English Clays Lovering Pochin & Company

Cyprus Mines Corporation

Norman O Clark

James H Watson

Thomas R Jones

Robert D Stewart

Yew C Chang

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.

Finely divided calcium carbonate compositions

A tube pressure filter is provided with a filter element comprising a filter cloth sleeve which is tailored from a woven material so that the warp and/or weft filaments extend helically around the inner tubular body on which the filter element is supported whereby the filter cloth sleeve can be stretched transversely of the length thereof.

Pressure filters

In a method of dewatering by pressure filtration an aqueous suspension of a clay containing a small proportion of particles having an equivalent spherical diameter smaller than 1 micron, the improvement which comprises treating the aqueous suspension of the clay, prior to dewatering by pressure filtration at a pressure in excess of 150 pounds per square inch, with a water-soluble polyelectrolyte flocculant having a high density of positive charges.

Mineral fillers

A magnetic field is established in a predetermined zone. A quantity of fluid, from which native magnetizable particles are to be separated, is passed through the predetermined zone; and, at the same time, a magnetizable material is passed through the predetermined zone in the same direction as the fluid, so that native magnetizable particles are attracted to the magnetizable material.

Magnetic separation

An apparatus and a method are described for separating magnetizable particles from a fluid in which they are suspended. The apparatus comprises a separating chamber having an inlet and an outlet for permitting fluid to enter and leave the separating chamber, a matrix of a plurality of ferromagnetic filaments arranged substantially parallel to one another and to the general direction of flow of fluid through the matrix and disposed in the separating chamber, magnet means for establishing a high intensity magnetic field in the separating chamber perpendicular to the general direction of flow of the fluid through the matrix, and removal means for removing magnetizable particles attracted to the matrix within the separating chamber. The method comprises establishing a high intensity magnetic field in a matrix of a plurality of ferromagnetic filaments arranged substantially parallel to one another and perpendicular to the direction of the magnetic field and passing fluid containing magnetizable particles through the matrix generally in the direction of alignment of the filaments and removing magnetizable particles retained on the matrix.

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Par, United Kingdom

Norman O Clark