Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: Paper, paperboard, or label stock coated with a synthetic nano-composite coating. A synthetic nano-composite coating includes a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: Paper, paperboard, or label stock coated with a synthetic nano-composite coating. A synthetic nano-composite coating includes a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

Abstract: A method and apparatus for the production of calcium carbonate and calcium silicate in common superatmospheric reactors. Multiple reactors can be provided for switching production between reactors, and advantageously utilizing process waste heat. On site production of both PCC and Calcium Silicate Hydrates is thus achieved in a paper mill.

Abstract: A method for the hydrothermal preparation of calcium silicate hydrates. Multi-phase calcium silicate hydrates, having unique physical and chemical properties, are prepared by hydrothermal reaction of specified ratios of CaO and SiO2, normally starting from slurries of slaked lime and from fluxed calcined diatomaceous earth, each of which is at about the atmospheric boiling point before being mixed and charged to a reactor, and pressurized. The hydrothermal reaction is carried out while maintaining the initial dilution for a preselected reaction time at a preselected reaction temperature. The calcium silicate hydrates produced have high water absorption and light scattering power, and have optical and physical properties making them highly desirable as a filler substitute in papermaking.

Abstract: A method and apparatus for the production of calcium carbonate and calcium silicate in common superatmospheric reactors. Multiple reactors can be provided for switching production between reactors, and advantageously utilizing process waste heat. On site production of both PCC and Calcium Silicate Hydrates is thus achieved in a paper mill.

Abstract: Precipitated calcium carbonate crystals of selected crystal habit. A pressure carbonation process is used to manufacture precipitated calcium carbonate. A slurry of calcium hydroxide is agitated in a pressurized reactor, and carbon dioxide is provided to a reactor to produce calcium ions and carbonate ions that react under pressure to produce precipitated calcium carbonate at a high reaction rate. Control of process conditions such as pressure, temperature, and hydroxide slurry concentration, enables production of (1) a desired crystal habit (including sclenohedral, rhombohedral, stacked rombohedral, or aragonite calcium carbonate crystal structures), (2) a desired crystal size, or (3) a desired crystal aspect ratio. The precipitated calcium carbonate produced by the process is useful as either a paper filler or as an ingredient in paper coatings, and provides a paper product with improved properties.

Abstract: A process for the production of precipitated calcium carbonate. A slurry of calcium hydroxide is agitated in a pressurized reactor, and carbon dioxide is provided under pressure to the reactor to produce precipitated calcium carbonate at a high reaction rate. Carbon dioxide is utilized at a high efficiency. Solubilized calcium ions and carbonate ions react to produce a calcium carbonate precipitate. Control of process conditions such as temperature, slurry concentration, and pressure, enables production of a desired crystal habit (including sclenohedral, rhombohedral, stacked rombohedral, or aragonite crystal structures), crystal size, or crystal aspect ratio. The precipitated calcium carbonate produced by the process under pressure is useful as either a paper filler or as an ingredient in paper coatings, and provides a paper product with improved preselected properties, which properties include opacity, density, and/or brightness.

Abstract: A method for preparing an acid resistant calcium carbonate pigment. An aqueous slurry of particulate calcium carbonate is provided at a pH of from about 11.0 to 12.0 and having from 2 to 5 g/l of excess calcium hydroxide. The slurry temperature is brought to the range of about 75.degree. to 80.degree. C., and sodium silicate solution is slowly mixed therewith to provide on a solid dry weight ratio from about 5 to 10% sodium silicate to calcium carbonate. Gaseous carbon dioxide is added to bring the slurry pH to the range of about 10.2 to 10.7, and the slurry is cooled to about 25.degree. to 30.degree. C. Finally zinc chloride is added to the cooled slurry to bring the pH to within the range of 7.5 to 8.0.