Method and equipment for producing single-particle ultra-dispersed nano-calcium

Abstract

The invention provides a single-particle ultra-dispersed nano-calcium production method and equipment, and the method comprises the following steps: S1, calcining limestone to form limestone, and putting quicklime into boiled slurry; s2, adding an organic silicon destaticizing dispersant into the boiled pulp tank, adding 0.5-1 part by weight of the organic silicon destaticizing dispersant into every 100 parts by weight of calcium carbonate pulp, and fully mixing the organic silicon destaticizing dispersant and the calcium carbonate pulp; s3, adding 2-3 parts by weight of stearyl alcohol coupling agent into the cooked pulp tank for wet modification; s4, dehydrating, drying and scattering the modified nano calcium carbonate slurry, and introducing scattered nano calcium carbonate into secondary modification equipment for secondary modification to obtain a nano calcium carbonate finished product. The stability and the modification quality of the modified nano calcium carbonate can be improved by combining two times of modification, and the calcining furnace is arranged and can be used for continuously calcining quick lime, so that the problems that an existing calcining furnace is relatively large in occupied area and easy to realize non-uniform calcination are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of nano calcium production, and specifically relates to a single-particle ultra-dispersed nano calcium production method and equipment. Background Art

[0002] Nano calcium is also called nano calcium carbonate and ultrafine calcium carbonate. It is a very important functional inorganic filler and is widely used in industrial fields such as plastics, rubber, coatings and papermaking. The surface of calcium carbonate particles has strongly hydrophilic hydroxyl groups, which are alkaline. They have different interface properties from organic polymer matrix materials and poor compatibility. It is difficult to disperse evenly in the matrix material and form a strong bond with the matrix material, resulting in interface defects between the two materials and reducing some mechanical properties of the composite material.

[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 purpose of the present invention is to overcome the deficiencies in the prior art. The present invention provides a method and equipment for producing single-particle ultra-dispersed nano-calcium.

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

[0006] A method for producing single-particle ultra-dispersed nano-calcium comprises the following steps:

[0007] Step S1, calcining limestone to form limestone, putting quicklime into a slurry tank and carbonizing it to form calcium carbonate slurry;

[0008] Step S2, adding an organosilicon antistatic dispersant into the cooked pulp tank, adding 0.5-1 weight part of the organosilicon antistatic dispersant to every 100 weight parts of the calcium carbonate slurry, and fully mixing the organosilicon antistatic dispersant and the calcium carbonate slurry;

[0009] Step S3, adding 2-3 parts by weight of stearyl alcohol coupling agent into the cooked pulp tank for wet modification;

[0010] Step S4, dehydrating, drying and breaking up the modified nano-calcium carbonate slurry, introducing the broken up nano-calcium carbonate into a secondary modification device for secondary modification to obtain a finished nano-calcium carbonate product.

[0011] Preferably, the secondary modification in step S4 is performed by dry modification.

[0012] Preferably, 0.6-1 parts by weight of an organic siloxane coupling agent is added during the secondary modification, and after the secondary modification is completed, the finished product is transported to a finished product warehouse for packaging by an air flow conveyor.

[0013] Preferably, the wet modification time is 20-40 minutes and the modification temperature is 60°C.

[0014] A single-particle ultra-dispersed nano-calcium production device produces single-particle ultra-dispersed nano-calcium through any of the above-mentioned production methods, comprising a calcining furnace, a pulp tank, a drying device and a modifier.

[0015] Preferably, a dispersing device is provided between the modifier and the drying device, and the modifier is any one of a high-speed mixer, a three-roller continuous modifier, a force modifier, and a honeycomb mill modifier.

[0016] Preferably, the calcining furnace comprises:

[0017] A furnace body, wherein a columnar calcining chamber extending in the longitudinal direction is provided inside the furnace body, a heating interlayer is provided on the side wall of the furnace body; a base is provided at the bottom of the furnace body; a feeding port is provided on the side wall at the lower end of the furnace body, passing through the heating interlayer and extending to the calcining chamber; and a discharging port is provided on the upper end of the furnace body, passing through the heating interlayer and extending obliquely downward;

[0018] Heating elements, the heating elements being evenly distributed in the heating interlayer;

[0019] A driving rod, the driving rod is concentrically distributed inside the calcining chamber, and its outer wall is provided with a spirally distributed spiral plate, a center hole is provided inside the driving rod, and a plurality of air holes are evenly distributed on the side wall of the driving rod. The upper end of the driving rod extends upward from the furnace body and is correspondingly connected to a fan, and the lower end of the driving rod extends downward from the furnace body and is correspondingly connected to a driving device.

[0020] Preferably, the outer diameter of the spiral plate is matched to the inner diameter of the calcining chamber to form a spirally extended material guide channel, and a plurality of longitudinally extended rollers are evenly distributed along the extension direction of the material guide channel, and the two ends of the rollers are respectively mounted on the corresponding spiral plates, and the outer walls of the rollers are in contact with the inner walls of the calcining chamber to rotate with the driving rod and generate self-rotation through friction with the inner wall of the calcining chamber.

[0021] Preferably, the outer wall of the roller is provided with a gear sleeve, and the inner wall of the calcining chamber is provided with internal teeth matched with the gear sleeve.

[0022] Preferably, the inner teeth are arranged along the inner wall of the calcining chamber;

[0023] The outer teeth of the tooth sleeve on the outer wall of the shifting roller are arranged throughout the entire length.

[0024] Beneficial effects: After drying, secondary modification is carried out to solve the problem of dispersion and solubility of nano-calcium carbonate due to agglomeration. At the same time, the combination of the two modifications can improve the stability and quality of the modified nano-calcium carbonate. A calcining furnace is set up, and the calcining furnace can continuously calcine quicklime, thereby reducing the problem of large footprint and uneven calcination of existing calcining furnaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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:

[0026] Figure 1 A schematic diagram of the structure of a calcining furnace in a specific embodiment provided by the present invention;

[0027] Figure 2 It is a simplified cross-sectional view of a calcining furnace in a specific embodiment provided by the present invention.

[0028] In the figure: 1. outer cylinder; 2. discharge port; 3. driving rod; 4. feed port; 5. base; 6. speed regulating motor; 7. spiral plate; 8. roller; 9. heating element; 10. inner cylinder. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] A method for producing single-particle ultra-dispersed nano-calcium comprises the following steps: step S1, calcining quicklime to form limestone by a calcining furnace, placing the limestone into a slurry tank and carbonizing it to form calcium carbonate slurry; placing a certain amount of quicklime and water in a certain proportion (such as a water-cement ratio of 8:1) into the slurry tank, wherein the slurry tank can be digested in hot water (such as 80°C) to generate a crude calcium hydroxide slurry, aging the crude calcium hydroxide solution for a period of time (such as 24 hours), and sieving it through a screen to obtain a refined calcium hydroxide slurry. The refined calcium hydroxide slurry is placed in a reactor, and an appropriate amount of additives is added. A suitable carbonization temperature and stirring speed are set, and a mixed gas of carbon dioxide and nitrogen or pure carbon dioxide gas is introduced to start a carbonization reaction. When the reaction system is acidic (the pH value drops below 7), carbonization is continued for a period of time (such as 15 minutes) to obtain a nano calcium carbonate solution. Step S2, add 0.5-1 weight part of organosilicon antistatic dispersant per 100 weight parts of calcium carbonate slurry, for example 0.5, 0.8, 1 weight parts, and fully mix the organosilicon antistatic dispersant and calcium carbonate slurry. The organosilicon antistatic dispersant is a kind of polymer compound with siloxane as the main structure, which usually has excellent surface activity, thermal stability, weather resistance, chemical inertness and safety. This type of dispersant can significantly reduce the surface tension of the liquid, effectively improve the wettability of solid particles, and promote its dispersion in the liquid. At the same time, since the main chain of organosilicon is a silicon-oxygen bond, this structure gives it excellent UV resistance and oxidation resistance, and increases the weather resistance of the product. In addition, the organosilicon dispersant also has a good antistatic effect, which can reduce the electrostatic attraction between particles and prevent agglomeration, thereby significantly improving the dispersibility and stability of the slurry, and providing high-quality raw materials for subsequent industrial production. Step S3, add 2-3 parts by weight of stearyl alcohol coupling agent into the cooked pulp tank for wet modification, such as 2, 2.5, 3 parts by weight, so as to improve the surface properties of calcium carbonate particles and enhance their performance in specific applications. Wet modification is by dissolving the modifier in a solvent (usually water), then mixing the calcium carbonate slurry with the modifier solution, and making the modifier fully contact with the calcium carbonate particles under stirring and chemical reaction or physical adsorption, thereby changing the surface characteristics of the calcium carbonate particles. The advantage of this method is that it is possible to achieve uniform distribution of the modifier and improve the modification effect. The modified calcium carbonate particles have better dispersibility in water or other solvents, and are not prone to agglomeration. The coating formed by the stearyl alcohol coupling agent on the surface of the calcium carbonate particles can enhance the stability of the particles and prevent them from deteriorating or degrading during storage and use. The compatibility of the modified calcium carbonate particles with organic matter is improved, and it can be better combined with matrix materials such as resins and rubbers to improve the performance of composite materials.

[0033] Step S4, dehydrating, drying and breaking up the modified nano calcium carbonate slurry, introducing the broken up nano calcium carbonate into a secondary modification device for secondary modification to obtain a finished nano calcium carbonate product, and then performing secondary modification after drying, thereby solving the problem of dispersion and solubility of nano calcium carbonate due to agglomeration problems, and combining the two modifications to improve the stability and quality of the modified nano calcium carbonate.

[0034] In an optional embodiment, the secondary modification in step S4 is performed by dry modification, and the modification machine may be a high-speed mixer, a three-roller continuous modification machine, a force modification machine, or a honeycomb mill modification machine.

[0035] In an optional embodiment, 0.6-1 parts by weight of an organosiloxane coupling agent is added during the secondary modification, for example, 0.6, 0.8, or 1 parts by weight. After the secondary modification is completed, the finished product is transported to a finished product warehouse for packaging by an air flow conveyor. The organosiloxane coupling agent molecules usually contain silicon-oxygen (Si-O) bonds and organic functional groups (such as quinone, amino, epoxy, etc.). These functional groups can chemically react or physically adsorb with groups such as hydroxyl (OH) on the surface of the calcium carbonate particles, thereby forming a layer of organic molecular film on the surface of the calcium carbonate particles. This film can significantly improve the dispersibility, stability, and compatibility of the calcium carbonate particles with organic matter.

[0036] In this embodiment, the wet modification time is 20-40 minutes, and the modification temperature is 60°C.

[0037] The present application also provides a single particle ultra-dispersed nano calcium production device, such as Figure 1-2 As shown, single-particle ultra-dispersed nano-calcium is produced by any of the above production methods, including a calcining furnace, a slurry tank, a drying device and a modifier. First, limestone is calcined to obtain quicklime, and the quicklime is put into the slurry tank for carbonization, and then the finished nano-calcium is obtained by secondary modification. A dispersing device is set between the modifier and the drying device, and the drying effect can be ensured by dispersing. The modifier is any one of a high-speed mixer, a three-roller continuous modifier, a force modifier, and a honeycomb mill modifier.

[0038] In an optional embodiment, the calcining furnace includes a furnace body, a heating element 9, and a driving rod 3, 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 10 which are concentrically sleeved with each other, and the outer cylinder 1 and the inner cylinder 10 are both heat-resistant metal cylinders, and the upper and lower ends thereof are sealed. A base 5 is provided at the bottom of the furnace body, and a support plate or a support frame corresponding to the outer cylinder 1 is provided on the base 5. A feed port 4 is provided on the side wall of the lower end of the furnace body, which passes through the heating interlayer and extends to the calcining chamber, and a corresponding feed nozzle is provided at the feed port 4, and the feed nozzle is correspondingly connected to the inner cylinder 10 and the outer cylinder 1. A discharge port 2 is provided at the upper end of the furnace body, which passes through the heating interlayer and extends obliquely downward, and a discharge port 2 is provided with a discharge nozzle, and the feed nozzle is correspondingly connected to the inner cylinder 10 and the outer cylinder 1, and the discharge nozzle extends to the cooked pulp pool through a conveyor belt. The heating element The components 9 are evenly distributed in the heating interlayer. The heating element 9 can be an electric heating wire or an electric heating tube, which is spirally extended outside the inner tube 10. The driving rod 3 is concentrically distributed inside the calcining chamber. The driving rod 3 is a hollow structure. A central hole is provided inside the driving rod 3. The outer wall of the driving rod 3 is provided with a spiral distribution sub-spiral plate 7. The spiral plate 7 forms a spiral material guide mechanism. As the driving rod 3 rotates, the limestone moves upward. During the movement, it is heated and calcined, 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 3. After the upper end of the driving rod 3 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 3 extends downward from the furnace body, a driving device is correspondingly connected. The lower end of the driving rod 3 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 6, which drives the limestone according to the heating efficiency.

[0039] In an optional embodiment, air holes are provided on the side wall of the inner cylinder 10, and a filter screen is provided on the outer wall of the inner cylinder 10 or the outer wall of the driving rod 3 to filter the limestone.

[0040] The outer diameter of the spiral plate 7 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 7. A plurality of longitudinally extending rollers 8 are evenly distributed along the extension direction of the material guide channel. The length of the roller 8 is matched with the width of the material guide channel. Both ends of the main shaft of the roller 8 are respectively assembled on the corresponding spiral plate 7 through bearings. The distribution area of ​​the roller 8 is located in the area between the feed port 4 and the discharge port 2. The outer wall of the roller 8 is in contact with the inner wall of the calcining chamber to rotate with the driving rod 3 and the inner wall of the calcining chamber through friction. During the rotation of the roller 8, the internal limestone is loosened, thereby enhancing the air permeability, improving the heating uniformity, and ensuring the calcining effect.

[0041] Furthermore, the outer wall of the roller 8 is provided with a tooth sleeve, the length of the tooth sleeve is adapted to the length of the roller 8, 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 3 rotates. The inner teeth are bar teeth extending in the longitudinal direction, so that the inner cylinder 10 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 8 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 8 can be assembled downward in the longitudinal direction. The roller 8 and the inner cylinder 10 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 8.

[0042] In an optional embodiment, the number of turns of the spiral body of the material guiding channel corresponding to the area between the feed port 4 and the discharge port 2 is N, and the number of the rollers 8 is not greater than N.

[0043] In an optional embodiment, a plurality of steel bars (rebars) extending along the axial direction are welded to the outer wall of the gear sleeve, and a plurality of steel bars (rebars) extending along the axial direction are provided on the inner wall of the inner cylinder 10, thereby forming mutually meshing external teeth and internal teeth, which move as gears 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.

[0044] 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 single-particle ultra-dispersed nano-calcium, characterized in that: The following steps are involved: Step S1, calcining limestone to form limestone, putting quicklime into a slurry tank and carbonizing it to form calcium carbonate slurry; Step S2, adding an organosilicon antistatic dispersant into the cooked pulp tank, adding 0.5-1 weight part of the organosilicon antistatic dispersant to every 100 weight parts of the calcium carbonate slurry, and fully mixing the organosilicon antistatic dispersant and the calcium carbonate slurry; Step S3, adding 2-3 parts by weight of stearyl alcohol coupling agent into the cooked pulp tank for wet modification; Step S4, dehydrating, drying and breaking up the modified nano-calcium carbonate slurry, introducing the broken up nano-calcium carbonate into a secondary modification device for secondary modification to obtain a finished nano-calcium carbonate product.

2. The method for producing single-particle ultra-dispersed nano-calcium according to claim 1, characterized in that: The secondary modification in step S4 is performed by dry modification.

3. The method for producing single-particle ultra-dispersed nano-calcium according to claim 2, characterized in that: During the secondary modification, 0.6-1 parts by weight of an organic siloxane coupling agent is added. After the secondary modification is completed, the finished product is transported to a finished product warehouse for packaging by an air flow conveyor.

4. The method for producing single-particle ultra-dispersed nano-calcium according to claim 1, characterized in that: The wet modification time is 20-40 minutes, and the modification temperature is 60°C.

5. A single-particle ultra-dispersed nano-calcium production device, which produces single-particle ultra-dispersed nano-calcium by the production method described in any one of claims 1 to 4, characterized in that: It includes a calcining furnace, a pulp pool, a drying device and a modifier.

6. The single-particle ultra-dispersed nano-calcium production equipment according to claim 5, characterized in that: A dispersing device is arranged between the modifier and the drying device, and the modifier is any one of a high-speed mixer, a three-roller continuous modifier, a force-type modifier, and a honeycomb mill modifier.

7. The single-particle ultra-dispersed nano-calcium production equipment according to claim 5, characterized in that: The calcining furnace comprises: A furnace body, wherein a columnar calcining chamber extending in the longitudinal direction is provided inside the furnace body, a heating interlayer is provided on the side wall of the furnace body; a base is provided at the bottom of the furnace body; a feeding port is provided on the side wall at the lower end of the furnace body, passing through the heating interlayer and extending to the calcining chamber; and a discharging port is provided on the upper end of the furnace body, passing through the heating interlayer and extending obliquely downward; Heating elements, the heating elements being evenly distributed in the heating interlayer; A driving rod, the driving rod is concentrically distributed inside the calcining chamber, and its outer wall is provided with a spirally distributed spiral plate, a center hole is provided inside the driving rod, and a plurality of air holes are evenly distributed on the side wall of the driving rod. The upper end of the driving rod extends upward from the furnace body and is correspondingly connected to a fan, and the lower end of the driving rod extends downward from the furnace body and is correspondingly connected to a driving device.

8. The single-particle ultra-dispersed nano-calcium production equipment according to claim 7, characterized in that: The outer diameter of the spiral plate is matched with the inner diameter of the calcining chamber to form a spirally extended material guide channel. A plurality of longitudinally extended rollers are evenly distributed along the extension direction of the material guide channel. Both ends of the rollers are respectively mounted on the corresponding spiral plates. The outer walls of the rollers are in contact with the inner walls of the calcining chamber to rotate with the driving rod and generate self-rotation through friction with the inner wall of the calcining chamber.

9. The single-particle ultra-dispersed nano-calcium production equipment according to claim 8, characterized in that: The outer wall of the roller is provided with a gear sleeve, and the inner wall of the calcining chamber is provided with internal teeth matched with the gear sleeve.

10. The single-particle ultra-dispersed nano-calcium production equipment according to claim 9, characterized in that: The inner teeth are arranged along the inner wall of the calcining chamber; The outer teeth of the tooth sleeve on the outer wall of the shifting roller are arranged throughout the entire length.

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