System device and method for preparing calcium carbonate by using micro-nano bubbles
阅读说明：本技术 一种利用微纳米气泡制备碳酸钙的系统装置及方法 (System device and method for preparing calcium carbonate by using micro-nano bubbles ) 是由 孟子衡 李会泉 朱干宇 李少鹏 颜坤 于 2021-05-10 设计创作，主要内容包括：本发明提供一种利用微纳米气泡制备碳酸钙的系统装置及方法,所述系统装置包括相连接的微纳米气泡发生装置和反应装置,还包括分别与反应装置相连接的第一分离装置和离心装置,以及分别与离心装置相连接的第二分离装置和第三分离装置；在所述系统装置中进行的微纳米气泡制备碳酸钙的方法,包括利用微纳米气泡发生装置产生微纳米气泡,进入反应装置与电石渣混合进行碳化反应,再通入离心装置进行分离,从而得到碳酸钙颗粒。本发明利用微纳米气泡碳化电石渣来控制碳酸钙的晶粒大小,避免使用晶型控制剂,即可以实现连续化操作,又可以是间歇操作,具有处理量大、碳化速度快、成本低等优点。(The invention provides a system device and a method for preparing calcium carbonate by utilizing micro-nano bubbles, wherein the system device comprises a micro-nano bubble generating device and a reaction device which are connected, and also comprises a first separating device and a centrifugal device which are respectively connected with the reaction device, and a second separating device and a third separating device which are respectively connected with the centrifugal device; the method for preparing calcium carbonate by using the micro-nano bubbles in the system device comprises the steps of generating the micro-nano bubbles by using a micro-nano bubble generating device, mixing the micro-nano bubbles with carbide slag in a reaction device to carry out carbonization reaction, and then introducing a centrifugal device to carry out separation, thereby obtaining calcium carbonate particles. The invention utilizes the micro-nano bubble carbide slag to control the grain size of the calcium carbonate, avoids using a crystal form control agent, can realize continuous operation and intermittent operation, and has the advantages of large processing capacity, high carbonization speed, low cost and the like.)
1. A system device for preparing calcium carbonate by utilizing micro-nano bubbles is characterized by comprising a micro-nano bubble generating device and a reaction device which are connected; the system device also comprises a first separation device, a second separation device, a third separation device and a centrifugal device;
the reaction device is respectively connected with the first separation device and the centrifugal device; the centrifugal device is provided with a light slurry outlet and a heavy slurry outlet; the centrifugal device is connected with the second separation device through a light slurry outlet; the centrifugal device is connected with the third separation device through a heavy slurry outlet;
the system device further comprises a storage device; the first separation device, the second separation device and the third separation device are circularly connected with the reaction device through a storage device; the first separation device, the second separation device and the third separation device are also circularly connected with the micro-nano bubble generation device through the storage device.
2. The system arrangement as claimed in claim 1, characterized in that at least two spray elements are arranged in a uniform distribution on the same horizontal plane of the housing of the reaction device.
3. The system device as claimed in claim 2, wherein the ratio of the distance from the spraying member to the bottom of the reaction device to the height of the reaction device is 1 (3-5).
4. The system apparatus as claimed in claim 2, wherein the angle between the central line of the jet orifice of the jet member and the corresponding diameter of the reaction device is 30 to 60 °.
5. The system set forth in claim 1, wherein said second separating means comprises a second agitating means and a second filtering means connected; the second stirring device comprises an ageing tank.
6. A method for preparing calcium carbonate by using micro-nano bubbles is characterized in that the method is carried out in the system device for preparing calcium carbonate by using micro-nano bubbles according to any one of claims 1 to 5.
7. The method according to claim 6, characterized in that it comprises the steps of:
(1) containing CO2The gas source forms micro-nano bubbles in the micro-nano bubble generating device, the micro-nano bubbles enter the reaction device to be mixed with carbide slag to obtain mixed slurry, and carbonization reaction is carried out to obtain scum liquid on the upper part of the reaction device and reaction slurry in the middle of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first separation device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, and the light slurry enters a second separation device to carry out aging reaction and solid-liquid separation in sequence, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, and enabling the heavy slurry to enter a third separation device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and circularly introducing the mixed liquid into the micro-nano bubble generating device and the reaction device.
8. The method of claim 7, wherein the gas source of step (1) further comprises solubility ratio CO in the mixed slurry2Small balance gas.
9. The method according to claim 7, wherein the aging reaction of step (2) comprises standing carbonization.
10. A method according to any one of claims 7 to 9, characterized in that the method comprises the steps of:
（1）CO2forming micro-nano bubbles in a micro-nano bubble generating device by using an air source with the concentration of 5-99 wt%, allowing the micro-nano bubbles to enter a reaction device and mixing with carbide slag to obtain mixed slurry with the pH of 5-8, wherein the carbide slag with the concentration of 0.1-20 wt% is subjected to carbonization reaction at the temperature of 5-80 ℃, and the carbonization reaction is carried out under the stirring condition of the speed of 50-300 rpm to obtain scum liquid on the upper part of the reaction device and reaction slurry in the middle of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first separation device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second separation device, and aging reaction for 5-20 hours at the temperature of 10-60 ℃ and solid-liquid separation are sequentially carried out on the light slurry, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, and enabling the heavy slurry to enter a third separation device to obtain third separation liquid and impurities;
(3) and (2) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and circularly introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is (1.5-8): 1, and the flow of an air source in the micro-nano bubble generating device is 1-10% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Technical Field
The invention relates to the technical field of calcium carbonate, in particular to a system device and a method for preparing calcium carbonate by utilizing micro-nano bubbles.
Background
The carbide slag is industrial solid waste formed in the process of producing acetylene by a calcium carbide method, mainly contains calcium hydroxide and impurities such as coke, ferrosilicon, aluminum-silicon mineral and the like. The calcium content in the carbide slag is high, and the carbide slag can replace hydrated lime to be used for preparing nano calcium carbonate (the grain size is less than 100 nm). However, since the carbide slag contains impurities such as coke, ferrosilicon, aluminum silicon minerals and the like and non-low-activity calcium particles, the purity of the nano calcium carbonate may be affected, and the crystal structure and morphology of the nano calcium carbonate may also be affected.
CN100457632C discloses a method for preparing nano active calcium carbonate, which comprises using carbide slag as raw material, adding water to calcium oxide obtained by purifying the carbide slag to digest it to obtain calcium hydroxide slurry with a certain concentration, then introducing carbon dioxide, and simultaneously adding additives to carry out carbonization reaction, and controlling a series of process parameters during the reaction to prepare nano calcium carbonate with a certain particle size.
CN100424015C discloses a method for preparing nano active calcium carbonate and co-producing carbon powder by using carbide slag, which comprises the steps of pretreating the carbide slag, then carrying out purification reaction on the carbide slag and ammonium chloride according to a certain proportion, filtering or precipitating to obtain clear liquid, and further processing the remainder into the carbon powder. And adding a proper amount of surfactant and a crystal form control agent into the clarified liquid, and introducing carbon dioxide for controllable carbonization until the pH value is 7.5-8. Finally, the carbonization liquid is filtered, washed, dried, crushed, sieved, packaged and the like to obtain the nano active calcium carbonate and the carbon powder.
CN100390064C discloses a method for preparing superfine calcium carbonate by using carbide slag, which comprises the step of passing dried carbide slag through NH4Dissolving Cl solution, removing residue, adding sodium stearate, and introducing CO2Controlling the reaction temperature of the gas to be 2-100 ℃.
CN100571847B discloses a mineral carbonation CO fixation method2Co-production of carbonA process for producing a calcium salt product comprising the steps of: crushing calcium-containing solid waste or/and silicate ore to obtain solid particles, adding an acidic medium into the solid particles, stirring for 30-120 minutes at 60-80 ℃, cooling, filtering to obtain a calcium ion leachate, adding a calcium-containing alkaline substance into the calcium ion leachate, adjusting the pH to be = 7-8, and filtering to obtain a calcium-containing raw material solution; adding organic solvent into calcium-containing raw material liquid, stirring, and introducing CO2Gas, carrying out carbonation reaction; filtering the reaction liquid after the carbonation reaction to obtain filtrate and a solid product; the solid product was washed with deionized water and dried to obtain calcium carbonate.
CN101293663B discloses a novel process for preparing fine calcium carbonate, which comprises the steps of reacting a calcium raw material with an amino acid solution in a reaction kettle, carrying out suction filtration and separation when the reaction is finished, and obtaining an amino acid calcium solution; transferring the amino acid calcium solution into a reactor, blowing carbon dioxide or adding a carbon dioxide-containing amino acid solution, and after the reaction reaches the end point, performing post-treatment to obtain the fine calcium carbonate, wherein the carbon dioxide is selected from pure gas, boiler tail gas or other carbon sources containing carbon dioxide and mixed gas.
CN102992373B discloses a method for preparing light calcium carbonate by using carbide slag as a raw material, which comprises the steps of adding the carbide slag into a fatty acid solution, fully stirring and reacting, then carrying out suction filtration, dropwise adding a carbonate or bicarbonate aqueous solution into a filtrate while stirring, controlling the pH value of a reaction solution to be 7.5-8 after dropwise adding is finished, namely the reaction is finished and the end point is reached, carrying out suction filtration on the reaction solution, and drying a filter cake to obtain the light calcium carbonate.
The calcium extraction and the removal of impurities in the carbide slag are carried out by using leaching agents (such as ammonium chloride, small molecular organic acid, amino acid or fatty acid and the like), and then CO is used2Or a method for carbonizing the leaching solution by carbonate to obtain calcium carbonate. Although the leaching-carbonization method can effectively remove impurities in the carbide slag, the leaching agent is difficult to recycle, secondary wastewater is generated, and the cost is high; meanwhile, leaching agent ions can remain in the product, and the quality of the product is influenced. In addition, in order to obtain micro-nano calcium carbonate or calcium carbonate with specific morphology, the carbonization process is adoptedIn (1), a crystal form control agent needs to be added. The preparation cost is increased due to the fact that the addition amount of the crystal form control agent is generally high. In addition, the carbide slag contains impurities, and the calcium carbonate prepared by direct carbonization has low purity and poor crystal morphology, so that a qualified nano calcium carbonate product is difficult to obtain.
Therefore, there is a need to develop a method for preparing nano calcium carbonate, which can prepare good nano calcium carbonate, and has simple operation and low cost.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a system device and a method for preparing calcium carbonate by using micro-nano bubbles, wherein the system device controls the grain size of calcium carbonate by using micro-nano bubble carbonized carbide slag, avoids using a crystal form control agent, can realize continuous operation and intermittent operation by using the method for preparing calcium carbonate by using micro-nano bubbles in the system device, and has the advantages of large treatment capacity, high carbonization speed, low cost and the like.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the invention provides a system device for preparing calcium carbonate by using micro-nano bubbles, which comprises a micro-nano bubble generating device and a reaction device which are connected; the system device also comprises a first separation device, a second separation device, a third separation device and a centrifugal device; the reaction device is respectively connected with the first separation device and the centrifugal device; the centrifugal device is provided with a light slurry outlet and a heavy slurry outlet; the centrifugal device is connected with the second separation device through a light slurry outlet; the centrifugal device is connected with the third separation device through a heavy slurry outlet; the system device further comprises a storage device; the first separation device, the second separation device and the third separation device are circularly connected with the reaction device through a storage device; the first separation device, the second separation device and the third separation device are also circularly connected with the micro-nano bubble generation device through the storage device.
The system device for preparing calcium carbonate by using micro-nano bubbles provided by the invention is characterized in that the micro-nano bubble generating device is used for forming a product containing micro-nano bubblesWith CO2The micro-nano bubble generating device is connected with the reaction device, so that CO is contained2The micro-nano bubbles enter the reaction device, so that the micro-nano bubbles and carbide slag are subjected to carbonization reaction to form calcium carbonate, the first separation device is used for separating first separation liquid and floating slag in floating slag liquid, the centrifugal device is used for separating light slurry containing calcium carbonate particles generated by carbonization and heavy slurry containing impurity particles in the carbide slag, the second separation device is used for aging the light slurry after the carbonization reaction is finished, so that calcium carbonate crystals in the light slurry are more complete and the particle size distribution of the light slurry is more uniform, and the third separation device is used for separating third separation liquid and impurities in the heavy slurry2The crystal grain size of calcium carbonate is controlled by the micro-nano bubble carbonized carbide slag, a crystal form control agent is avoided, the calcium carbonate particles and the impurity particles in the carbide slag are separated in situ by using a centrifugal device, the calcium carbonate is prepared from the carbide slag, the effect of quickly separating impurities is realized, the continuous operation and the intermittent operation can be realized, and the method has the advantages of simple process, high carbonization speed, low cost and the like.
Generally, the micro-nano bubbles refer to bubbles with the size of 100 nanometers to 100 micrometers.
Preferably, the micro-nano bubble generating device is provided with an air source inlet.
Preferably, the micro-nano bubble generating device is provided with a water source inlet.
Preferably, the reaction apparatus comprises a carbonation tank.
Preferably, a stirring device is arranged in the reaction device.
Preferably, at least two spraying parts are uniformly distributed on the same horizontal plane of the shell of the reaction device, and the number of the spraying parts can be 2, 3, 4, 5, 6, 7, 8 or 9, etc.
Preferably, the injection direction of the injection member is toward the inside of the reaction apparatus.
Preferably, the ratio of the distance from the spraying part to the bottom of the reaction device to the height of the reaction device is 1 (3-5), and may be, for example, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or the like.
Preferably, the angle between the central line of the jet orifice of the jet part and the corresponding diameter of the reaction device is 30-60 degrees, such as 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees or 60 degrees.
According to the invention, the shell of the reaction device is provided with the injection component with a specific angle, so that the slurry can rotate in the reaction device, the slurry can be rapidly dispersed to carry out carbonization reaction, and meanwhile, the flotation of coarse and fine coke particles in carbide slag on the upper layer of the liquid surface is facilitated.
Preferably, the included angle of any two adjacent injection components on the same horizontal plane of the reaction device shell is 30-90 degrees, for example, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees or 90 degrees.
Preferably, an outlet of the micro-nano bubble generating device is connected with a spraying part of the reaction device.
Preferably, the middle part of the reaction device is provided with a first outlet.
Preferably, the first outlet of the reaction device is connected to the inlet of the centrifugal device.
The reaction slurry containing calcium carbonate is positioned in the middle of the reaction device and enters the centrifugal device from the first outlet, so that calcium carbonate particles generated by carbonization and impurity particles in carbide slag are separated, and the product calcium carbonate is obtained.
Preferably, the top of the reaction device is provided with a second outlet.
Preferably, the first separation device comprises a first stirring device and a first filtering device which are connected.
Preferably, the second outlet of the reaction device is connected with a first stirring device.
In the invention, scum liquid containing scum is arranged at the top of the reaction device and enters the first stirring device and the first filtering device from the second outlet in sequence, so that the scum and the first separation liquid are separated.
Preferably, the first stirring device comprises a scum trough.
Preferably, the reaction device is provided with a first inlet.
Preferably, the reaction device is provided with a second inlet.
The second inlet of the reaction device is used for introducing the reaction raw material carbide slag into the reaction device.
Preferably, the second separation device comprises a second stirring device and a second filtering device which are connected; the second stirring device comprises an ageing tank.
The light slurry is introduced into a second separation device, an aging reaction is carried out in a second stirring device, and the materials after the aging reaction are introduced into a second filtering device for separation, so that the calcium carbonate and the second separation liquid are obtained.
Preferably, the top middle part of the centrifugal device is provided with a light slurry outlet.
Preferably, the light slurry outlet is connected to the inlet of the second stirring device.
Preferably, the number of the second stirring means is at least two.
The number of the second stirring devices in the present invention is at least two, and they may be used alternately.
Preferably, the top end side wall of the centrifugal device is provided with a heavy slurry outlet.
After the centrifugal device is used for centrifugation, the light slurry is positioned in the middle of the centrifugal device, the heavy slurry is positioned on the side wall of the centrifugal device, the light slurry and the heavy slurry are respectively led out through a light slurry outlet and a heavy slurry outlet and are respectively led into a second separation device and a third separation device for treatment.
Preferably, the third separation device comprises a third stirring device and a third filtering device which are connected.
Preferably, the heavy slurry outlet is connected to the inlet of the third stirring device.
Preferably, the third stirring device comprises an impurity tank.
The stirring in the first stirring device, the second stirring device and the third stirring device is all for promoting the scum liquid, the light slurry and the heavy slurry in the first stirring device, the second stirring device and the third stirring device to be introduced into the subsequent filtering device in a uniform state.
Preferably, the inlet of the storage device is connected to the light pulp outlet.
When the device is operated intermittently, the light slurry is led out from a light slurry outlet in the centrifugal device and enters a storage device, the storage device is used for recovering the light slurry coming out from the centrifugal device, and then the light slurry returns to the reaction device from the storage device to carry out a second carbonization process, the light slurry coming out from the centrifugal device enters a second stirring device to be aged after the carbonization is finished, and the calcium carbonate is obtained after the aging is finished and is filtered by a second filtering device.
When the operation is continuous, the light slurry is led out from the light slurry outlet of the centrifugal device and enters a second stirring device, the light slurry is aged in the second stirring device, then the light slurry is filtered by a second filtering device to obtain calcium carbonate, and the second separation liquid passing through the second filtering device is led into a storage device.
Preferably, the inlet of the storage means is connected to the outlet of the first filtration means.
Preferably, the inlet of the storage device is also connected to the outlet of the second filter device.
Preferably, the inlet of the storage device is also connected to the outlet of the third filtration device.
Preferably, the outlet of the storage means is connected to the first inlet of the reaction means.
Preferably, the outlet of the storage device is further connected with the water source inlet of the micro-nano bubble generation device.
The mixed filtrate at the outlet of the storage device is divided into two parts, one part is used as a water source of the micro-nano bubble generator, and the other part of the mixed solution is recycled to the reaction device to control the liquid level.
In a second aspect, the present invention provides a method for preparing calcium carbonate by using micro-nano bubbles, which is performed in the system apparatus for preparing calcium carbonate by using micro-nano bubbles according to the first aspect.
Preferably, the method comprises the steps of:
(1) containing CO2The air source generates in micro-nano bubblesMicro-nano bubbles are formed in the raw device, enter the reaction device and are mixed with the carbide slag to obtain mixed slurry, and carbonization reaction is carried out to obtain scum liquid on the upper part of the reaction device and reaction slurry in the middle of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first separation device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, and the light slurry enters a second separation device to carry out aging reaction and solid-liquid separation in sequence, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, and enabling the heavy slurry to enter a third separation device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid in the step (2) to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device.
The light slurry is introduced into a second separation device for aging reaction, and materials after the aging reaction are separated, so that calcium carbonate and a second separation solution are obtained.
According to the invention, the micro-nano bubbles are introduced into the reaction device to be mixed with the carbide slag and subjected to carbonization reaction, so that the micro-nano bubbles have small size, high internal pressure and high gas-liquid mass transfer rate, and are beneficial to gas dissolution. In the carbonization reaction, CO2Micro-nano bubbles are enlarged to accelerate CO2The mass transfer rate is favorable for accelerating the carbonization speed of the carbide slag. By regulating CO2The micro-nano bubbles can regulate and control the size of calcium carbonate crystal grains to obtain nano calcium carbonate, and a crystal form control agent is avoided. Through regulation and control carbonization process, can avoid heavy impurity granule such as ferrosilicon and aluminium silicon mineral in the calcium carbonate parcel carbide slag, recycle centrifugal device and carry out centrifugal separation to calcium carbonate granule and heavy impurity granule, realize the quick separation of impurity.
Set up agitating unit in the reaction unit and set up the injection part that has specific angle on the reaction unit casing, can realize mixing the thick liquid at the reaction unit internal rotation, be favorable to mixing the thick liquid fast dispersion and carrying out the carbonization reaction, also be favorable to the thick and thin coke particle flotation in the carbide slag at the liquid level upper strata simultaneously.
The invention utilizes micro-nano CO2The bubbles carbonize the carbide slag to generate calcium carbonate, so that calcium carbonate and impurities are prevented from being entrained mutually, and the generated nano calcium carbonate and impurity particles are centrifugally separated by using a centrifugal device, so that the purification of the nano calcium carbonate is realized, and a qualified nano calcium carbonate product is obtained.
Therefore, the micro-nano bubble technology and the centrifugal device are used in the process of preparing calcium carbonate from carbide slag, and the advantages are that: firstly, by regulating and controlling CO2The size of the calcium carbonate crystal grains can be regulated and controlled by the micro-nano bubbles, so that a crystal form control agent is avoided; secondly, by adding part of gas with low solubility into the micro-nano bubbles, bubbles with smaller size are formed after carbonization, which is beneficial to the flotation removal of fine coke particles; thirdly, the calcium carbonate particles and the heavy impurity particles are separated by using a centrifugal device, the separation speed is high, the treatment capacity is large, the product quality is improved, and the process cost is reduced.
Preferably, the calcium carbonate is nano calcium carbonate.
Preferably, the gas source of step (1) comprises CO2。
In the present invention, the gas source comprises CO2Can react with calcium hydroxide in the carbide slag quickly to generate calcium carbonate.
Preferably, the gas source further comprises a balance gas.
The balance gas is included in the gas source because the carbide slag contains a small amount of coke particles, and although the coke particles with larger particle size tend to float on the water surface, fine coke particles may be entrained inside the particles and are difficult to remove by physical means. By adding part of gas with low solubility (such as nitrogen, oxygen, hydrogen and the like) into the micro-nano bubbles, CO in the micro-nano bubbles is obtained2When the calcium hydroxide is dissolved into the liquid phase and reacts with calcium hydroxide in the carbide slag, carbide slag particles can be dissolved and crushed, and meanwhile, residual gas forms bubbles with smaller size, so that fine coke particles in the product can be removed by flotation, and the product quality is improved.
Preferably, step (1)The gas source also comprises CO with the solubility ratio in the mixed slurry2Small balance gas.
Preferably, the balance gas comprises any one of nitrogen, oxygen, hydrogen, ammonia, argon or helium or a combination of at least two of them, with typical but non-limiting combinations being: a combination of nitrogen and oxygen, a combination of hydrogen and ammonia, a combination of ammonia and argon, a combination of ammonia, argon and helium, and the like.
Preferably, the source of gas is CO2The concentration of (B) is 5 to 99wt%, and may be, for example, 5wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, 90wt%, or 99wt%, preferably 5 to 80 wt%.
Preferably, the pH of the mixed slurry is 5 to 8, and may be, for example, 5, 5.5, 6, 6.5, 7, 7.5, 8, or the like.
Preferably, the concentration of the carbide slag in the mixed slurry is 0.1 to 20wt%, and may be, for example, 0.1wt%, 1wt%, 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, or the like.
Preferably, the temperature of the carbonization reaction is 5 to 80 ℃, and may be, for example, 5 ℃, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃ or 80 ℃.
Preferably, the carbonization reaction is performed under stirring conditions.
Under the stirring condition, the slurry can be favorably and rapidly dispersed to carry out carbonization reaction.
Preferably, the stirring speed is 50-300 rpm, for example, 50rpm, 70rpm, 90rpm, 100rpm, 130rpm, 150rpm, 180rpm, 200rpm, 230rpm, 250rpm, 300rpm, or the like.
Preferably, the aging reaction of step (2) comprises standing carbonization.
The aging reaction can ensure that the calcium carbonate crystal is more complete and the particle size distribution is more uniform.
Preferably, the temperature of the aging reaction is 10 to 60 ℃, for example, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃ or 60 ℃.
Preferably, the aging reaction time is 5-20 h, for example, 5h, 8h, 10h, 12h, 14h, 16h, 18h or 20 h.
Preferably, the ratio of the flow rate of the mixed solution introduced into the micro-nano bubble generation device in the step (3) to the flow rate introduced into the reaction device is (1.5-8): 1, and may be, for example, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8: 1.
Preferably, the flow of the gas source in the micro-nano bubble generating device is 1-10% of the flow of the mixed solution introduced into the micro-nano bubble generating device, and may be, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or the like.
The flow rate in the present invention means a volume flow rate.
As a preferred technical scheme of the invention, the method comprises the following steps:
（1）CO2forming micro-nano bubbles in a micro-nano bubble generating device by using an air source with the concentration of 5-99 wt%, entering a reaction device, and mixing the micro-nano bubbles with carbide slag to obtain mixed slurry with the pH of 5-8, wherein the concentration of the carbide slag is 0.1-20 wt%, carrying out carbonization reaction at the temperature of 5-80 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 50-300 rpm to obtain scum liquid on the upper part of the reaction device and reaction slurry in the middle part of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first separation device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second separation device, and aging reaction for 5-20 hours at the temperature of 10-60 ℃ and solid-liquid separation are sequentially carried out on the light slurry, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, and enabling the heavy slurry to enter a third separation device to obtain third separation liquid and impurities;
(3) and (2) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, wherein the mixed liquid is introduced into the micro-nano bubble generating device and the reaction device, the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is (1.5-8): 1, and the flow of an air source in the micro-nano bubble generating device is 1-10% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the system device for preparing calcium carbonate by using micro-nano bubbles comprises a micro-nano bubble generating device and a reaction device which are connected, and also comprises a first separating device and a centrifugal device which are respectively connected with the reaction device, and a second separating device and a third separating device which are respectively connected with the centrifugal device, so that continuous operation and intermittent operation can be realized, and the system device has the advantages of simple operation and equipment, high carbonization speed, low cost and the like;
(2) according to the method for preparing calcium carbonate by using micro-nano bubbles, micro-nano bubbles are generated by using a micro-nano bubble generating device, enter a reaction device to be mixed with carbide slag for carbonization reaction, and then enter a centrifugal device for separation, so that calcium carbonate particles are obtained, the size of calcium carbonate crystal particles can be regulated and controlled by regulating and controlling the micro-nano bubbles, a crystal form control agent is avoided, the purity of the obtained calcium carbonate is more than or equal to 97wt%, and the average crystal particle size of the calcium carbonate is less than or equal to 97nm under the optimal condition;
(3) the method for preparing calcium carbonate by using the micro-nano bubbles provided by the invention adds part of CO with solubility ratio into the micro-nano bubbles2Small gas forms bubbles with smaller size after carbonization, which is beneficial to the flotation and removal of fine coke particles, and in the carbonization process, waste residue particles in the carbide slag float on the upper layer and are removed in real time;
(4) according to the method for preparing calcium carbonate by using the micro-nano bubbles, the calcium carbonate particles and the heavy impurity particles are separated by using the centrifugal device, the separation speed is high, the treatment capacity is large, the calcium carbonate is purified, the product quality is favorably improved, and the process cost is reduced.
Drawings
Fig. 1 is a schematic view of a system apparatus for preparing calcium carbonate by using micro-nano bubbles in embodiment 1 of the present invention.
FIG. 2 is a front view of the reaction apparatus of FIG. 1.
FIG. 3 is a top view of the reaction apparatus of FIG. 1.
Fig. 4 is a schematic view of a system apparatus for preparing calcium carbonate by using micro-nano bubbles in embodiment 6 of the present invention.
In the figure: 1-micro-nano bubble generating device; 2-a reaction device; 3-gas source inlet; 4-water source inlet; 5-a spray member; 6-a centrifugal device; 7-a first stirring device; 8-a first inlet; 9-a second inlet; 10-a first filtration device; 11-light weight pulp outlet; 12-heavy slurry outlet; 13-a second stirring device; 14-a third stirring device; 15-a second filtration device; 16-a third filtration device; 17-storage means.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.
Example 1
The embodiment provides a system device for preparing calcium carbonate by using micro-nano bubbles, as shown in fig. 1, the system device comprises a micro-nano bubble generating device 1 and a reaction device 2 which are connected with each other; the micro-nano bubble generating device 1 is provided with an air source inlet 3 and a water source inlet 4; a stirring device is arranged in a reaction device 2, 12 injection components 5 are uniformly distributed on the same horizontal plane of a shell, as shown in fig. 2, wherein the ratio of the distance between the injection component 5 and the bottom of the reaction device 2 to the height of the reaction device 2 is 1:4, the angle (beta) between the central line of the injection orifice of the injection component 5 and the corresponding diameter of the reaction device 2 is 45 degrees, the included angle (gamma) of any two adjacent injection components 5 on the same horizontal plane of the shell of the reaction device 2 is 30 degrees, as shown in fig. 3, and the outlet of a micro-nano bubble generating device 1 is connected with the injection component 5 of the reaction device 2;
the middle part of the reaction device 2 is provided with a first outlet which is connected with the inlet of the centrifugal device 6; a second outlet is formed in the top of the reaction device 2, the second outlet is connected with the first stirring device 7, and an outlet of the first stirring device 7 is connected with an inlet of the first filtering device 10; the reaction device 2 is also provided with a first inlet 8 and a second inlet 9;
the middle part of the top end of the centrifugal device 6 is provided with a light slurry outlet 11, the light slurry outlet 11 is connected with the inlet of a second stirring device 13, the number of the second stirring devices 13 is 2, and the outlet of the second stirring device 13 is connected with the inlet of a second filtering device 15; the side wall of the top end of the centrifugal device 6 is provided with a heavy slurry outlet 12, the heavy slurry outlet 12 is connected with the inlet of a third stirring device 14, and the outlet of the third stirring device 14 is connected with the inlet of a third filtering device 16;
the system device for preparing calcium carbonate by utilizing micro-nano bubbles further comprises a storage device 17, an inlet of the storage device 17 is connected with an outlet of the first filtering device 10, an outlet of the second filtering device 15 and an outlet of the third filtering device 16, and an outlet of the storage device 17 is connected with a first inlet 8 of the reaction device 2 and a water source inlet 4 of the micro-nano bubble generating device 1.
The embodiment also provides a method for preparing calcium carbonate by using the micro-nano bubbles, which comprises the following steps:
（1）CO2forming micro-nano bubbles with the size of 500 nanometers in a micro-nano bubble generating device by using an air source with the concentration of 40wt% (balance gas is nitrogen), entering a reaction device and mixing with carbide slag to obtain mixed slurry with the pH value of 6, wherein the concentration of the carbide slag is 5wt%, carrying out carbonization reaction at the temperature of 20 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 200rpm to obtain scum liquid at the upper part of the reaction device and reaction slurry in the middle part of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second stirring device for aging reaction at the temperature of 50 ℃ for 8 hours, and second filtration is carried out through a second filtration device, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 4:1, and the flow of an air source in the micro-nano bubble generating device is 5% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Example 2
The embodiment provides a system device for preparing calcium carbonate by using micro-nano bubbles, which comprises a micro-nano bubble generating device and a reaction device which are connected; the micro-nano bubble generating device is provided with an air source inlet and a water source inlet; a stirring device is arranged in the reaction device, 6 jetting parts are uniformly distributed on the same horizontal plane of the shell, the ratio of the distance between the jetting parts and the bottom of the reaction device to the height of the reaction device is 1:3, the angle between the central line of the jetting orifice of the jetting part and the corresponding diameter of the reaction device is 30 degrees, the included angle between any two adjacent jetting parts on the same horizontal plane of the shell of the reaction device is 60 degrees, and the outlet of the micro-nano bubble generating device is connected with the jetting parts of the reaction device;
the middle part of the reaction device is provided with a first outlet which is connected with the inlet of the centrifugal device; a second outlet is formed in the top of the reaction device, the second outlet is connected with the first stirring device, and the outlet of the first stirring device is connected with the inlet of the first filtering device; the reaction device is also provided with a first inlet and a second inlet;
the middle part of the top end of the centrifugal device is provided with a light slurry outlet, the light slurry outlet is connected with the inlet of a second stirring device, the number of the second stirring devices is 2, and the outlet of the second stirring device is connected with the inlet of a second filtering device; a heavy slurry outlet is formed in the side wall of the top end of the centrifugal device and connected with an inlet of a third stirring device, and an outlet of the third stirring device is connected with an inlet of a third filtering device;
the system device for preparing calcium carbonate by utilizing micro-nano bubbles further comprises a storage device, wherein an inlet of the storage device is connected with an outlet of the first filtering device, an outlet of the second filtering device and an outlet of the third filtering device, and an outlet of the storage device is connected with a first inlet of the reaction device and a water source inlet of the micro-nano bubble generating device.
The embodiment also provides a method for preparing calcium carbonate by using the micro-nano bubbles, which comprises the following steps:
（1）CO2forming micro-nano bubbles with the size of 100 nanometers in a micro-nano bubble generating device by using an air source with the concentration of 70wt% (balance gas is helium), entering a reaction device and mixing the micro-nano bubbles with carbide slag to obtain mixed slurry with the pH value of 7, wherein the concentration of the carbide slag is 10wt%, carrying out carbonization reaction at the temperature of 5 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 50rpm to obtain scum liquid at the upper part of the reaction device and reaction slurry in the middle part of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second stirring device for aging reaction at the temperature of 10 ℃ for 18 hours, and second filtration is carried out through a second filtration device, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 1.5:1, and the flow of an air source in the micro-nano bubble generating device is 1% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Example 3
The embodiment provides a system device for preparing calcium carbonate by using micro-nano bubbles, which comprises a micro-nano bubble generating device and a reaction device which are connected; the micro-nano bubble generating device is provided with an air source inlet and a water source inlet; a stirring device is arranged in the reaction device, 4 jetting parts are uniformly distributed on the same horizontal plane of the shell, the ratio of the distance between the jetting parts and the bottom of the reaction device to the height of the reaction device is 1:5, the angle between the central line of the jetting orifice of the jetting part and the corresponding diameter of the reaction device is 60 degrees, the included angle between any two adjacent jetting parts on the same horizontal plane of the shell of the reaction device is 90 degrees, and the outlet of the micro-nano bubble generating device is connected with the jetting parts of the reaction device;
the middle part of the reaction device is provided with a first outlet which is connected with the inlet of the centrifugal device; a second outlet is formed in the top of the reaction device, the second outlet is connected with the first stirring device, and the outlet of the first stirring device is connected with the inlet of the first filtering device; the reaction device is also provided with a first inlet and a second inlet;
the middle part of the top end of the centrifugal device is provided with a light slurry outlet, the light slurry outlet is connected with the inlet of a second stirring device, the number of the second stirring devices is 2, and the outlet of the second stirring device is connected with the inlet of a second filtering device; a heavy slurry outlet is formed in the side wall of the top end of the centrifugal device and connected with an inlet of a third stirring device, and an outlet of the third stirring device is connected with an inlet of a third filtering device;
the system device for preparing calcium carbonate by utilizing micro-nano bubbles further comprises a storage device, wherein an inlet of the storage device is connected with an outlet of the first filtering device, an outlet of the second filtering device and an outlet of the third filtering device, and an outlet of the storage device is connected with a first inlet of the reaction device and a water source inlet of the micro-nano bubble generating device.
The embodiment also provides a method for preparing calcium carbonate by using the micro-nano bubbles, which comprises the following steps:
（1）CO2a gas source with the concentration of 60wt% (balance gas is oxygen) forms a ruler in the micro-nano bubble generating deviceMicro-nano bubbles with the size of 100 microns enter a reaction device and are mixed with carbide slag to obtain mixed slurry with the pH value of 5, wherein the concentration of the carbide slag is 13wt%, carbonization reaction is carried out at the temperature of 40 ℃, the carbonization reaction is carried out under the stirring condition with the speed of 300rpm, and scum liquid at the upper part of the reaction device and reaction slurry in the middle part of the reaction device are obtained;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second stirring device for aging reaction at the temperature of 30 ℃ for 10 hours, and second filtration is carried out through a second filtration device, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 2:1, and the flow of an air source in the micro-nano bubble generating device is 10% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Example 4
The embodiment provides a method for preparing calcium carbonate by using micro-nano bubbles, which is performed in the system device for preparing calcium carbonate by using micro-nano bubbles provided in embodiment 1, and comprises the following steps:
（1）CO2forming micro-nano bubbles with the size of 50 microns in a micro-nano bubble generating device by using an air source with the concentration of 5wt% (balance gas is neon), entering a reaction device and mixing with carbide slag to obtain mixed slurry with the pH value of 8, wherein the concentration of the carbide slag is 0.1wt%, carrying out carbonization reaction at the temperature of 60 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 200rpm to obtain scum liquid and scum liquid on the upper part of the reaction deviceA reaction slurry in the middle of the reaction apparatus;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second stirring device for aging reaction at the temperature of 60 ℃ for 5 hours, and second filtration is carried out through a second filtration device, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid in the step (2) to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 8:1, and the flow of an air source in the micro-nano bubble generating device is 4% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
Example 5
The embodiment provides a method for preparing calcium carbonate by using micro-nano bubbles, which is performed in the system device for preparing calcium carbonate by using micro-nano bubbles provided in embodiment 1, and comprises the following steps:
（1）CO2forming micro-nano bubbles with the size of 5 microns in a micro-nano bubble generating device by using an air source with the concentration of 80wt% (balance gas is hydrogen), entering a reaction device, and mixing the micro-nano bubbles with carbide slag to obtain mixed slurry with the pH of 7.5, wherein the concentration of the carbide slag is 20wt%, carrying out carbonization reaction at the temperature of 80 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 200rpm to obtain scum liquid at the upper part of the reaction device and reaction slurry in the middle part of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry enters a second stirring device for aging reaction at the temperature of 20 ℃ for 20 hours, and second filtration is carried out through a second filtration device, so that second separation liquid and calcium carbonate are obtained; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 6:1, and the flow of an air source in the micro-nano bubble generating device is 5% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
The method for preparing calcium carbonate by using the micro-nano bubbles provided by the embodiments 1 to 5 is a continuous operation process.
Example 6
The present embodiment provides a system apparatus for preparing calcium carbonate using micro-nano bubbles, as shown in fig. 4, the system apparatus is different from embodiment 1 only in that an inlet of a storage device 17 is further connected to a light slurry outlet 11, and the rest is the same as embodiment 1.
The embodiment also provides a method for preparing calcium carbonate by using the micro-nano bubbles, which comprises the following steps:
（1）CO2forming micro-nano bubbles with the size of 5000 nanometers in a micro-nano bubble generating device by using an air source with the concentration of 40wt% (balance gas is nitrogen), entering a reaction device and mixing with carbide slag to obtain mixed slurry with the pH value of 6, wherein the concentration of the carbide slag is 5wt%, carrying out carbonization reaction at the temperature of 20 ℃, and carrying out the carbonization reaction under the stirring condition of the speed of 200rpm to obtain scum liquid at the upper part of the reaction device and reaction slurry in the middle part of the reaction device;
(2) allowing the scum liquid in the step (1) to enter a first stirring device, and performing first filtration by using a first filtering device to obtain first separated liquid and scum;
the reaction slurry obtained in the step (1) enters a centrifugal device, light slurry is obtained from a light slurry outlet of the centrifugal device, the light slurry is directly circulated and returned to the reaction device through a storage device to perform carbonization reaction at the temperature of 20 ℃ again, the carbonization reaction is performed under the stirring condition that the speed is 200rpm to obtain secondary reaction slurry in the middle of the reaction device, the secondary reaction slurry enters the centrifugal device to obtain secondary light slurry from a light slurry outlet of the centrifugal device, the secondary light slurry enters a second stirring device to perform aging reaction at the temperature of 50 ℃ for 8 hours, and secondary filtration is performed through a second filtration device to obtain second separation liquid and calcium carbonate; obtaining heavy slurry from a heavy slurry outlet of the centrifugal device, feeding the heavy slurry into a third stirring device, and performing third filtration through a third filtration device to obtain third separation liquid and impurities;
(3) and (3) enabling the first separation liquid, the second separation liquid and the third separation liquid to enter a storage device to obtain a mixed liquid, and introducing the mixed liquid into the micro-nano bubble generating device and the reaction device, wherein the ratio of the flow of the mixed liquid introduced into the micro-nano bubble generating device to the flow of the mixed liquid introduced into the reaction device is 4:1, and the flow of an air source in the micro-nano bubble generating device is 5% of the flow of the mixed liquid introduced into the micro-nano bubble generating device.
The method for preparing calcium carbonate by using micro-nano bubbles provided by the embodiment is an intermittent operation process.
Example 7
The embodiment provides a method for preparing calcium carbonate by using micro-nano bubbles, which is different from the embodiment 1 only in that a gas source does not comprise balance gas, and the rest is the same as the embodiment 1.
Example 8
This example provides a method for preparing calcium carbonate using micro-nano bubbles, which is different from example 1 only in that CO is contained in the gas source2The concentration was 3wt%, the equilibrium gas concentration was 97wt%, and the rest was the same as in example 1.
Example 9
This example provides a method for preparing calcium carbonate using micro-nano bubbles, which is different from example 1 only in that CO is contained in the gas source2The concentration was 85wt%, the equilibrium gas concentration was 15wt%, and the rest was the same as in example 1.
Comparative example 1
The present comparative example provides a method for preparing calcium carbonate using micro-nano bubbles, which is different from example 1 only in that the gas source enters the reaction device from the injection part on the reaction device shell in the bubbling manner in step (1), and the rest is the same as example 1.
In this comparative example, the gas source was formed to have a size of 2mm by bubbling.
Comparative example 2
The comparative example provides a method for preparing calcium carbonate by using micro-nano bubbles, and the method is different from the method in the example 1 only in that the reaction slurry in the middle of the reaction device in the step (2) directly enters a second stirring device for aging reaction without passing through a centrifugal device, and the rest is the same as the method in the example 1.
Comparative example 3
The comparative example provides a method for preparing calcium carbonate by using micro-nano bubbles, which is different from the method in example 1 in that a gas source in the step (1) enters a reaction device from a spraying part on a shell of the reaction device in a bubbling mode, reaction slurry in the middle of the reaction device in the step (2) directly enters a second stirring device for aging reaction without passing through a centrifugal device, and the rest is the same as that in example 1.
In this comparative example, the gas source was formed to have a size of 2mm by bubbling.
Comparative example 4
The comparative example provides a method for preparing calcium carbonate by using micro-nano bubbles, and the method is different from the method in the example 1 only in that a gas source is 100wt% of nitrogen, and the rest is the same as the method in the example 1.
No CO in this comparative example2The carbonization reaction does not proceed, and calcium carbonate is not produced, but calcium carbonate is present in the carbide slag in a very small amount.
Method for testing the purity of calcium carbonate: ethanol was added to wet the sample and the assay was performed according to 3.4 of GB/T19281-2003.
Method for testing the average grain size of calcium carbonate: the assay was performed according to 6.4 of GB/T19590-2011.
The test results of the above examples and comparative examples are shown in table 1.
TABLE 1
Purity of calcium carbonate (wt%)
Average grain size (nm) of calcium carbonate
Example 1
98
42
Example 2
99
60
Example 3
97
49
Example 4
99
73
Example 5
98
97
Example 6
98
87
Example 7
95
652
Example 8
96
127
Example 9
96
99
Comparative example 1
96
634
Comparative example 2
94
135
Comparative example 3
94
754
Comparative example 4
2
6839
From table 1, several points can be seen:
(1) the invention provides a system device and a method for preparing calcium carbonate by using micro-nano bubbles, wherein the system device comprises a micro-nano bubble generating device and a reaction device which are connected, a first separating device and a centrifugal device which are respectively connected with the reaction device, and a second separating device and a third separating device which are connected with the centrifugal device, the method for preparing calcium carbonate by using micro-nano bubbles in the system device comprises the steps of generating micro-nano bubbles by using the micro-nano bubble generating device, mixing the micro-nano bubbles with carbide slag to perform carbonization reaction, and separating the mixture by using the centrifugal device to obtain calcium carbonate particles, controlling the grain size of the calcium carbonate by using the micro-nano bubble carbonized carbide slag, improving the purity of the calcium carbonate, specifically, under the optimal condition, the purity of the calcium carbonate in examples 1-6 is more than or equal to 97wt%, the average grain size of the calcium carbonate is less than or equal to 97 nm;
(2) by combining example 1 and example 7, it can be seen that the gas source in example 1 comprises an equilibrium gas, and compared to example 7 in which the gas source does not comprise an equilibrium gas, the purity of the calcium carbonate obtained in example 1 is 98wt%, and the average grain size of the calcium carbonate is 42nm, while the purity of the calcium carbonate obtained in example 7 is 95wt%, and the average grain size of the calcium carbonate is 652nm, thus indicating that the present invention can further increase the purity of the calcium carbonate and reduce the average grain size of the calcium carbonate by including the equilibrium gas in the composition of the gas source;
(3) by combining the embodiment 1 and the embodiments 8 to 9, the CO in the gas source in the embodiment 1 can be known2The concentration was 40wt%, compared to CO in the gas source of examples 8-92The purity of the calcium carbonate obtained in example 1 was 98wt% and the average grain size of the calcium carbonate was 42nm for concentrations of 3wt% and 85wt%, respectively, whereas the purity of the calcium carbonate obtained in examples 8 to 9 was 96wt% and the average grain size of the calcium carbonate was 127nm and 99nm, respectively, thus indicating that the present invention provides CO in the gas source2The concentration is controlled within a certain range, so that the purity of the calcium carbonate can be further improved, and the average grain size of the calcium carbonate is reduced;
(4) as can be seen by combining the embodiment 1 and the comparative example 1, the air source in the embodiment 1 forms micro-nano bubbles in the micro-nano bubble generating device, and compared with the case that the air source in the comparative example 1 enters the reaction device from the injection part on the reaction device shell in a bubbling manner, the purity of the calcium carbonate obtained in the embodiment 1 is 98wt%, the average grain size of the calcium carbonate is 42nm, and the purity of the calcium carbonate obtained in the comparative example 1 is 96wt%, and the average grain size of the calcium carbonate is 634nm, so that the micro-nano bubbles formed in the micro-nano bubble generating device by using the air source can improve the purity of the calcium carbonate and reduce the average grain size of the calcium carbonate;
(5) it can be seen from the combination of example 1 and comparative example 2 that, the reaction slurry in the middle of the reaction apparatus in example 1 passes through the centrifugal apparatus and then enters the second stirring apparatus for aging reaction, compared with the reaction slurry in the middle of the reaction apparatus in comparative example 2 which directly enters the second stirring apparatus for aging reaction without passing through the centrifugal apparatus, the purity of the calcium carbonate obtained in example 1 is 98wt%, the average grain size of the calcium carbonate is 42nm, while the purity of the calcium carbonate obtained in comparative example 2 is 94wt%, and the average grain size of the calcium carbonate is 135nm, which shows that the aging reaction of the reaction slurry in the middle of the reaction apparatus after passing through the centrifugal apparatus in the invention can improve the purity of the calcium carbonate and reduce the average grain size of the calcium carbonate;
(6) as can be seen from the combination of the embodiment 1 and the comparative example 3, the air source in the embodiment 1 forms micro-nano bubbles in the micro-nano bubble generating device, and the reaction slurry in the middle of the reaction device enters the second stirring device for aging reaction after passing through the centrifugal device, compared with the comparative example 3 in which the air source enters the reaction device from the injection component on the shell of the reaction device in a bubbling manner, and the reaction slurry in the middle of the reaction device does not pass through the centrifugal device and directly enters the second stirring device for aging reaction, the purity of the calcium carbonate obtained in the embodiment 1 is 98wt%, the average grain size of the calcium carbonate is 42nm, the purity of the calcium carbonate obtained in the comparative example 3 is 94wt%, and the average grain size of the calcium carbonate is 754nm, further indicating that the air source forms micro-nano bubbles in the micro-nano bubble generating device, and the reaction slurry in the middle of the reaction device enters the second stirring device for aging reaction after passing through the, can improve the purity of the calcium carbonate and reduce the average grain size of the calcium carbonate.
In summary, the present invention provides a system device and a method for preparing calcium carbonate by using micro-nano bubbles, wherein the system device comprises a micro-nano bubble generating device and a reaction device which are connected, and further comprises a first stirring device and a centrifugal device which are respectively connected with the reaction device, the method for preparing calcium carbonate by using micro-nano bubbles in the system device comprises that micro-nano bubbles are generated by using the micro-nano bubble generating device, enter the reaction device to be mixed with carbide slag for carbonization reaction, and then enter the centrifugal device for separation, so as to obtain calcium carbonate particles, the crystal grain size of calcium carbonate is controlled by using the micro-nano bubble carbonized carbide slag, and the purity of calcium carbonate is improved, under an optimal condition, the purity of calcium carbonate is not less than 97wt%, and the average crystal grain size of calcium carbonate is not more than 97 nm.
The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
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