Abstract: Processes by which a mixture of two or more discrete particulate materials, each of said materials having a different sliding coefficient of friction, can be separated using methods which take advantage of velocity differences generated by the application of a force to said mixture to create movement of said mixture over a surface as a function of its sliding coefficient of friction. Various apparatus to effect such processes are also disclosed.

Abstract: Apparatus for the separation of a mixture of discrete particulate solid materials of disparate composition and a system utilizing such apparatus is described in which the material to be processed is caused to slide under the influence of gravity along a straight inclined surface to achieve a substantially uniform velocity and thereafter along an arcuately formed surface where, due to the existence of different coefficients of sliding friction between the mixture fractions, disparate velocities are achieved by the respective particles whereby particles of the respective fractions are separately collected on a velocity basis. The described apparatus utilizes a slide surface of different material and/or a water spray to produce the disparate velocities between the particles of the respective mixture fractions. Deflector plates of various forms may be employed to prevent contamination of the clean product fraction due to bouncing of materials of the waste product fraction from the slide surface.

Abstract: Processes by which a mixture of two or more discrete particulate materials, each of said materials having a different sliding coefficient of friction, can be separated using methods which take advantage of velocity differences generated by the application of a force to said mixture to create movement of said mixture over a surface as a function of its sliding coefficient of friction. Various apparatus to effect such processes are also disclosed.

Abstract: A method of and substances for reducing pitch in pulping and papermaking operations, particularly in furnishes made by mechanical pulping processes containing wood pulp in amounts greater than about 10% by weight, are disclosed. The method comprises adding to a pitch-containing furnish a stable, water dispersible particulate composite substance prepared by irreversibly adsorbing a water soluble cationic polymer, e.g., a poly(diallyldimethylammonium chloride), onto an essentially water insoluble particulate substrate, e.g., kaolin, thereby rendering the cationic polymer insoluble and immobile, the cationic polymer being sufficiently electropositive so that the particulate composite pitch control substance exhibits a zeta potential of at least about +30 mV, and preferably from about +60 mV to about +80 mV, the amount of the composite substance added to the furnish being effective to finely disperse pitch for removal as finely-dispersed pitch-containing aggregates in a paper sheet produced from said furnish.

Abstract: Means are disclosed for rendering talcs such as Montana talc or like talcs hitherto considered incompatible or unsuitable as fillers for thermoplastic resinous compositions, and particularly polypropylene molding resins, suitable for this use. Such talcs, which in their unbeneficiated state strongly discolor the resinous matrix and affect its long-term heat stability, are beneficiated in accordance with this invention, generally at low cost, while improving or at least not unacceptably diminishing other significant physical properties, particularly yellowness index, flexural modulus and impact strength, of the resulting molded article. This is accomplished by admixing Montana talc or the like with an effective amount of a combination of:(A) one or a mixture of certain octyl- or nonylphenol/poly(ethylene oxide) condensates, and(B) one or a mixture of certain poly(ethylene glycols) or alkoxypoly(ethylene glycols).

Abstract: Means are disclosed for rendering talcs such as Chinese talcs, Austrialian talcs, Italian talcs or like talcs which, when ground to an approximately 2.5-5.0 .mu.m median particle size, exhibit a wet powder brightness of at least about 30% and which have hitherto been considered acceptable as fillers for thermoplastic resinous compositions, and particularly polypropylene molding resins, even suitable for this use. Such talcs are beneficiated in accordance with this invention, generally at low cost, to further enhance brightness, heat stability or both these properties in thermoplastic molded articles filled with these beneficiated acceptable talcs, while also improving or at least not unacceptably diminishing other significant physical properties, particularly tensile properties, of the resulting molded article.

Abstract: Finely divided, wet-ground, dispersant-free calcium carbonate filler or pigment compositions are disclosed in which the particles of calcium carbonate are distributed in particular amounts in a particular fashion--broadly stated: in fine particle size distribution. Such compositions are useful in aqueous slurry or dry form as opacifying fillers for paper.

Abstract: Improved apparatus for disintegrating and slurrying unconsolidated overburden for transport to a distant site. A hopper-like enclosure having a sloping floor is provided with a plurality of high-pressure water jets near the upper end thereof. The jets are directed tangentially along the floor surface. A first, coarse grillwork across the top of the hopper opening screens out large, consolidated material fragments and assists in disintegrating lumps of unconsolidated overburden. The overburden passes through the upper grillwork and falls upon the sluicing, high pressure water which mixes with the overburden and carries it downwardly toward an aperture in the hopper floor. A pair of toothed rollers are disposed in the aperture along with a second, finer, grillwork having bars extending between the roller teeth. Fine material passes readily through the fine grillwork, the larger chunks of overburden being comminuted by the rollers.

Abstract: A process for removing tremolite impurity from talc by subjecting finely ground talc to a combination of steps including froth flotation and pressure leaching with a strong acid at an elevated temperature. The recovered talc is characterized by a tremolite content of less than 1.0 percent by weight.