Decomposition method and decomposition system of magnesium bicarbonate solution

Abstract

The invention relates to the technical field of magnesium carbonate preparation, in particular to a decomposition method and a decomposition system of a magnesium bicarbonate solution. The decomposition method comprises the following steps: carrying out first magnetization on a magnesium bicarbonate solution in a flowing state by using a fixed magnetic field to obtain a magnetized magnesium bicarbonate solution; mixing a surfactant and the magnetized magnesium bicarbonate solution to obtain a mixed solution; carrying out secondary magnetization on the mixed solution by using an alternating magnetic field, then carrying out heat preservation on the mixed solution subjected to secondary magnetization, and carrying out low-temperature decomposition on the mixed solution subjected to secondary magnetization to obtain an emulsion; carrying out solid-liquid separation on the emulsion to obtain a filter cake; and drying the filter cake to obtain a basic magnesium carbonate product, wherein the magnetic field intensity of the fixed magnetic field is less than or equal to 1600mT, and the magnetic field amplitude of the alternating magnetic field is less than or equal to 800mT. According to the decomposition method, the surface tension of the magnetized magnesium bicarbonate solution is reduced in a two-stage magnetization mode in cooperation with the surfactant, and therefore the decomposition rate of the magnetized magnesium bicarbonate solution for decomposing basic magnesium carbonate can be increased to 95% or above.

Description

Technical Field

[0001] The present application relates to the technical field of magnesium carbonate preparation, and in particular to a decomposition method and a decomposition system of a magnesium bicarbonate solution. Background Art

[0002] The decomposition process of magnesium bicarbonate solution is one of the methods for preparing hydrated basic magnesium carbonate. The principle is: magnesium bicarbonate solution undergoes a decomposition reaction under certain conditions: 5Mg(HCO 3 ) 2 →4MgCO 3 Mg(OH) 2 ·4H 2 O+6CO 2 ↑. At present, the industry mainly adopts the method of high temperature and normal pressure decomposition to prepare hydrated basic magnesium carbonate, that is, the magnesium bicarbonate solution is heated to 95℃~105℃ and then kept warm for a certain period of time. However, the weight content of magnesium in the solution used for the high temperature and normal pressure decomposition is only 5g / L~15g / L (in terms of MgO), so the high temperature and normal pressure decomposition process will heat a large amount of water. In addition, during the insulation process of the high temperature and normal pressure decomposition, water will continue to evaporate and take away a large amount of heat energy, which will cause the high energy consumption of the high temperature and normal pressure decomposition. In the context of energy conservation and emission reduction, green and low carbon, how to reduce the energy consumption of the decomposition process of magnesium bicarbonate solution is one of the main research directions for the preparation of basic magnesium carbonate.

[0003] At present, in order to achieve the effect of low-temperature decomposition of magnesium bicarbonate, the main method is to reduce CO by vacuum. 2 Partial pressure, lower boiling temperature, increase gas-liquid phase area, etc. However, under vacuum and low temperature (10℃~40℃), the decomposition rate of magnesium bicarbonate will be reduced; however, under vacuum and high temperature (50℃~70℃), the water content of magnesium bicarbonate solution will be in a boiling state, resulting in a large amount of water evaporation, which undoubtedly increases the energy consumption of low-temperature decomposition of magnesium bicarbonate and also affects the decomposition of magnesium bicarbonate.

[0004] At present, the technologies for decomposing magnesium bicarbonate solution include: (1) a process for hydrolyzing heavy magnesium water in vacuum at room temperature, which removes CO from the heavy magnesium water mother liquid by atomizing the heavy magnesium water in a vacuum environment; 2 , which can promote the decomposition of magnesium bicarbonate at room temperature without heating and precipitate magnesium carbonate crystals, but the weight content of magnesium bicarbonate in the heavy magnesium water mother liquor is determined by the removal of CO from the heavy magnesium water. 2The initial 8g / L to 12g / L drops to below 3g / L to 4g / L (in terms of MgO), and the decomposed magnesium bicarbonate mother liquor can be used as water replenishment for the front-end carbonization process. (2) A low-temperature pyrolysis reactor, which makes the magnesium bicarbonate solution boil and decompose at a low temperature (≤70°C) by vacuuming, and then reduces the pyrolysis temperature from 95°C to 105°C to below 70°C, which can reduce the energy consumption of the traditional pyrolysis reaction by about 50%. In addition, the vacuum environment will reduce CO 2 The partial pressure promotes the normal decomposition reaction of magnesium bicarbonate. Summary of the invention

[0005] The present application provides a decomposition method and a decomposition system for a magnesium bicarbonate solution to solve the following technical problem: how to improve the decomposition rate of magnesium bicarbonate in a low-temperature decomposition stage.

[0006] In a first aspect, the present application provides a method for decomposing a magnesium bicarbonate solution, the decomposition method comprising:

[0007] Using a fixed magnetic field to first magnetize the magnesium bicarbonate solution in a flowing state to obtain a magnetized magnesium bicarbonate solution;

[0008] Mixing a surfactant and the magnetized magnesium bicarbonate solution to obtain a mixed solution;

[0009] The mixed solution is subjected to a second magnetization using an alternating magnetic field, and then the mixed solution is kept warm so as to decompose the mixed solution at a low temperature to obtain an emulsion;

[0010] performing solid-liquid separation on the emulsion to obtain a filter cake; and

[0011] Drying the filter cake to obtain a basic magnesium carbonate product;

[0012] Wherein, the magnetic field intensity of the fixed magnetic field is ≤1600mT, and the magnetic field amplitude of the alternating magnetic field is ≤800mT.

[0013] Optionally, the magnetic field strength of the fixed magnetic field is 100mT to 1600mT, and the magnetic field amplitude of the alternating magnetic field is 100mT to 800mT.

[0014] Optionally, the first magnetization time is 15 min to 105 min, and the second magnetization time is 15 min to 60 min.

[0015] Optionally, the sudden change waveform of the alternating magnetic field includes:

[0016] Sine, square and triangle waveforms;

[0017] The changing frequency of the alternating magnetic field is 1kHz to 400kHz.

[0018] Optionally, the flow rate of the magnesium bicarbonate solution is 0.05 m / s to 0.35 m / s.

[0019] Optionally, the weight m1 of the surfactant and the weight m2 of the magnetized magnesium bicarbonate solution satisfy the relationship: m1:m2=(5×10 -5 )~(300×10 -5 ).

[0020] Optionally, the surfactant includes at least one of the following:

[0021] Octadecylamine, sodium lauryl sulfate, sodium dodecylbenzene yellow sulfate and Triton X100.

[0022] Optionally, the temperature of the low-temperature decomposition is 25°C to 70°C;

[0023] The insulation time is 30 min to 60 min.

[0024] In a second aspect, the present application provides a decomposition system of a magnesium bicarbonate solution, wherein the decomposition system is adapted to the decomposition method described in the first aspect, and the decomposition system comprises:

[0025] The low-temperature decomposition part includes a feed pipe, a feeding channel and a low-temperature decomposition reactor, wherein the feed pipe is used for the magnesium bicarbonate solution to enter the low-temperature decomposition reactor, and the feeding channel is used for the surfactant to enter the low-temperature decomposition reactor; a heating component is provided in the low-temperature decomposition reactor to perform low-temperature decomposition on the mixed solution of the magnesium bicarbonate solution and the surfactant;

[0026] The magnetization part includes an electromagnetic generator and an alternating magnetic field device, wherein the electromagnetic generator is arranged outside the feed pipe to perform a first magnetization on the magnesium bicarbonate solution in the feed pipe; the alternating magnetic field device is arranged on the inner wall of the reactor to perform a second magnetization on the mixed solution of the magnesium bicarbonate solution and the surfactant;

[0027] A separation and purification section is connected to the discharge port of the low-temperature decomposition reactor.

[0028] Optionally, the separation and purification section includes a filter and a dryer, the feed inlet of the filter is connected to the discharge port of the low-temperature decomposition reactor, and the feed inlet of the dryer is connected to the filter cake discharge port of the filter.

[0029] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0030] The present application provides a method for decomposing a magnesium bicarbonate solution. The method first uses a fixed magnetic field to perform a first magnetization on a flowing magnesium bicarbonate solution, and the magnetic field strength of the fixed magnetic field is ≤1600mT. The magnesium bicarbonate solution is non-uniformly distributed by the first magnetization. The non-uniformly distributed magnesium bicarbonate solution has a lower surface tension, which facilitates the subsequent mixing of a surfactant and the magnesium bicarbonate solution, so as to increase the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate; in addition, the surfactant is mixed with the magnetized magnesium bicarbonate solution, and the surfactant will quickly gather on the surface of the magnetized magnesium bicarbonate solution and be tightly oriented. The invention discloses a method for preparing a magnetized magnesium bicarbonate solution and a surface active agent, wherein the surface active agent is used to destroy the unbalanced intermolecular forces in the magnetized magnesium bicarbonate solution, thereby further reducing the surface tension of the magnetized magnesium bicarbonate solution through the surfactant, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate; the magnetic field amplitude of the external alternating magnetic field is ≤800mT, and the local ion concentration distribution of the surfactant and the magnetized magnesium bicarbonate solution in the mixed solution and the fluctuation frequency of the two can be increased through the alternating magnetic field, thereby increasing the generation of magnesium carbonate crystal nuclei and the growth of magnesium carbonate grains in the magnetized magnesium bicarbonate solution with low surface tension, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] In order to more clearly illustrate the embodiments of the present application 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] Figure 1 A schematic flow chart of a method for decomposing a magnesium bicarbonate solution provided in an embodiment of the present application;

[0034] Figure 2 A logical structure diagram of a decomposition system of a magnesium bicarbonate solution is provided for an embodiment of the present application;

[0035] Figure 3 A structural schematic diagram of a decomposition system of a magnesium bicarbonate solution is provided for an embodiment of the present application;

[0036] Among them, 1-feeding pipeline, 2-feeding channel, 3-low-temperature decomposition reactor, 31-heating component, 4-electromagnetic generator, 5-alternating magnetic field device, 6-separation and purification part, 61-filter, 62-dryer. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0038] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0039] In this article, the terms including "including" and the like mean "including but not limited to". Relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "At least one" means one or more, and "plurality" means two or more; "at least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in this application can be purchased on the market or prepared by existing methods.

[0040] It should be noted that, with respect to the prior art (1) described in the background technology, the inventors found that: although the process achieves maximum recycling of water resources and magnesium resources while saving a large amount of pyrolysis energy; however, the decomposition rate of the magnesium bicarbonate solution in the process is only 46.79% to 48.45%, and the concentration of magnesium bicarbonate after decomposition is far from the level of magnesium bicarbonate weight content ≤0.8g / L (in terms of MgO) required for high-temperature pyrolysis. In addition, the process requires the circulation of a large amount of magnesium bicarbonate mother liquor, and these circulation processes undoubtedly increase the process load and energy consumption.

[0041] With respect to the prior art (2) described in the background technology, the inventors found that: in the pyrolysis process of this method, the magnesium bicarbonate solution will always be in a boiling state, and the latent heat of water vaporization during the boiling state of the magnesium bicarbonate solution heated from 1°C to 100°C is about 5 times that of the same amount of water heated from 1°C to 100°C. The boiling magnesium bicarbonate solution will take away a large amount of heat by evaporation, and this process will also cause a waste of water resources, increasing the energy consumption of the method.

[0042] Figure 1 A schematic flow chart of a method for decomposing a magnesium bicarbonate solution provided in an embodiment of the present application is exemplarily shown;

[0043] like Figure 1 As shown, an embodiment of the present application provides a method for decomposing a magnesium bicarbonate solution, the decomposition method comprising:

[0044] S1. The magnesium bicarbonate solution is first magnetized in a flowing state using a fixed magnetic field to obtain a magnetized magnesium bicarbonate solution;

[0045] S2. The surfactant and the magnetized magnesium bicarbonate solution are mixed to obtain a mixed solution;

[0046] S3. The mixed solution is subjected to a second magnetization using an alternating magnetic field, and then the mixed solution is kept warm so that the mixed solution is decomposed at low temperature to obtain an emulsion;

[0047] S4. separating the emulsion into solid and liquid to obtain a filter cake; and

[0048] S5. The filter cake is dried to obtain a basic magnesium carbonate product;

[0049] Wherein, the magnetic field intensity of the fixed magnetic field is ≤1600mT, and the magnetic field amplitude of the alternating magnetic field is ≤800mT.

[0050] It should be noted that the surfactant is a special solute containing a hydrophilic group and a hydrophobic group. After the surfactant is added to the magnetized magnesium bicarbonate solution, it will quickly gather on the surface of the magnetized magnesium bicarbonate solution and be tightly oriented. The surfactant can destroy the unbalanced intermolecular forces in the surface layer of the original magnetized magnesium bicarbonate solution to greatly reduce the surface tension of the magnetized magnesium bicarbonate solution, and the magnetized magnesium bicarbonate solution with low surface tension will promote the decomposition reaction of the magnetized magnesium bicarbonate solution.

[0051] It should be noted that, in addition to the filter cake, the solid-liquid separation can also obtain a filtrate; the filtrate can be mixed with a magnesium bicarbonate solution to dilute the magnesium bicarbonate solution and then subjected to the first magnetization, or the filtrate can be directly used as the magnesium bicarbonate solution for the first magnetization.

[0052] In some optional embodiments, the magnetic field strength of the fixed magnetic field is 100mT to 1600mT, and the magnetic field amplitude of the alternating magnetic field is 100mT to 800mT;

[0053] In these embodiments, the magnetic field strength of the fixed magnetic field has a great influence on the surface tension coefficient of the magnesium bicarbonate solution. Within a certain range, the surface tension coefficient decreases with the increase of the magnetic field strength. However, after exceeding a certain magnetization strength, even after the magnesium bicarbonate solution has been subjected to the same magnetization time, the surface tension coefficient of the magnesium bicarbonate solution increases instead. Therefore, when the magnetic field strength of the fixed magnetic field can be 100mT to 1600mT, the magnesium bicarbonate solution is in a non-uniform distribution state by a first magnetization method with a fixed magnetic field. The non-uniformly distributed magnesium bicarbonate solution has a lower surface tension, thereby improving the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate; the magnetic field amplitude of the external alternating magnetic field can be 100mT to 800mT, and the local ion concentration distribution of the surfactant and the magnetized magnesium bicarbonate solution in the mixed solution and the fluctuation frequency of the two can be increased by the alternating magnetic field, so as to improve the generation of magnesium carbonate nuclei and the growth of magnesium carbonate grains in the magnetized magnesium bicarbonate solution with low surface tension, thereby improving the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0054] The magnetic field strength of the fixed magnetic field may be 100 mT, 200 mT, 300 mT, 400 mT, 500 mT, 600 mT, 700 mT, 800 mT, 900 mT, 1000 mT, 1100 mT, 1200 mT, 1300 mT, 1400 mT, 1500 mT or 1600 mT.

[0055] The magnetic field amplitude of the alternating magnetic field may be 100 mT, 200 mT, 300 mT, 400 mT, 500 mT, 600 mT, 700 mT or 800 mT.

[0056] In some optional embodiments, the first magnetization time is 15 min to 105 min, and the second magnetization time is 15 min to 60 min;

[0057] In these embodiments, the first magnetization time can be 15min to 105min. The magnesium bicarbonate solution is in a non-uniform distribution state by the first magnetization method with a fixed magnetic field. The non-uniformly distributed magnesium bicarbonate solution has a lower surface tension, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate. In addition, the second magnetization time can be 15min to 60min. The alternating magnetic field can increase the local ion concentration distribution of the surfactant and the magnetized magnesium bicarbonate solution in the mixed solution and accelerate the fluctuation frequency of the two, so as to increase the generation of magnesium carbonate nuclei and the growth of magnesium carbonate grains in the magnetized magnesium bicarbonate solution with low surface tension, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0058] The first magnetization time may be 15 min, 18 min, 30 min, 50 min or 105 min.

[0059] The second magnetization time may be 15 min, 20 min, 30 min, 45 min or 60 min.

[0060] In some optional embodiments, the sudden change waveform of the alternating magnetic field includes:

[0061] Sine, square and triangle waveforms;

[0062] The frequency of the alternating magnetic field is 1kHz to 400kHz;

[0063] In these embodiments, the sudden change waveform of the alternating magnetic field may include a sine waveform, a square waveform and a triangular waveform. In addition, the change frequency of the alternating magnetic field may be 1kHz to 400kHz. The local ion concentration distribution of the surfactant and the magnetized magnesium bicarbonate solution in the mixed solution and the fluctuation frequency of the two can be increased by using different waveforms and a high-frequency alternating magnetic field, so as to increase the generation of magnesium carbonate crystal nuclei and the growth of magnesium carbonate grains in the magnetized magnesium bicarbonate solution with low surface tension, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0064] The changing frequency of the alternating magnetic field may be 1 kHz, 5 kHz, 10 kHz, 20 kHz, 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, 90 kHz, 100 kHz, 150 kHz, 200 kHz, 250 kHz, 300 kHz, 350 kHz or 400 kHz.

[0065] In some optional embodiments, the flow rate of the magnesium bicarbonate solution is 0.05 m / s to 0.35 m / s;

[0066] In these embodiments, the flow rate of the magnesium bicarbonate solution can be 0.05 m / s to 0.35 m / s. The time of the magnesium bicarbonate solution in the fixed magnetic field can be increased by an appropriate flow rate to meet the time requirement of the first magnetization, so that the magnesium bicarbonate solution can be in a non-uniform distribution state. The non-uniformly distributed magnesium bicarbonate solution has a lower surface tension to increase the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0067] The flow rate of the magnesium bicarbonate solution can be 0.05 m / s, 0.10 m / s, 0.15 m / s, 0.20 m / s, 0.25 m / s, 0.30 m / s or 0.35 m / s.

[0068] It should be noted that, when the flow velocity of magnesium bicarbonate solution is less than 0.05m / s, the flow of magnesium bicarbonate solution is poor and it is difficult to meet the demand of the first magnetization; when the flow velocity of magnesium bicarbonate solution is greater than 0.35m / s, magnesium bicarbonate solution will be in a high-speed flow state, and the magnesium bicarbonate solution of high-speed flow will shorten the first magnetization time of magnesium bicarbonate solution in a fixed magnetic field, which is not conducive to the first magnetization; in addition, the collision of water molecules in the magnesium bicarbonate solution of high-speed flow is more intense to cause chaos in magnesium bicarbonate solution, thereby causing magnesium bicarbonate solution to be not easily magnetized.

[0069] In some optional embodiments, the weight m1 of the surfactant and the weight m2 of the magnetized magnesium bicarbonate solution satisfy the relationship: m1:m2=(5×10 -5 )~(300×10 -5 );

[0070] In these embodiments, the weight m1 of the surfactant and the weight m2 of the magnetized magnesium bicarbonate solution may satisfy the relationship: m1:m2=(5×10 -5 )~(300×10 -5), which can promote the mixed solution to have a sufficient amount of surface active agent, and the sufficient amount of surfactant will quickly gather on the surface of the magnetized magnesium bicarbonate solution and be closely oriented to destroy the unbalanced intermolecular forces in the magnetized magnesium bicarbonate solution, so that the surface tension of the magnetized magnesium bicarbonate solution can be further reduced by the surfactant, so as to improve the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0071] The weight m1 of the surfactant and the weight m2 of the magnetized magnesium bicarbonate solution can satisfy the relationship: m1:m2=5×10 -5 , 10×10 -5 , 15×10 -5 , 20×10 -5 , 25×10 -5 or 30×10 -5 .

[0072] In some optional embodiments, the surfactant includes at least one of the following:

[0073] Octadecylamine, sodium lauryl sulfate, sodium dodecylbenzene yellow sulfate, and Triton X100;

[0074] In these embodiments, the surfactant may include at least one of octadecylamine, sodium dodecyl sulfate, sodium dodecylbenzene yellow sulfate and Triton X100. The surfactant containing a hydrophilic group and a hydrophobic group will quickly gather and closely oriented on the surface of the magnetized magnesium bicarbonate solution to destroy the unbalanced intermolecular forces in the magnetized magnesium bicarbonate solution, so that the surface tension of the magnetized magnesium bicarbonate solution can be further reduced by the surfactant to increase the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate.

[0075] In some optional embodiments, the temperature of the low temperature decomposition is 25°C to 70°C;

[0076] The insulation time is 30min to 60min;

[0077] In these embodiments, the temperature of the low-temperature decomposition can be 25° C. to 70° C., and the insulation time can be 30 min to 60 min, which can provide sufficient activation energy for the magnetized magnesium bicarbonate solution in the mixed solution to promote the magnetized magnesium bicarbonate solution in the mixed solution to decompose fully; in addition, the temperature of the low-temperature decomposition can avoid boiling of the mixed solution to reduce the heat loss of the mixed solution due to boiling, thereby reducing the energy consumption of the low-temperature decomposition.

[0078] The temperature of the low temperature decomposition may be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C or 70°C.

[0079] The insulation time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min or 70 min.

[0080] Figure 2 The present application provides a schematic diagram of the logical structure of a decomposition system for a magnesium bicarbonate solution;

[0081] Figure 3 The present application provides a schematic structural diagram of a decomposition system for a magnesium bicarbonate solution;

[0082] Based on a general inventive concept, such as Figure 2 and Figure 3 As shown, an embodiment of the present application provides a decomposition system of a magnesium bicarbonate solution, the decomposition system is adapted to the decomposition method, and the decomposition system includes:

[0083] The low-temperature decomposition part includes a feed pipe 1, a feed channel 2 and a low-temperature decomposition reactor 3. The feed pipe 1 is used for the magnesium bicarbonate solution to enter the low-temperature decomposition reactor 3, and the feed channel 2 is used for the surfactant to enter the low-temperature decomposition reactor 3. A heating component 31 is provided in the low-temperature decomposition reactor 3 to perform low-temperature decomposition on the mixed solution of the magnesium bicarbonate solution and the surfactant.

[0084] The magnetization part includes an electromagnetic generator 4 and an alternating magnetic field device 5. The electromagnetic generator 4 is arranged outside the feeding pipeline 1 to perform a first magnetization on the magnesium bicarbonate solution in the feeding pipeline 1; the alternating magnetic field device 5 is arranged on the inner wall of the reactor to perform a second magnetization on the mixed solution of the magnesium bicarbonate solution and the surfactant;

[0085] The separation and purification section 6 is connected to the discharge port of the low-temperature decomposition reactor 3 .

[0086] The decomposition system is implemented based on the above-mentioned decomposition method. The specific steps of the decomposition method can refer to the above-mentioned embodiments. Since the decomposition system adopts part or all of the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0087] It should be noted that the heating component 31 in the low-temperature decomposition reactor 3 can be a heating resistor or a heating pipe, and the mixed solution of the magnesium bicarbonate solution and the surfactant can undergo a low-temperature decomposition reaction by heat exchange.

[0088] It should be noted that a stirrer may be provided in the low-temperature decomposition reactor 3 to fully mix the magnesium bicarbonate solution and the surfactant to facilitate the low-temperature decomposition; in addition, the stirrer may be provided with a heating unit to cooperate with the heating component 31 to promote the low-temperature decomposition reaction of the mixed solution of the magnesium bicarbonate solution and the surfactant.

[0089] It should be noted that the alternating magnetic field device 5 can emit a magnetic field waveform of at least one of a sine waveform, a square waveform and a triangular waveform.

[0090] In some optional embodiments, the separation and purification unit 6 includes a filter 61 and a dryer 62, the feed port of the filter 61 is connected to the discharge port of the low-temperature decomposition reactor 3, and the feed port of the dryer 62 is connected to the filter cake discharge port of the filter 61;

[0091] In these embodiments, the separation and purification unit 6 may include a filter 61 and a dryer 62, and the feed port of the filter 61 is connected to the discharge port of the low-temperature decomposition reactor 3, and the feed port of the dryer 62 is connected to the filter cake discharge port of the filter 61. The filter 61 can be used to perform solid-liquid separation on the emulsion treated by the alternating magnetic field device 5 to collect the crude basic magnesium carbonate generated in the emulsion, and then the dryer 62 is used to dry the collected crude basic magnesium carbonate product, so as to remove moisture from the basic magnesium carbonate product to obtain a pure basic magnesium carbonate product.

[0092] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples that do not specify specific conditions are usually measured according to industry standards; if there are no corresponding industry standards, they are carried out according to common international standards, conventional conditions, or conditions recommended by the manufacturer.

[0093] Example 1

[0094] A magnesium bicarbonate solution with a mass concentration of 5.2 g / L (in terms of MgO) was selected.

[0095] like Figure 1 As shown, a method for decomposing a magnesium bicarbonate solution comprises:

[0096] S1. The magnesium bicarbonate solution is first magnetized in a flowing state using a fixed magnetic field to obtain a magnetized magnesium bicarbonate solution;

[0097] S2. The surfactant and the magnetized magnesium bicarbonate solution are mixed to obtain a mixed solution;

[0098] S3. The mixed solution is subjected to a second magnetization using an alternating magnetic field, and then the mixed solution is kept warm so that the mixed solution is decomposed at low temperature to obtain an emulsion;

[0099] S4. The emulsion is subjected to solid-liquid separation to obtain a filter cake; and

[0100] S5. The filter cake is dried to obtain a basic magnesium carbonate product;

[0101] Among them, the magnetic field strength of the fixed magnetic field is 220mT, and the magnetic field amplitude of the alternating magnetic field is 800mT.

[0102] The time for the first magnetization was 105 min, and the time for the second magnetization was 60 min.

[0103] The insulation time is 30 minutes.

[0104] The sudden change waveform of the alternating magnetic field is a sine waveform;

[0105] The frequency of the alternating magnetic field is 60kHz.

[0106] The flow rate of the magnesium bicarbonate solution is 0.05 m / s.

[0107] The weight of the surfactant m1 and the weight of the magnetized magnesium bicarbonate solution m2 satisfy the relationship: m1:m2=10×10 -5 .

[0108] The surfactant is octadecylamine.

[0109] The temperature of low temperature decomposition is 25℃.

[0110] Example 2

[0111] Based on the method disclosed in Example 1, a system is further constructed.

[0112] like Figure 2 and Figure 3 As shown, a decomposition system of a magnesium bicarbonate solution, the decomposition system is adapted to the decomposition method, and the decomposition system comprises:

[0113] The low-temperature decomposition part includes a feed pipe 1, a feed channel 2 and a low-temperature decomposition reactor 3. The feed pipe 1 is used for the magnesium bicarbonate solution to enter the low-temperature decomposition reactor 3, and the feed channel 2 is used for the surfactant to enter the low-temperature decomposition reactor 3. A heating component 31 is provided in the low-temperature decomposition reactor 3 to perform low-temperature decomposition on the mixed solution of the magnesium bicarbonate solution and the surfactant;

[0114] The magnetization part includes an electromagnetic generator 4 and an alternating magnetic field device 5. The electromagnetic generator 4 is arranged outside the feed pipe 1 to perform a first magnetization on the magnesium bicarbonate solution in the feed pipe 1; the alternating magnetic field device 5 is arranged on the inner wall of the reactor to perform a second magnetization on the mixed solution of the magnesium bicarbonate solution and the surfactant;

[0115] The separation and purification section 6 comprises a filter 61 and a dryer 62 . The feed port of the filter 61 is connected to the discharge port of the low-temperature decomposition reactor 3 , and the feed port of the dryer 62 is connected to the filter cake discharge port of the filter 61 .

[0116] Example 3

[0117] Based on the method disclosed in Example 1, the following modifications are further made:

[0118] A magnesium bicarbonate solution with a mass concentration of 8.1 g / L (in terms of MgO) was selected.

[0119] The magnetic field strength of the fixed magnetic field is 650mT, and the magnetic field amplitude of the alternating magnetic field is 500mT.

[0120] The time for the first magnetization was 50 min, and the time for the second magnetization was 45 min.

[0121] The insulation time is 45 minutes.

[0122] The sudden change waveform of the alternating magnetic field is a sine waveform;

[0123] The frequency of the alternating magnetic field is 100kHz.

[0124] The flow rate of the magnesium bicarbonate solution is 0.10 m / s.

[0125] The weight of the surfactant m1 and the weight of the magnetized magnesium bicarbonate solution m2 satisfy the relationship: m1:m2=300×10 -5 .

[0126] The surfactant is sodium lauryl sulfate.

[0127] The temperature of low temperature decomposition is 40℃.

[0128] Example 4

[0129] Based on the method disclosed in Example 1, the following modifications are further made:

[0130] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0131] The magnetic field strength of the fixed magnetic field is 860mT, and the magnetic field amplitude of the alternating magnetic field is 600mT.

[0132] The first magnetization time is 30 min, and the second magnetization time is 30 min.

[0133] The insulation time is 60 minutes.

[0134] The sudden change waveform of the alternating magnetic field is a square waveform;

[0135] The frequency of the alternating magnetic field is 200kHz.

[0136] The flow rate of the magnesium bicarbonate solution is 0.17 m / s.

[0137] The weight of the surfactant m1 and the weight of the magnetized magnesium bicarbonate solution m2 satisfy the relationship: m1:m2=200×10 -5 .

[0138] The surfactant is sodium dodecylbenzene yellow sulfate.

[0139] The temperature of low temperature decomposition is 50℃.

[0140] Example 5

[0141] Based on the method disclosed in Example 1, the following modifications are further made:

[0142] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0143] The magnetic field strength of the fixed magnetic field is 1600mT, and the magnetic field amplitude of the alternating magnetic field is 220mT.

[0144] The time for the first magnetization was 18 min, and the time for the second magnetization was 20 min.

[0145] The insulation time is 60 minutes.

[0146] The sudden change waveform of the alternating magnetic field is a triangular waveform;

[0147] The frequency of the alternating magnetic field is 300kHz.

[0148] The flow rate of the magnesium bicarbonate solution is 0.30 m / s.

[0149] The weight of the surfactant m1 and the weight of the magnetized magnesium bicarbonate solution m2 satisfy the relationship: m1:m2=50×10 -5 .

[0150] The surfactant was Triton X100.

[0151] The temperature of low temperature decomposition is 55℃.

[0152] Example 6

[0153] Based on the method disclosed in Example 1, the following modifications are further made:

[0154] A magnesium bicarbonate solution with a mass concentration of 15.0 g / L (in terms of MgO) was selected.

[0155] The magnetic field strength of the fixed magnetic field is 1000mT, and the magnetic field amplitude of the alternating magnetic field is 100mT.

[0156] The first magnetization time was 15 min, and the second magnetization time was 15 min.

[0157] The insulation time is 60 minutes.

[0158] The sudden change waveform of the alternating magnetic field is a triangular waveform;

[0159] The frequency of the alternating magnetic field is 400kHz.

[0160] The flow rate of the magnesium bicarbonate solution is 0.27 m / s.

[0161] The weight of the surfactant m1 and the weight of the magnetized magnesium bicarbonate solution m2 satisfy the relationship: m1:m2=100×10 -5 .

[0162] The surfactant is sodium dodecylbenzene yellow sulfate.

[0163] The temperature of low temperature decomposition is 70℃.

[0164] Comparative Example 1

[0165] Based on the contents disclosed in Example 1, the following modifications are further made:

[0166] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0167] Without using the first magnetization and the second magnetization, the magnesium bicarbonate solution is directly subjected to low-temperature pyrolysis at normal pressure at 55° C. to obtain an emulsion.

[0168] Comparative Example 2

[0169] Based on the contents disclosed in Example 1, the following modifications are further made:

[0170] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0171] Without using the first magnetization and the second magnetization, the magnesium bicarbonate solution is directly subjected to low-temperature pyrolysis at normal pressure at 95° C. to obtain an emulsion.

[0172] Comparative Example 3

[0173] Based on the contents disclosed in Example 5, the following modifications are further made:

[0174] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0175] The magnesium bicarbonate solution and the surfactant are directly subjected to the second magnetization without using the first magnetization method.

[0176] Comparative Example 4

[0177] Based on the contents disclosed in Example 5, the following modifications are further made:

[0178] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0179] Without using the second magnetization method, the magnetized magnesium bicarbonate solution and the surfactant are directly mixed.

[0180] Comparative Example 5

[0181] Based on the contents disclosed in Example 5, the following modifications are further made:

[0182] A magnesium bicarbonate solution with a mass concentration of 11.9 g / L (in terms of MgO) was selected.

[0183] No surfactants are used.

[0184] Related experiments and effect data:

[0185] The decomposition rate of the basic magnesium carbonate product obtained in each embodiment and comparative example was statistically analyzed, and the weight content of magnesium (in terms of MgO) in the filtrate after solid-liquid separation was statistically analyzed. The results are shown in Table 1.

[0186] Table 1 Decomposition rate of basic magnesium carbonate products of various embodiments and comparative examples and weight content of magnesium in the filtrate after solid-liquid separation

[0187]

[0188]

[0189] As can be seen from Table 1, a method for decomposing a magnesium bicarbonate solution provided in an embodiment of the present application uses a two-stage magnetization method and a surfactant to reduce the surface tension of the magnetized magnesium bicarbonate solution, thereby increasing the decomposition rate of the magnetized magnesium bicarbonate solution to generate basic magnesium carbonate to more than 95%.

[0190] In addition, the present application provides a method for decomposing a magnesium bicarbonate solution. The method can effectively decompose the magnetized magnesium bicarbonate solution under a relatively low decomposition temperature condition, and has the advantages of low energy consumption, low water consumption, low cost and high decomposition rate, indicating that the decomposition method is suitable for large-scale industrial production.

[0191] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features applied for by the present application.

Claims

1. A method for decomposing a magnesium bicarbonate solution, characterized in that: The decomposition method comprises: Using a fixed magnetic field to first magnetize the magnesium bicarbonate solution in a flowing state to obtain a magnetized magnesium bicarbonate solution; Mixing a surfactant and the magnetized magnesium bicarbonate solution to obtain a mixed solution; The mixed solution is subjected to a second magnetization using an alternating magnetic field, and then the mixed solution is kept warm so as to decompose the mixed solution at a low temperature to obtain an emulsion; performing solid-liquid separation on the emulsion to obtain a filter cake; and Drying the filter cake to obtain a basic magnesium carbonate product; Wherein, the magnetic field intensity of the fixed magnetic field is ≤1600mT, and the magnetic field amplitude of the alternating magnetic field is ≤800mT.

2. The decomposition method according to claim 1, characterized in that: The magnetic field strength of the fixed magnetic field is 100mT to 1600mT, and the magnetic field amplitude of the alternating magnetic field is 100mT to 800mT.

3. The decomposition method according to claim 1, characterized in that: The first magnetization time is 15 min to 105 min, and the second magnetization time is 15 min to 60 min.

4. The decomposition method according to claim 1, characterized in that: The sudden change waveform of the alternating magnetic field includes: Sine, square and triangle waveforms; The changing frequency of the alternating magnetic field is 1kHz to 400kHz.

5. The decomposition method according to claim 1, characterized in that: The flow rate of the magnesium bicarbonate solution is 0.05 m / s to 0.35 m / s.

6. The decomposition method according to claim 1, characterized in that: The weight m1 of the surfactant and the weight m2 of the magnetized magnesium bicarbonate solution satisfy the relationship: m1:m2=(5×10 -5 )~(300×10 -5 ).

7. The decomposition method according to claim 1 or 6, characterized in that: The surfactant comprises at least one of the following: Octadecylamine, sodium lauryl sulfate, sodium dodecylbenzene yellow sulfate and Triton X100.

8. The decomposition method according to claim 1, characterized in that: The temperature of the low temperature decomposition is 25°C to 70°C; The insulation time is 30 min to 60 min.

9. A decomposition system of magnesium bicarbonate solution, characterized in that: The decomposition system is adapted to the decomposition method according to any one of claims 1 to 7, and the decomposition system comprises: The low-temperature decomposition part comprises a feed pipe (1), a feed channel (2) and a low-temperature decomposition reactor (3), wherein the feed pipe (1) is used for the magnesium bicarbonate solution to enter the low-temperature decomposition reactor (3), and the feed channel (2) is used for the surfactant to enter the low-temperature decomposition reactor (3); a heating component (31) is provided in the low-temperature decomposition reactor (3) to perform low-temperature decomposition of a mixed solution of the magnesium bicarbonate solution and the surfactant; The magnetization part comprises an electromagnetic generator (4) and an alternating magnetic field device (5), wherein the electromagnetic generator (4) is arranged outside the feed pipe (1) to perform a first magnetization on the magnesium bicarbonate solution in the feed pipe (1); and the alternating magnetic field device (5) is arranged on the inner wall of the reaction kettle to perform a second magnetization on the mixed solution of the magnesium bicarbonate solution and the surfactant. A separation and purification section (6), wherein the separation and purification section (6) is connected to the discharge port of the low-temperature decomposition reactor (3).

10. The system according to claim 9, characterized in that The separation and purification section (6) comprises a filter (61) and a dryer (62), wherein the feed port of the filter (61) is connected to the discharge port of the low-temperature decomposition reactor (3), and the feed port of the dryer (62) is connected to the filter cake discharge port of the filter (61).

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