Abstract:
A method of producing a stable aqueous dispersion of a latex, solid particles and a dispersing agent, comprising contacting the latex with an anionic dispersing agent to form a modified latex, feeding the modified latex and the solid particles to a zone of high shear forces, and simultaneously subjecting essentially all of the modified latex and the solid particles fed to said zone to high shear forces to form a latex-particle slurry. By means of the invention, over 60 wt-% of the latex can be adsorbed on the solids. Latex immobilization increases the surface strength of final coating layer and allows for a decrease of latex consumption in paper and cardboard and paint applications.
Abstract:
The present invention relates to 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 according to the invention the lime is slaked in a slaking apparatus (52) at a temperature of at least 80 degrees, preferably over 85 degrees, more preferably at over 100 degrees, the produced milk of lime is cleaned (58) by separating excessively large calcium hydroxide particles from it immediately prior to introducing (38) the milk of lime into the production process of PCC an 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 (28).
Abstract:
The present invention relates to a method of and reactor for in-line production of calcium carbonate into a target suspension flow. The method and reactor according to the invention are suitable for introducing and mixing lime milk and carbon dioxide into a target suspension flow so that the calcium carbonate crystals formed during their reaction are not allowed to precipitate onto the walls (12) of the reactor (10), because the reactor is provided with means (16, 18, 20) for preventing the carbonate crystals from attaching to the surfaces of the structures located in the reaction zone.
Abstract:
The present invention relates to a method of and reactor for in-line production of calcium carbonate into a target suspension flow. The method and reactor according to the invention are suitable for introducing and mixing lime milk and carbon dioxide into a target suspension flow so that the calcium carbonate crystals formed during their reaction are not allowed to precipitate onto the walls (12) of the reactor (10), because the reactor is provided with means (16, 18, 20) for preventing the carbonate crystals from attaching to the surfaces of the structures located in the reaction zone.
Abstract:
A method and an apparatus for producing precipitated calcium carbonate (PCC). Interesting and at the same time surprising is the very small size of the continuous carbonation reactor and very fast reaction speed in it. All these together and alone reduce investment and production costs of this carbonation process. This achievement is reached by maximizing mass transfer speed from gas phase (carbon dioxide) to liquid phase and from solid phase (calcium hydroxide) to liquid phase. In this innovation the fast mass transfer is made by pulsating high shear forces and ultra sound at high pressure in a rotor-stator system. Surprisingly it was seen in the test runs that 100 % conversion was achieved in this continuous process in less than 5 seconds when in the conventional batch processes the reaction can take several hours and even in the most advanced continuous reactors several minutes.
Abstract:
A method and an apparatus for producing precipitated calcium carbonate (PCC). Interesting and at the same time surprising is the very small size of the continuous carbonation reactor and very fast reaction speed in it. All these together and alone reduce investment and production costs of this carbonation process. This achievement is reached by maximizing mass transfer speed from gas phase (carbon dioxide) to liquid phase and from solid phase (calcium hydroxide) to liquid phase. In this innovation the fast mass transfer is made by pulsating high shear forces and ultra sound at high pressure in a rotor-stator system. Surprisingly it was seen in the test runs that 100 % conversion was achieved in this continuous process in less than 5 seconds when in the conventional batch processes the reaction can take several hours and even in the most advanced continuous reactors several minutes.