Preparation method, use and device of surface modified nano-CaCO3 and CaCO3@Fe3O4

Abstract

The application provides a surface modified nano-CaCO3, a preparation method, application and device of CaCO3@Fe3O4. 2+ The content is 100-800 mg / l; S2, respectively, the concentration is 0.1-0.5 mol / l (NH4)2CO3 solution and 0.5-2.5 mol / l sodium pyrophosphate solution.The preparation method of the surface modified nano-CaCO3 provided by the application obtains the surface modified nano-CaCO3 by in-situ modification during the preparation of spherical nano-CaCO3, which is superior to nano-CaCO3 particles, the surface active site is more, and due to the chemical properties, the adsorption of F ‑ in the brine can be completed by physical and chemical adsorption, Ca + is prepared in the brine, and the prepared nano-CaCO3 can be applied to remove fluorine ions in the brine, so that the effect of one stone two birds is achieved, and the calcium source does not need to be additionally obtained.

Description

TECHNICAL FIELD

[0001] The application relates to the field of nano-CaCO3 preparation, in particular to a surface-modified nano-CaCO3, a preparation method and device of CaCO3@Fe3O4 and application. BACKGROUND

[0002] The battery-grade lithium carbonate is an indispensable lithium salt for manufacturing lithium ion batteries, and the production process starts from key steps such as leaching, concentration and synthesis of lithium mica. Fluoride ions in the lithium mica are diffused from the lithium mica ore to the brine during the leaching process. In order to avoid the influence of fluoride ions on the product quality, deep fluorine removal is required. Nano calcium carbonate is a new type of solid material, which has three crystal forms, namely calcite, aragonite and vaterite. The vaterite nano calcium carbonate has high specific surface area, low density, good solubility and dispersibility, and is widely used in the field of fluorine removal.

[0003] In the prior art, the preparation method of nano calcium carbonate includes carbonization method, double decomposition method, microemulsion method and mechanochemical method, wherein the double decomposition method is mostly used for preparing nano calcium carbonate, and calcium chloride is used as a calcium source and a crystal form control agent is added to prepare spherical nano calcium carbonate. The calcium source needs to be obtained additionally. In the application, Ca 2+ is used as the calcium source by adding the crystal form control agent to prepare the nano calcium carbonate, so that the calcium source can be saved.

[0004] Therefore, it is necessary to provide a preparation method of surface-modified nano-CaCO3 to solve the above technical problems. SUMMARY

[0005] The application provides a preparation method of surface-modified nano-CaCO3, which solves the problem that calcium chloride is usually used as a calcium source when spherical nano calcium carbonate is prepared at present, and there is still room for improvement in saving the acquisition of the calcium source.

[0006] To solve the above technical problems, the preparation method of surface-modified nano-CaCO3 provided by the application comprises the following steps:

[0007] S1, a certain volume of brine is taken, and the Ca 2+ content in the brine is detected and is 100-800 mg / l;

[0008] S2, (NH4)2CO3 solution with a concentration of 0.1-0.5 mol / l and sodium pyrophosphate solution with a concentration of 0.5-2.5 mol / l are respectively prepared;

[0009] S3, the prepared (NH4)2CO3 solution, sodium pyrophosphate solution and anhydrous ethanol are uniformly mixed to form a crystal form control agent solution;

[0010] S4, the brine is added dropwise to the crystal form control agent solution at a speed of 10-20 ml / min by using a peristaltic pump, to obtain a white suspension;

[0011] S5, 0.25-2.50 g of sodium dodecyl sulfate, 0.25-2.50 g of sodium stearate and 0.25-2.50 g of cetyltrimethylammonium bromide are added to the suspension, and the mixture is stirred at 60-100 ℃ for 20-50 min;

[0012] S6, the white precipitate obtained by filtering the solution in S5 is washed and dried to obtain the surface-modified nano-CaCO3.

[0013] Preferably, the volume of the (NH4)2CO3 solution is 3-10% of the volume of the brine, the volume of the sodium pyrophosphate solution is 4-6% of the volume of the brine, and the volume of the anhydrous ethanol is 2-4% of the volume of the brine.

[0014] Preferably, the surface-modified nano-CaCO3 is prepared into nano-CaCO3 with a porous structure, comprising the following steps:

[0015] S01, the prepared nano-CaCO3 is placed in a container, and ZnCl2 is added to the container, wherein the mixing ratio of the nano-CaCO3 to the ZnCl2 is 1:3-1:6;

[0016] S02, the container is shaken by a shaker to mix the nano-CaCO3 and the ZnCl2 to allow self-assembly therebetween;

[0017] S03, the mixed material in S02 is placed in a high-temperature tube furnace and calcined in a protective gas at a temperature of 300-800 ℃ to obtain a powdery material;

[0018] S04, the powdery material is washed with anhydrous ethanol and deionized water for three times and dried to obtain spherical nano-CaCO3 with a porous structure.

[0019] The application also provides a preparation method of surface-modified nano-CaCO3@Fe3O4, comprising the following steps:

[0020] T1, 10-50 ml of an ethylene glycol solution is placed in a container, and 5.404-6.755 g of FeCl3·6H2O is dissolved in the ethylene glycol solution;

[0021] T2, 0.05-0.2 mol / l of a sodium acetate solution is dissolved in the ethylene glycol solution, and the amount of the sodium acetate added is 1-5% of the volume of the ethylene glycol;

[0022] T3, the polyethylene glycol solution is slowly added into the mixed solution, and stirring is carried out for 30-60 min, wherein the addition amount of the polyethylene glycol solution is 1-10% of the volume of the ethylene glycol;

[0023] T4, the solution in T3 is placed in a polytetrafluoroethylene liner and sealed in a high-pressure reaction kettle, and is placed in an electric oven for heat preservation for 6-12 h;

[0024] T5, after the heat preservation is completed, the liquid is removed, and the reaction product is transferred to a container and washed three times by using ethanol and ultrasonic vibration;

[0025] T6, the prepared wet magnetic nano Fe3O4 is mixed with nano CaCO3, and deionized water is added to form a slurry, and stirring is carried out for 30-60 min;

[0026] T7, the mixed slurry is dried in a vacuum oven to obtain surface-modified nano CaCO3@Fe3O4 particles with a porous structure.

[0027] The application also provides a use of the surface-modified nano CaCO3@Fe3O4, wherein the surface-modified nano CaCO3@Fe3O4 is used for adsorbing and removing F - .

[0028] The application also provides a device for preparing surface-modified nano CaCO3, which is used for filtering and washing the white precipitate in step S6;

[0029] The device comprises a support;

[0030] A cleaning filter cartridge is installed on the support, and the inside of the cleaning filter cartridge is provided with a support seat, and a valve is installed at the discharge end of the cleaning filter cartridge;

[0031] A filter assembly is detachably installed on the support seat;

[0032] A lifting device is installed on the support through a mounting frame and is suspended on the cleaning filter cartridge;

[0033] A stirring assembly is installed at the output end of the lifting device.

[0034] Preferably, the stirring assembly comprises a mounting frame, a motor, a stirring shaft and stirring blades, the mounting frame is installed at the output end of the lifting device, the motor is installed on the mounting frame, the stirring shaft is fixedly connected to the output end of the motor, and the stirring blades are installed on the stirring shaft.

[0035] Preferably, the filter assembly includes a base, a pressure ring, and a filter element, wherein the pressure ring is detachably connected to the base, and the filter element is located between the pressure ring and the base.

[0036] Preferably, the filter assembly further includes a folded bag, the base includes a mounting ring, a support ring and a plurality of convex shafts, the support ring is rotatably connected inside the mounting ring, the plurality of convex shafts are mounted around the support ring, and the side of the filter element is sleeved on the plurality of convex shafts;

[0037] The bottom of the pressure ring is provided with a storage groove, one end of the folded bag is connected to the storage groove, and the other end is connected to the support ring. The mounting ring is threadedly connected to the pressure ring.

[0038] The pressure ring is symmetrically equipped with drive sleeves, and the stirring assembly also includes two L-shaped shafts. The two L-shaped shafts are installed clockwise at the bottom of the two stirring blades, and the distance between the two L-shaped shafts is the same as the distance between the two drive sleeves.

[0039] Preferably, the support includes a support ring and a plurality of positioning shafts. The support ring is installed inside the cleaning filter cartridge, and the plurality of positioning shafts are mounted around the support ring. The bottom of the mounting ring is provided with a positioning hole, and the positioning hole is fitted onto the positioning shaft.

[0040] Compared with related technologies, the preparation method of surface-modified nano-CaCO3 provided by this invention has the following beneficial effects:

[0041] This invention provides a method for preparing surface-modified nano-CaCO3. The method involves in-situ modification during the preparation of spherical nano-CaCO3 to obtain surface-modified nano-CaCO3. This method offers advantages over traditional nano-CaCO3, which has small particle size, numerous surface active sites, and, due to its inherent chemical properties, can adsorb F from brine through both physical and chemical adsorption. - The adsorption utilizes the Ca present in the brine. + Nano-CaCO3 particles are prepared, and the resulting nano-calcium carbonate can be used to remove fluoride ions from brine, achieving a dual benefit without the need for an additional calcium source. Attached Figure Description

[0042] Figure 1 A flowchart illustrating the steps for preparing surface-modified nano-CaCO3 provided by this invention;

[0043] Figure 2 A flowchart illustrating the steps for preparing porous nano-CaCO3 provided by this invention;

[0044] Figure 3 A flowchart illustrating the steps for preparing surface-modified nano-CaCO3@Fe3O4 provided by this invention.

[0045] Figure 4 A schematic diagram of the apparatus for preparing surface-modified nano-CaCO3 provided by the present invention;

[0046] Figure 5 A cross-sectional view of the cleaning filter cartridge provided by the present invention;

[0047] Figure 6 for Figure 5 The enlarged schematic diagram of part A shown below;

[0048] Figure 7 This is a schematic diagram illustrating the usage state of the filter component provided by the present invention, wherein... Figure 7 (a) in the diagram is a schematic diagram of the filter component as a filter. Figure 7 (b) in the diagram is a schematic diagram of the filter component as the bag body;

[0049] Figure 8 This is a schematic diagram showing the state of the pressure ring after it has been separated from the base and the folded bag has been disassembled, as provided by the present invention.

[0050] Figure 9 for Figure 8 A schematic diagram of the filter component from another perspective;

[0051] Figure 10 This is a schematic diagram showing the assembly of the L-shaped shaft and the drive assembly provided by the present invention;

[0052] Figure 11 This is a schematic diagram of the lifting device provided by the present invention, which lifts the stirring component and causes the folded bag to unfold.

[0053] Numbering on the map:

[0054] 1. Bracket; 11. Mounting bracket;

[0055] 2. Cleaning filter cartridge; 21. Support; 22. Positioning lug; 23. Feed pipe; 24. Valve;

[0056] 211. Support ring; 212. Positioning shaft;

[0057] 3. Lifting device;

[0058] 4. Mixing assembly; 41. Assembly frame; 42. Motor; 43. Mixing shaft; 44. Mixing blades; 45. L-shaped shaft; 431. Support block;

[0059] 5. Filter assembly; 51. Base; 52. Pressure ring; 53. Filter element; 54. Folded bag;

[0060] 511. Mounting ring; 512. Support ring; 513. Protruding shaft; 510. Positioning hole;

[0061] 521. Drive sleeve; 522. Storage slot; 523. Cylindrical hole;

[0062] 6. Pressure cap; 61. Limiting shaft. Detailed Implementation

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0064] This invention provides a method, application, and apparatus for preparing surface-modified nano-CaCO3 and CaCO3@Fe3O4.

[0065] Please see Figure 1 In one embodiment of the present invention, the method for preparing the surface-modified nano-CaCO3 is characterized by comprising the following steps:

[0066] S1. Take a certain volume of brine and test the Ca in the brine. 2+ The content ranges from 100 to 800 mg / L;

[0067] S2. Prepare (NH4)2CO3 solutions with concentrations of 0.1–0.5 mol / L and sodium pyrophosphate solutions with concentrations of 0.5–2.5 mol / L, respectively;

[0068] S3. Mix the prepared (NH4)2CO3 solution, sodium pyrophosphate solution and anhydrous ethanol evenly to form a crystal form control agent solution;

[0069] S4. Add the brine dropwise to the crystal form control agent solution using a peristaltic pump at a rate of 10 ml / min to 20 ml / min to obtain a white suspension;

[0070] S5. Add 0.25–2.50 g sodium dodecyl sulfate, 0.25–2.50 g sodium stearate and 0.25–2.50 g hexadecyltrimethylammonium bromide to the suspension and stir at 60–100 °C for 20–50 min.

[0071] S6. The white precipitate obtained by filtering the solution in S5 is washed and dried to obtain surface-modified nano-CaCO3.

[0072] This invention obtains surface-modified nano-CaCO3 by in-situ modification during the preparation of spherical nano-CaCO3. This is superior to nano-CaCO3, which has small particle size, numerous surface active sites, and, due to its inherent chemical properties, can adsorb F from brine through physical and chemical adsorption.- The adsorption utilizes the Ca present in the brine. 2+ Nano-CaCO3 particles are prepared, and the resulting nano-calcium carbonate can be used to remove fluoride ions from brine, achieving a dual benefit without the need for an additional calcium source.

[0073] The volume of the (NH4)2CO3 solution is 3-10% of the volume of the brine, the volume of the sodium pyrophosphate solution is 4-6% of the volume of the brine, and the volume of the anhydrous ethanol is 2-4% of the volume of the brine.

[0074] In this embodiment, when 500ml of brine is taken, the Ca in the brine... 2+ The content ranges from 100 to 800 mg / L;

[0075] As a preferred embodiment, 25 ml of 0.3 mol / L (NH4)2CO3 solution, 25 ml of 1.5 mol / L sodium pyrophosphate solution, and 15 ml of anhydrous ethanol were measured and mixed to form a homogeneous solution, which is the crystal form control agent solution. Then, 500 ml of brine was added dropwise to the crystal form control agent solution using a peristaltic pump at a rate of 15 ml / min. After about 30 minutes, a white suspension was obtained. Then, 1.5 g each of sodium dodecyl sulfate, sodium stearate, and hexadecyltrimethylammonium bromide were added to it, and the mixture was stirred continuously at 80°C and 700 rpm for 45 minutes. After stirring, solid-liquid separation was performed, and the solid was dried at 40°C for 6 hours to obtain surface-modified nano-CaCO3.

[0076] Then, 100 ml of the concentrated leachate was placed in an Erlenmeyer flask and its F content was measured. - The concentration was 497.35 mg / L. 2.5 g of modified nano-CaCO3 was added, and the mixture was shaken at 35°C for 30 min. After adsorption was complete, centrifugation was performed, and the supernatant was used to determine its F content. - The content was 44.76 mg / L, and the adsorption rate was 91.00%.

[0077] Please see Figure 2 As a preferred embodiment, the surface-modified nano-CaCO3 is prepared into nano-CaCO3 with a porous structure, including the following steps:

[0078] S01. Place the prepared nano-CaCO3 in a container, and then add ZnCl2 to the container. The mixing ratio of nano-CaCO3 to ZnCl2 is between 1:3 and 1:6.

[0079] S02. The container is shaken and mixed using a shaker to allow self-assembly of nano-CaCO3 and ZnCl2.

[0080] S03. Place the mixed material from S02 into a high-temperature tube furnace and calcine it in a protective gas at a temperature of 300-800°C until a powdery material is obtained.

[0081] S04. The powdered material was washed three times with anhydrous ethanol and deionized water and then dried to obtain spherical nano-CaCO3 with a porous structure.

[0082] By preparing porous CaCO3 nanoparticles with exposed pores, agglomeration is greatly reduced, and these nanoparticles possess a higher specific surface area, greater surface free energy, and more active sites, making them more conducive to the processing of F. - Adsorption.

[0083] As a preferred embodiment, the preparation process of the surface-modified nano-CaCO3 is the same as described above. Appropriately dried nano-CaCO3 and ZnCl2 are mixed in a ratio of 1:4.5, and then placed in a shaking flask and shaken for 2.5 hours to allow self-assembly. The mixed material is then placed in a high-temperature tube furnace with a N2 flow rate of 200 ml / min, a heating rate of 5°C / min, and a final temperature of 600°C for calcination. After calcination, a powdery material is obtained, which is then washed three times each with an appropriate amount of anhydrous ethanol and deionized water, and then dried at 60°C for 8 hours to obtain surface-modified nano-CaCO3 with a porous structure.

[0084] Then, 100 ml of the concentrated leachate was placed in an Erlenmeyer flask and its F content was measured. - The concentration was 497.35 mg / L. 2.5 g of surface-modified nano-CaCO3 with a porous structure was added, and the mixture was shaken at 35°C for 30 min. After adsorption was complete, centrifugation was performed, and the supernatant was used to determine its F content. - The content was 24.87 mg / L, and the adsorption rate was 95.00%.

[0085] Please see Figure 3 The present invention also provides a method for preparing surface-modified nano-CaCO3@Fe3O4.

[0086] Please refer to the figure for a method of preparing surface-modified nano-CaCO3@Fe3O4, which includes the following steps:

[0087] T1. Place 10-50 ml of ethylene glycol solution in a container, and weigh 5.404-6.755 g of FeCl3·6H2O and dissolve it in the ethylene glycol solution.

[0088] T2. Dissolve a 0.05-0.2 mol / L sodium acetate solution in an ethylene glycol solution, with the amount of sodium acetate added being 1-5% of the volume of ethylene glycol.

[0089] T3. Take a polyethylene glycol solution and slowly add it dropwise to the mixture, stirring for 30-60 minutes. The amount of polyethylene glycol solution added is 1-10% of the volume of ethylene glycol.

[0090] T4. Place the solution from T3 in a polytetrafluoroethylene liner and seal it in a high-pressure reactor. Then place it in an electric oven and keep it warm for 6-12 hours.

[0091] T5. After the heat preservation is completed, remove the liquid, transfer the reaction product to a container, and clean it three times with ethanol and ultrasound.

[0092] T6. Mix the prepared wet magnetic nano Fe3O4 with the nano CaCO3 as described in any one of claims 1-3, add deionized water to form a slurry, and stir for 30-60 min.

[0093] T7. Dry the mixed slurry in a vacuum oven to obtain surface-modified nano-CaCO3@Fe3O4 particles with a porous structure.

[0094] Due to the ultrafine particle size, nano-CaCO3 exhibits altered surface electronic structures, resulting in quantum size effects, small size effects, surface effects, and macroscopic quantum tunneling effects not found in ordinary CaCO3. Nano-CaCO3 also possesses a high specific surface area and high surface activation rate. Activation and surface modification further enhance its already high specific surface area. Furthermore, the modifier adsorbs onto the surface of nano-CaCO3, creating charge repulsion and improving its dispersibility, thus preventing the nano-carbon from agglomerating. The modification process also alters the hydrophilicity of nano-CaCO3 to hydrophobicity, improving its adsorption and activation effects. In addition to physical adsorption primarily due to electrostatic interactions and van der Waals forces, and chemical adsorption due to the nano-calcium itself, the F in the brine... - The surface-modified nano-CaCO3 also enhances the adsorption effect through hydrogen bonding interactions.

[0095] After activation of nano-CaCO3, the exposed CaCO3 in the pores significantly reduces agglomeration and has a better specific surface area and higher surface free energy, providing more active sites and making it more conducive to the oxidation of F. - The adsorption of Fe3O4 alters the surface structure of the nano-calcium carbonate and, after activation, allows it to be loaded with Fe3O4, thus enabling the nano-calcium carbonate to not only possess magnetic separation capabilities but also allowing the nano-Fe3O4 to adsorb a portion of the Fe. - Meanwhile, its magnetic properties allow it to be adsorbed a second time, achieving the purpose of recycling.

[0096] As a preferred embodiment, the preparation process of surface-modified nano-CaCO3 with porous structure is the same as described above. 5.404 g of FeCl3·6H2O is poured into a polytetrafluoroethylene (PTFE) liner containing 25 ml of ethanol, followed by the addition of 0.75 ml of sodium acetate and the slow addition of 1.25 ml of polyethylene glycol. The mixture is stirred continuously for 45 min. The PTFE liner is then sealed in a stainless steel reactor and placed in an electric oven at 180°C for 30 min. After the reaction is complete, the waste liquid is discarded, and the mixture is washed three times with ethanol and ultrasonic vibration to obtain wet magnetic nano-Fe3O4. The wet magnetic nano-Fe3O4 and nano-CaCO3 are then mixed in a 2:1 ratio, and an appropriate amount of deionized water is added to form a slurry. The mixture is stirred for 40 min, and then dried in an oven at 60°C for 12 h to obtain surface-modified nano-CaCO3@Fe3O4 particles with porous structure.

[0097] Then, 100 ml of the concentrated leachate was placed in an Erlenmeyer flask, and its F- content was measured to be 497.35 mg / L. 2.5 g of surface-modified CaCO3@Fe3O4 nanoparticles with a porous structure was added, and the mixture was shaken at 35 °C for 30 min. After adsorption was complete, centrifugation was performed, and the F- content of the supernatant was measured. - The concentration was 15.36 mg / L, and the adsorption rate was 96.92%. Subsequently, desorption and washing with 2 mol / L NaOH were performed to remove F. - The above adsorption operation was repeated using the desorbed adsorbent, and the supernatant was taken to measure its F. - The concentration was 39.79 mg / L, and the adsorption rate was 91.95%.

[0098] The present invention also provides an application of surface-modified nano-CaCO3@Fe3O4.

[0099] An application of surface-modified nano-CaCO3@Fe3O4, wherein the surface-modified nano-CaCO3@Fe3O4 is used for adsorbing and removing F from liquids. - .

[0100] In this embodiment, CaCO3@Fe3O4 is used to adsorb F in the brine. - In other embodiments, CaCO3@Fe3O4 can also be used to adsorb and remove F from other waste liquids or sewage. - .

[0101] The present invention also provides an apparatus for preparing surface-modified nano-CaCO3.

[0102] Please see Figure 4 and Figure 5An apparatus for preparing surface-modified nano-CaCO3, wherein the apparatus is used to filter and wash the white precipitate in step S6.

[0103] Includes: 1 support bracket;

[0104] Cleaning filter cartridge 2 is installed through the support 1. The cleaning filter cartridge 2 has a support 21 inside and a valve 24 is installed at the discharge end of the cleaning filter cartridge 2.

[0105] Filter assembly 5, which is detachably installed on the support 21;

[0106] Lifting device 3, which is mounted on the bracket 1 via mounting frame 11 and suspended on the cleaning filter cartridge 2;

[0107] A stirring assembly 4 is installed at the output end of the lifting device 3.

[0108] In this embodiment, the discharge end of the cleaning filter cartridge 2 is connected to the liquid storage container through a pipe, and the input end of the vacuum pump is connected to the liquid storage container. By drawing gas differential pressure from inside the liquid storage container through the vacuum pump, the speed at which the solution in the cleaning filter cartridge 2 passes through the filter assembly 5 can be controlled, so that the white precipitate is located on the filter assembly 5.

[0109] During operation, the lifting device 3 lowers the stirring assembly 4 into the cleaning filter cartridge 2, such as... Figure 5 Then, the white precipitate and solution to be filtered are continuously added to the cleaning filter cartridge 2 through the feed pipe 23. The valve 24 is opened, and the solution is discharged through the outlet after passing through the filter assembly 5. The white precipitate remains in the filter assembly 5. During the filtration process, the stirring assembly 4 can stir the solution so that the white precipitate can be suspended and avoid accumulating on the filter assembly 5, which would prevent the solution from flowing down at a normal speed. When all the filtered solution has been added into the cleaning filter cartridge 2, the stirring assembly 4 stops working. After the last solution flows out, the valve 24 is closed.

[0110] Deionized water is added into the cleaning filter cartridge 2 through the feed pipe 23. The stirring component 4 continues to work to stir and clean the white precipitate. After the preset stirring time, the valve 24 is opened and the cleaning liquid flows out. The cleaning operation is performed no less than three times.

[0111] This device allows for the removal and cleaning of white precipitates without the need for separate transfer and cleaning procedures, thus improving filtration and cleaning efficiency.

[0112] As an optional approach in this embodiment, in order to improve cleaning efficiency, an ultrasonic cleaning device can be installed on the side wall of the cleaning filter cartridge 2, which, together with the stirring assembly 4, can improve cleaning efficiency.

[0113] Please see Figure 5 In this embodiment, the stirring assembly 4 includes an assembly frame 41, a motor 42, a stirring shaft 43, and a stirring blade 44. The assembly frame 41 is installed at the output end of the lifting device 3, the motor 42 is installed on the assembly frame 41, the stirring shaft 43 is fixedly connected to the output end of the motor 42, and the stirring blade 44 is installed on the stirring shaft 43.

[0114] When the stirring assembly 4 is working, the motor 42 drives the stirring shaft 43 to rotate, and the stirring shaft 43 drives the stirring blade 44 to rotate, thereby realizing the stirring function;

[0115] When it is necessary to clean the stirring shaft 43 and stirring blades 44, and to remove the white precipitate inside, the lifting device 3 lifts the assembly frame 41 to move the stirring shaft 43 and stirring blades 44 out of the cleaning filter cartridge 2.

[0116] The lifting device 3 can be a pneumatic cylinder, a hydraulic cylinder, or an electric push cylinder.

[0117] There are two stirring blades 44, which are symmetrically installed at both ends of the stirring shaft 43.

[0118] Please see Figure 6 and Figure 8 In a preferred embodiment, the filter assembly 5 includes a base 51, a pressure ring 52, and a filter element 53. The pressure ring 52 is detachably connected to the base 51, and the filter element 53 is located between the pressure ring 52 and the base 51.

[0119] By detachably installing the filter element 53 between the base 51 and the pressure ring 52, when it is necessary to clean or replace the filter element 53, the base 51 and the pressure ring 52 can be disassembled, and then the filter element 53 can be cleaned or replaced with a new one, thus preserving the use of the base 51 and the pressure ring 52, which is more environmentally friendly.

[0120] Among them, filter element 53 can be a filter membrane or filter screen, etc.

[0121] Please see Figures 6 to 9 In a preferred embodiment, the filter assembly 5 further includes a folded bag 54, and the base 51 includes a mounting ring 511, a support ring 512 and a plurality of convex shafts 513. The support ring 512 is rotatably connected inside the mounting ring 511, and the plurality of convex shafts 513 are mounted around the support ring 512. The side of the filter element 53 is sleeved on the plurality of convex shafts 513.

[0122] The bottom of the pressure ring 52 is provided with a storage groove 522. One end of the folded bag 54 is connected to the storage groove 522, and the other end is connected to the support ring 512. The mounting ring 511 is threadedly connected to the pressure ring 52.

[0123] The pressure ring 52 is symmetrically equipped with drive sleeves 521. The stirring assembly 4 also includes two L-shaped shafts 45. The two L-shaped shafts 45 are symmetrically installed at the bottom of the two stirring blades 44, and the bottom ends of the two L-shaped shafts 45 face opposite directions. The distance between the two L-shaped shafts 45 is the same as the distance between the two drive sleeves 521.

[0124] The axis of the stirring shaft 43 is concentric with the center line of the cleaning filter cartridge 2.

[0125] Please see Figure 5 When the stirring component 4 is cleaning and stirring the white precipitate, the L-shaped shaft 45 at the bottom of the stirring blade 44 is located above the filter component 5.

[0126] When the white precipitate has been cleaned and needs to be removed, the lifting device 3 lowers the stirring assembly 4 so that the L-shaped shaft 45 is level with the height of the drive sleeve 521. At this time, the motor 42 drives the stirring shaft 43 to rotate, and the stirring shaft 43 drives the stirring blade 44 to rotate accordingly. The stirring blade 44 drives the two L-shaped shafts 45 to be inserted into the two drive sleeves 521 respectively. Subsequently, the motor 42 continues to rotate, and the L-shaped shafts 45 drive the pressure ring 52 to rotate through the drive sleeve 521. Since the pressure ring 52 and the mounting ring 511 are threadedly connected, the pressure ring 52 rotates and disengages from the thread of the mounting ring 511. Subsequently, the lifting device 3 raises the stirring assembly 4, and the L-shaped shafts 45 drive the pressure ring 52 to move upward through the drive sleeve 521. The pressure ring 52 drives the folding bag 54 to unfold, forming a storage space. Figure 7 (b) and Figure 11 At this time, the white precipitate will gradually enter the folded bag 54. Subsequently, the lifting device 3 raises the stirring component 4 to move the upper end of the folded bag 54 out of the cleaning filter cartridge 2, making it easy to disassemble the L-shaped shaft 45 and the drive sleeve 521 and remove the white precipitate.

[0127] At this point, the filter assembly 5 forms a bag to hold the white precipitate. The white precipitate can be discharged by removing the filter assembly 5. The operation is convenient.

[0128] During this process, the lifting device 3, together with the stirring component 4, forms a mechanical arm that lifts the filter component 5. When the stirring component 4 switches from stirring function to mechanical arm function for lifting the filter component 5, it can unlock the base 51 and the pressure ring 52, so that the filter component 5 can form a bag.

[0129] Since the side of the filter element 53 is sleeved on the convex shaft 513, the convex shaft 513 supports the filter element 53. After the pressure ring 52 is separated from the base 51, the filter element 53 can still support the white precipitate.

[0130] Preferably, the L-shaped shaft 45 is assembled with the drive sleeve 521 before the last cleaning fluid is discharged, when the white precipitate is suspended in the cleaning fluid.

[0131] When the L-shaped shaft 45 needs to be assembled with the drive sleeve 521, preferably, the two stirring blades 44 are made perpendicular to the two drive sleeves 521 and then the rotation is stopped. Then, the stirring blades 44 are rotated 90 degrees counterclockwise to assemble the L-shaped shaft 45 with the drive sleeve 521. Subsequently, according to the number of threads on the surfaces of the pressure ring 52 and the mounting ring 511, the corresponding number of rotations are continued to unlock the pressure ring 52 and the mounting ring 511. For example, if the thread is set to two turns, it can be rotated two and a half turns to ensure separation.

[0132] Preferably, the length of the convex shaft 513 is greater than the thickness of the filter element 53. In this case, the bottom of the pressure ring 52 is provided with a cylindrical hole 523. When the pressure ring 52 is installed with the base 51, the cylindrical hole 523 is fitted onto the convex shaft 513.

[0133] During the rotation of the pressure ring 52, since the support ring 512 is rotatably set inside the mounting ring 511, during the threaded unlocking process between the pressure ring 52 and the mounting ring 511, the pressure ring 52 can drive the support ring 512 to rotate along with it through the convex shaft 513, so that the folded bag 54 will not get tangled.

[0134] The folding bag 54 has concave and convex folds spaced apart, allowing it to be folded up along these folds when closed. The folding bag 54 is a cylindrical bag with openings at the top and bottom.

[0135] The outer wall of the mounting ring 511 is fitted to the cleaning filter cartridge 2. Both the pressure ring 52 and the top of the mounting ring 511 are provided with inclined surfaces, and the two inclined surfaces are smoothly connected, so that the white precipitate located on the top of the pressure ring 52 and the mounting ring 511 can automatically slide down along the inclined surfaces into the unfolded folded bag 54.

[0136] Please see Figure 6 As an optional embodiment, the support 21 includes a support ring 211 and a plurality of positioning shafts 212. The support ring 211 is installed inside the cleaning filter cartridge 2, and the plurality of positioning shafts 212 are mounted around the support ring 211. The bottom of the mounting ring 511 is provided with a positioning hole 510, and the positioning hole 510 is sleeved on the positioning shaft 212.

[0137] The support ring 211 can support the filter assembly 5. By setting the positioning shaft 212 to be inserted into the positioning hole 510, the axial position of the support ring 512 can be limited. When the drive sleeve 521 drives the pressure ring 52 to rotate, the drive sleeve 521 and the support ring 512 can rotate relative to each other, realizing thread unlocking.

[0138] As another optional embodiment, the support 21 includes a plurality of support blocks, each of which is provided with a positioning shaft 212, and the plurality of support blocks are mounted around the inside of the cleaning filter cartridge 2.

[0139] Please see Figure 5 The apparatus for preparing surface-modified nano-CaCO3 further includes a pressure cap 6, which is sleeved on a stirring shaft 43. A support block 431 is installed on the stirring shaft 43, and the support block 431 supports and limits the pressure cap 6. Multiple limiting shafts 61 are installed around the side of the pressure cap 6. Correspondingly, multiple positioning ears 22 are provided on the side of the cleaning filter cartridge 2, and each positioning ear 22 has a limiting hole.

[0140] When the lifting device 3 lowers the stirring assembly 4, the stirring blades 44 move down to a preset depth, such as... Figure 5 At this time, the pressure cap 6 is placed on the top of the cleaning filter cartridge 2, and the limiting shaft 61 is inserted into the limiting hole of the positioning ear 22 to seal the top of the cleaning filter cartridge 2 and prevent the solution from splashing out when the stirring blade 44 is stirring.

[0141] The top of the assembly frame 41 is provided with multiple sliding rods, the top of which penetrates the mounting frame 11, so that the assembly frame 41 and the mounting frame 11 form a vertical sliding connection, thereby improving the stability of the stirring assembly 4 during lifting and lowering.

[0142] The preparation method, applications, and working principle of the apparatus for surface-modified nano-CaCO3 and CaCO3@Fe3O4 provided by this invention are as follows:

[0143] During operation, the lifting device 3 lowers the stirring assembly 4 into the cleaning filter cartridge 2, such as... Figure 5 Then, the white precipitate and solution to be filtered are continuously added to the cleaning filter cartridge 2 through the feed pipe 23. The valve 24 is opened, and the solution is discharged through the outlet after passing through the filter assembly 5. The white precipitate remains in the filter assembly 5. During the filtration process, the stirring assembly 4 can stir the solution so that the white precipitate can be suspended and avoid accumulating on the filter assembly 5, which would prevent the solution from flowing down at a normal speed. When all the filtered solution has been added into the cleaning filter cartridge 2, the stirring assembly 4 stops working. After the last solution flows out, the valve 24 is closed.

[0144] Deionized water is added into the cleaning filter cartridge 2 through the feed pipe 23. The stirring component 4 continues to work to stir and clean the white precipitate. After the preset stirring time, the valve 24 is opened and the cleaning liquid flows out. The cleaning operation is repeated at least three times.

[0145] Please see Figure 5 When the stirring component 4 is cleaning and stirring the white precipitate, the L-shaped shaft 45 at the bottom of the stirring blade 44 is located above the filter component 5.

[0146] When the white precipitate has been cleaned and needs to be removed, the lifting device 3 lowers the stirring assembly 4 so that the L-shaped shaft 45 is level with the height of the drive sleeve 521. At this time, the motor 42 drives the stirring shaft 43 to rotate, and the stirring shaft 43 drives the stirring blade 44 to rotate accordingly. The stirring blade 44 drives the two L-shaped shafts 45 to be inserted into the two drive sleeves 521 respectively. Subsequently, the motor 42 continues to rotate, and the L-shaped shafts 45 drive the pressure ring 52 to rotate through the drive sleeve 521. Since the pressure ring 52 and the mounting ring 511 are threadedly connected, the pressure ring 52 rotates and disengages from the thread of the mounting ring 511. Subsequently, the lifting device 3 raises the stirring assembly 4, and the L-shaped shafts 45 drive the pressure ring 52 to move upward through the drive sleeve 521. The pressure ring 52 drives the folding bag 54 to unfold, forming a storage space. Figure 7 (b) and Figure 11 At this time, the white precipitate will gradually enter the folded bag 54. Subsequently, the lifting device 3 raises the stirring component 4 to move the upper end of the folded bag 54 out of the cleaning filter cartridge 2, making it easy to disassemble the L-shaped shaft 45 and the drive sleeve 521 and remove the white precipitate.

[0147] At this point, the filter assembly 5 forms a bag to hold the white precipitate. The white precipitate can then be discharged by removing the filter assembly 5, making the operation convenient.

[0148] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing surface-modified nano-CaCO3, characterized in that, Includes the following steps: S1. Take a certain volume of brine and test the Ca in the brine. 2+ The content ranges from 100 to 800 mg / L; S2. Prepare (NH4)2CO3 solutions with concentrations of 0.1~0.5 mol / L and sodium pyrophosphate solutions with concentrations of 0.5~2.5 mol / L respectively; S3. Mix the prepared (NH4)2CO3 solution, sodium pyrophosphate solution and anhydrous ethanol evenly to form a crystal form control agent solution; Wherein, the volume of the (NH4)2CO3 solution is 3-10% of the volume of the brine, the volume of the sodium pyrophosphate solution is 4-6% of the volume of the brine, and the volume of the anhydrous ethanol is 2-4% of the volume of the brine; S4. Add the brine dropwise to the crystal form control agent solution using a peristaltic pump at a rate of 10 mL / min to 20 mL / min to obtain a white suspension; S5. Add 0.25~2.50g sodium dodecyl sulfate, 0.25~2.50g sodium stearate and 0.25~2.50g hexadecyltrimethylammonium bromide to the suspension and stir at 60~100℃ for 20~50min. S6. The white precipitate obtained by filtering the solution in S5 is washed and dried to obtain surface-modified nano-CaCO3.

2. The method for preparing surface-modified nano-CaCO3 according to claim 1, characterized in that, The preparation of the surface-modified nano-CaCO3 into nano-CaCO3 with a porous structure includes the following steps: S01. Place the prepared nano-CaCO3 in a container, and then add ZnCl2 to the container. The mixing ratio of nano-CaCO3 to ZnCl2 is between 1:3 and 1:

6. S02. The container is shaken and mixed using a shaker to allow self-assembly of nano-CaCO3 and ZnCl2. S03. Place the mixed material from S02 into a high-temperature tube furnace and calcine it in a protective gas at a temperature of 300~800℃ until a powdery material is obtained. S04. The powdered material was washed three times with anhydrous ethanol and deionized water and then dried to obtain spherical nano-CaCO3 with a porous structure.

3. A method for preparing surface-modified nano-CaCO3@Fe3O4, characterized in that, Includes the following steps: T1. Place 10-50 mL of ethylene glycol solution in a container, and weigh 5.404-6.755 g of FeCl3·6H2O and dissolve it in the ethylene glycol solution; T2. Dissolve a 0.05~0.2mol / L sodium acetate solution in an ethylene glycol solution, with the amount of sodium acetate added being 1~5% of the volume of ethylene glycol; T3. Take a polyethylene glycol solution and slowly add it dropwise to the mixture, stirring for 30-60 minutes. The amount of polyethylene glycol solution added is 1-10% of the volume of ethylene glycol. T4. Place the solution from T3 in a polytetrafluoroethylene liner and seal it in a high-pressure reactor. Then place it in an electric oven and keep it warm for 6-12 hours. T5. After the heat preservation is completed, remove the liquid, transfer the reaction product to a container, and clean it three times with ethanol and ultrasound. T6. Mix the prepared wet magnetic nano Fe3O4 with the nano CaCO3 prepared in the preparation method of surface modified nano CaCO3 as described in any one of claims 1-2, add deionized water to form a slurry, and stir for 30-60 min. T7. Dry the mixed slurry in a vacuum oven to obtain surface-modified nano-CaCO3@Fe3O4 particles with a porous structure.

4. An application of surface-modified nano-CaCO3@Fe3O4 prepared using the preparation method of surface-modified nano-CaCO3@Fe3O4 as described in claim 3, characterized in that, The surface-modified nano-CaCO3@Fe3O4 is used to adsorb and remove F from the liquid. - .

5. An apparatus for preparing surface-modified nano-CaCO3, characterized in that, The apparatus for preparing surface-modified nano-CaCO3 is used to filter and wash the white precipitate in step S6 of the preparation method of surface-modified nano-CaCO3 as described in any one of claims 1-2. Includes: support frame; A cleaning filter cartridge is installed through the support. The cleaning filter cartridge has a support inside and a valve is installed at the discharge end of the cleaning filter cartridge. A filter assembly, which is detachably mounted on the support; A lifting device is mounted on the bracket via a mounting frame and suspended on the cleaning filter cartridge; A stirring assembly, which is installed at the output end of the lifting device; The stirring assembly includes an assembly frame, a motor, a stirring shaft, and stirring blades. The assembly frame is installed at the output end of the lifting device, the motor is installed on the assembly frame, the stirring shaft is fixedly connected to the output end of the motor, and the stirring blades are installed on the stirring shaft. The filter assembly includes a base, a pressure ring, and a filter element. The pressure ring is detachably connected to the base, and the filter element is located between the pressure ring and the base. The filter assembly also includes a folded bag, and the base includes a mounting ring, a support ring and a plurality of convex shafts. The support ring is rotatably connected inside the mounting ring, and the plurality of convex shafts are mounted around the support ring. The side of the filter element is sleeved on the plurality of convex shafts. The bottom of the pressure ring is provided with a storage groove, one end of the folded bag is connected to the storage groove, and the other end is connected to the support ring. The mounting ring is threadedly connected to the pressure ring. The pressure ring is symmetrically equipped with drive sleeves, and the stirring assembly also includes two L-shaped shafts. The two L-shaped shafts are installed clockwise at the bottom of the two stirring blades, and the distance between the two L-shaped shafts is the same as the distance between the two drive sleeves.

6. The apparatus for preparing surface-modified nano-CaCO3 according to claim 5, characterized in that, The support includes a support ring and multiple positioning shafts. The support ring is installed inside the cleaning filter cartridge, and the multiple positioning shafts are mounted around the support ring. The bottom of the mounting ring has a positioning hole, which is fitted onto the positioning shaft.

Images