, a polar organic molecule capable of being absorbed by the clay, a clay dispersant (such as a polyphosphate), or a mixture thereof. For clay-activity-modifying agents which comprise a cation or a polar organic molecule, the agent is preferably added to the clay before water is introduced to the clay.

Abstract: The present invention relates to novel low molecular weight, structured polymer compositions. The invention also relates to methods for inhibiting scale formation, precipitation or deposition; increasing dispersion of insoluble precipitates in process waters; treating cooling and boiler water; and reducing the viscosity of mineral slurries using the aforementioned polymer compositions.

Abstract: A nanocomposite composition is disclosed which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer. In one embodiment, the presence of the benzoxazine monomer, oligomer, and/or polymer in the clay results in an at least about 5% increase in the spacing between the platelets of the clay. In another embodiment, the presence of the presence of the benzoxazine monomer, oligomer, and/or polymer in the clay results in at least about 5 wt. % of the clay being exfoliated. Also disclosed are a method for making (1) an intercalated nanocomposite clay composition which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer; (2) an exfoliated nanocomposite clay composition which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer; and (3) a method for making a nanocomposite clay composition that is both exfoliated and intercalated.

Abstract: Intercalated layered materials prepared by co-intercalation of a multi-charged onium ion spacing/coupling agent and a matrix polymer between the planar layers of a swellable layered material, such as a phyllosilicate, preferably a smectite clay. The spacing of adjacent layers of the layered materials is expanded at least about 3 Å, preferably at least about 5 Å, usually to about 15-20 Å, e.g., 18 Å with the di-charged onium ion spacing/coupling agent. The intercalation of the matrix polymer then increases the spacing between adjacent layers to at least about 15 Å, preferably to about 20 Å to about 30 Å.

Abstract: Intercalates formed by contacting a layered material, e.g., a phyllosilicate, with an intercalant monomer ether and/or ester to sorb or intercalate the intercalant monomer between adjacent platelets of the layered material. Sufficient intercalant monomer is sorbed between adjacent platelets to expand the adjacent platelets to a spacing of at least about 5 Å (as measured after water removal to a maximum of 5% by weight water), up to about 100 Å and preferably in the range of about 10-45 Å, so that the intercalate easily can be exfoliated into individual platelets. The intercalated complex can be combined with an organic liquid into a viscous carrier material, for delivery of the carrier material, or for delivery of an active compound; or the intercalated complex can be combined with a matrix polymer to form a strong, filled polymer matrix. Alternatively, the intercalated complex can be exfoliated prior to combination with the organic liquid or the matrix polymer.

Abstract: Intercalated layered materials prepared by co-intercalation of a multi-charged onium ion spacing/coupling agent and a matrix polymer between the planar layers of a swellable layered material, such as a phyllosilicate, preferably a smectite clay. The spacing of adjacent layers of the layered materials is expanded at least about 3 Å, preferably at least about 5 Å, usually to about 15-20 Å, e.g., 18 Å with the di-charged onium ion spacing/coupling agent. The intercalation of the matrix polymer then increases the spacing between adjacent layers to at least about 15 Å, preferably to about 20 Å to about 30 Å.

Abstract: Disclosed is a method for forming a polymer nanocomposite, which comprises (a) modifying a clay material comprising layered silicate particles by ion exchange with a surfactant to form an organoclay; (b) dispersing the organoclay in a vinyl monomer and bulk polymerizing said monomer in the presence of a catalyst; and (c) adding a liquid suspension to the above mixture to effect suspension polymerization when the conversion rate of the polymerization is about 10% to 50%, thereby forming a composite having the particles uniformly dispersed in a vinyl polymer matrix.

Abstract: A method for the treatment of a kaolin clay crude to separate by selective flocculation impurity particles contained in the crude from finely divided kaolinite particle contained in the crude, comprising: (a) forming said crude into a dispersed aqueous slurry b adding water and at least one dispersant to said crude; (b) conditioning said dispersed aqueous slurry by adding conditioning chemical thereto, the conditioning chemical providing addition of monovalent cations to the slurry without adding multivalent cations thereto; (c) selectively flocculating said conditioned slurry by adding to said conditioned slurry a composition comprising (i) a high molecular weight component comprising an organic anionic polymer having a molecular weight of at least 1 million; and (ii) a low molecular weight component comprising an inorganic anionic polyphosphate; said composition causing impurity particles in said slurry to flocculate and settle as a dense lower layer and kaolinite particles in said slurry to be defloccul

Abstract: An improved process for the beneficiation of mixtures of mineral particles (such as kaolin clays) containing minerals which chelate with hydroxamates. The use of a silicon-containing compound in combination with a hydroxamate results in a more effective separation of minerals which chelate with the hydroxamate.

Abstract: A process for preparing organoclays as thixotropic agents to control the rheology of water-based paints and other aqueous and polar-organic systems. The process relates to treating low-grade clay ores to achieve highly purified organoclays and/or to incorporate surface modifying agents onto the clay by adsorption and/or to produce highly dispersed organoclays without excessive grinding or high shear dispersion. The process involves the treatment of impure, or run-of-mine, clay using an aqueous biphasic extraction system to produce a highly dispersed clay, free of mineral impurities and with modified surface properties brought about by adsorption of the water-soluble polymers used in generating the aqueous biphasic extraction system. This invention purifies the clay to greater than 95%.

Abstract: A composition of clay, water and an additive chosen from the group consisting of tannin, modified tannin and mixtures thereof. A clay brick made from a composition of clay, water and an additive chosen from the group consisting of tannin, modified tannin and mixtures thereof. A method for producing clay bricks in which a composition comprising clay, water and an additive chosen from the group consisting of tannin, modified tannin and mixtures thereof is prepared. A clay brick made by a method in which a composition comprising clay, water and an additive chosen from the group consisting of tannin, modified tannin and mixtures thereof is prepared. A method for producing brick in which the water content necessary to facilitate the extrusion of a plastic mixture of clay and water is reduced by incorporating an additive chosen from the group consisting of tannin, modified tannin and mixtures thereof into the plastic mixture of clay and water.

Abstract: Matte grade coated ink jet paper comprises a cellulosic substrate coated with a coating composition comprising a calcined kaolin clay particulate pigment comprising porous aggregates with a total pore volume of 0.60 cm.sup.3 /g to 2.00 cm.sup.3 /g, a narrow particle size distribution where about 90 weight % has an E.S.D. less than 2 microns a mean pore size less than 0.8 microns in diameter, and a cationic polymer with an average molecular weight in the range of 1,000 to 5 million daltons which polymer acts as a dispersant in a precursor slurry and produces a net positive charge on the calcined clay pigment. This chemically treated clay pigment is used in a final coating formulation for the substrate to provide high printing ink density, printed and coating gloss, water fastness resistance, low wicking, and low bleeding on most ink jet papers.

Abstract: A method of producing a porous inorganic particulate material which comprises treating a particulate aluminosilicate material with a leaching agent which chemically reacts with or solubilizes aluminum and thereby leaches aluminum from the aluminosilicate material, wherein the particulate aluminosilicate material is a particulate hydrous aluminosilicate material which has been flash calcined.

Abstract: A method for producing an attapulgite clay (Fuller's Earth) that significantly removes other types of clays and minerals, resulting in improved performance. A unique dispersant is used that will fully disperse the individual attapulgite particles in water such that the particles remain in suspension, and said dispersant will not fully disperse other clay and mineral species, which then can be easily separated through various techniques. The attapulgite clay may be recovered from the dispersion and dried in such a manner to produce a finely sized powder from ore, without the need for any grinding or milling operation. The dried attapulgite clay with adsorbed dispersant is redispersed in water and retain thixotropic properties.

Abstract: Intercalates formed by contacting a layered material, e.g., a phyllosilicate, with an intercalant monomer having a hydroxyl and/or an aromatic ring functionality to sorb or intercalate the intercalant monomer between adjacent platelets of the layered material. Sufficient intercalant monomer is sorbed between adjacent platelets to expand the adjacent platelets to a spacing of at least about 5 .ANG. (as measured after water removal to a maximum of 5% by weight water), up to about 100 .ANG. and preferably in the range of about 10-45 .ANG., so that the intercalate easily can be exfoliated into individual platelets. The intercalated complex can be combined with an organic liquid into a viscous carrier material, for delivery of the carrier material, or for delivery of an active compound; or the intercalated complex can be combined with a matrix polymer to form a strong, filled polymer matrix.

Abstract: Intercalates formed by contacting a layered material, e.g., a phyllosilicate, with an intercalant monomer having a hydroxyl and/or an aromatic ring functionality to sorb or intercalate the intercalant monomer between adjacent platelets of the layered material. Sufficient intercalant monomer is sorbed between adjacent platelets to expand the adjacent platelets to a spacing of at least about 5 .ANG. (as measured after water removal to a maximum of 5% by weight water), up to about 100 .ANG. and preferably in the range of about 10-45 .ANG., so that the intercalate easily can be exfoliated into individual platelets. The intercalated complex can be combined with an organic liquid into a viscous carrier material, for delivery of the carrier material, or for delivery of an active compound; or the intercalated complex can be combined with a matrix polymer to form a strong, filled polymer matrix.

Abstract: The present invention relates to a composition comprising platelet particles treated with at least one polyalkoxylated ammonium salt comprising at least one polyalkoxylated group consisting of greater than 5 repeating alkyl oxide groups. The treated particles of the present invention display particularly good dispersion when incorporated into various polyester compositions at concentrations up to about 25 weight %. Also disclosed is a process incorporating said treated platelet particles into a polyester and for forming said treated platelet particles.

Abstract: A method of enhancing the brightness and increasing the yield of a kaolin clay by optimizing the removal of the titania and mica impurities in the clay and the amount of clay remaining in the slurry is disclosed. The method is a selective flocculation process wherein the clay is blunged, dispersed, and conditioned before flocculation. In the flocculation step, a high molecular weight anionic polymer and a low molecular weight anionic polymer, such as sodium polyacrylate, are added to the slurry after the conditioning process, whereby the titania-mica enriched flocs are separated from the suspension which is enriched with kaolin. This final kaolin product has titania levels ranging from 0.1% to 0.5%, a reduced mica level, a high usable product yield, and a brightness greater than 89.5 and at least 91.5.

Abstract: An organoclay composition comprising a mineral clay mixture which has been treated with an alkyl quaternary ammonium salt said mixture comprising: mineral clay (a) comprising 50 to 95 wt. %, based on the weight of the mineral clay mixture, of a mineral clay selected from the group consisting of sepiolite, palygorskite and mixtures of sepiolite and palygorskite; and mineral clay (b) comprising the balance by weight of the mineral clay mixture, of a smectite.

Abstract: Kaolin clays are conditioned for the removal of colored titaniferous impurities by (A) first mixing the kaolin clay with a collector to condition the impurities, in the absence of a dispersant, but in the presence of sufficient water to yield a mixture having a solids content of at least 65 percent by weight and (B) then deflocculating the kaolin clay mixture at a pH of at least 4.0 with a dispersant in amounts sufficient to yield a kaolin clay slurry which is suitable for subsequent processing to remove colored titaniferous impurities.

Abstract: A method of improving the strength and/or plasticity of a clay composition comprising a kandite clay and an organic additive comprising at least one water soluble compound having a plurality of basic groups wherein the organic additive is present in an amount of from about 0.05% by weight to about 0.5% by weight based on the dry weight of the kandite clay present, which method comprises treating the kandite clay by adding thereto a monovalent ion activated smectite clay or a monovalent ion activating agent for a smectite clay or both whereby the amount of monovalent ion activated non-calcined smectite clay present in the clay composition is adjusted to be in the range from about 1% by weight to about 5% by weight based upon the dry weight of the kandite clay present.

Abstract: A process for filtering kaolin clay slurries in the presence of a filter aid which increases the percent solids in the filter cake, decreases the product solids in the waste filtrate, increases the rate of filtration, and yet does not interfere with redispersal of the filter cake after filtration. The process utilizes high molecular weight, highly anionic polyacrylic acid homopolymers or copolymers, or water soluble salts thereof, as filter aids for thickening and dewatering kaolin clay slurries. The flocculated clay may be redispersed after the separation process by normal means, such as the addition of low molecular weight anionic polymers with mixing.

Abstract: High performance acid activated clays suitable for bleaching oil are produced by contacting an intercalating clay mineral with a strong acid in a polar organic liquid.

Abstract: Colored impurities are removed from kaolin clay by an improved flotation process in which a blend of a fatty acid compound and a hydroxamate compound is used as a collector.

Abstract: An effective production method for silane-treated clays having exceptional reinforcing effects with respect to rubber, and compositions using these silane-treated clays are offered. With the silane-treated clay production method, a functional silane is predispersed or emulsified in water by means of a surfactant in order to mix the functional silane with kaolin clay and thereby uniformly surface-treat the kaolin clay with the functional silane. The surfactant should preferably be a non-ionic surfactant with an HLB value in the range of 8-18. The silane-treated clay formed by surface-treating kaolin clay by means of these functional silanes characteristically contains low residual levels of the non-ionic surfactants. The functional silanes can be either vinyl or sulfur functional silanes. The silane treated clays are useful as fillers or extenders in rubber compositions, particularly those employing silicas and/or carbon blacks.

Abstract: An improved finely divided rubber-reinforcing clay mineral composition can be produced by employing a hydrous kaolin clay surface treated with a functional silane, a methylene donor compound such as hexamethylenetetramine, and a multifunctional methylene acceptor such as resorcinol. A novel process of preparation is provided. The improved reinforcing, treated clay filler can be combined with natural or synthetic elastomer compositions which can be cured to elastomer products which have improved physical properties, such as modulus, tensile, tear, wear resistance and/or resistance to heat build-up.

Abstract: An improved finely divided rubber-reinforcing clay mineral composition can be produced by employing a hydrous kaolin clay surface treated with a functional silane, a methylene donor compound such as hexamethylenetetramine, and a multifunctional methylene acceptor such as resorcinol. A novel process of preparation is provided. The improved reinforcing, treated clay filler can be combined with natural or synthetic elastomer compositions which can be cured to elastomer products which have improved physical properties, such as modulus, tensile, tear, wear resistance and/or resistance to heat build-up.

Abstract: The present invention relates to a mineral eluting material for drinking water with granite as raw material and manufacturing method thereof and a structural body of mineral eluting material. The mineral eluting material includes granite crushed to sizes of 0.075.about.0.145 mm, submerged in 3.about.10% glucose solution for 24 hours, baked at 380.degree..about.400.degree. C. for 12.about.24 hours, and cooled at room temperature in a tightly sealed vessel. The structural body according to the present invention is manufactured by piling up granular granite and silver activated charcoal in 2-10 layers respectively and alternately in a cylindrical column. Water having passed the structural body according to the present invention comprising granular granite contains no impurities and abounds in minerals.

Abstract: Intercalates formed by contacting a layered material, e.g., a phyllosilicate, with an intercalant monomer having a hydroxyl and/or an aromatic ring functionality to sorb or intercalate the intercalant monomer between adjacent platelets of the layered material. Sufficient intercalant monomer is sorbed between adjacent platelets to expand the adjacent platelets to a spacing of at least about 5 .ANG. (as measured after water removal to a maximum of 5% by weight water), up to about 100 .ANG. and preferably in the range of about 10-45 .ANG., so that the intercalate easily can be exfoliated into individual platelets. The intercalated complex can be combined with an organic liquid into a viscous carrier material, for delivery of the carrier material, or for delivery of an active compound; or the intercalated complex can be combined with a matrix polymer to form a strong, filled polymer matrix.

Abstract: Fine-grained kaolin clays having improved brightness can be produced by (a) using centrifugation to fractionate the clay starting material into finer and coarser fractions, (b) subjecting the coarser fraction to flotation to remove discoloring impurities and (c) combining the finer and floated coarser fractions to produce fine-grained kaolin clays having improved brightness.

Abstract: Organoclay compositions which comprise the reaction product of a smectite-type clay having an ion exchange capacity of at least 50 meq. wt. per 100 g. clay (active basis), and mixture of a quaternary ammonium compound and a chain transfer agent which is a thiol, .alpha.-methylketone, .alpha.-methylalcohol or a halogen compound are useful agents for use in the processes for the preparation of thermoplastic materials.

Abstract: An aqueous slurry of smectite clay of elevated solids content, comprising an aqueous solution or emulsion of at least 0.2% by weight of said slurry of a salt of a low molecular weight amine salt, in which is dispersed from about 10 to 47% by weight of the slurry, of a smectite clay. The amine salt is effective to prevent the smectite from swelling appreciably, whereby the slurry can be shipped and stored without creating a gelling problem. The inhibiting or suppressing effect of the amine salt on the swelling of the clay and on gelling of the slurry is reversible upon subsequent dilution with water, thereby facilitating use of the smectite in typical applications, e.g. as a retention aid in paper making, or as a viscosifier.

Abstract: Quaternary ammonium compositions are described which are made using diluents including soya bean oil, caster oil, mineral oils, isoparaffin/naphthenic and coconut oil. Such diluents remain as diluents in the final product and generally have a vapor pressure of 1 mm of Hg or less at 25.degree. C., and are liquid at ambient temperature. The quaternary/ammonium diluent compositions have low volatile organic compound emission rates and high flash points, and can be tailored to particular applications. Such applications include use a fabric softeners, cosmetics ingredients, deinking additives, surfactants, and reaction materials in the manufacture of organoclays.

Abstract: A process for improving the rheological properties of an aqueous suspension of a particulate inorganic material which comprises the steps of: (a) forming an aqueous suspension of the particulate inorganic material and an effective amount of an anionic polyelectrolyte dispersing agent; (b) diluting the suspension formed in step (a) with water while maintaining the particulate in the dispersed state of step (a) to give a solids concentration of not less than 20% by weight of the particulate inorganic material; and (c) reconcentrating the diluted suspension formed in step (b) to give a solids concentration of at least 50% by weight of the particulate inorganic material.

Abstract: Structured paper coatings having good opacifying characteristics and good rheological properties are manufactured by a process which consists essentially of mixing a fine particle size kaolin clay pigment; water; at least one material selected from the group consisting of dispersing agents, thickening agents, pH adjusting agents, wetting agents, defoaming agents and mixtures thereof; and at least one cationic flocculant; and then adding a non-cationic binder material to the mixture under continued mixing conditions for a time sufficient to produce the structured paper coating.

Abstract: Novel silicate minerals that have undergone a cation exhange with at least one heteroaromatic cation comprising a positively charged organo-substituted heteroatom and/or at least one positively charged heteroatom not part of an aromatic ring with at least one bond having a bond order greater than one and compositions comprising the same are described.

Abstract: Described is a process for separating a mixture of finely divided minerals into constituents thereof. In particular, the invention relates to a procedure for effecting such separation by a novel selective flocculation technique wherein a dispersed aqueous pulp containing the mixture of minerals is preconditioned for selective flocculation with an anionic polymer by addition of both a fatty acid such as oleic acid and source of polyvalent cation such as calcium chloride. The fatty acid and cation of the salt selectively coat the component of the mixture that is subsequently flocculated with the anionic polymer. A polyacrylate salt dispersant is preferably used in the process. The invention is especially adapted to the separation of colored titaniferous impurities from kaolin clay in which case both a white purified kaolin product and a strongly flocculated dun-colored titania/kaolin mixture are recovered and then dispersed producing a material useful as a paper coating pigment.

Abstract: Kaolin clays are conditioned for the removal of colored titaniferous impurities by (A) first mixing the kaolin clay with a collector to condition the impurities, in the absence of a dispersant, but in the presence of sufficient water to yield a mixture having a solids content of at least 65 percent by weight and (B) then deflocculating the kaolin clay mixture at a pH of at least 4.0 with a dispersant in amounts sufficient to yield a kaolin clay slurry which is suitable for subsequent processing to remove colored titaniferous impurities.

Abstract: A method for beneficiating a low brightness fine particle size discolored kaolin crude to produce a high brightness coating clay. By combining the two beneficiating techniques of selective flocculation and ozonation, a synergistic phenomena occurs and a clay product of superior brightness and whiteness can be obtained from fine discolored clays that cannot be achieved by beneficiation with either process singularly. By passing the flocced clay through ozonation, the flocculant polymer left in the clay can be completely destroyed.

Abstract: A process for intercalating potassium acetate molecules in kaolin clay particles to achieve delamination has been developed by mixing kaolin clay particles, potassium acetate and water. A maximum intercalation, and hence a maximum degree of delamination, can be achieved with potassium acetate levels between 10% and 75% by weight, based on the weight of kaolin clay particles, and 5% and 50% water by weight, based on the weight of potassium acetate.

Abstract: A biologically stable kaolin clay slurry is manufactured by heating a kaolin clay slurry for at least 15 minutes at a temperature of at least 93.degree. C., cooling the slurry to a temperature no greater than about 35.degree. C. and then adding a microbiocide to the slurry.

Abstract: Quaternary ammonium compositions are described which are made using diluents including soya bean oil, caster oil, mineral oils, isoparaffin/naphthenic and coconut oil. Such diluents remain as diluents in the final product and generally have a vapor pressure of 1 mm of Hg or less at 25.degree. C., and are liquid at ambient temperature. The quaternary/ammonium diluent compositions have low volatile organic compound emission rates and high flash points, and can be tailored to particular applications. Such applications include use a fabric softeners, cosmetics ingredients, deinking additives, surfactants, and reaction materials in the manufacture of organoclays.

Abstract: A process for preparing a liquid slurry of bentonite which comprises the steps of charging a reactor vessel with between about 25 to about 75% of water by weight. The water is heated to a temperature range between about 50.degree. C. to about 95.degree. C. The reactor vessel is charged with between about 0, 1 and about 10% of sodium salt of silicic acid by weight and with between about 15 to about 35% of bentonite by weight. The reactor vessel is also charged with between about 10 to about 30% of a polyacrylate by weight.

Abstract: Organically modified clays are advantageously prepared in a direct addition, low moisture process by mixing clay, a cationic, organic material, and an optional dispersant under high pressure conditions such that the cationic organic compound substitutes for inorganic cations in the clay. Processing is preferably carried out in several separate stages under pressure conditions of at least 3,000 psi, and it is preferred that at least one of the processing stages takes place at a pressure of at least 8,000 psi.

Abstract: A method for activating smectite clays to give swelling power and/or dispersibility in an aqueous electrolyte solution and resulting activated smectite clays are disclosed, the method comprising previously adding an adequate amount of an aprotic polar solvent having a higher relative permittivity than those of alcohols (e.g., N,N-dimethylformamide, N,N-dimethylacetamide, ethylene carbonate, propylene carbonate or dimethyl sulfoxide) to an aqueous electrolyte solution in which the clays (or the clays previously suspended) are to be swollen and/or dispersed, or treating the clays to be swollen and/or dispersed with the compound.

Abstract: A low brightness pigment and method is provided from a heretofore rejected waste kaolin stream. Kaolin processing rejects are high in iron-stained TiO.sub.2. After separating the stained TiO.sub.2 from the high brightness kaolin and concentrating the resulting fraction, the material can be processed to produce a low brightness pigment suitable of many applications where lower brightness is desirable, such as coating paper board without mottling.

Abstract: A stable high solids structured clay slurry is manufactured by a process which comprises the sequential steps of forming a high solids slurry by mixing a structured clay material with water in a first stage mixing step under conditions which promote particle to liquid contact and which substantially prevent interaction between the structured clay particles, terminating the first stage mixing and then, in a second stage mixing step, mixing the high solids slurry under conditions which are different from the first stage mixing conditions and which promote substantial interaction between the structured clay particles.