Ecc International Limited

Ecc America Inc.

Anglo-american Clays Corporation

Gary L Cobb

Michael W Ginn

Kelly R McNeely

Lawrence E Broxton

Jerry Allen Cook

Dursun E Ince

L Gene Broxton

Apparatus for filtering mineral slurries

Method for filtering mineral slurries

A method which enables economical and highly effective preparation of refined kaolin clay products having preselected particle size distributions and brightnesses, by means of separate, efficient and economical processing of at least two crude components. A fine particle size kaolin crude having a PSD such that at least 85% by weight of the particles are of less than 2 micrometers ESD is wet beneficiated to provide a first product component having a PSD of at least 95% by weight less than 2 micrometers and a brightness of at least 89 on the G.E. scale. This wet beneficiation is conducted without use of a froth flotation step. A coarse particle size kaolin crude having a PSD such that less than 85% by weight of particles are of less than 2 micrometers ESD, is separately wet beneficiated to produce a second product component having a PSD of no more than 85% by weight less than 2 micrometers and a brightness of at least 89 on the G.E. scale. This last wet beneficiation is, however, conducted with use of a conventional froth flotation step. The first and second product components are then blended in proportions to produce the desired refined kaolin clay product having a preselected PSD and brightness. The first and second components can also be used as is.

Method for preparing refined kaolin in clay products

A method for beneficiating a kaolin clay which includes quantities of smectite contaminants to reduce the low and high shear viscosities of high solids aqueous slurries of the kaolin. The smectite is converted into a pillared clay by intercalating it with a polymeric cationic hydroxy metal complex wherein the metal is ferromagnetic or diamagnetic. The kaolin and pillared smectite is then subjected as an aqueous slurry to high intensity magnetic separation, to separate the pillared smectite, and the beneficiated kaolin is recovered as product.

Method for improving rheological properties of kaolin clays

An improvement is disclosed which is applicable to the method for filtering an aqueous mineral slurry by flowing the slurry through a ceramic filter plate which is characterized by a porous support layer and an overlying porous filtration layer, the pore sizes in said filtration layer being in the range of from about 1 to 3 .mu.m, and the flow through the filter plate being from the filter layer side toward the base layer, and being effected by establishing a fluid pressure differential across the said filter plate by applying suction to the the porous support layer. The improvement facilitates effective discharge of the filter cake from the plate which accumulates upon the porous filtration layer. According to such improvement the suction is extinguished and the support layer side of the plate is subjected to one ore more positive water pressure pulses to effect a transient reverse flow through the plate. Via the uniform pore structure this generates a uniform back pressure and a lubricating film of water at the interface between the filtration layer and the filter cake. Oscillations or vibrations are applied to the surface of the porous filtration layer to facilitate separation of the filter cake.

An apparatus for filtering slurries of minerals or other fine particles is disclosed. The apparatus includes a ceramic filter plate and a fluid flow device for drawing a partial vacuum across said filter plate and to supply a pulsed liquid to the filtrate side of said filter plate. The apparatus also includes an oscillating device that facilitates removal of cake which accumulates on the filter plate when sued simultaneously with or successively with said pulsed liquid.

In the process for beneficiating a crude kaolin by the method which includes a wet classification step to provide a classified kaolin fraction having a PSD such that at least 50% by weight thereof are of less than 1/2.mu.m ESD and substantially 100% by weight are of less than 10 .mu.m ESD; and one or more steps wherein an aqueous slurry of the classified kaolin is at least partially dewatered by filtration; the improvement which comprises effecting at least one of said one or more filtration steps, by flowing said aqueous kaolin slurry through a ceramic filter plate which is characterized by a porous support layer and an overlying porous filtration layer, the ratio between the respective mean pore sizes of the filtration layer material and the base layer material being between about 2 and 50; the pore size in said filtration layer being in the range of from about 1 to 3 .mu.m, and the pore size in the base layer being in the range of from about 4 to 50 .mu.m; and said flow through said filter plate being from said filter layer toward said base layer, and being effected by establishing a fluid pressure differential across the said filter plate.

Method for producing high solids slurries of clay water products

Flotation of a kaolin clay slurry to remove titanium-based impurities is improved by adding a biocide to the slurry prior to the flotation and effecting the flotation in the presence of the biocide. The addition of the biocide improves the efficacy of flotation and thereby increases the brightness of the clay. Preferred biocides are tetrahydrothiadiazine thiones, especially tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione.

Method for improved flotation of discoloring impurities from kaolinite

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. The floatation-beneficiated slurry is then subjected to a magnetic separation by passing the slurry through a porous ferromagnetic matrix positioned in a magnetic field, having an intensity of at least 0.5 kilogauss, to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with said discolorants. The product from said magnetic separation may then be calcined at a temperature of at least 1500.degree. F. to yield an exceptionally high brightness, low abrasion product.

Process for producing high brightness clays utilizing magnetic

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. The flotation-beneficiated slurry is then subjected to a magnetic separation by passing the slurry through a porous ferromagnetic matrix positioned in a magnetic field, having an intensity of at least 0.5 kilogauss, to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with said discolorants.

Growing community of inventors

Davisboro, GA, United States of America

Gary L Cobb