Abstract: A composition comprising titanium dioxide and additives useful for enhancing the optical performance of titanium dioxide or for allowing substitution of at least part of the titanium dioxide in said composition for additives. At least two additives are added, wherein a first additive comprises a composite pigment and a second additive comprises a reactive polymer. The invention also provides a method for enhancing the optical properties of titanium dioxide compositions.

Abstract: Composition of precipitated calcium carbonate and method of producing the same and the uses of the composition. The composition comprises a plurality of essentially spherical granules having an average diameter of 1-50 um formed from primary precipitated calcium carbonate particles having an average diameter of 30 to 60 nm, capable of liberating at least a part of the primary particles by deagglomeration in aqueous suspension. The present compositions can be used for modifying binders of paints, printing inks, plastics, adhesives, sealants and surface sizes and pulp sizes. The invention further concerns a method for storing of precipitated calcium carbonate particles having an average diameter in the nanometer range.

Abstract: A stable aqueous dispersion of platy particles and precipitated calcium carbonate, a method of producing the same and uses of the dispersion. The aqueous dispersion comprises 50 to 95 parts by weight of platy particles; and 5 to 50 parts by weight of precipitated calcium carbonate particles having an average diameter of 30 to 60 nm. The dispersion has a dry matter content of more than 30% by weight of the dispersion, and a Brookfield viscosity (100 rpm) of 200 to 5000 cP. The dispersion is suitable for forming barrier coatings on a substrate, having properties of improved gas barrier and improved mineral oil barrier.

Abstract: A pigment particle composition which comprises calcium carbonate particles and pigment particles, its method of manufacture and its use. According to the present invention, the calcium carbonate particles are carbonated so that they bind to each other, in which case calcium carbonate structures are generated, which comprise pigment particles and which form essentially opaque and stable pigment-calcium carbonate aggregates. It is possible to manufacture the composition by atomizing calcium hydroxide-bearing pigment slurry into a carbon dioxide-bearing gas, in which case the calcium hydroxide is carbonated in order to precipitate the calcium hydroxide particles to be attached to each other and the carbonation is continued until essentially all of the calcium hydroxide has been converted into calcium carbonate. The composition is suitable for use, among others, in paints, coating materials, fillers, polymers and printing inks.

Abstract: A pigment particle composition which comprises calcium carbonate particles and pigment particles, its method of manufacture and its use. According to the present invention, the calcium carbonate particles are carbonated so that they bind to each other, in which case calcium carbonate structures are generated, which comprise pigment particles and which form essentially opaque and stable pigment-calcium carbonate aggregates. It is possible to manufacture the composition by atomizing calcium hydroxide-bearing pigment slurry into a carbon dioxide-bearing gas, in which case the calcium hydroxide is carbonated in order to precipitate the calcium hydroxide particles to be attached to each other and the carbonation is continued until essentially all of the calcium hydroxide has been converted into calcium carbonate. The composition is suitable for use, among others, in paints, coating materials, fillers, polymers and printing inks.

Abstract: A method and apparatus for pretreating fibre material to be used in manufacturing paper or the like, for example, by precipitating mineral substances to the fibres. During precipitation, fibre material, which is advantageously pretreated in a through-flow mixer operating on the principle of an impact mill, is fed to the precipitation reactor. Gas is led to the precipitation reactor in order to generate a gas space in the reactor. The gas contains a substance, which precipitates the mineral substance such as carbon dioxide (CO2). The fibre material is fed to the gas space of to the precipitation reactor as small liquid and solid substance fractions such as drops and/or particles.

Abstract: A method and apparatus for pretreating fiber material to be used in manufacturing paper or the like, for example, by precipitating mineral substances to the fibers. During precipitation, fiber material, which is advantageously pretreated in a through-flow mixer operating on the principle of an impact mill, is fed to the precipitation reactor. Gas is led to the precipitation reactor in order to generate a gas space in the reactor. The gas contains a substance, which precipitates the mineral substance such as carbon dioxide (CO2). The fiber material is fed to the gas space of the precipitation reactor as small liquid and solid substance fractions such as drops and/or particles.

Abstract: A method and apparatus for producing a calcium carbonate product formed of small <100 ?m sized separate calcium carbonate particles. Calcium hydroxide is fed through a disintegration and spraying apparatus (14), operating on the principle of a pin mill, into a gas which contains carbon dioxide for precipitating calcium carbonate particles and which is inside a precipitation reactor (10). The temperature in the precipitation reactor is maintained at <65° C.

Abstract: A method and apparatus for producing a calcium carbonate product formed of small <100 ?m sized separate calcium carbonate particles. Calcium hydroxide is fed through a disintegration and spraying apparatus (14), operating on the principle of a pin mill, into a gas which contains carbon dioxide for precipitating calcium carbonate particles and which is inside a precipitation reactor (10). The temperature in the precipitation reactor is maintained at <65° C.

Abstract: A pigment particle composition which comprises calcium carbonate particles and pigment particles, its method of manufacture and its use. According to the present invention, the calcium carbonate particles are carbonated so that they bind to each other, in which case calcium carbonate structures are generated, which comprise pigment particles and which form essentially opaque and stable pigment-calcium carbonate aggregates. It is possible to manufacture the composition by atomizing calcium hydroxide-bearing pigment slurry into a carbon dioxide-bearing gas, in which case the calcium hydroxide is carbonated in order to precipitate the calcium hydroxide particles to be attached to each other and the carbonation is continued until essentially all of the calcium hydroxide has been converted into calcium carbonate. The composition is suitable for use, among others, in paints, coating materials, fillers, polymers and printing inks.

Abstract: A paper pulp used in papermaking is produced as follows: fiber material is fed into a precipitation reactor; a reactive mineral material is fed into the reactor; the reactive mineral material and the fiber material are combined to form a fiber suspension in the reactor and/or before feeding these materials into the reactor; a gas containing a precipitant is fed into the reactor thereby precipitating the reactive mineral material in order to form a gas space containing the precipitant; the fiber suspension fed into the reactor and/or formed there is dispersed into small parts into the gas space, whereby the precipitated mineral material forms a filler on the fibers; the treated fiber suspension is discharged from the reactor; the filler-containing paper pulp is fed to the forming section of the paper machine; water is removed from the paper pulp; and the resulting paper web is dried and finished.

Abstract: According to the process, limestone is burned at a high temperature to form calcium oxide and, thereafter, calcium carbonate is formed from calcium oxide in the presence of water and carbonate ions and the formed calcium carbonate is recovered. The formation of the carbonate may be performed by carbonating calcium oxide with carbon dioxide gas in the presence of water or water vapour, or by reacting calcium oxide with soda solution. According to the invention calcium oxide is converted to calcium carbonate without separate slaking and essentially without intermediate storage, in particular without intermediate storage between the burning of the starting material and the forming of calcium carbonate. With the aid of the invention a quite advantageous solution in view of heat economy is achieved.

Abstract: The present invention concerns a process for preparing calcium carbonate pigment from calcium oxide and/or calcium hydroxide and carbon dioxide in the presence of water. According to the invention, the starting materials are reacted in fluid state containing at least 20 parts of volume of gas for each part by volume of suspension formed by water and solid substances, and the amount of water is essentially equivalent to the amount which is evaporated during the reaction together with the amount left in a calcium carbonate product which behaves like a powder. By means of the present invention, PCC in powder form can be prepared without the product first having to be separated from a slurry.

Abstract: The invention concerns precipitated calcium carbonate products containing polynuclear regular agglomerates having a number of calcium carbonate particles (aggregates) attached to each other and having a particle size of about 40 to 200 nm. According to the invention, these products are prepared by adjusting the Z potential of the calcium carbonate suspension to −1 . . . −20 mV by adjusting the pH of the suspension to 6.5 . . . 9.5. The pH of the calcium carbonate slurry obtained by causticizing is adjusted to a desired value in a box filter, where after the suspension is stirred by a heavy-duty mixer such that it is subjected to differences of about 50 to 200 m/s in peripheral speed. The products according to the invention have good opacity and are very well suited for coating paper.

Abstract: The invention is related to a method for forming calcium carbonate. In the method, calcium oxide is reacted with carbonate ions in the presence of water to produce calcium carbonate. According to the invention, the formation is carried out directly from calcium oxide to calcium carbonate without intermediate stages in a three-phase precipitation, whereby the hydration of the calcium oxide to calcium hydroxide and the carbonation of the hydrated part are carried out immediately after one another under so intensive agitation that the calcium carbonate elements thus created are detached from the surface of the calcium hydroxide. The mixing is preferably carried out in a fluid medium where the amount of gaseous phase is at least 20 parts by volume and the amount of liquid phase is 0.5 to 1 part per one part by volume of the solid matter of the suspension. In the process, the desired end product, PCC, can be prepared in a very short residence time and with a small operational content.

Abstract: A process and an apparatus for the preparation of precipitated calcium carbonates calcium hydroxide using gaseous carbon dioxide, whereby the carbonation is performed in a gaseous phase by mixing calcium-hydroxide-containing liquor mist with the carbon dioxide gas in a turbulence having an energy intensity in excess of 1000 kW/m3. The reaction is advantageously carried out in an apparatus, comprising at least two serially arranged pin mills having one or more rotatable vane rings which can be used to impose a great energy intensity on the material which is fed into the apparatus, whereby the first pin mill is provided with at least an inlet for slaked lime and carbon dioxide and an outlet for the reaction product, and the second pin mill is provided with an inlet for the product from the previous mill and an outlet for the reaction product. Carbonating is extremely swift. The residence time of the reaction is even less than 1 second.

Abstract: This invention relates to a pigment particle product and a method for its preparation. According to the invention pigment particles, such as kaolin, natural calcium carbonate or titanium dioxide, and precipitated calcium carbonate are mixed together in an aqueous phase at pH 6-11, which causes the pigment particles to become coated with particles of precipitated calcium carbonate. The brightness of the product is excellent, and it is quite inexpensive to produce.