Preparation method of nano manganese carbonate

Abstract

The invention discloses a preparation method of nano manganese carbonate, and relates to the technical field of preparation of nano manganese carbonate. The method comprises the following steps: preparing a manganese source continuous phase, wherein the manganese source continuous phase is a Mn (OH) 2 suspension or a solution containing Mn < 2 + >; a manganese source continuous phase and CO2 gas are communicated with the microreactor, or the manganese source continuous phase and a carbonate dispersed phase are communicated with the microreactor, and the carbonate dispersed phase is ammonium carbonate or ammonium bicarbonate; reacting the manganese source continuous phase with CO2 gas or carbonate dispersed phase in the microreactor; returning the reacted mixed solution to the manganese source continuous phase, and enabling the reacted mixed solution to enter the micro-flow reactor again for circular reaction; and carrying out vacuum drying on the mixed solution obtained by the circular reaction to obtain the nano manganese carbonate particles. The method provided by the invention can be used for preparing manganese carbonate particles with the particle size of 20-500nm, and the particles can be spherical or microcube-shaped.

Description

Technical Field

[0001] The invention relates to the technical field of nano manganese carbonate preparation, and in particular to a method for preparing nano manganese carbonate. Background Art

[0002] Manganese carbonate has attracted extensive research interest due to its unique physical and chemical properties and its potential applications in the fields of catalysts, electronics, ceramics, medicine, coatings, cosmetics, etc. In particular, nano-manganese carbonate is of great significance because of its large specific surface area and small size, which can bring some novel electrical, magnetic and catalytic properties different from bulk materials.

[0003] Nano manganese carbonate is widely used in materials. Through the manganese carbonate template method, a variety of complex structure materials can be generated. For example, hollow MoS2 micro-nanostructures and hollow manganese oxides can be prepared through the manganese carbonate template method, and the synthesis of the hollow structure can also be regulated by changing the template material, that is, the size and morphology of manganese carbonate. In addition, nano manganese carbonate can also be used to prepare manganese silicate and manganese carbonate with a specific core-shell structure, and these materials are widely used in the fields of catalysts, magnetic functional materials, electrode materials, etc. The performance of nano manganese carbonate is determined by its crystal structure morphology characteristics to a great extent. Therefore, controlling the morphology and granularity of manganese carbonate is the key to improve its application effect.

[0004] At present, the method for preparing nano manganese carbonate has multiple, including chemical precipitation method, liquid phase chemical method, coprecipitation method etc. In the related art, spherical or nano manganese carbonate is prepared by adding urea (publication number is the patent of CN115872451A) or the method of surfactant (publication number is the patent of CN117105271A), but the adding of these materials can increase the cost of nano manganese carbonate accordingly. The inventor finds that the method for preparing nano manganese carbonate at present has the problem that the nano particle size prepared is large and has high ubiquitous cost. Therefore, a kind of preparation method of manganese carbonate is provided, to reduce the preparation cost of nano manganese carbonate and reduce the size of nano manganese carbonate particles, become the technical problem that those skilled in the art need to be solved urgently. Summary of the invention

[0005] The invention discloses a method for preparing nano manganese carbonate, so as to solve the technical problems that the method for preparing nano manganese carbonate in the related art has high cost and the size of the prepared nano particles is large.

[0006] In order to solve the above problems, the present invention adopts the following technical solutions:

[0007] The preparation method of nano manganese carbonate of the present invention comprises the following steps:

[0008] The preparation method of nano manganese carbonate of the present invention comprises the following steps:

[0009] S100: preparing a manganese source continuous phase, wherein the manganese source continuous phase is a Mn(OH)2 suspension or a Mn-containing 2+ of solution;

[0010] S200: connecting a manganese source continuous phase and CO2 gas to a microreactor, or connecting a manganese source continuous phase and a carbonate dispersed phase to a microreactor, wherein the carbonate dispersed phase is ammonium carbonate or ammonium bicarbonate;

[0011] S300: a manganese source continuous phase reacts with CO2 gas or a carbonate dispersed phase in a microreactor;

[0012] S400: the mixed solution after the reaction is returned to the manganese source continuous phase, and the mixed solution after the reaction enters the microfluidic reactor again for a cyclic reaction;

[0013] S500: vacuum drying the mixed solution obtained by the cyclic reaction to obtain nano manganese carbonate particles.

[0014] According to an optional embodiment, in step S300, when the manganese source continuous phase is a Mn(OH)2 suspension, the dispersed phase is CO2 gas, and

[0015] The flow rate of the manganese source continuous phase is 5 to 30 mL / min,

[0016] The CO2 gas flow rate is 0.5~1L / min.

[0017] According to an optional embodiment, in step S300, when the manganese source continuous phase is a phase containing Mn 2+ When the dispersed phase is a carbonate solution,

[0018] The flow rate of the manganese source continuous phase is 5 to 30 mL / min,

[0019] The flow rate of the carbonate dispersed phase is 5-30 mL / min.

[0020] According to an optional embodiment, in step S300, the reaction temperature of the manganese source continuous phase and the CO2 gas or carbonate dispersed phase is 25-60°C.

[0021] According to an optional embodiment, in step S400, the cyclic reaction time of the manganese source continuous phase and the CO2 gas or carbonate dispersed phase is 5S to 1h.

[0022] According to an optional embodiment, when the manganese source continuous phase is a Mn(OH)2 suspension, the manganese source continuous phase is prepared by the following method:

[0023] Mn 2+The solution is mixed with a dispersant to obtain a first mixed solution;

[0024] Aqueous ammonia is added to the first mixed solution under stirring to obtain a Mn(OH)2 suspension.

[0025] According to an optional embodiment, when preparing the manganese source continuous phase,

[0026] Mn 2+ The solution is MnCl2, MnSO4 or manganese acetate, and Mn 2+ The concentration is 2.5~50g / L;

[0027] The dispersant is ethanol, and the dispersant is mixed with Mn 2+ The volume ratio of the solution is 1:10 to 1:20;

[0028] The ammonia water and Mn 2+ The volume ratio of the solution is 1:11 to 1:50.

[0029] According to an optional embodiment, when preparing the manganese source continuous phase,

[0030] Mn 2+ The solution is MnCl2, MnSO4 or manganese acetate, and Mn 2+ The concentration is 2.5~50g / L;

[0031] The dispersant is ethylene glycol, and Mn 2+ The volume ratio of the solution to the dispersant is 2.5:1 to 50:1;

[0032] The ammonia water and Mn 2+ The volume ratio of the solution is 1:11 to 1:50.

[0033] According to an optional embodiment, the concentration of the carbonate dispersed phase is 10 to 50 g / L.

[0034] According to an optional embodiment, when the manganese source continuous phase is a Mn-containing 2+ When the solution is prepared, the manganese source continuous phase includes MnCl2 solution, MnSO4 solution or manganese acetate solution, and the manganese source continuous phase also includes a dispersant ethanol or ethylene glycol, and the volume ratio of the dispersant to the MnCl2 solution, MnSO4 solution or manganese acetate solution is 1:20.

[0035] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0036] The preparation method of nano manganese carbonate of the present invention uses a manganese source continuous phase and a CO2 gas or a carbonate dispersed phase to react in a microreactor, and by regulating the raw material concentration and the two-phase flow rate, as well as the cyclic reaction time and temperature, manganese carbonate particles with a particle size of 20nm to 500nm can be prepared, and the particle morphology can be spherical or microcubic. The preparation method of manganese carbonate of the present invention passes the mixed solution after the reaction into a microfluidic reactor again for cyclic reaction, so that the manganese source can be fully reacted and the utilization rate of the manganese source can be improved. The preparation method of manganese carbonate of the present invention also has the advantages of fast and uniform mixing speed, controllable particle size and shape, low operating energy consumption, high stability, etc., and provides a new way for preparing nano manganese carbonate particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 This is a schematic diagram of a device for preparing nano-MnCO3 by microfluidics in an embodiment of the present application;

[0039] Figure 2 It is a schematic diagram of the structure of the microreactor of the embodiment of the present application;

[0040] Figure 3 This is a SEM image of the product obtained in Example 1 of the present application;

[0041] Figure 4 The XRD diagrams of the products obtained in Examples 1 and 3 of the present application;

[0042] Figure 5 This is a SEM image of the product obtained in Example 2 of the present application;

[0043] Figure 6 This is a SEM image of the product obtained in Example 3 of the present application;

[0044] Figure 7 This is a SEM image of the product obtained in Example 4 of the present application;

[0045] Figure 8 This is a SEM image of the product obtained in Example 5 of the present application;

[0046] Fig. 9 This is a SEM image of the product obtained in Comparative Example 1 of this application;

[0047] Fig.10 This is the SEM image of the product obtained in Comparative Example 2 of this application.

[0048] In the figure: 1, manganese source continuous phase storage tank; 2, first pump; 3, microreactor; 4, CO2 gas cylinder; 5, pressure gauge; 6, carbonate dispersed phase storage tank; 7, second pump; 8, microchannel; 9, mixed solution after reaction; 3-1, microreactor lower cover; 3-2, stainless steel sintered membrane; 3-3, first polytetrafluoroethylene gasket; 3-4, reaction chamber; 3-5, second polytetrafluoroethylene gasket; 3-6, microreactor upper cover. DETAILED DESCRIPTION

[0049] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0050] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0051] The following is combined with Figures 1 to 10 , the preparation method of nano manganese carbonate provided by the present application is described in detail through specific embodiments and application scenarios.

[0052] Figure 1 The schematic diagram of the device for preparing nano-MnCO3 by microfluidics in the embodiment of the present application is shown. Figure 1 As shown, the device for preparing nano MnCO3 by microfluidics includes a manganese source continuous phase storage tank 1, a first pump 2, a microreactor 3, a CO2 gas cylinder 4, a pressure gauge 5, a carbonate dispersed phase storage tank 6, a second pump 7, and a microchannel 8. Among them, the manganese source continuous phase storage tank 1 is connected to the microreactor 3 through the first pump 2, the CO2 gas cylinder 4 is connected to the microreactor 3, the carbonate dispersed phase storage tank 6 is connected to the microreactor 3 through the second pump 7, and one of the CO2 gas cylinder 4 and the second pump 7 is opened. A pressure gauge 5 is provided between the CO2 gas cylinder 4 and the microreactor 3. The manganese source continuous phase storage tank 1 is used to store the manganese source continuous phase, and the carbonate dispersed phase storage tank 6 is used to store the carbonate dispersed phase. The various components are connected by a microchannel 8. The microchannel 8 is made of polytetrafluoroethylene. As Figure 1 As shown, the manganese source continuous phase and CO2 gas or carbonate dispersed phase enter the microreactor 3 for reaction, and the mixed solution 9 after the reaction enters the manganese source continuous phase storage tank 1, and then enters the microreactor 3 again with the manganese source continuous phase, and the reaction is cyclically carried out to ensure that the manganese source reacts fully and completely.

[0053] Figure 2 The schematic diagram of the structure of the microreactor in the embodiment of the present application is shown. Figure 2 As shown, the microreactor 3 includes a microreactor lower cover 3-1 and a microreactor upper cover 3-6, between which a stainless steel sintered film 3-2, a first polytetrafluoroethylene gasket 3-3, a reaction chamber 3-4 and a second polytetrafluoroethylene gasket 3-5 are arranged in sequence.

[0054] The stainless steel sintered membrane 3-2 in the microreactor 3 serves as a dispersion medium. After the CO2 or carbonate dispersed phase flowing out of the CO2 gas cylinder 4 or the carbonate dispersed phase storage tank 6 enters the microreactor 3, it is located at the lower side of the stainless steel sintered membrane 3-2. The manganese source continuous phase flowing out of the manganese source continuous phase storage tank 1 is located at the upper side of the stainless steel sintered membrane 3-2. The CO2 or carbonate dispersed phase is carried away from the surface of the stainless steel sintered membrane 3-2 by the manganese source continuous phase in the reaction chamber 3-4, and the two phases are quickly and evenly mixed during the flow process, and then flow out of the microreactor 3.

[0055] In some embodiments, the dispersion medium is not limited to the stainless steel sintered membrane 3-2, but a microfiltration membrane can also be used as the dispersion medium. The pore size of the dispersion medium is 1-10 μm.

[0056] In some embodiments, the diameter of the microchannel 8 is 1.0 mm (inner diameter) × 3 mm (outer diameter), 1.5 mm (inner diameter) × 3 mm (outer diameter), 2 mm (inner diameter) × 3 mm (outer diameter), 1.0 mm (inner diameter) × 2 mm (outer diameter), 1.2 mm (inner diameter) × 2 mm (outer diameter) or 1.6 mm (inner diameter) × 2 mm (outer diameter).

[0057] The present embodiment uses microfluidic technology to prepare nano manganese carbonate. Compared with the traditional kettle method, the high specific surface area of ​​the microreactor 3 enhances the heat transfer and mass transfer performance, shortens the reaction time, and has the advantages of controllable reaction process and compatibility with online analysis. Microfluidic technology can also effectively define the nanoparticle nucleation and growth stages, realize the accurate control of particle size, size distribution, morphology, and improve repeatability. In addition, the use of microfluidic technology to prepare nano manganese carbonate also has the advantages of one-step molding, high-throughput production, accurate control of reaction conditions, efficient mixing, low sample consumption, easy operation, and applicable to a variety of nanoparticles.

[0058] In this embodiment, the microfluidic technology is used to prepare nano manganese carbonate. Compared with the traditional kettle method, it is conducive to the production of nano manganese carbonate particles with smaller size and uniformity. The specific reasons are as follows:

[0059] (1) In traditional batch reactions, due to the large reaction system, the control of reaction conditions (such as temperature, pH value, and reactant concentration) may be uneven, resulting in inconsistent particle nucleation and growth processes, thereby producing larger particles. Microfluidic technology can carry out reactions in tiny channels, which provide a uniform reaction environment so that the reaction conditions can be precisely controlled, which is conducive to the production of smaller and more uniform manganese carbonate particles.

[0060] (2) In traditional stirring reactions, the mixing efficiency may not be sufficient to achieve rapid and uniform mixing, which may lead to supersaturation of reactants in local areas, thereby promoting the formation of large particles; in contrast, fluid mixing in microfluidic systems mainly relies on laminar diffusion. By precisely designing the geometry of the microchannels, the mixing and reaction times can be effectively controlled, thereby promoting the uniform nucleation and growth of particles.

[0061] (3) Microfluidic technology allows the spatial separation of nucleation, growth, and formation processes. Each step can be carried out in the most suitable microenvironment, which helps to control the size and shape of the particles. In traditional methods, these steps usually occur simultaneously in the same reactor, lacking spatial separation and optimization.

[0062] Example 1

[0063] The preparation method of nano manganese carbonate in this embodiment comprises the following steps:

[0064] A MnSO4·H2O solution with a concentration of 5 g / L is prepared, and ethanol is added to the MnSO4·H2O solution in a volume ratio of ethanol to the MnSO4·H2O solution of 1:10 to obtain a mixed solution;

[0065] Under stirring, adding ammonia water to the mixed solution at a volume ratio of ammonia water to MnSO4·H2O solution of 1:50 to obtain a Mn(OH)2 suspension;

[0066] The length and diameter of the microchannel were adjusted to 5 m and 1.5 mm × 3 mm respectively, and then the microreactor was set up as Figure 2 After the connection is complete, turn on the CO2 cylinder switch;

[0067] The flow rate of CO2 gas was adjusted to 1 L / min to allow CO2 gas to enter the microreactor, and the flow rate of the first pump was adjusted to 20 mL / min to pump the Mn(OH)2 suspension into the microreactor;

[0068] The reaction was carried out at 60° C. for 8 seconds, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0069] Depend on Figure 3 It can be seen that the prepared manganese carbonate particles are spherical and have a relatively uniform size, with a particle size of less than 40 nm. Figure 4 (a) is the X-ray diffraction pattern of Example 1, and its main peaks are all characteristic peaks of MnCO3.

[0070] Example 2

[0071] The preparation method of nano manganese carbonate in this embodiment comprises the following steps:

[0072] A MnSO4·H2O solution with a concentration of 5 g / L is prepared, and ethylene glycol is added to the MnSO4·H2O solution in a volume ratio of 1:10 to obtain a mixed solution;

[0073] Under stirring, adding ammonia water to the mixed solution at a volume ratio of ammonia water to MnSO4·H2O solution of 1:50 to obtain a Mn(OH)2 suspension;

[0074] The length and diameter of the microchannel were adjusted to 5 m and 1.5 mm × 3 mm respectively, and then the microreactor was set up as Figure 2 After the connection is complete, turn on the CO2 cylinder switch;

[0075] The flow rate of CO2 gas was adjusted to 0.5 L / min to allow CO2 gas to enter the microreactor, and the flow rate of the first pump was adjusted to 20 mL / min to pump the Mn(OH)2 suspension into the microreactor;

[0076] The reaction was carried out at 60° C. for 8 seconds, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0077] Depend on Figure 5 It can be seen that the prepared manganese carbonate particles are spherical and have a relatively uniform size, with a particle size of about 20-70 nm.

[0078] Example 3

[0079] The preparation method of nano manganese carbonate in this embodiment comprises the following steps:

[0080] A 20 g / L MnSO4·H2O solution was prepared, and ethanol was added to the MnSO4·H2O solution in a volume ratio of ethanol to the MnSO4·H2O solution of 1:10 to obtain a mixed solution;

[0081] Under stirring, adding ammonia water to the mixed solution at a volume ratio of ammonia water to MnSO4·H2O solution of 1:50 to obtain a Mn(OH)2 suspension;

[0082] The length and diameter of the microchannel were adjusted to 5 m and 2.0 mm × 3 mm respectively, and then the microreactor was set up as Figure 2 After the connection is complete, turn on the CO2 cylinder switch;

[0083] The flow rate of CO2 gas was adjusted to 1 L / min to allow CO2 gas to enter the microreactor, and the flow rate of the first pump was adjusted to 20 mL / min to pump the Mn(OH)2 suspension into the microreactor;

[0084] The reaction was carried out at 60° C. for 8 seconds, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0085] Depend on Figure 6 It can be seen that the prepared manganese carbonate particles are microcubic and have a relatively uniform size, with a particle size of about 350 nm. Figure 4 (b) is the X-ray diffraction pattern of Example 3, and its main peaks are all characteristic peaks of MnCO3.

[0086] Example 4

[0087] The preparation method of nano manganese carbonate in this embodiment comprises the following steps:

[0088] A MnSO4·H2O solution with a concentration of 5 g / L is prepared, and ethanol is added to the MnSO4·H2O solution in a volume ratio of ethanol to the MnSO4·H2O solution of 1:20 to obtain a mixed solution;

[0089] Under stirring, ammonium sulfate solid was added to the MnSO4·H2O mixed solution to dissolve it, and the concentration of ammonium sulfate in the mixed solution reached 18.84 g / L (the purpose of adding ammonium sulfate is to control the crystallization speed and crystal transformation of manganese carbonate by adjusting the ion concentration ratio and pH value in the solution, so as to prepare microcubic manganese carbonate with a specific morphology), and Mn-containing 2+ of solution;

[0090] Prepare 20g / L NH4HCO3 solution;

[0091] The length and diameter of the microchannel were adjusted to 30 m and 1 mm × 3 mm respectively, and then the microreactor was set up as Figure 2 The connection is complete;

[0092] After adjusting the flow rates of the first pump and the second pump to 20 mL / min, the Mn-containing 2+ solution and NH4HCO3 solution;

[0093] The reaction was carried out at 50° C. for 3 minutes, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0094] Depend on Figure 7 It can be seen that the prepared manganese carbonate particles are microcubic and have a relatively uniform size, with a particle size of about 500 nm.

[0095] Example 5

[0096] The preparation method of nano manganese carbonate in this embodiment comprises the following steps:

[0097] Using ethylene glycol as solvent, a solution with a concentration of 42 g / LMnCl2·4H2O was prepared;

[0098] Under stirring, adding ammonia water to the MnCl2·4H2O solution at a volume ratio of ammonia water to MnCl2·4H2O solution of 1:11.7 to obtain a Mn(OH)2 suspension;

[0099] The length and diameter of the microchannel were adjusted to 5 m and 1.6 mm × 3 mm respectively, and then the microreactor was set up as Figure 2 After the connection is complete, turn on the CO2 cylinder switch;

[0100] The flow rate of CO2 gas was adjusted to 0.5 L / min to allow CO2 gas to enter the microreactor, and the flow rate of the first pump was adjusted to 25 mL / min to pump the Mn(OH)2 suspension into the microreactor;

[0101] The reaction was carried out at 60° C. for 5 seconds, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0102] Depend on Figure 8 It can be seen that the prepared manganese carbonate particles are spherical and have a relatively uniform size, with a particle size of about 20 to 100 nm.

[0103] Comparative Example 1

[0104] The preparation method of nano manganese carbonate in this comparative example comprises the following steps:

[0105] Using ethylene glycol as solvent, a solution with a concentration of 42 g / LMnCl2·4H2O was prepared;

[0106] Under stirring, adding ammonia water to the MnCl2·4H2O solution at a volume ratio of ammonia water to MnCl2·4H2O solution of 1:11.7 to obtain a Mn(OH)2 suspension;

[0107] The CO2 gas with a flow rate of 1 L / min was passed into the Mn(OH)2 suspension;

[0108] The reaction was carried out at 60° C. for 2 h, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0109] Depend on Fig. 9It can be seen that the prepared manganese carbonate particles are not uniform in size, with a particle size of 200 to 500 nm.

[0110] Comparative Example 2

[0111] The preparation method of nano manganese carbonate in this comparative example comprises the following steps:

[0112] A MnSO4·H2O solution with a concentration of 5 g / L is prepared, and ethanol is added to the MnSO4·H2O solution in a volume ratio of ethanol to the MnSO4·H2O solution of 1:20 to obtain a mixed solution;

[0113] Under stirring, ammonium sulfate solid was added to the MnSO4·H2O mixed solution to dissolve it, and the concentration of ammonium sulfate in the mixed solution reached 18.84 g / L (the purpose of adding ammonium sulfate is to control the crystallization speed and crystal transformation of manganese carbonate by adjusting the ion concentration ratio and pH value in the solution, so as to prepare microcubic manganese carbonate with a specific morphology), and Mn-containing 2+ of solution;

[0114] Prepare 20g / L NH4HCO3 solution;

[0115] Mn 2+ The solution is mixed with NH4HCO3 solution.

[0116] The reaction was aged at 50° C. for 7 h, and the reaction product was filtered and dried to obtain manganese carbonate particles.

[0117] Depend on Fig.10 It can be seen that the prepared manganese carbonate particles are not microcubic and are relatively large in size, with a particle size of 1.5 to 4 μm.

[0118] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0119] In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0120] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing nano manganese carbonate, characterized in that: The steps include: S100: preparing a manganese source continuous phase, wherein the manganese source continuous phase is a Mn(OH)2 suspension or a Mn-containing 2+ of solution; S200: connecting a manganese source continuous phase and CO2 gas to a microreactor, or connecting a manganese source continuous phase and a carbonate dispersed phase to a microreactor, wherein the carbonate dispersed phase is ammonium carbonate or ammonium bicarbonate; S300: a manganese source continuous phase reacts with CO2 gas or a carbonate dispersed phase in a microreactor; S400: the mixed solution after the reaction is returned to the manganese source continuous phase, and the mixed solution after the reaction enters the microfluidic reactor again for a cyclic reaction; S500: vacuum drying the mixed solution obtained by the cyclic reaction to obtain nano manganese carbonate particles.

2. The method for preparing nano manganese carbonate according to claim 1, characterized in that: In step S300, when the manganese source continuous phase is a Mn(OH)2 suspension, the dispersed phase is a CO2 gas, and The flow rate of the manganese source continuous phase is 5 to 30 mL / min, The CO2 gas flow rate is 0.5~1L / min.

3. The method for preparing nano manganese carbonate according to claim 1, characterized in that: In step S300, when the manganese source continuous phase is a phase containing Mn 2+ When the dispersed phase is a carbonate solution, The flow rate of the manganese source continuous phase is 5 to 30 mL / min, The flow rate of the carbonate dispersed phase is 5-30 mL / min.

4. The method for preparing nano manganese carbonate according to claim 2 or 3, characterized in that: In step S300, the reaction temperature of the manganese source continuous phase and the CO2 gas or carbonate dispersed phase is 25-60°C.

5. The method for preparing nano manganese carbonate according to claim 4, characterized in that: In step S400, the cyclic reaction time of the manganese source continuous phase and the CO2 gas or carbonate dispersed phase is 5S to 1h.

6. The method for preparing nano manganese carbonate according to claim 1, characterized in that: When the manganese source continuous phase is a Mn(OH)2 suspension, the manganese source continuous phase is prepared by the following method: Mn 2+ The solution is mixed with a dispersant to obtain a first mixed solution; Aqueous ammonia is added to the first mixed solution under stirring to obtain a Mn(OH)2 suspension.

7. The method for preparing nano manganese carbonate according to claim 6, characterized in that: When preparing the manganese source continuous phase, Mn 2+ The solution is MnCl2, MnSO4 or manganese acetate, and Mn 2+ The concentration is 2.5~50g / L; The dispersant is ethanol, and the dispersant is mixed with Mn 2+ The volume ratio of the solution is 1:10 to 1:20; The ammonia water and Mn 2+ The volume ratio of the solution is 1:11 to 1:

50.

8. The method for preparing nano manganese carbonate according to claim 6, characterized in that: When preparing the manganese source continuous phase, Mn 2+ The solution is MnCl2, MnSO4 or manganese acetate, and Mn 2+ The concentration is 2.5~50g / L; The dispersant is ethylene glycol, and Mn 2+ The volume ratio of the solution to the dispersant is 2.5:1 to 50:1; The ammonia water and Mn 2+ The volume ratio of the solution is 1:11 to 1:

50.

9. The method for preparing nano manganese carbonate according to claim 1, characterized in that: The concentration of the carbonate dispersed phase is 10 to 50 g / L.

10. The method for preparing nano manganese carbonate according to claim 1, characterized in that: When the manganese source continuous phase is a phase containing Mn 2+ When the solution is prepared, the manganese source continuous phase comprises a MnCl2 solution, a MnSO4 solution or a manganese acetate solution, and the manganese source continuous phase further comprises a dispersant such as ethanol or ethylene glycol, and The volume ratio of the dispersant to the MnCl2 solution, the MnSO4 solution or the manganese acetate solution is 1:20.

Images