Abstract: A process for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein(a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the resulting mixture is from 10 to 30% by weight, especially from 12 to 20% by weight,(b) this sludge mixture is treated with an aqueous solution of an organic flocculant, preferably of anionic nature,(c) the greater part of the sludge water is removed by gravity filtration,(d) the pre-dewatered sludge mixture is treated with an aqueous solution of aluminum salts or trivalent iron salts and(e) this mixture is substantially dewatered by pressure filtration, in the course of which the greater part of the petroleum present is also removed.

Abstract: Fibrids of polymers of styrene, which are obtained in a fluid precipitation medium under the action of shearing forces.

Abstract: Manufacture of fibrids from polymers or copolymers containing fluorine in a fluid precipitation medium under the action of shearing forces.

Abstract: Fibrids are prepared by introducing a solution of a polymer into a liquid precipitation medium while exposing it to shearing forces. A poly(amide-imide) resin solution is admixed with a solvent which is miscible with the resin solvent but which is a non-solvent for the resin itself.

Abstract: Fibrids of polyolefins showing a high degree of fibrillation and a high specific surface area are obtained by flashing a pressurized solution or polyolefin in pentane or in a pentane-containing solvent by passing said solution through an orifice into a space which is at a lower pressure and in which shearing forces are applied to said solution. The fibrids directly obtained may be used, for example, for the manufacture of paper or for the manufacture of textile-like webs.

Abstract: Fibrids of polyolefins showing a high degree of fibrillation and a high specific surface area are obtained by flashing a pressurized solution of polyolefin in pentane or in a pentane-containing solvent mixture at a temperature above the boiling point of the solvent by passing said solution through an orifice into a space which is at a lower pressure and in which shearing forces are applied to said solution. The fibrids directly obtained may be used, for example, for the manufacture of paper or for the manufacture of textile-like webs.

Abstract: Fibrids are prepared by introducing a solution of a polymer into a liquid precipitation medium while exposing it to shearing forces. A poly(amide-imide) resin solution is admixed with a solvent which is miscible with the resin solvent but which is a non-solvent for the resin itself.