Production method of submicron functional calcium carbonate

Abstract

The invention provides a submicron functional calcium carbonate production method, which comprises: S1, calcining limestone, adding into a slurry cooking pool, cooking to obtain a calcium carbonate slurry, drying the calcium carbonate slurry to obtain calcium carbonate powder, grinding to form calcium carbonate powder, and carrying out primary modification to make the micron-sized content in the calcium carbonate powder not less than 80%; s2, modifying the calcium carbonate powder to obtain a submicron functional calcium carbonate finished product, and adding a coupling agent for secondary modification during modification; and S3, filtering the submicron functional calcium carbonate finished product, packaging and storing. An organic silicon dispersing agent and a modifier are added during grinding, so that the powder is not agglomerated, good in dispersion and fusion and good in work performance, and the final mechanical property and various comprehensive performance indexes are ensured; and secondary modification is performed, so that the stability and the modification quality of the modified calcium carbonate can be improved, and the possibility of aggregation or deformation is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of calcium carbonate production, and in particular relates to a method for producing submicron functional calcium carbonate. Background Art

[0002] Submicron functional calcium carbonate refers to calcium carbonate particles with a particle size at the submicron level. These particles have a large specific surface area and high surface energy, which give them a series of special physical and chemical properties. For example, submicron calcium carbonate particles can be more effectively dispersed in polymers, improving the mechanical properties of composite materials; at the same time, their unique surface structure also makes them show good application prospects in adsorption, catalysis and other fields. Nano calcium carbonate has a very small particle size and is easily affected by environmental factors such as temperature and humidity. These factors may cause conventional production methods to cause the product to aggregate or deform, thereby affecting the quality stability of the product.

[0003] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0004] The object of the present invention is to overcome the above-mentioned deficiencies in the prior art, and the present invention provides a method for producing submicron functional calcium carbonate.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for producing submicron functional calcium carbonate, comprising:

[0007] Step S1, calcining limestone and then putting it into a slurry tank for slaking to obtain calcium carbonate slurry, drying the calcium carbonate slurry to obtain calcium carbonate granules, grinding them to form calcium carbonate powder for primary modification, so that the micron content of the calcium carbonate powder is not less than 80%;

[0008] Step S2, modifying the calcium carbonate powder to obtain a submicron functional calcium carbonate product, and adding a coupling agent during the modification to perform secondary modification;

[0009] Step S3, filtering the submicron functional calcium carbonate product, packaging and storing it.

[0010] Preferably, 0.5-1 parts by weight of an organosilicon dispersant is added during grinding in step S1.

[0011] Preferably, in step S2, the calcium carbonate powder is 100 parts by weight, and the coupling agent is 1-5 parts by weight of an organosilicon coupling agent.

[0012] Preferably, in step S2, calcium carbonate powder and 50% semi-active light calcium are compounded, the calcium carbonate powder is 80-100 parts by weight, and the semi-active light calcium is 10-20 parts by weight.

[0013] Preferably, the coupling agent is 1-5 parts by weight of an organic titanium coupling agent.

[0014] A submicron functional calcium carbonate production device produces submicron functional calcium carbonate by any of the above-mentioned production methods, comprising a grinder, a primary modifier and a secondary modifier connected by an air flow conveyor.

[0015] Preferably, the modifying machine is a drying device, comprising:

[0016] A drying cylinder, the drying cylinder is rotatably connected to the base, an air outlet pipe and a feed pipe are connected to the first end of the drying cylinder, and a discharge pipe and an air inlet pipe are provided at the second end of the drying cylinder;

[0017] A material guide plate, the material guide plate is located on the inner wall of the drying cylinder and extends spirally along the axial direction of the drying cylinder;

[0018] A mixing mechanism extends from the second end of the drying cylinder into the inner cavity of the drying cylinder.

[0019] Preferably, the mixing mechanism comprises:

[0020] A spiral material guide pipe, the spiral material guide pipe extends into the interior of the drying cylinder along the axial direction of the drying cylinder and is rotatably sealed and connected to the second end of the drying cylinder;

[0021] A material distributing nozzle, one end of which is fixed to the end of the spiral material guiding tube, and the other end is provided with a conical bottom, a plurality of discharge ports are provided at the lower side of the material distributing nozzle, and a plurality of elastic columns corresponding to the inner wall of the drying cylinder are evenly distributed on the periphery of the material distributing nozzle.

[0022] Preferably, the discharge pipe is connected to a breaking device.

[0023] Beneficial effects: Adding silicone dispersant modifier during grinding can prevent the powder from agglomerating, disperse well and have good performance, thus ensuring the final mechanical properties and various comprehensive performance indicators; secondary modification can improve the stability and quality of modified calcium carbonate and reduce the possibility of aggregation or deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0025] Figure 1 A schematic diagram of the calcining furnace structure in a specific embodiment provided by the present invention;

[0026] Figure 2 This is a simplified structural diagram of a drying device in a specific embodiment provided by the present invention.

[0027] In the figure: 1. outer cylinder; 2. heating element; 3. calcination discharge port; 4. inner cylinder; 5. driving rod; 6. spiral plate; 7. paddle roller; 8. calcination feed port; 9. speed regulating motor; 10. drying cylinder; 11. second end cover; 12. first end cover; 13. air inlet pipe; 14. spiral material guide pipe; 15. discharge pipe; 16. air outlet pipe; 17. scattering cylinder; 18. annular baffle; 19. base; 20. auxiliary heating cylinder; 21. material distribution nozzle; 22. paddle plate; 23. elastic column. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0029] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0031] A method for producing submicron functional calcium carbonate, in step S1, limestone is calcined in a calcining furnace, such as Figure 1As shown, the calcining furnace includes a furnace body, a heating element 2, and a driving rod 5, wherein a columnar calcining chamber extending in the longitudinal direction is provided inside the furnace body, and a heating interlayer is provided on the side wall of the furnace body. Specifically, the furnace body includes an outer cylinder 1 and an inner cylinder 4 which are concentrically sleeved with each other, and the outer cylinder 1 and the inner cylinder 4 are both heat-resistant metal cylinders, and the upper and lower ends thereof are sealed. A base is provided at the bottom of the furnace body, and a supporting plate or a supporting frame corresponding to the outer cylinder 1 is provided on the base. A calcining feed port 8 which passes through the heating interlayer and extends to the calcining chamber is provided on the side wall of the lower end of the furnace body, and a corresponding feed nozzle is provided at the calcining feed port 8, and the feed nozzle is correspondingly connected to the inner cylinder 4 and the outer cylinder 1. A calcining discharge port 3 which passes through the heating interlayer and extends obliquely downward is provided at the upper end of the furnace body, and the calcining discharge port 3 is provided with a discharge nozzle, and the feed nozzle is correspondingly connected to the inner cylinder 4 and the outer cylinder 1, and the discharge nozzle extends to the cooked pulp pool through a conveyor belt. The heating element 2 Uniformly distributed in the heating interlayer, the heating element 2 can be an electric heating wire or an electric heating tube, which is spirally extended outside the inner tube 4, and the driving rod 5 is concentrically distributed inside the calcining chamber. The driving rod 5 is a hollow structure, and a central hole is provided inside the driving rod 5. The outer wall of the driving rod 5 is provided with a spiral distribution sub-spiral plate 6, and the spiral plate 6 forms a spiral material guide mechanism. As the driving rod 5 rotates, the limestone moves upward, and is calcined by heating during the movement, thereby meeting the assembly line calcination and reducing the volume of the equipment. There are multiple air holes evenly distributed on the side wall of the driving rod 5. After the upper end of the driving rod 5 extends upward from the furnace body, a fan is correspondingly connected through a rotating sealing joint. Under the action of the fan, the interior is ventilated. The main purpose of ventilation is to help the limestone decompose at high temperature and discharge the generated carbon dioxide and other waste gases, so as to ensure uniform temperature distribution in the kiln and improve the calcination efficiency. After the lower end of the driving rod 5 extends downward from the furnace body, a driving device is correspondingly connected. The lower end of the driving rod 5 is a closed end, which is rotatably connected to the lower end surface of the furnace body. The driving device is a speed regulating motor 9, which drives the limestone according to the heating efficiency.

[0032] The side wall of the inner cylinder 4 is provided with air holes, and the outer wall of the inner cylinder 4 or the outer wall of the driving rod 5 is provided with a filter screen to filter the limestone.

[0033] The outer diameter of the spiral plate 6 is matched with the inner diameter of the calcining chamber to form a spirally extended material guide channel, so that the limestone is pushed upward through the spiral channel. The material guide channel is a spiral structure corresponding to the spiral plate 6. A plurality of longitudinally extending rollers 7 are evenly distributed along the extension direction of the material guide channel. The length of the roller 7 is matched with the width of the material guide channel. Both ends of the main shaft of the roller 7 are respectively assembled on the corresponding spiral plate 6 through bearings. The distribution area of ​​the roller 7 is located in the area between the calcining feed port 8 and the calcining discharge port 3. The outer wall of the roller 7 is in contact with the inner wall of the calcining chamber to rotate with the driving rod 5 and the inner wall of the calcining chamber through friction to generate self-rotation. During the rotation of the roller 7, the internal limestone is loosened, thereby enhancing the air permeability, improving the heating uniformity, and ensuring the calcining effect.

[0034] Furthermore, the outer wall of the roller 7 is provided with a tooth sleeve, the length of the tooth sleeve is adapted to the length of the roller 7, and the outer teeth extending in the longitudinal direction are provided on the outer side of the tooth sleeve, and the outer teeth form a tooth roller structure outside the tooth sleeve (similar to the gear stretched in the axial direction), and the inner wall of the calcining chamber is provided with inner teeth adapted to the tooth sleeve, so as to ensure the driving of the tooth sleeve when the driving rod 5 rotates. The inner teeth are bar teeth extending in the longitudinal direction, so that the inner cylinder 4 forms an internal gear (similar to the inner gear ring extending in the axial direction). And the setting of the external teeth can increase the friction with the limestone and ensure the loosening effect of the limestone. The inner teeth are arranged throughout the inner wall of the calcining chamber, and the outer teeth of the tooth sleeve on the outer wall of the roller 7 are arranged throughout the length. The top plate at the upper end of the furnace body is installed in a detachable form by bolts, so that the roller 7 can be assembled downward in the longitudinal direction. The roller 7 and the inner cylinder 4 are formed into a gear structure through the inner teeth and teeth through installation, and after installation in place, it is ensured that the meshing with the inner teeth is achieved in the rotating area of ​​the roller 7.

[0035] The number of turns of the spiral body corresponding to the area between the calcination feed port 8 and the calcination discharge port 3 of the material guide channel is N, and the number of the rollers 7 is not greater than N. The outer wall of the gear sleeve is welded with a plurality of steel bars (rebars) extending along its axial direction, and the inner wall of the inner cylinder 4 is provided with a plurality of steel bars (rebars) extending along its axial direction, so as to form mutually meshing external teeth and internal teeth, and the two perform gear motion under the action of the steel sleeve as they rotate, thereby reducing the weight of the device and the equipment cost while meeting the purpose.

[0036] The quicklime is calcined in a calcining furnace to form limestone, and the limestone is placed in a cooked pulp tank and carbonized to form calcium carbonate slurry; an organosilicon antistatic dispersant is added to the cooked pulp tank, and 0.5-1 weight part of the organosilicon antistatic dispersant is added to every 100 weight parts of calcium carbonate slurry, for example, 0.5, 0.8, and 1 weight part, and the organosilicon antistatic dispersant and the calcium carbonate slurry are fully mixed to reduce the electrostatic attraction between particles and prevent agglomeration.

[0037] Step S1, limestone is calcined to form quicklime, quicklime is put into a slurry tank for slaking to obtain calcium carbonate slurry, the calcium carbonate slurry is dehydrated by a drying device and then dried by a drying device, limestone is calcined and put into a slurry tank for slaking to obtain calcium carbonate slurry, calcium carbonate granules are obtained after drying, the calcium carbonate granules are ground by a vertical grinder to form calcium carbonate powder for primary modification, so that the micron content in the calcium carbonate powder is not less than 80%, step S2, the calcium carbonate powder is modified to obtain a submicron functional calcium carbonate product, a coupling agent is added during the modification for secondary modification, and the stability and modified quality of the modified calcium carbonate can be improved by performing secondary modification, and the possibility of aggregation or deformation can be reduced. Step S3, the submicron functional calcium carbonate product is filtered, packaged, and stored.

[0038] In an optional embodiment, 0.5-1 parts by weight of an organosilicon dispersant, such as 0.5, 0.8, or 1 parts by weight, is added during grinding in step S1. The organosilicon dispersant is mainly adsorbed on the surface of the calcium carbonate particles to generate electrostatic repulsion and steric hindrance, thereby effectively preventing the agglomeration between the particles, so that the particles can exist stably in a suspended state. This mechanism of action helps to maintain the dispersibility of the calcium carbonate particles during the grinding process and improve the grinding efficiency. The use of a dispersant helps to obtain a calcium carbonate product with a more uniform particle size distribution and a smoother surface, which helps to improve the overall quality of the product. By preventing agglomeration between particles, the dispersant can also improve the storage stability of the calcium carbonate product and prevent problems such as agglomeration of the product during storage.

[0039] In another optional embodiment, in step S2, calcium carbonate powder is 100 parts by weight, and coupling agent is an organosilicon coupling agent of 1-5 parts by weight, such as 1, 3, and 5 parts by weight. After adding organosilicon coupling agent to calcium carbonate powder, these coupling agent molecules will be adsorbed on the surface of calcium carbonate particles, and through its special chemical structure, one end reacts with inorganic groups (such as hydroxyl groups) on the surface of calcium carbonate, and the other end interacts with organic groups in organic materials, thereby forming a bridge between calcium carbonate and organic materials, improving the interfacial bonding force between the two. The adhesion between calcium carbonate powder and organic materials (such as polymers) can be significantly improved, so that composite materials are not prone to delamination or peeling when subjected to external forces. By adjusting the charge distribution on the surface of calcium carbonate particles and reducing surface energy, organosilicon coupling agent helps to prevent the agglomeration of calcium carbonate particles in composite materials, thereby improving its dispersibility. The addition of organosilicon coupling agent can enhance the mechanical properties of composite materials, such as tensile strength, impact strength, etc., making composite materials more durable. The silicone coupling agent also has a certain degree of weather resistance, which can protect the calcium carbonate particles from erosion by environmental factors such as ultraviolet rays and moisture, thereby extending the service life of the composite material.

[0040] In another optional embodiment, a new production method is provided, which is different from the above method in that in step S2, calcium carbonate powder and 50% semi-active light calcium are compounded, the calcium carbonate powder is 80-100 weight parts, and the semi-active light calcium is 10-20 weight parts. Preferably, the calcium carbonate powder is 80 weight parts and the semi-active light calcium is 20 weight parts. Through compounding, the difference between heavy calcium carbonate (assuming that the calcium carbonate powder is the main component) and light calcium carbonate (semi-active light calcium) can be balanced, combining the advantages of both. Heavy calcium carbonate usually has higher filling capacity and lower cost, while light calcium carbonate has a smaller particle size and a larger specific surface area, which can provide better dispersibility and enhancement effect.

[0041] In this embodiment, the coupling agent used is 1-5 parts by weight of an organic titanium coupling agent, for example, 1, 3, or 5 parts by weight. The titanate coupling agent has excellent surface activity and dispersibility, and can reduce the interaction force between calcium carbonate particles, making it easier to disperse in the matrix and avoid agglomeration. At the same time, an organic layer will be formed on the surface of the calcium carbonate particles, which helps to enhance the interaction between calcium carbonate and organic polymer materials and improve the compatibility between the two. It can significantly improve the mechanical properties of the material, such as impact strength and tensile strength. This is because the coupling agent forms a molecular bridge between the inorganic filler and the organic matrix, thereby enhancing the interfacial bonding force between the two.

[0042] like Figure 2 As shown, a submicron functional calcium carbonate production equipment is used to produce submicron functional calcium carbonate by any of the above production methods, including a grinder, a primary modifier and a secondary modifier connected by an air flow conveyor. The grinder is a vertical grinder, and the primary modification is performed by a drying device. The secondary modifier can be any one of a high-speed mixer, a three-roller continuous modifier, a force modifier, and a honeycomb mill modifier.

[0043] In this embodiment, the main body of the primary modification machine is a drying device, including a drying cylinder 10, a material guide plate and a mixing mechanism. The drying cylinder 10 is a metal cylinder with open ends. The drying cylinder 10 is rotatably connected to a base 19. There are two bases 19, which are respectively located at the two ends of the drying cylinder 10. The base 19 can be concrete or a metal truss, and a U-shaped or arc-shaped supporting surface is provided above it for supporting the drying cylinder 10. Rollers or rollers are provided on the arc-shaped supporting surface so that the drying cylinder 10 can rotate. A gear ring is provided in the middle of the drying cylinder 10, and a speed regulating motor 9 is provided below the drying cylinder 10, which is engaged with the gear ring through a driving gear.

[0044] An air outlet duct 16 and a feed pipe are connected at the first end of the drying cylinder 10. Specifically, a first end cover 12 is provided at the first end of the drying cylinder 10. The first end cover 12 is a square cavity, and a corresponding side of the drying cylinder 10 is rotatably sealed and connected through corresponding perforations. The air outlet duct 16 is located on a side of the first end cover 12 away from the drying cylinder 10. The feed pipe extends from top to bottom into the first end cover 12 and then extends obliquely into the drying cylinder 10. The upper end of the feed pipe is correspondingly connected to a lifting machine.

[0045] A discharge pipe 15 and an air inlet pipe 13 are provided at the second end of the drying cylinder 10; a second end cover 11 is provided at the second end of the drying cylinder 10, and the end cover is a square cavity, which is connected to the corresponding side of the drying cylinder 10 by a corresponding perforation for rotation and sealing. The discharge pipe 15 is located at the lower end of the second end cover 11, and a corresponding conical nozzle is provided at the lower part of the second end cover 11. The discharge pipe 15 is connected to the feed end of the first modifier (high-speed mixer), and then the organic siloxane coupling agent is added to perform a modification. An air inlet is provided above the second end cover 11. Tube 13, the air inlet pipe 13 is connected to the fan correspondingly, and hot air or conventional drying air can be supplied to the drying cylinder 10. A material guide plate is provided on the inner wall of the drying cylinder 10, and the material guide plate is a metal plate, which is fixed to the drying cylinder 10 by welding. The material guide plate extends spirally along the axial direction of the drying cylinder 10, and the two ends of the material guide plate extend to the two ends of the drying cylinder 10. The mixing mechanism extends into the inner cavity of the drying cylinder 10 from the second end of the drying cylinder 10, and the mixing mechanism is used to introduce the mixed antimony trioxide, nano zinc oxide and silica aerogel into the inner cavity of the drying cylinder 10.

[0046] In an optional embodiment, the mixing mechanism includes a spiral material guide tube 14 and a material distribution nozzle 21, wherein the spiral material guide tube 14 is provided with a spiral material guide shaft, which passes through the second end cover 11 along the axis of the drying cylinder 10 and extends into the drying cylinder 10, specifically located at one-third of the drying cylinder 10. A feeding end is provided at one end of the spiral material guide tube 14, and the other end is open and correspondingly connected to the material distribution nozzle 21. The material distribution nozzle 21 is a metal tube. The spiral material guide tube 14 extends into the interior of the drying cylinder 10 along the axial direction of the drying cylinder 10, and is rotatably sealed and connected to the second end of the drying cylinder 10.

[0047] One end of the distribution nozzle 21 is connected to the end of the spiral guide tube 14, and the other end is provided with a conical bottom, which is sealed by the conical bottom. A plurality of discharge ports are provided on the lower side of the distribution nozzle 21, and the discharge ports are distributed in an array, and the area range in the circumferential direction is not more than 180 degrees of the arc corresponding to the distribution nozzle 21. A plurality of elastic columns 23 corresponding to the inner wall of the drying cylinder 10 are evenly distributed on the outer periphery of the distribution nozzle 21. During the rotation of the drying cylinder 10, the elastic columns 23 strike the inner wall of the drying cylinder 10, thereby generating vibration, so that the internal powder can quickly flow into the drying cylinder 10, so that the material passes through the discharge port and is preliminarily mixed during the subsequent rotation process.

[0048] The discharging end of the drying cylinder 10 is tilted downward, with an inclination angle of 2-5°. The second end of the drying cylinder 10 is provided with a dispersing cylinder 17 corresponding to the feed pipe. The main body of the dispersing cylinder 17 is welded from metal rods. One end of the dispersing cylinder 17 is fixed to the drying cylinder 10 through an annular baffle 18, so that a seal is formed between the end of the dispersing cylinder 17 and the drying cylinder 10 to prevent powder from overflowing. The other end is fixed to the inner wall of the drying cylinder 10 through multiple fixing rods. There are multiple fixing rods, which extend radially along the drying cylinder 10 and are evenly distributed around it. One end of the drying cylinder 10 corresponding to the fixing rod is a closed end. During the rotation process, the material is dispersed and then enters the drying cylinder 10 from between the metal rods without affecting the internal hot air circulation, thereby improving the drying effect and the looseness of the material.

[0049] In another optional embodiment, the elastic column 23 is a metal column, connected to the outer wall of the material dispensing nozzle 21 by a spring, and a plurality of paddles 22 corresponding to the elastic column 23 are provided on the inner wall of the drying cylinder 10, so that the elastic column 23 can vibrate after passing through the paddles 22, and the material can be lifted on the inner wall along with the drying cylinder 10, thereby improving the mixing uniformity. The paddles 22 extend radially along the drying cylinder 10, and the width is adapted to the guide plate. The paddles 22 are arc-shaped, and the bending direction is away from the rotation direction of the drying cylinder 10.

[0050] In an optional embodiment, a lifting plate is provided in the inner arm of the drying cylinder 10. The lifting plate is L-shaped and bent in the rotation direction of the drying cylinder 10, so that the material is lifted as it rotates, ensuring that the material is fully in contact with the hot air.

[0051] Furthermore, an auxiliary heating cylinder 20 is provided between the mixing mechanism and the dispersing cylinder 17. The auxiliary heating cylinder 20 has a certain length and is welded from a hollow metal tube, including two annular hoops and multiple branch pipes. Multiple branch pipes are connected between the two annular hoops. The annular hoops and branch pipes of the auxiliary heating cylinder 20 are both provided with heating wires, so that the internal materials can be heated by correspondingly connecting a power source, and the auxiliary lifting plate improves the drying effect. Multiple positioning columns corresponding to the inner wall of the fixed drying cylinder 10 are provided on the outer wall of the auxiliary heating cylinder 20. The outer diameter of the auxiliary heating cylinder 20 is smaller than the diameter of the corresponding circumference on the inner side of the lifting plate, so that the materials after lifting are scattered and sprinkled on the auxiliary heating cylinder 20.

[0052] In an optional embodiment, the discharge pipe 15 is connected to a dispersing device to fully disperse the mixed materials for subsequent modification.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A method for producing submicron functional calcium carbonate, characterized in that: include: Step S1, calcining limestone and then putting it into a slurry tank for slaking to obtain calcium carbonate slurry, drying the calcium carbonate slurry to obtain calcium carbonate granules, grinding them to form calcium carbonate powder for primary modification, so that the micron content of the calcium carbonate powder is not less than 80%; Step S2, modifying the calcium carbonate powder to obtain a submicron functional calcium carbonate product, and adding a coupling agent during the modification to perform secondary modification; Step S3, filtering the submicron functional calcium carbonate product, packaging and storing it.

2. The method for producing submicron functional calcium carbonate according to claim 1, characterized in that: During grinding in step S1, 0.5-1 parts by weight of an organosilicon dispersant is added.

3. The method for producing submicron functional calcium carbonate according to claim 1, characterized in that: In step S2, the calcium carbonate powder is 100 parts by weight, and the coupling agent is 1-5 parts by weight of an organosilicon coupling agent.

4. The method for producing submicron functional calcium carbonate according to claim 1, wherein: In step S2, calcium carbonate powder and 50% semi-active light calcium are compounded, with the calcium carbonate powder accounting for 80-100 parts by weight and the semi-active light calcium accounting for 10-20 parts by weight.

5. The method for producing submicron functional calcium carbonate according to claim 4, characterized in that: The coupling agent is 1-5 parts by weight of an organic titanium coupling agent.

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