Abstract: A method and apparatus for in-line production of milk of lime into an in-line production process of PCC arranged in connection with a fibrous web machine. In the solution, lime is slaked in a slaking apparatus at a temperature of at least 80 degrees. The produced milk of lime is cleaned by separating excessively large calcium hydroxide particles immediately prior to introducing the milk of lime into the production process of PCC. The milk of lime is introduced into the in-line production process of PCC located in the production line of the end or intermediate product of the fibrous web machine.

Abstract: A method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fiber suspension containing cellulose-containing fibers, the calcium hydroxide is allowed to attach onto the surfaces of fibers for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibers is brought into contact with carbon dioxide for precipitating the calcium carbonate. A corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibers and a fibrous product, which comprises pulp material produced by the method and comprising calcium carbonate, are also set forth.

Abstract: The invention relates to a method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fiber suspension containing cellulose-containing fibers, the calcium hydroxide is allowed to attach onto the surfaces of fibers for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibers is brought into contact with carbon dioxide for precipitating the calcium carbonate. The invention also relates to a corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibers. In addition, the invention relates to a fibrous product, which comprises pulp material produced by said method and comprising calcium carbonate.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

Abstract: A method and apparatus for in-line production of milk of lime into an in-line production process of PCC arranged in connection with a fibrous web machine. In the solution, lime is slaked in a slaking apparatus at a temperature of at least 80 degrees. The produced milk of lime is cleaned by separating excessively large calcium hydroxide particles immediately prior to introducing the milk of lime into the production process of PCC. The milk of lime is introduced into the in-line production process of PCC located in the production line of the end or intermediate product of the fibrous web machine.

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: The invention relates to a method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fibre suspension containing cellulose-containing fibres, the calcium hydroxide is allowed to attach onto the surfaces of fibres for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibres is brought into contact with carbon dioxide for precipitating the calcium carbonate. The invention also relates to a corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibres. In addition, the invention relates to a fibrous product, which comprises pulp material produced by said method and comprising calcium carbonate.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

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 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 the precipitation reactor as small liquid and solid substance fractions such as drops and/or particles.

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.