The invention relates to a method for preparing synthetic mineral particles with formula (Al.sub.yM.sub.1-y).sub.2(Si.sub.xGe.sub.1-x).sub.2O.sub.5(OH).sub.4, wherein M designates at least one trivalent metal selected from the group made up of gallium and the rare earths, which comprises the following steps: preparing a gel which is a precursor of said synthetic mineral particles by a co-precipitation reaction of at least one salt of metal selected among aluminium and M with at least one silicon source selected from the group made up of potassium metasilicate, sodium metasilicate, potassium metagermanate and sodium metagermanate, the molar ratio of (Al.sub.yM.sub.1-y) to (Si.sub.xGe.sub.1-x) during the preparation of said precursor gel being equal to 1, at least one base being added during said co-precipitation reaction; and performing a solvothermal treatment of said precursor gel at a temperature of 250° C. to 600° C.

The present invention relates to a method for producing mineral particles grinding a mineral material in the presence of a specific anionic polymer. The polymer used is obtained by means of polymerisation in the presence of sodium hypophosphite, disodium dipropionate trithiocarbonate and at least one radical-generating compound. The invention also relates to an aqueous composition comprising particles of ground mineral material and such a polymer, in particular a paper coating slip composition.

A process for treatment of nanoparticles of mineral filler for obtaining processed nanoparticles for use in polymerization in the presence of nanoparticles which includes the steps of (a) drying a mineral filler with an inert gas to remove catalyst poisons; (b) mixing the mineral filler dried obtained in step (a) with a swelling agent in a liquid state or near a critical state or in the supercritical state; (c) subjecting the swelling agent of the mixture obtained in step (b) to an endoenthalpic or isoentalphic phase change by altering the conditions of the temperature and/or pressure; (d) subjecting the nanoparticles of the mixture obtained in step (c) to contact of scavenging agent to react with catalyst poisons; then the mixture obtained in step (d) can be dried in a step (e) with an inert gas to remove sub-products from scavenging agent and catalyst poisons to obtain the treated nanoparticles.

A process for treatment of nanoparticles of mineral filler for obtaining processed nanoparticles for use in polymerization in the presence of nanoparticles which includes the steps of (a) drying a mineral filler with an inert gas to remove catalyst poisons; (b) mixing the mineral filler dried obtained in step (a) with a swelling agent in a liquid state or near a critical state or in the supercritical state; (c) subjecting the swelling agent of the mixture obtained in step (b) to an endoenthalpic or isoentalphic phase change by altering the conditions of the temperature and/or pressure; (d) subjecting the nanoparticles of the mixture obtained in step (c) to contact of scavenging agent to react with catalyst poisons; then the mixture obtained in step (d) can be dried in a step (e) with an inert gas to remove sub-products from scavenging agent and catalyst poisons to obtain the treated nanoparticles.

A process is described for manufacturing white pigment containing products. The white pigment containing products are obtained from at least one white pigment and impurities containing material via froth flotation.

A process is described for manufacturing white pigment containing products. The white pigment containing products are obtained from at least one white pigment and impurities containing material via froth flotation.

Use of a particulate mineral having a coating of one or more rosin acid(s) and/or one or more derivative(s) thereof as a pitch and/or stickies control agent in a composition comprising cellulosic pulp, a method of reducing dissolved and/or colloidal pitch and/or stickies in cellulosic pulp using said coated particulate minerals, said coated particulate mineral, a method of making said coated particulate mineral, a composition comprising cellulosic pulp and said coated particulate mineral and paper comprising said coated particulate mineral.

The present invention relates to an inorganic particulate material suitable for use in polymeric films, compositions such as polymeric films comprising the inorganic particulate materials, methods of making said compositions and the various uses of the inorganic particulate materials and compositions.

The present invention relates to an inorganic particulate material suitable for use in polymeric films, compositions such as polymeric films comprising the inorganic particulate materials, methods of making said compositions and the various uses of the inorganic particulate materials and compositions.

The present invention relates to a nanomaterial comprising a nanoclay having a layered structure and carbon nanotubes being intercalated between layers of the layered of the nanoclay, and manufacturing method thereof.