Abstract: Composite pigments are provided which comprise a mineral pigment (such as kaolin clay, titanium dioxide, talc, mica or a mixture of two or more of these mineral pigments) and calcium carbonate precipitated in-situ on the surfaces of the particles of the mineral pigment.

Abstract: Described herein are technologies for concentrating rare-earth elements from a heavy fraction of grit in gangue produced in kaolin mining. In some examples, grit is separated as a non-clay fraction of gangue produced in a kaolin mining operation. The grit is separated into a heavy mineral grit sub-fraction and a light mineral grit sub-fraction. Rare-earth elements, particularly heavy rare-earth elements, are thereafter extracted from the heavy mineral grit sub-fraction using various extraction technologies.

Abstract: Composite pigments are provided which comprise a mineral pigment (such as kaolin clay, titanium dioxide, talc, mica or a mixture of two or more of these mineral pigments) and calcium carbonate precipitated in-situ on the surfaces of the particles of the mineral pigment.

Abstract: Deinking of waste paper is obtained with the use of a hydrophobic kaolin-based deinking composition. The hydrophobic kaolin-based deinking composition is produced by hydrophobizing the kaolin clay and then blending the hydrophobic kaolin-based particles with a deinking surfactant. Separation and removal of ink is achieved either by washing deinking, flotation deinking or combination of these methods.

Abstract: Fluffy powders, such as calcined kaolin clays or air floated clays, can be compacted using a process which comprises applying increasing amounts of pressure to a powder moving through a confinement area. The compacted product has an improved bulk density and improved wet out and slurry incorporation times as compared to the non-compacted starting material feed.

Abstract: Fluffy powders, such as calcined kaolin clays or air floated clays, can be compacted using a process which comprises applying increasing amounts of pressure to a powder moving through a confinement area. The compacted product has an improved bulk density and improved wet out and slurry incorporation times as compared to the non-compacted starting material feed.

Abstract: Mineral pigments (such as kaolin clay) having a high surface area and particle size in the nano scale range are provided which are useful in paper coating and filling, ink jet coating formulations, paint compositions, and as a filler in rubbers, plastics and polymers. These pigments are manufactured by intensive wet milling of a mineral composition which may have undergone prior dry grinding and then optionally subjecting the wet milled mineral composition to an acid treatment.

Abstract: Waste paper is deinked by a composition which comprises a surfactant and a hydrophobic-based deinking component.

Abstract: Calcined kaolin clay having a high bulk density, improved wet out and slurry incorporation times is produced by using pressure to compact the clay. Other properties of the compacted clay are improved or equivalent to the non-compacted starting calcined clay material.

Abstract: Aggregated mineral pigments (such as kaolin clay pigments) having a high surface area and useful in coating and filling compositions for ink jet printing media are manufactured by dry grinding an unground mineral composition starting material and then optionally acid treating the ground material.

Abstract: Aggregated mineral pigments (such as kaolin clay pigments) having a high surface area and useful in coating compositions for ink jet printing media are manufactured by dry grinding an unground mineral composition starting material and then optionally acid treating the ground material.

Abstract: Fine-grained Tertiary kaolin clay pigments providing improved opacity, sheet gloss and print gloss to paper coated with these pigments are produced by removing fine and coarse particles to produce pigments having a narrow particle size distribution.

Abstract: Calcined kaolin clay pigments having improved color are manufactured by adding a blue agent to the kaolin clay pigment prior to calcination, and then calcining the pigment and blue agent mixture.

Abstract: Kaolin clay agglomerates having improved bulk density, improved rheological properties and good optical properties are provided by mixing calcined kaolin clay, hydrous kaolin clay and water and then subjecting the mixture to high pressure in a compaction system.

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 improved process for beneficiating kaolin clays to remove discoloring impurities is disclosed. The beneficiation of kaolin clay is improved by fractionating a kaolin clay starting material into a lower brightness first fraction having a majority of the discoloring impurities and a higher brightness second fraction with less impurities. The first fraction is then beneficiated (such as by flotation, selection flocculation, high intensity magnetic separation and/or leaching) to produce a kaolin clay product with improved optical properties. The first and second fractions may be combined to produce a product with improved optical properties.

Abstract: A process which uses selective flocculation with hydroxamates for the beneficiation of mixtures of mineral particles (such as kaolin clays). The increased selectivity of hydroxamates for certain mineral phases within kaolin clays and other mixtures of mineral particles improves the process over selective flocculation processes utilizing other activators.

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 process for significantly improving the physical properties of formed particles is disclosed. The process includes adding an effective amount of an acid stable surfactant or an alkaline stable surfactant to a component of the material before drying the particles. The preferred particles are microspheroidal for use in fluid bed reactors, but can include granules and beads.

Abstract: Materials, such as kaolin clays, which are discolored by the presence of goethite mineral impurities are first heated to convert the goethite to hematite and then treated to remove the hematite, whereby the color and brightness of the product are improved over the starting material.