Abstract: A process for improving the rheological properties of an aqueous suspension of a particulate inorganic material which comprises the steps of: (a) forming an aqueous suspension of the particulate inorganic material and an effective amount of an anionic polyelectrolyte dispersing agent; (b) diluting the suspension formed in step (a) with water while maintaining the particulate in the dispersed state of step (a) to give a solids concentration of not less than 20% by weight of the particulate inorganic material; and (c) reconcentrating the diluted suspension formed in step (b) to give a solids concentration of at least 50% by weight of the particulate inorganic material.

Abstract: A method for producing a delaminated kaolin clay having a G.E. brightness of at least 85, a solids content of at least 67 percent by weight, and a viscosity below 500 cps is disclosed. An aqueous slurry of kaolin clay is subjected to agitation in the presence of a hard grinding media. The slurry is then subjected to agitation in the presence of a soft grinding media. The result is that at least 80 percent of the delaminated kaolin has an equivalent spherical diameter of less than or equal to 2 microns.

Abstract: The invention provides a filler for ink jet recording paper which is composed of an amorphous silica containing 0.3-1.0% by weight of Al.sub.2 O.sub.3 and having a BET specific surface area of 250-400 m.sup.2 /g, a mean particle size of 3.6-10.0 .mu.m and a peak position of pore radius as measured by mercury injection method of 37.5-75 angstrom. A coat layer of ink jet recording paper formed of this filler excels not only in true circle property of dots and ink absorbing property when printed by ink jet recording system, but also in surface strength and writing quality. Furthermore, the coating liquid containing this filler has a low viscosity and hence exhibits good coating workability.

Abstract: An improvement is disclosed applicable to the method for producing a calcined kaolin by the steps of wet beneficiating a crude kaolin to form a slurry of the beneficiated kaolin; dewatering the slurry to form a substantially dry calciner feed; and calcining the feed at a temperature of at least 1450.degree. F. by passing a stream of hot gases through a calciner in which the kaolin feed is resident, whereby an exhaust stream of hot gases is generated which entrains quantities of partially calcined and hydrous kaolin pigment fines. The improvement, enabling useful application of the kaolin pigment fines, comprises recovering the kaolin pigment fines from the exhaust stream for use in papermaking. The fines can be recovered at a wet scrubber, and after being partially dewatered, shipped directly as a product slurry to the paper maker.

Abstract: A finely divided inorganic filler material is a sintered composite which consists of larger macro-filler particles of glass and of smaller micro-filler particles of glass or ceramics partially covering the macro-filler particle and firmly connected to it by sintering. Plastic materials reinforced with the filler are distinguished by improved abrasion resistance.

Abstract: A fluidized bed reactor is supplied with fuel, oxygen-containing gas, and kaolinite, which contains water of crystallization. At least 80% by weight of the kaolinite have particle sizes in the range from 0.1 to 3 mm. A fluidized bed at temperatures in the range from 850.degree. to 950.degree. C. is formed in the fluidized bed reactor. A meta-kaolin white pigment which contains water of crystallization not in excess of 2% by weight is withdrawn from the fluidized bed reactor.

Abstract: A selected kaolin crude or crude fraction is purified by physical or physical/chemical means, such as froth flotation and/or selective flocculation, to remove discrete particles of TiO.sub.2 and in some cases, discrete iron minerals. The pure (or purified clay) must then be agitated in the presence of water with a particulate grinding media such as, for example, sand, alumina or zirconia beads, to increase the 2 micron content of the kaolin. An intermediate ground product that contains a substantial weight percentage of particles finer than 1 micron is generated as a result of grinding. The particles finer than 1 micron in the ground kaolin also include those particles in the previously pure or purified kaolin that were present in the naturally occurring clay. A pulp of the ground clay is then fractionated to remove particles larger than 2 microns, e.g., to remove at least 95%, preferably at 100% by weight, of the particles larger than 2 microns, while minimizing the removal of particles finer than 1 micron.

Abstract: A kaolin clay slurry having a reduced viscosity is manufactured by a process which comprises the sequential steps of mechanically working an undispersed crude kaolin clay material having a solids content of at least about 65 percent, by weight, under conditions which insure that the kaolin clay material will be subjected to an energy level of at least 10 horsepower-hours per ton of dry kaolin clay material and then subjecting the mechanically worked kaolin clay material to centrifugation to substantially remove any particles having a diameter less than about 0.2 microns.

Abstract: A process is disclosed for the production of a blended smectite clay with enhanced rheology, particle size restriction and reduced abrasion characteristics which is useful for the coating of paper. The process comprises slurrying of a predominantly sodium smectite clay, slurrying a predominantly calcium smectite clay, degritting of the clay slurries to remove coarse grained impurities, removing a substantial portion of the undesirable soluble salts from the clay slurries, fractionating the clay slurries to control particle size of the smectite clays in the slurry and blending together the predominantly sodium smectite clay slurry with the predominantly calcium smectite clay slurry to form a blended clay slurry.

Abstract: A process for preparing a high brightness, low abrasion calcined kaolin. A cretaceous crude is wet beneficiated by subjecting same as an aqueous slurry to degritting, classification, magnetic separation, and scrub grinding. The slurry from the foregoing is diluted to less than 15% solids and subjected while well dispersed to a separation in a centrifuge to yield an underflow and an overflow fine fraction having less than 5% solids and a P.S.D. such that at least 85% by weight are of <0.5 .mu.m E.S.D. and at least 30% by weight are of <0.25 .mu.m E.S.D. The overflow fine fraction slurry of dispersed kaolin is subjected to a partial filtration by passing same in cross flow relation to a microporous membrane through which substantially none of the suspended kaolin particles pass, to raise the solids content of the said slurry to at least 20%.

Abstract: An improvement is disclosed in the method for producing a calcined kaolin clay powder for use in paper manufacture, by the steps of wet beneficiating a kaolin crude, drying the beneficiated crude, milling the dried beneficiated crude to provide a calciner feed, and calcining the feed to destroy the crystallinity thereof and provide an amorphous calcined kaolin powder. According to the improvement, the dried beneficiated crude is milled and classified to provide a calciner feed having substantially no +325 mesh residue, and not greater than 0.0003% by weight +635 mesh residue. This enables lowered abrasion in the calcined powder, and lowered viscocity in the slurried calcined powder product to thereby enable a higher solids slurry.

Abstract: Inorganic oxide pigments (ceramics) are prepared by mixing the starting materials in the presence of water and in the presence or absence of assistants, drying and subsequent calcining in a rotary furnace by processing the starting materials in the presence of water into a pumpable suspension having particle sizes of 50%<10 .mu.m and 100%<50 .mu.m, dewatering the suspension by spray drying it to leave porous granules, and calcining those granules>97% from 20 to 800 .mu.m in size.

Abstract: 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.

Abstract: There is disclosed a process for preparing a filler composition suitable for incorporation in a polyester film-forming material, which process comprises the following steps:(a) calcining a crude kaolin clay under conditions such that the calcined product comprises particles consisting of aggregates of fine kaolin platelets;(b) suspending the calcined clay product from step (a) in water containing a dispersing agent for the calcined clay, so as to form a suspension containing from 40% to 70% by weight of dry calcined clay;(c) subjecting the suspension formed in step (b) to comminution by attrition grinding with a particulate grinding medium for a time sufficient to reduce the average diameter of the aggregate particles to within the range from 0.3 .mu.m to 0.9 .mu.m, and to ensure that the calcined clay is substantially free of particles having an equivalent spherical diameter larger than 5 .mu.

Abstract: The invention relates to novel metakaolin pigments which are characterized by a unique combination of exceptionally high brightness and exceptionally low abrasion along with the excellent hiding power equal to that achieved by premium conventional calcined kaolin pigments. The invention relates also to a method of producing such metakaolin pigments by subjecting relatively coarse high purity and high crystallinity kaolin booklets to highly intensive media grinding to generate fine kaolin particles of reduced crystallinity, and calcining the ground particles while limiting calcination temperature and time such as to form metakaolin.

Abstract: A process for producing micropellets of lightweight aggregate having a substantially spheroidal configuration which includes continuously mixing ceramic clay and liquid in a high speed rotating pin mixer to encapsulate substantially all other non-volatile inorganic solid materials present in micropellets having a diameter not exceeding about six mesh. The spheroidal micropellets are then fired at a temperature of at least 2,000.degree. F. to oxidize all volatile organic compounds present. The light-weight aggregate of micropellets can advantageously-be used to replace sand in a cement or concrete matrix, as a well as for numerous other uses.

Abstract: Calcined kaolin clay is pelletized in a pelletizer by a process wherein the calcined clay has ammonia added to it, suitably in relatively small amounts such as less than 1% by weight. The pelletized clay is preferably coated with a binder to improve its flowability.

Abstract: Alumina hydrate particles have a high surface area and low dispersity and may have a low soluble soda content. They may be made by milling a liquid suspension of alumina hydrate, subjecting the milled suspension to classification into coarse and fine fractions, recycling the coarse fraction to the mill and recycling the fine fraction to the classification stage. A narrow particle size distribution is obtained.

Abstract: A method for preparing a calcined kaolin clay powder having good high shear rheology in high solids aqueous slurries. A kaolin clay powder of fine particle size is calcined at a sufficient temperature and for a sufficient period to destroy the crystallinity thereof; and the calcined product is dry milled in a media mill, using a work input of from 100 to 160 hp-hr/ton of dry clay.

Abstract: The bulk handling characteristics of a calcined kaolin clay powder, including the bulk density and flowability, are significantly improved by forming an aqueous slurry of the calcined kaolin clay powder and spray drying the slurry.

Abstract: A defined and delaminated kaolin composition exhibiting high opacity is produced by defining and delaminating a base kaolin clay so as to reduce its colloidal content. The defined and delaminated kaolin composition may also be treated with hexamethylenediamine and aluminum sulfate to further enhance opacity. Whether treated or untreated, the defined and delaminated kaolin composition functions superiorly in paper coating formulations, alone or blended with known coating clays, improving the opacity, print gloss, sheet gloss and printability of paper sheet coated therewith.

Abstract: Pyrogenically prepared silicic acid is compressed by a rotary filter equipped with a pressing band.

Abstract: An organo-clay is prepared by treating a clay mineral of the smectite type with a mixture of di(lower alkyl) arylkyl (higher alkyl) ammonium compound and a di(lower alkyl) di(higher alkyl) ammonium compound and thereafter subjecting the treated clay mineral to high shear mixing for a time sufficient to dissipate in the mixture at least 100 KJ of energy per Kg of dry solids in the mixture. The organo-clay is useful in gelling compositions containing one or more liquid aliphatic alcohols.

Abstract: A structured kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler in paper. The pigment is also useful in paper coating applications. The pigment consists of porous aggregates of kaolin particles which are chemically bonded together. The pigment may be produced by chemically reacting a particulate kaolin with a metal chloride, such as silicon tetrachloride. The process is conducted under conditions such that the kaolinite structure is not impaired.