A preparation method of micron-scale laminated cubic calcium carbonate

Abstract

The present invention discloses a preparation method of micron-sized laminated cubic calcium carbonate, comprising the following steps: S1: Prepare a calcium hydroxide suspension for standby; S2: Add water to a carbonization tower, then add seed calcium carbonate into the water, and start stirring; S3: Add a composite additive composed of polyepoxysuccinic acid and a dispersant hydrolyzed polymaleic anhydride, and introduce a carbon dioxide mixed gas; S4: Monitor the pH during the reaction process, add the calcium hydroxide suspension into the carbonization tower for reaction, maintain the pH ≤ 11 during the process. After adding the calcium hydroxide suspension, continue to introduce the carbon dioxide mixed gas until the ventilation stops when the pH ≤ 7.5. The obtained suspension is filtered, dried and sieved, and finally micron-sized laminated cubic calcium carbonate is obtained. The present invention innovates from the raw materials, uses low-cost calcium hydroxide, seed calcium carbonate and carbon dioxide as raw materials, and prepares laminated cubic calcium carbonate by a carbonization method. The prepared sample has regular morphology and good dispersion.

Description

Technical Field

[0001] The present invention relates to the technical field of calcium carbonate preparation, and specifically relates to a method for preparing micron-sized laminated cubic calcium carbonate. Background Art

[0002] Calcium carbonate is an important inorganic material, which has the advantages of stable chemical properties, non-toxicity, good biocompatibility, high whiteness, etc., and is widely used in many industries such as papermaking, plastics, printing ink, medicine, cosmetics, food, coatings, etc. For calcium carbonate, crystal morphology and particle size are extremely important technical indicators, which determine the application fields and prices of calcium carbonate products. By artificially controlling the crystallization of calcium carbonate to prepare calcium carbonate products with different crystal forms, thereby expanding the application fields and added value of calcium carbonate is a hot spot in the development of the calcium carbonate industry.

[0003] The chemical synthesis methods of calcium carbonate are mainly divided into two categories. One is the carbonization method, and the other is the solution method (or called the double decomposition method). Considering environmental protection and economic benefits, the carbonization method is often selected to prepare calcium carbonate. The carbonization method for preparing calcium carbonate is a method with low cost, high efficiency and simple operation, and can produce high-purity calcium carbonate products on a large scale. Its relatively key advantage is that kiln gas (CO2) for carbonization can be obtained by calcining limestone in the early stage of preparation, which provides a prerequisite guarantee for green closed-loop production.

[0004] At present, in China, the carbonization method is mainly used to prepare nano-scale calcium carbonate. When using the carbonization method to prepare micron calcium carbonate, the morphologies are mostly spindle-shaped, rod-shaped, spherical, etc. There are few reports on the research of preparing micron laminated cubic calcium carbonate by the carbonization method. The large-particle-size calcium carbonate products sold in the market are generally a mixture of nano-calcium carbonate and heavy calcium carbonate after physical pulverization. The particle size distribution is severely uneven, and the regularity of the crystal morphology is poor, resulting in poor product stability and poor actual application effect.

[0005] Chinese Patent CN104445334A provides a method for preparing laminated cubic micron-scale calcium carbonate, which uses soluble calcium salt as the calcium source, soluble carbonate as the carbon source, and inorganic material graphene sheet as the template to synthesize micron-scale calcium carbonate particles at room temperature. The prepared calcium carbonate particles are cubic formed by stacking of sheets, and the particle size distribution is uniform. However, the method uses graphene sheets which are expensive, and is prepared at a low concentration by the solution method, with low yield. For subsequent separation of graphene, multiple precipitation and washing are required. The cost of multiple washing and precipitation is high, the production cycle is long, the pollution is serious, and it is difficult to wash metal impurity ions cleanly, and the purity of calcium carbonate is not high. The raw materials used in production are soluble calcium salts and carbonates, and the cost is relatively higher.

[0006] Chinese Patent CN108928844A provides a method for preparing regular cubic calcium carbonate. In a calcium carbonate aqueous suspension, calcium hydroxide emulsion and carbon dioxide are simultaneously provided for carbonization reaction. By reasonably controlling the ratio, total amount and rate of carbon dioxide to calcium hydroxide, the calcium carbonate particles grow from different shapes such as spherical, cubic, polyhedral, etc. into regular cubic particles. The sub-micron calcium carbonate produced by this method has regular morphology, but serious particle aggregation and poor dispersibility, and the production of micron-scale laminated square calcium carbonate is not mentioned in this method.

[0007] Chinese Patent CN106587125A discloses a method for preparing light calcium carbonate. In this method, a certain mass of calcium hydroxide is dissolved in deionized water to prepare a calcium hydroxide suspension. The calcium hydroxide suspension and carbon dioxide compressed gas are respectively connected to the liquid inlet end and the gas inlet end of a two-fluid atomizing nozzle, and the two-fluid atomizing nozzle is used to achieve the microscopic mixing of the gas-liquid two phases, and a carbonization reaction occurs to generate light calcium carbonate, which is quickly dried to directly obtain light calcium carbonate dry powder. The calcium carbonate produced by this method is micron-scale and has good dispersibility, but the particle morphology is spherical.

[0008] Chinese Patent CN111592025B discloses a method for preparing chrysanthemum-shaped micron calcium carbonate. In this method, water, oil, co-surfactant and surfactant are fully mixed to prepare a clear reverse microemulsion: the aqueous phase is an aqueous calcium chloride solution. Under stirring, carbon dioxide is introduced into the reverse microemulsion for a certain reaction time until no more precipitation occurs, then the introduction of carbon dioxide gas is stopped, the stirring is ended, and after aging, centrifugal separation is carried out, and the obtained precipitate is dried to obtain the chrysanthemum-shaped micron calcium carbonate. The calcium carbonate produced by this method is micron-scale and has good dispersibility, but the particle morphology is chrysanthemum-shaped.

[0009] Chinese Patent CN114408961A discloses a sub-micron spindle-shaped calcium carbonate prepared by a high-activity lime rotating packed bed reaction crystallization method and its method. The calcium carbonate prepared by this method has regular morphology, but the particles are spindle-shaped.

[0010] In summary, the existing patents for preparing micron-scale laminated cubic calcium carbonate adopt the solution method, using soluble carbonate and soluble calcium salt calcium chloride as raw materials and graphene as a template, and preparing it at a lower concentration. The raw materials used in this production method are expensive, the cost is high, the production yield is low, and the pollution is serious. And when using the carbonization method to prepare micron-scale calcium carbonate, the morphology is often cubic, spherical, spindle-shaped, chrysanthemum-shaped, etc. There are few reports on the preparation of laminated cubic calcium carbonate by the carbonization method. Summary of the Invention

[0011] In view of the above problems, the present invention provides a method for preparing micron-sized laminated cubic calcium carbonate, which innovates in terms of raw materials. Using low-cost calcium hydroxide, seed calcium carbonate and carbon dioxide as raw materials, laminated cubic calcium carbonate is prepared by a carbonization method. The prepared samples have regular morphology and good dispersibility.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A method for preparing micron-sized laminated cubic calcium carbonate, comprising the following steps:

[0014] S1: Prepare a calcium hydroxide suspension for later use;

[0015] S2: Add water to the carbonization tower, then add seed calcium carbonate to the water, and start stirring;

[0016] S3: Add a composite additive composed of polyepoxysuccinic acid and the dispersant hydrolyzed polymaleic anhydride, and introduce a carbon dioxide mixed gas;

[0017] S4: Monitor the pH during the reaction process, slowly add the calcium hydroxide suspension to the carbonization tower for reaction, maintain the process pH ≤ 11. After adding the calcium hydroxide suspension, continue to introduce the carbon dioxide mixed gas until the ventilation stops when pH ≤ 7.5. The obtained suspension is filtered, dried and sieved, and finally micron-sized laminated cubic calcium carbonate is obtained.

[0018] Preferably, in step S1, the mass concentration of the calcium hydroxide suspension is 10-15%.

[0019] Preferably, in step S2, the addition amount of water is 1 / 2 of the calcium hydroxide suspension, and the water temperature is 20-30 °C.

[0020] Preferably, in step S2, the addition amount of the seed calcium carbonate is 0.5-1.5% of the dry basis mass of calcium hydroxide.

[0021] Preferably, in step S2, the stirring speed is 250-350 r / min.

[0022] Preferably, in step S2, the preparation method of the calcium carbonate seeds refers to the examples in the invention patent CN201811559082.8 - A method for preparing monodisperse cubic precipitated calcium carbonate of Guangxi Heshan Huana New Material Technology Co., Ltd.

[0023] Preferably, in step S3, the mass ratio of polyepoxysuccinic acid to the dispersant hydrolyzed polymaleic anhydride is 1:1.

[0024] Preferably, in step S3, the concentration of the carbon dioxide mixed gas is 20-30%, and the flow rate of the mixed gas is 0.8-1.2 m3 / h.

[0025] Preferably, in step S3, the addition amount of the composite additive is 0.05-0.3% of the dry basis mass of calcium hydroxide.

[0026] Preferably, in step S4, the dropping rate of the calcium hydroxide suspension ≤ 200 mL / min.

[0027] Preferably, in step S4, the temperature of the drying process is 115-125 °C.

[0028] The preparation principle of the present invention is as follows:

[0029] Using regular cubic calcium carbonate as the seed crystal, carbon dioxide is introduced, and the reaction rate is controlled by slowly dropping the calcium hydroxide suspension. At the same time, a composite additive composed of polyepoxysuccinic acid and hydrolyzed polymaleic anhydride is added. Polyepoxysuccinic acid can promote the formation of a layered structure, chelate calcium ions, and inhibit the nucleation and growth rate of calcium carbonate crystals. Adding polyepoxysuccinic acid on the basis of controlling the dropping rate of the calcium hydroxide suspension can ensure the growth of calcium carbonate on the surface of the seed crystal calcium carbonate, inhibit independent nucleation, and promote the formation of layered cubes; the hydrolyzed polymaleic anhydride in the composite additive has the function of preventing calcium carbonate clusters and dispersing calcium carbonate. Under the synergistic effect of the two, micron-sized laminated square calcium carbonate with good dispersibility is finally prepared.

[0030] The beneficial effects of the present invention compared with the prior art:

[0031] (1) The present invention can prepare laminated square calcium carbonate. Due to its laminated structure, filling it into the system will increase the contact area between the particles and the matrix, enhance the binding force between the calcium carbonate particles and the matrix, and thus modify the properties of the composite material.

[0032] (2) The present invention innovates in raw materials, uses low-cost calcium hydroxide, seed crystal calcium carbonate and carbon dioxide as raw materials, adopts the carbonization method, combines scientific and reasonable process parameter control and the synergistic effect of the composite additive, and the prepared laminated square calcium carbonate sample has regular morphology and good dispersibility. Description of the Drawings

[0033] Figure 1 is the electron microscope photograph of the product of Example 1 of the present invention;

[0034] Figure 2 is the electron microscope photograph of the product of Example 2 of the present invention;

[0035] Figure 3 is the electron microscope photograph of the product of Example 3 of the present invention;

[0036] Figure 4 is the electron microscope photograph of the product of Comparative Example 1 of the present invention;

[0037] Figure 5 It is the electron microscope photograph of the product of Comparative Example 2 of the present invention;

[0038] Figure 6 It is the electron microscope photograph of the product of Comparative Example 3 of the present invention;

[0039] Figure 7 It is the electron microscope photograph of the product of Comparative Example 4 of the present invention;

[0040] Figure 8 It is the electron microscope photograph of the product of Comparative Example 5 of the present invention. Detailed Embodiments

[0041] The following is a detailed description of the specific embodiments of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0042] Example 1

[0043] A preparation method of micron-scale laminated cubic calcium carbonate includes the following steps:

[0044] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0045] S2: Weigh 5 kg of water and pour it into the carbonization tower, control the water temperature at 25°C, add 1% of the calcium carbonate seed based on the dry mass of calcium hydroxide to the water, and start stirring with a stirring speed of 250 r / min; the preparation method of the calcium carbonate seed refers to the preparation in Example 1 of the invention patent CN201811559082.8 - A preparation method of monodisperse cubic precipitated calcium carbonate by Guangxi Heshan Warner New Materials Technology Co., Ltd.;

[0046] S3: Add 0.15% of the composite additive based on the dry mass of calcium hydroxide, and introduce a carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m 3 / h; the composite additive is composed of polyepoxysuccinic acid (PESA) and hydrolyzed polymaleic anhydride (HMPA) mixed in a ratio of 1:1;

[0047] S4: Monitor the pH during the reaction process, use a peristaltic pump to drop the calcium hydroxide suspension into the carbonization tower for reaction at a rate of 150 mL / min. After adding all the calcium hydroxide suspension, continue to introduce the carbon dioxide mixed gas until the pH reaches 7.5 and then stop ventilation. The obtained suspension is filtered by suction, dried in an oven at 120°C, sieved, and finally calcium carbonate powder is obtained.

[0048] Example 2

[0049] A preparation method of micron-scale laminated cubic calcium carbonate includes the following steps:

[0050] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 10% for standby.

[0051] S2: Weigh 5 kg of water and pour it into the carbonization tower. Control the water temperature at 20 °C. Add seed calcium carbonate with a mass of 0.5% of the dry basis of calcium hydroxide to the water. Start stirring, and the stirring speed is 350 r / min. The preparation method of the calcium carbonate seed crystal refers to Example 2 in the invention patent CN201811559082.8 - A preparation method of monodisperse cubic precipitated calcium carbonate of Guangxi Heshan Warner New Materials Technology Co., Ltd.

[0052] S3: Add a composite additive with a mass of 0.05% of the dry basis of calcium hydroxide, and introduce a carbon dioxide mixed gas with a concentration of 20% and a flow rate of 1.0 m 3 / h. The composite additive is composed of polyepoxysuccinic acid (PESA) and hydrolyzed polymaleic anhydride (HMPA) mixed in a ratio of 1:1.

[0053] S4: Monitor the pH during the reaction process. Use a peristaltic pump to drop the calcium hydroxide suspension into the carbonization tower for reaction at a rate of 100 mL / min. After adding all the calcium hydroxide suspension, continue to introduce the carbon dioxide mixed gas until the pH reaches 7.2, then stop ventilation. Filter the obtained suspension, dry it in an oven at 115 °C, sieve it, and finally obtain calcium carbonate powder.

[0054] Example 3

[0055] A preparation method of micron - scale laminated block - shaped calcium carbonate, comprising the following steps:

[0056] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 15% for standby;

[0057] S2: Weigh 5 kg of water and pour it into the carbonization tower. Control the water temperature at 30 °C. Add seed calcium carbonate with a mass of 1.5% of the dry basis of calcium hydroxide to the water. Start stirring, and the stirring speed is 300 r / min. The preparation method of the calcium carbonate seed crystal refers to Example 3 in the invention patent CN201811559082.8 - A preparation method of monodisperse cubic precipitated calcium carbonate of Guangxi Heshan Warner New Materials Technology Co., Ltd.

[0058] S3: Add a composite additive with a mass of 0.3% of the dry basis of calcium hydroxide, and introduce a carbon dioxide mixed gas with a concentration of 30% and a flow rate of 1.2 m 3 / h. The composite additive is composed of polyepoxysuccinic acid (PESA) and hydrolyzed polymaleic anhydride (HMPA) mixed in a ratio of 1:1.

[0059] S4: Monitor the pH during the reaction, and use a peristaltic pump to drop the calcium hydroxide suspension into the carbonation tower for reaction at a rate of 200 mL / min. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when pH ≤ 7.5. Filter the obtained suspension by suction, dry it in an oven at 125 °C, sieve it, and finally obtain calcium carbonate powder.

[0060] Comparative Example 1

[0061] A method for preparing calcium carbonate, comprising the following steps:

[0062] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0063] S2: Weigh 5 kg of water and pour it into the carbonation tower, control the water temperature at 25 °C, add calcium carbonate seeds accounting for 1% of the dry basis mass of calcium hydroxide to the water, turn on the stirrer, and the stirring speed is 250 r / min; the preparation method of the calcium carbonate seeds refers to the preparation of Example 1 in the invention patent CN201811559082.8 of Guangxi Heshan Warner New Materials Technology Co., Ltd. - A method for preparing monodisperse cubic precipitated calcium carbonate;

[0064] S3: Pass a carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m 3 / h;

[0065] S4: Monitor the pH during the reaction, and use a peristaltic pump to drop the calcium hydroxide suspension into the carbonation tower for reaction at a rate of 150 mL / min. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when pH is 7.5. Filter the obtained suspension by suction, dry it in an oven at 120 °C, sieve it, and finally obtain calcium carbonate powder.

[0066] Comparative Example 2

[0067] A method for preparing calcium carbonate, comprising the following steps:

[0068] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0069] S2: Weigh 5 kg of water and pour it into the carbonation tower, control the water temperature at 25 °C, add calcium carbonate seeds accounting for 1% of the dry basis mass of calcium hydroxide to the water, turn on the stirrer, and the stirring speed is 250 r / min; the preparation method of the calcium carbonate seeds refers to the preparation of Example 1 in the invention patent CN201811559082.8 of Guangxi Heshan Warner New Materials Technology Co., Ltd. - A method for preparing monodisperse cubic precipitated calcium carbonate;

[0070] S3: Add polyepoxysuccinic acid (PESA) accounting for 0.15% of the dry basis mass of calcium hydroxide, and pass a carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m3 carbon dioxide mixed gas at [X] / h;

[0071] S4: Monitor the pH during the reaction process. Dropwise add calcium hydroxide suspension into the carbonization tower at a rate of 150 mL / min for reaction. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when the pH reaches 7.5. Filter the obtained suspension by suction, dry it in an oven at 120 °C, sieve it, and finally obtain calcium carbonate powder.

[0072] Comparative Example 3

[0073] A method for preparing calcium carbonate, comprising the following steps:

[0074] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0075] S2: Weigh 5 kg of water and pour it into the carbonization tower. Control the water temperature at 25 °C. Add seed calcium carbonate with a mass of 1% of the calcium hydroxide dry basis to the water, and start stirring at a stirring speed of 250 r / min; The preparation method of the calcium carbonate seed is prepared with reference to Example 1 in the invention patent CN201811559082.8 - A method for preparing monodisperse cubic precipitated calcium carbonate by Guangxi Heshan Huana New Material Technology Co., Ltd.;

[0076] S3: Add hydrolyzed polymaleic anhydride (HMPA) with a mass of 0.15% of the calcium hydroxide dry basis, and pass carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m 3 / h;

[0077] S4: Monitor the pH during the reaction process. Dropwise add calcium hydroxide suspension into the carbonization tower at a rate of 150 mL / min for reaction. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when the pH reaches 7.5. Filter the obtained suspension by suction, dry it in an oven at 120 °C, sieve it, and finally obtain calcium carbonate powder.

[0078] Comparative Example 4

[0079] A method for preparing calcium carbonate, comprising the following steps:

[0080] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0081] S2: Weigh 5 kg of water and pour it into the carbonization tower. Control the water temperature at 25 °C, start stirring, and the stirring speed is 250 r / min;

[0082] S3: Add a composite additive with a mass of 0.15% of the calcium hydroxide dry basis, and pass carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m 3A carbon dioxide mixed gas of / h; the composite additive is composed of polyepoxysuccinic acid (PESA) and hydrolyzed polymaleic anhydride (HMPA) mixed in a ratio of 1:1;

[0083] S4: Monitor the pH during the reaction process, use a peristaltic pump to drop the calcium hydroxide suspension into the carbonization tower for reaction at a rate of 150 mL / min. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when the pH reaches 7.5. The obtained suspension is filtered by suction, dried in an oven at 120 °C, sieved, and finally calcium carbonate powder is obtained.

[0084] Comparative Example 5

[0085] A method for preparing calcium carbonate includes the following steps:

[0086] S1: Prepare 10 kg of calcium hydroxide suspension with a mass concentration of 12.5% for standby;

[0087] S2: Weigh 5 kg of water and pour it into the carbonization tower, control the water temperature at 25 °C, add calcium carbonate seeds accounting for 1% of the dry basis mass of calcium hydroxide to the water, and start stirring. The stirring speed is 250 r / min; the preparation method of the calcium carbonate seeds refers to the preparation in Example 1 of the invention patent CN201811559082.8 - A method for preparing monodisperse cubic precipitated calcium carbonate by Guangxi Heshan Warner New Materials Technology Co., Ltd.;

[0088] S3: Add a composite additive accounting for 0.15% of the dry basis mass of calcium hydroxide, and pass a carbon dioxide mixed gas with a concentration of 25% and a flow rate of 0.8 m 3 / h; the composite additive is composed of polyepoxysuccinic acid (PESA) and hydrolyzed polymaleic anhydride (HMPA) mixed in a ratio of 1:1;

[0089] S4: Monitor the pH during the reaction process, use a peristaltic pump to drop the calcium hydroxide suspension into the carbonization tower for reaction at a rate of 250 mL / min. After adding the calcium hydroxide suspension, continue to pass the carbon dioxide mixed gas until the ventilation stops when the pH reaches 7.5. The obtained suspension is filtered by suction, dried in an oven at 120 °C, sieved, and finally calcium carbonate powder is obtained.

[0090] Comparative experiment

[0091] The calcium carbonate products prepared in Examples 1 - 3 of the present invention and Comparative Examples 1 - 5 are subjected to electron microscopy scanning, and the results are as Figures 1 to 8 shown.

[0092] Figures 1 to 3 All are micron - sized laminated square - shaped calcium carbonate.

[0093] Figure 4Among them, compared with Example 1, in Comparative Example 1, since no composite additive was added, the prepared sample was micron-sized cubic calcium carbonate, without lamination, and with serious clustering and poor dispersibility.

[0094] Figure 5 Among them, in Comparative Example 2, based on Comparative Example 1, the polyepoxysuccinic acid (PESA) additive was added. The prepared sample was micron-sized cubic calcium carbonate, with lamination, but with serious particle clustering and poor dispersibility.

[0095] Figure 6 Among them, in Comparative Example 3, based on Comparative Example 1, the hydrolyzed polymaleic anhydride (HMPA) additive was added. The prepared sample was micron-sized cubic calcium carbonate, without lamination, but with good particle dispersibility.

[0096] Figure 7 Among them, compared with Example 1, in Comparative Example 4, since no seed calcium carbonate particles were added, more independent nucleations of particles occurred and the particle sizes were uneven.

[0097] Figure 8 Among them, compared with Example 1, in Comparative Example 5, due to the too fast acceleration rate of the calcium hydroxide suspension droplets, although most of them were micron-sized laminated cubic calcium carbonate, there were some particles with independent nucleation and serious aggregation.

[0098] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A preparation method of micron-scale laminated cubic calcium carbonate, characterized in that, It includes the following steps: S1: Prepare a calcium hydroxide suspension for standby; S2: Add water into the carbonization tower, then add seed calcium carbonate into the water, and start stirring; S3: Add a composite additive composed of polyepoxysuccinic acid and dispersant hydrolyzed polymaleic anhydride, and introduce a carbon dioxide mixed gas. The addition amount of the composite additive is 0.05 - 0.3% of the dry basis mass of calcium hydroxide; S4: Monitor the pH during the reaction process, slowly drop the calcium hydroxide suspension into the carbonization tower for reaction, and maintain the process pH ≤ 11. The dropping rate of the calcium hydroxide suspension ≤ 200 mL / min; After adding the calcium hydroxide suspension, continue to introduce the carbon dioxide mixed gas until the ventilation stops when pH ≤ 7.

5. The obtained suspension is filtered, dried, and sieved, and finally micron-sized laminated block-shaped calcium carbonate is obtained.

2. The preparation method of the micron-sized laminated block calcium carbonate according to claim 1, characterized in that: In step S1, the mass concentration of the calcium hydroxide suspension is 10 - 15%.

3. The preparation method of the micron-scale laminated cubic calcium carbonate according to claim 1, characterized in that: In step S2, the addition amount of water is 1 / 2 of the calcium hydroxide suspension, and the water temperature is 20 - 30 °C.

4. The preparation method of the micron-scale laminated block calcium carbonate according to claim 1, characterized in that: In step S2, the addition amount of the seed calcium carbonate is 0.5 - 1.5% of the dry basis mass of calcium hydroxide.

5. The preparation method of the micron-sized laminated cubic calcium carbonate according to claim 1, characterized in that: In step S2, the stirring speed is 250 - 350 r / min.

6. The preparation method of the micron-scale laminated block-shaped calcium carbonate according to claim 1, wherein: In step S3, the mass ratio of polyepoxysuccinic acid to dispersant hydrolyzed polymaleic anhydride is 1:

1.

7. The preparation method of the micron-scale laminated square calcium carbonate according to claim 1, characterized in that: In step S3, the concentration of the carbon dioxide mixed gas is 20-30%, and the flow rate of the mixed gas is 0.8-1.2 m 3 / h.

8. The preparation method of the micron-scale laminated block calcium carbonate according to claim 1, characterized in that: In step S4, the temperature during the drying process is 115 - 125 °C.

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