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: 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.

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 improving the brightness and whiteness of kaolin clays or the like. An aqueous slurry of the clay is initially treated with a solution of sodium borohydride and sodium hydroxide at a pH of above 7.0 up to about 10.0. Sulphur dioxide is then bubbled through the slurry or otherwise brought into contact with same, the pH being permitted to attain a value of between 6.0 and 7.0. The pH may thereupon be adjusted to between 2.5 and 4.0 with an acid, at which pH the leach reaction may occur; or the application of gaseous sulphur dioxide may be continued to yield a pH of the indicated 2.5 to 4.0 range.