Abstract: A method for increasing the bulk density and decreasing the time of wetting with water of a substantially anhydrous kaolin clay powder, comprising dry ball-milling said powder using work inputs of from about 5 to about 40 HP-hrs/ton of dry clay. The milling may be effected by grinding the clay with ceramic balls of less than 5 inches diameter. The process enables improved handling characteristics for the treated clay with respect to bulk material handling systems.

Abstract: Aliphatic complex phosphate esters or salts thereof, of a non-ionic surface active compound, are utilized together with aliphatic fatty acids as collector agents during flotation for removing titanium-based impurities from kaolin clays in a froth flotation process.

Abstract: A method for continuously processing a kaolin clay which has relatively poor high-shear viscosity when prepared as a high-solids suspension, so as to obtain therefrom a fraction having a value of high-shear viscosity in high-solids suspension which is low relative to the starting clay, thereby being desirable for use in coating of paper. The method comprises the steps of forming the kaolin clay into a dilute aqueous suspension having from 10% to 20% solids by weight and forming said suspension into a continuous flow stream; mixing the stream of flowing suspension at a given point with from about 0.001% to 0.

Abstract: A method is disclosed for separating titaniferous and ferruginous discolorants from a crude kaolin clay. A dispersed aqueous slurry of the clay is formed containing a deflocculant and a fatty acid collecting agent, and the slurry is conditioned to coat the discolorants with the collecting agent to thereby render the discolorants hydrophobic. A system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, is thereupon added to the slurry. The seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles, and the slurry is then subjected to a froth flotation, which removes substantial quantities of the discolorants and seeding partices coalesced therewith, and also removes excess seeding particles and excess collecting agent.

Abstract: An anhydrous white kaolin clay pigment is disclosed, which consists of porous aggregates of kaolin clay platelets. The pigment exhibits exceptionally high light-scattering ability when incorporated as a filler in paper. The aggregates have an average specific gravity in the range of 0.5 to 0.6, and a size distribution such that not more than 5% by weight thereof are of greater than 10 microns ESD, at least 75% are of less than 2 microns ESD, and not more than 15% are of less than 1 micron ESD. The pigment has a Valley abrasion value below 30 mg, and preferably below 20 mg, and a GE brightness of at least 93. The mean size of the internal pores in the aggregates is less than 0.55 microns and preferably is less than 0.5 microns. This low mean pore size is deemed instrumental in producing the aforementioned high scattering ability. A method for producing the said pigment is also disclosed and claimed.

Abstract: A method is disclosed for separating titaniferous and ferruginous discolorants from a crude kaolin clay. A dispersed aqueous slurry of the clay is formed containing a deflocculant and a fatty acid collecting agent, and the slurry is conditioned to coat the discolorants with the collecting agent to thereby render the discolorants hydrophobic. A system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, is thereupon added to the slurry. The seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles, and the slurry is then subjected to a froth flotation, which removes substantial quantities of the discolorants and seeding particles coalesced therewith, and also removes excess seeding particles and excess collecting agent.

Abstract: A method is disclosed for beneficiating a kaolin clay pigment to improve the rheological properties of a high solids suspension subsequently formed therefrom. According to the method, a 10 to 20% solids aqueous suspension of a kaolin clay is subjected to a selective rheological separation, by mixing the suspension with from about 0.001% to 0.1% by weight of dry clay, of a high molecular weight anionic polymer, and allowing the thereby treated suspension to separate into a sedimented phase, and a supernatant phase which is substantially free of aggregates; and separating the supernatant phase containing the beneficiated kaolin pigment in suspension. The suspended product of the process can then be conventionally processed, as by reductive bleaching, floccing, filtering, washing, dispersing, and drying.

Abstract: A method is disclosed for processing a natural calcitic ore to yield a finely divided calcium carbonate particulate of very high brightness characteristics. The natural calcitic ore is initially coarse-milled to produce a product wherein no more than 5% by weight of the particulate is +325 mesh, and no more than 35% by weight of the particles are of less than 2 microns E.S.D. This coarse-milled product is then subjected as an aqueous slurry containing less than 40% and preferably less than 30% solids by weight, to a froth flotation, which separates with the froth the relatively coarse colorbodies liberated in the initial grinding. Preferable compositions for use in the froth flotation comprise 1-substituted-2-alkyl imidazolines or the salt derivatives thereof, with such compounds being utilized in admixture with a substantially non-polar aliphatic compound having from 10 to 20 carbon atoms in its longest straight chain.

Abstract: A method for magnetically separating titaniferous discolorants from a crude kaolin clay. A dispersed aqueous slurry of the clay is formed and ferrimagnetic particles are thereupon spontaneously coflocculated with the titaniferous discolorants by seeding the slurry with a system of said particles. The system includes predominantly sub-micron size particles, and the particles further, have an isoelectric point in relation to that of the titaniferous discolorants to enable the spontaneous coflocculation. The slurry is thereupon passed through a porous ferromagnetic matrix in the presence of a magnetic field, to separate the coflocculated particles and discolorants at the matrix.

Abstract: A method for separating a metallic mineral from an ore containing same. An aqueous dispersed slurry of the ore is formed, and the slurry is mixed with a system of transiently suspended ferrimagnetic particles of predominantly colloidal size. The particles are further characterized by an isoelectric point in relation to the slurried mineral sought to be separated, such that the particles spontaneously co-flocculate with the mineral to seed same. The resultant seeded slurry is passed through a porous ferromagnetic matrix in the presence of a magnetic field, which separates the seeded mineral at the matrix.

Abstract: A method for magnetically beneficiating an ore by removing therefrom undesired metallic minerals of inherently low magnetic attractability. An aqueous dispersed slurry of the ore is formed, and the slurry is mixed with a system of transiently suspended ferrimagnetic particles of predominantly colloidal size. The particles are further characterized by an isoelectric point in relation to the mineral sought to be removed, such that the particles spontaneously co-flocculate with the mineral to seed same. The resultant seeded slurry is passed through a porous ferromagnetic matrix in the presence of a magnetic field, which separates the seeded mineral at the matrix, with the purified ore emerging from the matrix being recovered as product. This beneficiated product, i.e. now relatively free of the undesired species, can then (as appropriate) be further processed.

Abstract: In the process for producing a refined kaolin clay pigment by forming a crude kaolin clay into an aqueous slurry, performing a particle size classification, and subjecting the slurry to reductive bleaching with an alkali metal hydrosulfite; a method is disclosed for reducing the viscosity of a slurried product including the refined pigment, which method comprises adding a source of barium ion to the said bleached slurry, to thereby precipitate at least the sulfate ion present in that slurry from oxidation of the hydrosulfite ion during the bleaching step. The barium ion may be derived, e.g., from barium carbonate, which is added while the slurry preferably includes at least a 50% solids content by weight. The bleached slurry may be one which has been partially purified by an initial flotation, and which includes at least 99% by weight of particles less than 5 microns E.S.D., with substantially 100% by weight of the particles having an E.S.D. less than 10 microns.

Abstract: A method is disclosed for processing a natural calcitic ore to yield a finely divided calcium carbonate particulate of very high brightness characteristics. The natural calcitic ore is initially coarse-milled to produce a product wherein no more than 5% by weight of the particulate is +325 mesh, and no more than 35% by weight of the particles are of less than 2 microns E.S.D. This coarse-milled product is then subjected as an aqueous slurry including less than 40% solids, to a froth flotation, which separates with the froth the relatively coarse colorbodies liberated in the initial grinding. The purified underflow is then dewatered to at least 60% solids by weight, and is wet-milled, as for example in a sand mill, to yield an output product wherein at least 80% by weight of the resultant particulate has an E.S.D. of less than 2 microns, the product being further characterized by a brightness of at least 94 on the G.E. scale.

Abstract: A method for magnetically separating discoloring contaminants of low magnetic attractability from a crude kaolin clay containing said contaminants. A dispersed aqueous slurry of the clay is admixed with a finely divided magnetic particulate. The slurry is thereupon passed through a porous, ferromagnetic matrix in the presence of an applied magnetic field, whereby contaminants seeded by the particulate are separated from the slurry.

Abstract: Complex phosphate esters or salts thereof, of a non-ionic surface active compound, are utilized as collector agents for removing titanium-based impurities from kaolin clays in a froth flotation process.

Abstract: A method for brightening a kaolin clay wherein an aqueous dispersion is initially formed of said clay, which dispersion is blunged and conditioned and the resulting slurry thereupon subjected to a froth flotation treatment to remove titaniferous impurities. The purified product from the froth flotation treatment is thereupon subjected to magnetic separation by passing such product through a slurry-pervious ferromagnetic matrix positioned in a high intensity magnetic field, which results in substantial, additional brightening of the clay.

Abstract: A method for magnetically separating discoloring contaminants of low magnetic attractability from a crude kaolin clay containing said contaminants. A dispersed aqueous slurry of the clay is seeded with a finely divided magnetic particulate. The seeded slurry is then subjected to a magnetic field, to magnetically flocculate the contaminants and the magnetic particulate, and thereupon remove same.

Abstract: A method for brightening a kaolin clay wherein an aqueous dispersion is initially formed of said clay, which dispersion is blunged and conditioned and the resultant slurry thereupon subjected to a froth flotation treatment to remove titaniferous impurities. The purified product from the froth flotation treatment is thereupon subjected to magnetic separation by passing such product through a slurry-pervious ferromagnetic matrix positioned in a high intensity magnetic field, which results in substantial, additional brightening of the clay.

Abstract: A method for brightening a natural dolomitic ore by removal of discoloring contaminants. The ore is crushed and formed into an aqueous slurry, which slurry is then coarse-milled to produce a product wherein no more than 1% of the particulate matter is +325 mesh. This coarse-milled product is then subjected to a further, wet-milling step, to alter the particulate such that at least 70% of the particles are less than 2 microns, E.S.D. thereby liberating substantial quantities of the discoloring contaminants. The liberated impurities are thereupon separated by subjecting the slurry to a high intensity magnetic field.

Abstract: A method for brightening a natural calcitic ore by removal of discoloring contaminants. The ore is crushed and formed into an aqueous slurry, which slurry is then coarse-milled to produce a product wherein no more than 1 percent of the particulate matter is +325 mesh. This coarse-milled product is then subjected to a further, wet-milling step, to alter the particulate such that at least 70 percent of the particles are less than 2 microns, thereby liberating substantial quantities of the discoloring contaminants. The liberated impurities are thereupon separated from the slurry by flotation and/or by subjecting the slurry to a high intensity magnetic field.