Mixed calcium carbonate, preparation method and application thereof

Abstract

The invention discloses mixed calcium carbonate, a preparation method and application thereof. The preparation method comprises the following steps of: (1) performing ultrafine grinding on heavy calcium carbonate water slurry with solid content (weight) of between 20 and 30 percent to obtain water slurry of which the weight content of the heavy calcium carbonate with grain diameter less than 2 mu m is between 60 and 90 percent; (2) adding a cationic polyelectrolyte solution which is equivalent to 0.2 to 2.0 percent of the weight of heavy calcium carbonate dry powder into the water slurry, and stirring the mixture for 0.5 to 1.0 hour; (3) then adding light calcium carbonate which is equivalent to 60 to 120 percent of the weight of the heavy calcium carbonate dry powder into the slurry, and then stirring the mixture for 20 to 30 minutes to obtain mixed calcium carbonate slurry; and (4) then collecting the mixed calcium carbonate from the mixed calcium carbonate slurry, wherein the mixed calcium carbonate slurry or calcium carbonate can be used as a paper-making filler. The mixed calcium carbonate synchronously has the respective advantages of the heavy calcium carbonate and the light calcium carbonate.

Description

Technical field

[0001] The invention relates to calcium carbonate and its preparation method and application. Background technique

[0002] The industrial products of calcium carbonate are powder materials made by mechanical or chemical processing of natural limestone ore. It is one of the most widely used inorganic fillers and pigments. Calcium carbonate is the most widely used internationally in the paper industry. It is mainly used as a filler for paper and as a coating material for high-quality paper such as white paper and coated paper. It can significantly improve the optical properties of paper and reduce costs. Titanium dioxide has high refractive index and scattering coefficient, which is a good papermaking filler. However, due to its high price, it is generally only used for high-grade tissue printing paper to increase the opacity of the paper; while calcium carbonate is low in price, and It can also improve the opacity of the paper and increase the ink absorption perfo...

Examples

Embodiment 1

[0021] Add 7kg of methacryloxyethyltrimethylammonium chloride (DMC) monomer aqueous solution with a weight content of 78% into a 20-liter reactor, heat it to 75°C, and add 25g of dodecyl mercaptan To methacryloyloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution, then 1.0 kg weight concentration of 10% sodium persulfate solution is slowly added dropwise to the monomer aqueous solution, the dropping time is 4.0 hours , 6.8 kg of cationic polyelectrolyte solution was obtained.

[0022] Add 2.5 tons of 300-mesh heavy calcium carbonate powder to 16.0 tons of deionized water, stir to prepare a slurry, and stir thoroughly to make the slurry obtain good fluidity. Then, the slurry is sent to a 300-liter peeling machine with a pump, and the heavy calcium carbonate is ground by the peeling machine to prepare a heavy calcium carbonate slurry, in which the weight content of particles with a particle size of less than 2 μm is 70%. Then 6.8 kg of cationic polyelectrolyte soluti...

Embodiment 2

[0024] Add 12kg of methacryloxyethyltrimethylammonium chloride (DMC) monomer aqueous solution with a weight content of 78% into a 50-liter reactor, heat it to 85°C, and add 35g of dodecyl mercaptan To the methacryloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution, then slowly add 0.9 kg of the 5% potassium persulfate aqueous solution by weight to the monomer aqueous solution, the dripping time is 3.5 Within hours, 11.6 kg of cationic polyelectrolyte solution was obtained.

[0025] Add 3.0 tons of 100-mesh heavy calcium carbonate powder to 16.0 tons of deionized water, stir to prepare a slurry, and stir thoroughly to make the slurry obtain good fluidity. Then the slurry is sent to a 300-liter peeling machine with a pump, and the heavy calcium carbonate is ground by the peeling machine to prepare a heavy calcium carbonate slurry, in which the weight content of particles with a particle size of less than 2 μm is 80%. Then 11.6 kg of cationic polyelectrolyte solution...

Embodiment 3

[0027] Add 28 kg of 78% by weight methacryloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution into a 100-liter reactor, heat to 80°C, and add 80 g of dodecyl mercaptan Into the monomer aqueous solution of methacryloyloxyethyl trimethyl ammonium chloride (DMC), 3 kg of 20% ammonium persulfate aqueous solution by weight was slowly added dropwise to the monomer aqueous solution for 5 hours. 30.2 kg of cationic polyelectrolyte solution was obtained.

[0028] Add 2.5 tons of 200-mesh heavy calcium carbonate powder to 8.0 tons of deionized water, stir to prepare a slurry, and fully stir to make the slurry obtain good fluidity. Then use a pump to send the slurry to a 300-liter peeling machine, and use the peeling machine to grind the heavy calcium carbonate to prepare a heavy calcium carbonate slurry, where the weight content of particles with a particle size of less than 2μm is less than 2μm and the content is 50 %. Then 30.2 kg of cationic polyelectrolyte solution was ...

Technical field

[0001] The invention relates to calcium carbonate and its preparation method and application. Background technique

[0002] The industrial products of calcium carbonate are powder materials made by mechanical or chemical processing of natural limestone ore. It is one of the most widely used inorganic fillers and pigments. Calcium carbonate is the most widely used internationally in the paper industry. It is mainly used as a filler for paper and as a coating material for high-quality paper such as white paper and coated paper. It can significantly improve the optical properties of paper and reduce costs. Titanium dioxide has high refractive index and scattering coefficient, which is a good papermaking filler. However, due to its high price, it is generally only used for high-grade tissue printing paper to increase the opacity of the paper; while calcium carbonate is low in price, and It can also improve the opacity of the paper and increase the ink absorption perfo...

Examples

Embodiment 1

[0021] Add 7kg of methacryloxyethyltrimethylammonium chloride (DMC) monomer aqueous solution with a weight content of 78% into a 20-liter reactor, heat it to 75°C, and add 25g of dodecyl mercaptan To methacryloyloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution, then 1.0 kg weight concentration of 10% sodium persulfate solution is slowly added dropwise to the monomer aqueous solution, the dropping time is 4.0 hours , 6.8 kg of cationic polyelectrolyte solution was obtained.

[0022] Add 2.5 tons of 300-mesh heavy calcium carbonate powder to 16.0 tons of deionized water, stir to prepare a slurry, and stir thoroughly to make the slurry obtain good fluidity. Then, the slurry is sent to a 300-liter peeling machine with a pump, and the heavy calcium carbonate is ground by the peeling machine to prepare a heavy calcium carbonate slurry, in which the weight content of particles with a particle size of less than 2 μm is 70%. Then 6.8 kg of cationic polyelectrolyte soluti...

Embodiment 2

[0024] Add 12kg of methacryloxyethyltrimethylammonium chloride (DMC) monomer aqueous solution with a weight content of 78% into a 50-liter reactor, heat it to 85°C, and add 35g of dodecyl mercaptan To the methacryloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution, then slowly add 0.9 kg of the 5% potassium persulfate aqueous solution by weight to the monomer aqueous solution, the dripping time is 3.5 Within hours, 11.6 kg of cationic polyelectrolyte solution was obtained.

[0025] Add 3.0 tons of 100-mesh heavy calcium carbonate powder to 16.0 tons of deionized water, stir to prepare a slurry, and stir thoroughly to make the slurry obtain good fluidity. Then the slurry is sent to a 300-liter peeling machine with a pump, and the heavy calcium carbonate is ground by the peeling machine to prepare a heavy calcium carbonate slurry, in which the weight content of particles with a particle size of less than 2 μm is 80%. Then 11.6 kg of cationic polyelectrolyte solution...

Embodiment 3

[0027] Add 28 kg of 78% by weight methacryloxyethyl trimethyl ammonium chloride (DMC) monomer aqueous solution into a 100-liter reactor, heat to 80°C, and add 80 g of dodecyl mercaptan Into the monomer aqueous solution of methacryloyloxyethyl trimethyl ammonium chloride (DMC), 3 kg of 20% ammonium persulfate aqueous solution by weight was slowly added dropwise to the monomer aqueous solution for 5 hours. 30.2 kg of cationic polyelectrolyte solution was obtained.

[0028] Add 2.5 tons of 200-mesh heavy calcium carbonate powder to 8.0 tons of deionized water, stir to prepare a slurry, and fully stir to make the slurry obtain good fluidity. Then use a pump to send the slurry to a 300-liter peeling machine, and use the peeling machine to grind the heavy calcium carbonate to prepare a heavy calcium carbonate slurry, where the weight content of particles with a particle size of less than 2μm is less than 2μm and the content is 50 %. Then 30.2 kg of cationic polyelectrolyte solution was ...