Ultrafine cerium oxide atomization precipitation preparation system and method

Abstract

The invention discloses a superfine cerium oxide atomization precipitation preparation system and method, the preparation system comprises a controller, a reaction tank, a first liquid storage mechanism and a second liquid storage mechanism, and the reaction tank is provided with a heating mechanism and an emulsifying mechanism; an operation space is arranged in the reaction tank, and the reaction tank is respectively provided with a feed port and a discharge port; the first liquid storage mechanism and the second liquid storage mechanism are respectively communicated with the feeding hole; the controller is used for feeding the solution in the first liquid storage mechanism into the working space, atomizing the solution in the second liquid storage mechanism to a preset particle size according to a preset flow and a preset proportion, and feeding the atomized solution into the working space; the controller is also used for respectively controlling the heating structure and the emulsifying mechanism, so that the two solutions entering the operation space are mixed and emulsified according to the preset temperature, the preset time and the preset rotating speed. By automatically controlling the flow, the rotating speed, the heating temperature, the heating time and the ratio of the two solutions, the particle size range and the particle size of the precursor meet the test requirements after the two solutions are mixed and emulsified.

Description

Technical Field

[0001] The invention relates to the technical field of ultrafine cerium oxide preparation, and in particular to an ultrafine cerium oxide atomization precipitation preparation system and method. Background Art

[0002] A continuous reactor is one in which the reaction is carried out continuously. Unless there is a failure in the continuous reactor, the continuous reactor will not be shut down. The most commonly used continuous reactors are catalyst fixed bed reactors and continuous stirred tank reactors (CSTR).

[0003] Rare earth oxides prepared by traditional precipitation methods require the use of continuous reactors. Since the existing continuous reactors have average stirring and flow control effects, this leads to uneven addition of reactants, uncontrollable precipitation nucleation and growth, and unclear inheritance and laws of precursor morphology. In addition, the high surface activity of ultrafine particles, impurity adsorption and agglomeration result in large product agglomerate particle size and a wide particle size range, making it difficult to efficiently prepare high-purity ultrafine rare earth oxides. Summary of the invention

[0004] The main purpose of the present invention is to provide a system and method for preparing ultrafine cerium oxide by atomization precipitation, aiming to solve the problem that the precursor particle size is large and the particle size range is wide.

[0005] To achieve the above purpose, the technical solution proposed by the present invention is:

[0006] A system for preparing ultrafine cerium oxide by atomization precipitation comprises a controller, a reaction tank, a first liquid storage mechanism and a second liquid storage mechanism, wherein the reaction tank is provided with a heating mechanism and an emulsifying mechanism respectively; a working space is provided in the reaction tank, and a feed port and a discharge port are provided in the reaction tank respectively, wherein the feed port and the discharge port are connected to the working space respectively; the first liquid storage mechanism and the second liquid storage mechanism are connected to the feed port respectively, and the first liquid storage mechanism and the second liquid storage mechanism are used to respectively contain different solutions; the controller is respectively electrically connected to the heating mechanism, the emulsifying mechanism, the first liquid storage mechanism and the second liquid storage mechanism, and the controller is used to control the first liquid storage mechanism and the second liquid storage mechanism respectively, first send the solution in the first liquid storage mechanism into the working space, and then according to a preset flow rate and a preset ratio, atomize the solution in the second liquid storage mechanism to a preset particle size before entering the working space; the controller is also used to control the heating structure and the emulsifying mechanism respectively, so that the two solutions entering the working space are mixed and emulsified according to a preset temperature, a preset time and a preset speed.

[0007] Preferably, the first liquid storage mechanism includes a first liquid container, a first pump body and a first connecting tube, the first pump body is arranged on the first connecting tube, one end of the first connecting tube is connected to the first liquid container, and the other end of the first connecting tube is detachably connected to the feed port.

[0008] Preferably, the first liquid container is used to store an ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L.

[0009] Preferably, the second liquid storage mechanism includes a second liquid container, a second pump body, a second connecting pipe and an atomizer, the second pump body is arranged on the second connecting pipe, one end of the second connecting pipe is connected to the second liquid container, the other end of the second connecting pipe is connected to the atomizer, and the end of the second connecting pipe away from the second liquid container is detachably connected to the feed port through the atomizer.

[0010] Preferably, the second liquid container is used to store a cerium nitrate solution with a concentration of 0.05 mol / L to 0.15 mol / L.

[0011] Preferably, the preset temperature is 75° C. to 85° C.; the preset rotation speed is 4500 RPM to 5500 RPM; and the preset time is 100 minutes to 130 minutes.

[0012] Preferably, the ratio of the amount of the solution substance in the first liquid storage mechanism to the amount of the solution substance in the second liquid storage mechanism is 1:3.5.

[0013] Preferably, a water bath space is also provided in the reaction tank, and the water bath space is arranged around the working space; the reaction tank is also provided with a liquid inlet and a liquid outlet, and the water bath space is respectively connected to the liquid inlet and the liquid outlet; the heating mechanism includes an electric heating rod and a temperature detector, and the electric heating rod and the temperature detector are both arranged in the water bath space; the controller is electrically connected to the electric heating rod and the temperature detector, respectively, and the controller is used to control the electric heating rod and the temperature detector according to a preset time and a preset temperature, so that the water bath space heats the working space.

[0014] A method for preparing ultrafine cerium oxide by atomization precipitation, the method using any of the above-mentioned ultrafine cerium oxide atomization precipitation preparation systems, characterized in that the method comprises:

[0015] Inputting an ammonium bicarbonate solution having a concentration of 0.3 mol / L to 1.2 mol / L into the reaction tank through the first liquid storage mechanism;

[0016] A cerium nitrate solution having a concentration of 0.05 mol / L to 0.15 mol / L and atomized to a preset particle size is input into the reaction tank through the second liquid storage mechanism according to a preset flow rate;

[0017] The emulsifying mechanism is controlled according to a preset speed to mix and emulsify an ammonium bicarbonate solution having a concentration of 0.3 mol / L to 1.2 mol / L and a cerium nitrate solution having a concentration of 0.05 mol / L to 0.15 mol / L in a preset ratio;

[0018] The heating mechanism is controlled according to a preset temperature and a preset time to keep a constant temperature during the mixing and emulsification process, and ultrafine cerium oxide precursor powder is obtained through subsequent processes after the emulsification is completed;

[0019] The ultrafine cerium oxide precursor powder is calcined to obtain the ultrafine cerium oxide powder.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] Through the automatic control of flow rate, rotation speed, heating temperature, heating time and the ratio of the two solutions, it is ensured that the particle size range and particle size of the precursor meet the test requirements after the two solutions are mixed and emulsified. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 the structures shown in these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of an embodiment of a system for preparing ultrafine cerium oxide by atomization precipitation according to the present invention;

[0024] Figure 2 The figure is a schematic flow chart of a method for preparing ultrafine cerium oxide by atomization precipitation according to the present invention;

[0025] Figure 3 This is the actual SEM image of the precursor powder;

[0026] Figure 4 This is the SEM image of ultrafine cerium oxide;

[0027] Figure 5 TEM image of ultrafine cerium oxide.

[0028] Description of Figure Numbers:

[0029] 1-reaction tank; 11-operation space; 12-feed port; 13-discharge port; 14-water bath space; 15-liquid inlet; 16-liquid outlet;

[0030] 2-heating mechanism; 21-electric heating rod; 22-temperature detector;

[0031] 3- emulsification mechanism; 31- agitator; 32- emulsification head;

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] The invention provides a system and method for preparing ultrafine cerium oxide by atomization precipitation.

[0039] like Figure 1 The ultrafine cerium oxide atomization precipitation preparation system shown in the figure includes a controller, a reaction tank 1, a first liquid storage mechanism (not shown in the figure) and a second liquid storage mechanism (not shown in the figure), the reaction tank 1 is respectively provided with a heating mechanism 2 and an emulsifying mechanism 3; a working space 11 is arranged in the reaction tank 1, and a feed port 12 and a discharge port 13 are respectively arranged in the reaction tank 1, and the feed port 12 and the discharge port 13 are respectively connected to the working space 11; the first liquid storage mechanism and the second liquid storage mechanism are respectively connected to the feed port 12, and the first liquid storage mechanism and the second liquid storage mechanism are used to respectively contain different solutions; the controller is respectively electrically connected to the heating mechanism 2, the emulsifying mechanism 3, the first liquid storage mechanism and the second liquid storage mechanism, and the controller is used to control the first liquid storage mechanism and the second liquid storage mechanism respectively, first send the solution in the first liquid storage mechanism into the working space 11, and then according to the preset flow rate and preset ratio, atomize the solution in the second liquid storage mechanism to a preset particle size and then enter the working space 11; the controller is also used to control the heating structure and the emulsifying mechanism 3 respectively, so that the two solutions entering the working space 11 are mixed and emulsified according to the preset temperature, preset time and preset speed.

[0040] Through the automatic control of flow rate, rotation speed, heating temperature, heating time and the ratio of the two solutions, it is ensured that the particle size range and particle size of the precursor meet the test requirements after the two solutions are mixed and emulsified.

[0041] Specifically, an acidity meter (not shown in the figure) and a liquid level meter (not shown in the figure) are also provided in the working space 11. The controller is electrically connected to the acidity meter and the liquid level meter. The controller is used to control the acidity meter and the liquid level meter respectively, so that the controller can obtain the pH value and liquid level data of the solution in the working space 11 in real time. The acidity meter is mainly used to detect the reaction process and the reaction end point in the working space 11 to ensure that the reaction in the working space 11 is carried out according to the design; the liquid level meter is used to monitor the liquid level under stirring conditions in the working space 11 in real time to avoid abnormal overflow. The acidity meter and the liquid level meter simultaneously monitor the reaction process and the reaction end point in the working space 11, assisting the staff to understand the internal working conditions of the working space 11 in real time and ensure process consistency.

[0042] Specifically, the atomization pressure in the second liquid storage mechanism is 3MPa to 10MPa; the aperture of the atomizing nozzle in the second liquid storage mechanism connected to the working space 11 is 0.15mm to 0.5mm; the particle size of the solution particles sprayed by the atomizing nozzle is 50μm to 200μm; the flow rate of the atomizing nozzle is 1.2L / min to 5L / min. The cerium nitrate solution added by the atomizing nozzle in the form of ultrafine droplets reacts rapidly with the ammonium bicarbonate in the container to form crystal nuclei. Due to its microreactor reaction with droplets as the basic unit, its reaction and nucleation have higher accuracy and uniformity than conventional (drip addition, etc.) reactions.

[0043] Specifically, the calculation formula for the precursor powder particle size is:

[0044] d=K(n*M / ρ)^(1 / 3)Q^(1 / 2) / U;

[0045] Among them, d is the particle size of the precursor powder; K is the correction coefficient obtained by fitting; n is the concentration of the spray solution in the working space 11, M is the molar mass of the precursor product; ρ is the theoretical density of the precursor; Q is the flow rate of the atomized solution sent into the working space 11 by the atomizing nozzle; U is the droplet velocity of the atomized solution sent into the working space 11 by the atomizing nozzle.

[0046] The newly formed crystal nuclei are very small in size, have a significant tendency to agglomerate and grow, and have a large viscosity. Through the high-speed action of emulsification shear, the chemical environment in the reaction vessel is maintained stable, the growth of the crystal nuclei is inhibited, and highly uniform ultrafine powders are obtained.

[0047] A highly uniform precipitation core is obtained through atomization, and the high-speed action of emulsification shearing maintains the consistency of the chemical environment in the reactor and inhibits the growth of the crystal nucleus. Thus, high-performance ultrafine powders can be obtained quickly and efficiently through an extremely simple chemical process (without low concentration, complex conditions, dispersants, long time, high temperature and high pressure, etc.).

[0048] The first liquid storage mechanism includes a first liquid container, a first pump body and a first connecting pipe. The first pump body is arranged on the first connecting pipe. One end of the first connecting pipe is connected to the first liquid container, and the other end of the first connecting pipe is detachably connected to the feed port 12.

[0049] The first liquid container is used to store an ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L.

[0050] The second liquid storage mechanism includes a second liquid container, a second pump body, a second connecting pipe and an atomizer. The second pump body is arranged on the second connecting pipe. One end of the second connecting pipe is connected to the second liquid container, and the other end of the second connecting pipe is connected to the atomizer. The end of the second connecting pipe away from the second liquid container is detachably connected to the feed port 12 through the atomizer.

[0051] The second liquid container is used to store a cerium nitrate solution with a concentration of 0.05 mol / L to 0.15 mol / L.

[0052] The preset temperature is 75℃ to 85℃; the preset speed is 4500RPM to 5500RPM; the preset time is 100 minutes to 130 minutes.

[0053] Specifically, the preset temperature is 80° C., the preset speed is 5000 RPM, and the preset time is 120 minutes.

[0054] Specifically, the preset time is the heating time of the solution in the working space 11 .

[0055] The ratio of the solution in the first liquid storage mechanism to the solution in the second liquid storage mechanism is 7:10.

[0056] Specifically, the ratio of the amount of the ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L to the amount of the cerium nitrate solution with a concentration of 0.05 mol / L to 0.15 mol / L is 1:3.5.

[0057] A water bath space 14 is also provided in the reaction tank 1, and the water bath space 14 is provided around the working space 11; the reaction tank 1 is also provided with a liquid inlet 15 and a liquid outlet 16, and the water bath space 14 is connected to the liquid inlet 15 and the liquid outlet 16 respectively; the heating mechanism 2 includes an electric heating rod 21 and a temperature detector 22, and the electric heating rod 21 and the temperature detector 22 are both provided in the water bath space 14; the controller is electrically connected to the electric heating rod 21 and the temperature detector 22 respectively, and the controller is used to control the electric heating rod 21 and the temperature detector 22 respectively according to the preset time and the preset temperature, so that the water bath space 14 heats the working space 11. The water bath space 14 is provided around the working space 11, and the heating effect is ensured by the temperature detector 22 and the electric heating rod 21, and the constant temperature of the mixing and emulsification process is effectively guaranteed.

[0058] Specifically, the emulsifying mechanism 3 includes a stirrer 31 and an emulsifying head 32 .

[0059] Specifically, the liquid inlet 15 and the liquid outlet 16 are both connected to an external water source.

[0060] like Figures 2 to 5 A method for preparing ultrafine cerium oxide by atomization precipitation is shown, and the method uses any of the above-mentioned ultrafine cerium oxide atomization precipitation preparation systems, and the method comprises:

[0061] Step S10, inputting an ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L into the reaction tank 1 through the first liquid storage mechanism;

[0062] Step S20, inputting a cerium nitrate solution having a concentration of 0.05 mol / L to 0.15 mol / L and atomized to a preset particle size into the reaction tank 1 through the second liquid storage mechanism according to a preset flow rate;

[0063] Step S30, controlling the emulsifying mechanism 3 according to a preset rotation speed to mix and emulsify the ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L and the cerium nitrate solution with a concentration of 0.05 mol / L to 0.15 mol / L in a preset ratio;

[0064] Step S40, controlling the heating mechanism 2 according to a preset temperature and a preset time to keep a constant temperature during the mixing and emulsification process, and obtaining ultrafine cerium oxide precursor powder through subsequent processes after the emulsification is completed;

[0065] Step S50, calcining the ultrafine cerium oxide precursor powder to obtain ultrafine cerium oxide powder.

[0066] The subsequent steps are filtering and drying, which are common processes and will not be described in detail here.

[0067] Example:

[0068] The first liquid storage mechanism inputs 40 liters of 0.5 mol / L ammonium bicarbonate solution into the reaction tank 1;

[0069] The second liquid storage mechanism inputs 27 liters of atomized 0.1 mol / L cerium nitrate solution into the reaction tank 1, wherein the particle size of the atomized 0.1 mol / L cerium nitrate solution is 50 μm to 70 μm; the flow rate of the second liquid storage mechanism inputting the 0.1 mol / L cerium nitrate solution into the reaction tank 1 is 1500 mL / min;

[0070] The rotation speed of the emulsifying mechanism 3 is 5000 rpm; the temperature in the working space 11 is 80° C., and the heating time of the solution in the working space 11 is 120 minutes.

[0071] The cerium dioxide precursor is obtained by successively going through filtering process and drying process.

[0072] The cerium dioxide precursor powder is placed in a muffle furnace and burned to obtain ultrafine cerium dioxide powder.

[0073] Test results: The particle size of the cerium dioxide precursor in the D50 index is 0.320um; the particle size of the cerium dioxide precursor in the D90 index is 0.798um; both the D50 index and the D90 index are less than 1um.

[0074] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A system for preparing ultrafine cerium oxide by atomization precipitation, characterized in that: It comprises a controller, a reaction tank, a first liquid storage mechanism and a second liquid storage mechanism, wherein the reaction tank is provided with a heating mechanism and an emulsifying mechanism respectively; a working space is provided in the reaction tank, and a feed port and a discharge port are provided in the reaction tank respectively, wherein the feed port and the discharge port are connected to the working space respectively; the first liquid storage mechanism and the second liquid storage mechanism are connected to the feed port respectively, and the first liquid storage mechanism and the second liquid storage mechanism are used to respectively contain different solutions; The controller is electrically connected to the heating mechanism, the emulsifying mechanism, the first liquid storage mechanism and the second liquid storage mechanism respectively, and the controller is used to control the first liquid storage mechanism and the second liquid storage mechanism respectively, firstly send the solution in the first liquid storage mechanism into the working space, and then according to the preset flow rate and preset ratio, atomize the solution in the second liquid storage mechanism to a preset particle size and then enter the working space; The controller is also used to control the heating structure and the emulsifying mechanism respectively, so that the two solutions entering the working space are mixed and emulsified according to a preset temperature, a preset time and a preset rotation speed.

2. The ultrafine cerium oxide atomization precipitation preparation system according to claim 1, characterized in that: The first liquid storage mechanism includes a first liquid container, a first pump body and a first connecting pipe. The first pump body is arranged on the first connecting pipe. One end of the first connecting pipe is connected to the first liquid container, and the other end of the first connecting pipe is detachably connected to the feed port.

3. The ultrafine cerium oxide atomization precipitation preparation system according to claim 2, characterized in that: The first liquid container is used to store an ammonium bicarbonate solution with a concentration of 0.3 mol / L to 1.2 mol / L.

4. The ultrafine cerium oxide atomization precipitation preparation system according to claim 1, characterized in that: The second liquid storage mechanism includes a second liquid container, a second pump body, a second connecting pipe and an atomizer. The second pump body is arranged on the second connecting pipe. One end of the second connecting pipe is connected to the second liquid container, and the other end of the second connecting pipe is connected to the atomizer. The end of the second connecting pipe away from the second liquid container is detachably connected to the feed port through the atomizer.

5. The ultrafine cerium oxide atomization precipitation preparation system according to claim 4, characterized in that: The second liquid container is used to store a cerium nitrate solution with a concentration of 0.05 mol / L to 0.15 mol / L.

6. A system for preparing ultrafine cerium oxide by atomization precipitation according to any one of claims 1 to 5, characterized in that: The preset temperature is 75° C. to 85° C.; the preset speed is 4500 RPM to 5500 RPM; and the preset time is 100 minutes to 130 minutes.

7. A system for preparing ultrafine cerium oxide by atomization precipitation according to any one of claims 1 to 5, characterized in that: The ratio of the amount of the solution substance in the first liquid storage mechanism to the amount of the solution substance in the second liquid storage mechanism is 1:3.

5.

8. A system for preparing ultrafine cerium oxide by atomization precipitation according to any one of claims 1 to 5, characterized in that: A water bath space is also provided in the reaction tank, and the water bath space is provided around the working space; a liquid inlet and a liquid outlet are also provided in the reaction tank, and the water bath space is connected to the liquid inlet and the liquid outlet respectively; the heating mechanism includes an electric heating rod and a temperature detector, and the electric heating rod and the temperature detector are both provided in the water bath space; the controller is electrically connected to the electric heating rod and the temperature detector respectively, and the controller is used to control the electric heating rod and the temperature detector respectively according to a preset time and a preset temperature, so that the water bath space heats the working space.

9. A method for preparing ultrafine cerium oxide by atomization precipitation, the method using an ultrafine cerium oxide atomization precipitation preparation system as claimed in any one of claims 1 to 8, characterized in that: The preparation method comprises: Inputting an ammonium bicarbonate solution having a concentration of 0.3 mol / L to 1.2 mol / L into the reaction tank through the first liquid storage mechanism; A cerium nitrate solution having a concentration of 0.05 mol / L to 0.15 mol / L and atomized to a preset particle size is input into the reaction tank through the second liquid storage mechanism according to a preset flow rate; The emulsifying mechanism is controlled according to a preset speed to mix and emulsify an ammonium bicarbonate solution having a concentration of 0.3 mol / L to 1.2 mol / L and a cerium nitrate solution having a concentration of 0.05 mol / L to 0.15 mol / L in a preset ratio; The heating mechanism is controlled according to a preset temperature and a preset time to keep a constant temperature during the mixing and emulsification process, and ultrafine cerium oxide precursor powder is obtained through subsequent processes after the emulsification is completed; The ultrafine cerium oxide precursor powder is calcined to obtain the ultrafine cerium oxide powder.

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