Abstract: Disclosed herein are methods for removing discoloring impurities, such as carbon impurities, particularly graphite, from kaolin clay to enhance the brightness of the kaolin clays. The methods include reverse flotation processes. Also disclosed herein are high brightness kaolin products, and the uses thereof.

Abstract: The present invention relates to a kaolin composition having improved physical properties, for example, for use in the production of paper products. The composition can comprise kaolin having a shape factor of at least about 20. The kaolin can have a particle size distribution such that at least about 94% by weight of the kaolin can have an esd of less than about 2 ?m and/or at least about 80% by weight of the kaolin can have an esd of less than 1 ?m. The amount of the kaolin having an esd of less than about 0.25 ?m can range from about 25% to about 60% by weight. The Hercules viscosity of the kaolin product is less than 4000 rpm at 18 dynes at 63% solids and less than 1500 rpm at 18 dynes at 69% solids when measured using the “A” bob. The present invention also relates to an improved method for making the kaolin product from sedimentary kaolin.

Abstract: Spherical and rod-shaped proppants and anti-flowback agents made from sillimanite minerals possess high strength and high conductivity. The sillimanite minerals may be selected from the group consisting of kyanite, sillimanite, and andalusite and may be used alone or in combination with other materials, such as bauxite, kaolin, meta-kaolin, pure or technical grade alumina (about 98%-99.9% alumina by weight), alumina-containing slag, zirconia, silica, iron, alkali elements (such as calcium, magnesium, and sodium), and virtually any other mineral containing alumina. The starting material may optionally be milled to achieve better compacity and crush resistance in the final proppant or anti-flowback agent. A fracturing fluid may comprise the rods or spheres alone, or in combination with each other or other proppants or anti-flowback agents of different shapes.

Abstract: The Rio Capim Kaolin deposit contains a lower bed of soft kaolin clay that averages 10 meters thick, and an upper bed of “hard” kaolin (“RCC hard kaolin”) that may be as thick as 6 to 8 meters. Due to their high impurity content fine particle size, cementetious nature, and high degree of particle aggregation, hard kaolins are difficult to process. Disclosed herein are compositions comprising kaolin having a particle size distribution such that at least about 90% of the kaolin has a particle size of less than 1 micron and a GE brightness of at least about 91, where the kaolin may be derived from a crude kaolin having a Fe2O3 content of at least about 1.0% by weight, and optionally comprises titania in an amount of at least about 1.5% by weight. Also disclosed herein are methods of refining the hard kaolins, such as RCC hard kaolins, by dispersing the kaolin with at least one anionic organic dispersant and at least one inorganic dispersant.

Abstract: Disclosed herein, in one embodiment, are spunlaid fibers comprising at least one polymeric resin and at least one filler having an average particle size of less than or equal to about 5 microns and/or having a top cut of less than about 15 microns, wherein the at least one filler is present in an amount of less than about 40% by weight, relative to the total weight of the spunlaid fibers. Also disclosed herein is a method for producing spunlaid fibers comprising adding calcium carbonate to at least one polymeric resin and extruding the resulting mixture. Further disclosed herein are nonwoven fabrics comprising such spunlaid fibers and methods for producing them.

Abstract: A coating composition for paper and other substrates, particularly mechanical papers such as lightweight coated (LWC) paper, comprises an aqueous suspension of a particulate pigment together with a binder, wherein the particulate pigment comprises: (a) a first component which is a precipitated calcium carbonate consisting predominantly of aragonitic or rhombohedral particle shapes or of aragonitic and rhombohedral particle shapes in a weight ratio of between around 40:60 and about 60:40 (e.g.

Abstract: The present invention relates to a composition comprising calcined kaolin having a narrow particle size distribution. The composition can have many uses, such as fillers or extenders in paint, plastics, polymers, papermaking, and coating compositions. More generally, the inventive products may be used wherever calcined kaolins are used.

Abstract: The present disclosure relates to a coating composition for use in producing a coating on paper and other substrates comprising an aqueous suspension of a particulate pigment together with a binder, wherein the particulate pigment comprises a mixture of: a first pigment component comprising particulate ground calcium carbonate (GCC) having a particle size distribution (psd) steepness factor ranging from about 30 to about 45; and a second pigment component comprising particulate precipitated calcium carbonate (PCC) having a psd steepness factor ranging from about 55 to about 75. The particulate pigment may optionally further include a particulate kaolin clay.

Abstract: Spherical and rod-shaped proppants and anti-flowback agents made from sillimanite minerals possess high strength and high conductivity. The sillimanite minerals may be selected from the group consisting of kyanite, sillimanite, and andalusite and may be used alone or in combination with other materials, such as bauxite, kaolin, meta-kaolin, pure or technical grade alumina (about 98%-99.9% alumina by weight), alumina-containing slag, zirconia, silica, iron, alkali elements (such as calcium, magnesium, and sodium), and virtually any other mineral containing alumina. The starting material may optionally be milled to achieve better compacity and crush resistance in the final proppant or anti-flowback agent. A fracturing fluid may comprise the rods or spheres alone, or in combination with each other or other proppants or anti-flowback agents of different shapes.

Abstract: Disclosed herein is a kaolin composition having nanosize dimensions. At least about 75% of the kaolin particles by weight have an equivalent spherical diameter (esd) of less than about 0.25 ?m. The kaolin can also have a particle size distribution wherein at least about 99% of the particles by weight have an esd of less than about 2 ?m, and/or wherein at least about 98% of the particles by weight have an esd of less than about 1 ?m, and/or wherein at least about 97% of the particles by weight have an esd of less than about 0.5 ?m. The kaolin can have a mean diameter ranging from about 0.075 ?m to about 0.2 ?m, and a shape factor of about 30 or less.

Abstract: There is disclosed a composition comprising a fine particulate glass cullet. The particulate material may be obtained by a suitable grinding process. The particulate cullet is useful as an inexpensive filler for polymer compositions and in abrasive compositions.

Abstract: Disclosed herein are granulated kaolin compositions exhibiting at least one of improved material handling properties, low dusting during transit, easy make-down into mineral-water slurries, and requiring less energy to produce than spray dried kaolin products. The granulated kaolin compositions may, in one embodiment, be characterized by a moisture content ranging from about 12% to about 23% by weight relative to the total weight of the composition. In another embodiment, the granulated kaolin compositions may have an average granule size of greater than about 10 mesh. Also disclosed herein are granulated kaolin compositions having a moisture content ranging from about 12% to about 23% by weight relative to the total weight of the composition, wherein the composition is friable when subjected to a shear force.

Abstract: The invention provides a method for preparing particulate brucite comprising grinding and beneficiating particulate brucite wherein the ground beneficiated particulate brucite has a d90 of less than or equal to about 6.4 ?m as measured by laser light scattering.

Abstract: There is disclosed a particulate glass cullet having a d90 less than about 20 ?m, and a particulate glass cullet having a d90 wherein the particles have been surface treated to modify on or more properties of the cullet. The particulate materials may be obtained by a suitable grinding process. The particulate glass cullet and surface treated particulate glass cullet are useful as anti-blocking pigments in polymer compositions.

Abstract: An embodiment consistent with the present invention is a high strength proppant comprising an electrofused pellet. In another embodiment, a high strength proppant comprises a substantially solid and substantially spherical pellet produced by electrofusion of at least one metal oxide. A method of making a proppant is also provided, with that method comprising melting at least one metal oxide in an electrical arc furnace, pouring the molten metal oxide to create a pour stream, and separating the pour stream to form at least one electrofused pellet. A method of fracturing subterranean formations is also provided, with that method comprising injecting a fluid containing at least one electrofused pellet.

Abstract: Disclosed herein are a method of reductively bleaching a mineral slurry comprising adding in the mineral slurry an effective amount of a formamidine sulfinic acid (FAS) and an effective amount of a borohydride to reductively bleach the mineral slurry, compositions comprising a mineral slurry, a FAS, and a borohydride, and final products comprising a mineral obtained by the method disclosed herein.

Abstract: A method of treating a kaolin particulate material to improve one or more of its properties by removal of impurity particles therein which includes: producing a dispersed aqueous suspension of a kaolin particulate material containing at least 0.1% by weight, based on the dry weight of the kaolin particulate material of separable particulate impurity; diluting said dispersed aqueous suspension by adding a diluent thereto; adding a selective flocculation polymer to the diluted suspension; allowing the suspension containing the polymer to separate in a selective flocculation separator into layers comprising a flocculated product layer and a deflocculated impurity layer containing the separable impurity; and extracting the separated layers from the separator, wherein at least a portion of said deflocculated impurity layer is recirculated for use as at least a portion of the aforementioned diluent.

Abstract: The present invention relates to coarse calcined kaolin slurries having a high solids content. The invention also relates to methods of making such slurries. The resulting slurries can have a solids content of at least about 58% by weight wherein at least about 40% by weight of the calcined kaolin particles has a particle size of at least about 1 ?m. The slurries can be stabilized where the solids show little settling from suspension. The slurries have many uses, including fillers or extenders in paint and coating compositions for paper or paper board. More generally, the inventive products may be used wherever calcined kaolins are used. The present invention also related to coarse calcined kaolin slurries having a multimodal particle size distribution and a high solids content.

Abstract: A pigment product for use in a coating composition to provide a gloss coating on paper, the pigment product comprising a processed particulate kaolin having a particle size distribution such that at least about 80% by weight of the particles have an equivalent spherical diameter less than about 2 p,m and in the range of from about 10% to about 20% by weight of the particles have an equivalent spherical diameter less than about 0.25 wm, the particles have a shape factor in the range of from about 20 to about 36 and the particles have a particle steepness in the range of about greater than about 35, more preferably in the range of about 35 to about 40, and wherein the kaolin is derived from a secondary kaolin source.

Abstract: Disclosed herein are compositions comprising novel delaminated kaolins having a large particle size and low levels of alkali metal oxides. Methods of making the disclosed delaminated kaolin by calcining hydrous kaolin are described. Applications using the disclosed compositions in preparing catalyst substrates, paints, coatings, sealants, cementitious products, ceramics, rubbers, polymers and other compositions are also described.