CN110627100A - Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase - Google Patents
Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase Download PDFInfo
- Publication number
- CN110627100A CN110627100A CN201910849885.5A CN201910849885A CN110627100A CN 110627100 A CN110627100 A CN 110627100A CN 201910849885 A CN201910849885 A CN 201910849885A CN 110627100 A CN110627100 A CN 110627100A
- Authority
- CN
- China
- Prior art keywords
- reactor
- calcium carbonate
- stage
- micron
- sized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/19—Oil-absorption capacity, e.g. DBP values
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention relates to a production method of micron-sized calcium carbonate, in particular to a two-stage series method for producing micron-sized calcium carbonate by a carbonization method with a liquid phase as a continuous phase. The system comprises two reactors connected in series, wherein solid suspension of each reactor is fed and discharged continuously, calcium hydroxide raw material is fed continuously from the first reactor, calcium carbonate precipitation suspension is discharged from the second reactor, carbonic acid gas raw material is continuously supplied to the first reactor and the second reactor respectively, the second reactor consists of two reactors operated alternately, and one second reactor receives the effluent of the first reactor to carry out carbonization operation; the other secondary reactor performs the operations of degassing and discharging the calcium carbonate suspension, the operating conditions of each secondary reactor are adjusted and controlled according to the technical indexes of crystal form, morphology and particle size of the target micron-sized calcium carbonate product, and the operating conditions comprise average retention time tau, operating temperature T, calcium hydroxide feeding concentration C0And the supply amount of carbon dioxide Q, Q having molCO unit2/min。
Description
Technical Field
The invention relates to a production method of micron-sized calcium carbonate, in particular to a two-stage series method for producing micron-sized calcium carbonate by a carbonization method with a liquid phase as a continuous phase.
Background
The precipitated calcium carbonate is also called light calcium carbonate, and the industrial production method mainly adopts a carbonization method using calcium hydroxide lime milk and carbon dioxide as raw materials. The production processes that are now industrialized can be divided into the following categories: batch processes, semi-continuous processes and continuous processes. In the prior art, a batch process is mostly adopted, namely, a calcium hydroxide emulsion raw material is filled into a reactor, then carbon dioxide gas is introduced, the carbonation reaction degree in the reactor is changed from 0% to 100% along with the change of time, and discharging is carried out after the carbonation reaction is finished, and then the charging and the carbonation in the next batch are carried out. The main feature of the so-called semi-continuous production process is that a specified total amount of calcium hydroxide raw material is gradually added in portions in a reactor until the addition of all calcium hydroxide is completed, and after the completion of the carbonization reaction, the product is discharged from the reactor to prepare for the next round. Such a semi-continuous process is described in publication No. CN103717681A, entitled: a method for manufacturing precipitated calcium carbonate, precipitated calcium carbonate and its use, and chinese patent publication No. CN1429772, a method for manufacturing calcium carbonate having a specific form, which is a method for circulating slurry after carbonization together with raw materials through the outside of a reactor in a semi-continuous process, and has a reaction and a circulation service tank. The prior art is a continuous carbonization Process in which a plurality of towers are connected in series and the gas phase is a continuous phase, which is proposed earlier by Baishi corporation and used for industrial production, for example, U.S. Pat. No. 4,4124688, which is used for preparing cubic precipitated calcium carbonate (Process for preparing cubic crystals of calcium carbonate) of 0.1 to 1 micron.
Continuous carbonization processes and methods using a liquid phase as a continuous phase are rarely reported, and the main difficulty may be that a lime milk raw material is easily wrapped by a calcium carbonate product due to a large amount of solid calcium hydroxide particles, and an unreacted raw material is mixed into the product calcium carbonate due to the liquid phase continuous method under the condition of incomplete carbonization, so that the free alkali content of the product is higher. For example, chinese patent publication No. CN102482111A, entitled process for producing calcium carbonate, proposes a process flow in which a first carbonization unit (two or more) can be connected in series or in parallel in a continuous or batch process, and in series with a second unit, the process is limited to lower calcium hydroxide feed concentrations, and the first unit employs a high pressure tubular reactor, and the example products only show particle size and electron micrographs. Chinese patent publication No. CN107032381A, entitled stirring type continuous carbonization apparatus and calcium carbonate particle synthesis method, proposes a stirring type continuous carbonization apparatus and calcium carbonate particle synthesis method, and the examples do not give clear product performance.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a two-stage series connection method for producing micron-sized calcium carbonate by a carbonization method with a continuous liquid phase, and calcium carbonate products with various shapes produced by the method.
The invention relates to a two-stage series method for producing micron-sized calcium carbonate by a carbonization method with a continuous liquid phase, which comprises two-stage series reactors, wherein solid suspension of each stage reactor is continuously fed and discharged, calcium carbonate precipitation suspension is discharged from the second stage reactor, carbonic acid gas raw materials containing carbon dioxide are respectively and continuously supplied to the first stage reactor and the second stage reactor, the second stage reactor consists of two reactors operated alternately, and one reactor receives the effluent of the first stage reactor to carry out carbonization operation; the other reactor performs the operations of degassing and discharging the calcium carbonate suspension.
In the two-stage series reactor of the invention, calcium hydroxide raw material is continuously fed from the first-stage reactor;
in the present invention, the operating conditions of the reactors of each stage include the average residence time T, the operating temperature T, and the calcium hydroxide feed concentration C0And the supply amount Q (molCO) of carbon dioxide2Min), adjusting and controlling according to technical indexes such as crystal form, appearance, particle size and the like of the target micron-sized calcium carbonate product.
The volume concentration of carbon dioxide in the carbonic acid gas can be 25-100V%, the kiln gas collected by lime calcination is usually adopted, and the volume concentration of carbon dioxide is 25-48V%.
The technological process of the two-stage series reactor of the invention is shown in figure 1. Wherein, 1 is calcium hydroxide emulsion raw material, 2 is carbonic acid gas raw material, and 3 is precipitated calcium carbonate suspension.
In the present invention, the form of the reactor is not particularly limited, and a carbonization reactor such as a stirred carbonization reactor, a bubble column, or a circulating jet carbonization reactor can be used. In order to adapt to continuous operation, the common feature is that, in addition to the secondary reactor, the upper part of the primary reactor is provided with an overflow port for overflowing the material from the primary reactor and smoothly introducing it into the next secondary reactor, the supply point of the calcium hydroxide raw material is set in the region where the mixing intensity is the greatest, and the supply of carbon dioxide is usually passed into the reactor from the bottom of the reactor.
The term of the invention: the operation volume refers to the total volume of the liquid phase and the gas phase below the overflow port of the reaction kettle.
In the invention, the method for producing micron-sized spindle-shaped precipitated calcium carbonate by two-stage series connection has an operation volume V1The operating conditions of the first reactor (in liters, the same applies hereinafter) were: tau is1＝20～60min，T1＝55～70℃，C0＝0.6～2.0mol/L，Q10.4 to 1.0, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a Operating volume V2The two secondary reactors A and B are operated alternately under the following operating conditions: v2≤V1，T2＝58～75℃，Q2/V20.02-0.04 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1min。
Obtaining spindle-shaped micron-sized calcium carbonate products, the weight average particle diameter D of the particles50The content of free calcium oxide is less than 0.05 wt% in the range of 1-6 μm. The free base is calculated as CaO (same below).
In the invention, the two-stage series production method of micron-sized cubic precipitated calcium carbonate has an operation volume of V1The operating conditions of the first reactor of (2) are: tau is1＝25～60min，T1＝35～70℃，C0＝0.4～1.2mol/l，Q11.1 to 1.5, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a Operating volume V2The two secondary reactors A and B are operated alternately under the following operating conditions: v2≤V1，T2＝35～70℃，Q/V20.01-0.03 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1min。
Obtaining a micron-sized cubic calcium carbonate product having a weight average particle diameter D501.1-4.5 μm, D97 is less than or equal to 9 μm, and the content of free calcium oxide is 0.05%.
In the invention, the method for producing the micron-sized aragonite crystal form precipitated calcium carbonate by two-stage series connection has an operation volume of V1The operating conditions of the first reactor of (2) are: tau is1＝25～60min，T1＝45～70℃，C0＝0.4～1.6mol/1，Q11.1 to 3.4, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a Operating volume V2The operating conditions of the two secondary reactors of (a) are: v2≤V1，T2＝45～70℃，Q/V20.01-0.03 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1min。
The precipitated calcium carbonate containing columnar aragonite crystal forms is obtained, the aragonite crystal form content of the product is more than 55 wt%, and the rest is cubic calcium carbonate with calcite crystal forms, and the content of free calcium oxide is less than 0.05 wt%.
The invention has the beneficial effects that:
compared with the existing intermittent carbonization, the method saves the feeding and discharging time, has large capacity per unit equipment volume, and has the characteristics of low equipment investment and small occupied area of the device.
The method adopts the technical scheme of two-stage series continuous carbonization, does not need to add crystal form auxiliary agents, can produce micron-sized calcium carbonate products with various shapes, has controllable and stable product quality, and is suitable for producing high-quality precipitated calcium carbonate products.
Drawings
FIG. 1 is a two-stage series process flow diagram, wherein 1, 2 and 3 represent a calcium hydroxide emulsion raw material, a carbonic acid gas raw material and a calcium carbonate suspension, respectively.
FIG. 2 SEM photograph of calcium carbonate product obtained in example 1, with scale of 80 μm.
FIG. 3 SEM partial magnification of calcium carbonate product obtained in example 1, 3 μm scale.
FIG. 4 SEM photograph of calcium carbonate product obtained in example 2, with scale of 80 μm.
FIG. 5 SEM, 8 μm scale, of a partial magnification of the calcium carbonate product obtained in example 2.
FIG. 6 SEM photograph of calcium carbonate product obtained in example 3, with scale of 80 μm.
FIG. 7 is a partially enlarged SEM photograph of the calcium carbonate product obtained in example 3, with a 2 μm scale.
FIG. 8 the XRD pattern of the calcium carbonate product obtained in example 3 is plotted on the abscissa 2. theta. and on the ordinate the intensity.
FIG. 9 SEM photograph of calcium carbonate product obtained in example 4, with scale 3 μm.
FIG. 10 the XRD pattern of the calcium carbonate product obtained in example 4 is shown on the abscissa of 2 theta and on the ordinate of intensity.
FIG. 11 SEM photograph of calcium carbonate product obtained in example 5, with scale of 1 μm.
FIG. 12 an XRD pattern of the calcium carbonate product obtained in example 5 is shown on the abscissa of 2 theta and on the ordinate of intensity.
FIG. 13 SEM photograph of calcium carbonate product obtained in example 6, with 2 μm scale.
FIG. 14 XRD pattern of calcium carbonate product obtained in example 6, with 2 theta on the abscissa and intensity on the ordinate.
FIG. 15 SEM photograph of calcium carbonate product obtained in example 7, with scale of 1 μm.
FIG. 16 an XRD pattern of the calcium carbonate product obtained in example 7 is shown on the abscissa of 2 theta and on the ordinate of intensity.
FIG. 17 SEM photograph of calcium carbonate product obtained in example 8, with scale of 5 μm.
FIG. 18 laser particle size distribution of calcium carbonate product obtained in example 8.
FIG. 19 SEM photograph of calcium carbonate product obtained in example 9, with 8 μm scale.
FIG. 20 laser particle size distribution of the calcium carbonate product obtained in example 9.
FIG. 21 SEM photograph of calcium carbonate product obtained in example 10, with 20 μm scale.
FIG. 22 laser particle size distribution of calcium carbonate product from example 10.
FIG. 23 SEM photograph of calcium carbonate product obtained in example 11, with scale of 5 μm.
FIG. 24 SEM photograph of calcium carbonate product obtained in example 12, with 8 μm scale.
FIG. 25 SEM photograph of calcium carbonate product obtained in example 13, with scale of 5 μm.
FIG. 26 SEM photograph of the calcium carbonate product obtained in example 14, with 20 μm scale.
FIG. 27 SEM photograph of calcium carbonate product obtained in example 14, with 2 μm scale.
FIG. 28 SEM photograph of the ground calcium carbonate product obtained in example 14, with 3 μm scale.
Detailed Description
The technical solution of the present invention is further specifically explained by the specific embodiments with reference to the drawings.
Test method of specific surface area of calcium carbonate in suspension: taking 50-100ml of suspension, carrying out suction filtration by using qualitative filter paper to obtain a filter cake, adding 15ml of ethanol to the filter cake for infiltration, carrying out suction drying, carrying out vacuum drying on the filter cake for 8 hours at 60 ℃ to obtain dry powder, weighing 0.2-0.5 g of the dry powder, filling the dry powder into a quartz sample tube, measuring the nitrogen adsorption capacity by using a JW-BK400 type specific surface area and pore size analyzer (Beijing Jingwei Gaobaokou technology Co., Ltd.), and calculating the specific surface area BET (of the calcium carbonate product) ((of the formulam2/g)。
The calcium carbonate particle morphology scanning electron microscope test method comprises the following steps: the powder sample prepared by the specific surface area test is subjected to powder spraying on a monocrystalline silicon substrate, and low-temperature plasma gold spraying is carried out for 50 seconds to prepare a scanning electron microscope sample, and a PHENOM PRO (the company PHENOM-World, the Netherlands) is used for observing and photographing under different magnifications to obtain an SEM picture.
The product crystal form analysis method comprises the following steps: according to the method, a dry powder sample is continuously scanned by an X-ray diffractometer (a Japanese physical motor) and X-ray (40kV/100mA), the scanning range (2 theta) is 10-80 degrees, an XRD (X-ray diffraction) pattern is obtained, and whether an aragonite crystal form exists or not is determined according to the pattern. According to peak area integrals of strongest characteristic spectrum peaks of calcite and aragonite crystal form calcium carbonate in the map data, the weight percentage ratio Xc of calcite crystal form calcium carbonate in the product is calculated according to the following formula:
in the formula, Fc and Fa are peak area integral values corresponding to strongest characteristic peaks of calcite and aragonite on an XRD spectrum of a sample respectively.
Example 1
Three stirred carbonation reaction kettles with an operation volume of 3.0L are connected according to the flow of the attached figure 1, and the operation is as follows: the concentration of the calcium hydroxide emulsion is 0.80mol/L, the calcium hydroxide emulsion is continuously supplied by a peristaltic pump, the supply speed is set to be 100.0ml/min, the temperature is 38.2-38.4 ℃, and the calcium hydroxide emulsion is introduced into the position of the same level of a stirring blade of the reactor through a conduit; introducing carbonic acid gas into the first-stage reaction kettle from the bottom of the reactor, wherein the flow rate is 9.0L/min, the volume content of carbon dioxide in the calcium carbonate gas is 65V%, and the balance is air; the stirring speed of the reaction kettle is 1200rpm, and the temperature in the first-stage reaction kettle is 44.9-45.2 ℃.
Feeding the material overflowing from the first-stage reactor into a second-stage stirring reactor A, starting stirring after the material is fed to the liquid level of about 1L, and introducing the carbonic acid gas with the same concentration, wherein the flow rate of the carbonic acid gas is 4.0L/min; after 23 minutes (from the beginning of feeding, the same below), the operation volume of 3.0L was reached, the feeding three-way valve was switched to the second-stage stirred reactor B, the reactor B started feeding, and the reactor B was operated according to the same procedure as the reactor a; and (3) continuously introducing air into the reactor A until the pH value is reduced to 6.5, introducing the air for 4min, measuring the temperature in the reactor A to be 45.4-45.7 ℃, stopping introducing the air, discharging the material from the bottom of the reactor after 2min, and taking 58min after the three-way valve is switched to discharge the material, wherein the reactor A is ready for the next round of operation.
From the row material sample of second grade reation kettle A and B, use EDTA complex method analysis titration total calcium ion concentration, when total calcium ion concentration relative deviation is less than 2% in two batches of row materials, can judge that continuous operation system has reached stable operating condition, later from row material sample of second grade stirred tank reactor A, suction filtration, dry in 105 ℃ drying cabinet to the moisture content is less than 0.2 wt%, be used for the test and the analysis.
The SEM pictures showed that the product was in an agglomerated state (fig. 2), with agglomerates up to 23 microns. The magnified SEM showed (fig. 3) that the agglomerates consisted of a small number of 1.5 micron scalene triangles, a large number of prisms with sides 100 nm long by 1 micron, and a large number of 70-100 nm cuboidal particles.
BET of the product powder was 3.39m2(ii)/g, DOP oil absorption value of 36.6g/100g, free base content of 0.044 wt%.
Example 2
The same procedure and operating conditions as in example 1 were used except that the temperature of the calcium hydroxide raw material was changed to 55 deg.C, the operating temperature in the primary reactor was 65.1 deg.C-65.7 deg.C, and the operating temperature in the secondary reactor was 65.4 deg.C-66.1 deg.C.
After stable operation conditions are achieved, sampling and analyzing the obtained product, wherein the appearance of the product is hedgehog spherical aggregate, as shown in figure 4, and the maximum diameter of the aggregate reaches 24 micrometers. The magnified SEM photograph shows (fig. 5) that the agglomerates are composed of a large number of prisms with side lengths of about 100 nm and an aspect ratio of greater than 10 and a small number of nanoscale cubes.
BET5.06m of product powder2(ii) oil absorption of 52.80g DOP/00g, free base content of 0.048 wt%.
Example 3
The same method and operation conditions as in example 1, except that the concentration, temperature and feed rate of the calcium hydroxide raw material were changed to 1.2mol/L, the feed temperature was 48.3 ℃ and the feed flow rate was changed to 66.7 mL/min; the temperature in the first-stage reactor is raised to 60.5-60.9 ℃, and the temperature in the second-stage reactor is 61.2-61.9 ℃.
After stable operating conditions were achieved, the product was sampled and analyzed and its morphology was hedgehog spherical aggregates, see fig. 6, with a maximum aggregate diameter of 22 microns. The magnified SEM image (FIG. 7) shows that the agglomerates are composed of a large number of prisms with side lengths of 100-200 nm and a length of about 1 micron and a small number of nanoscale cubes.
The XRD pattern of the powder sample is shown in figure 8. The first characteristic peak of aragonite appeared at 26.16, 2 θ, and the peak area integral of the first characteristic peak of calcite at 29.38, calculated as the ratio of calcite crystalline phases Xc was 27.36%, indicating that there was about 72.64% aragonite crystalline phase calcium carbonate in the calcium carbonate sample. In connection with the SEM photograph (fig. 8), it can be seen that a large amount of prismatic crystals in the agglomerate structure are aragonitic calcium carbonate, and the remaining cubic calcium carbonate should be calcitic crystalline phase calcium carbonate.
BET4.08m of product powder2(iv)/g, oil absorption of 43.22gDOP/00g, free base content of 0.046 wt%.
Example 4
The same procedure and operation conditions as in example 3, except that the feed temperature of the calcium hydroxide raw material was changed to 45.4 ℃, and the measured temperature of the material in the primary reactor was 59.8 to 60.5 ℃, and the temperature in the secondary reactor was 60.1 to 60.7 ℃.
After reaching stable operation conditions, the product was sampled and analyzed, the shape of the product was mostly rod-like, and a small amount thereof was cube-like and platelet-triangular, see fig. 9, and the length of the rod-like was not more than 1 μm.
The XRD pattern of the powder sample is shown in figure 10. The first characteristic peak of aragonite appeared at 26.16, 2 θ, and the peak area integral of the first characteristic peak of calcite at 29.38, calculated as the ratio of calcite crystalline phases Xc was 20.74%, indicating that the calcium carbonate sample had approximately 79.26% aragonite crystalline phase calcium carbonate. In the SEM photograph (FIG. 9), it can be seen that the rod-like or columnar crystals are aragonitic calcium carbonate, and the balance is calcitic crystalline phase calcium carbonate.
BET5.19m of product powder2(iv)/g, oil absorption of 48.40gDOP/00g, free base content of 0.047 wt%.
Example 5
The same method and operation conditions as in example 4, except that the concentration, temperature and feed rate of the calcium hydroxide raw material were changed to 1.6mol/L, the raw material temperature was changed to 53 ℃ and the feed flow rate was changed to 50.0 mL/min; the temperature in the first stage reactor is measured to be 66.9-67.5 ℃, and the temperature in the second stage reactor is measured to be 67.4-68.6 ℃.
After reaching the stable operation condition, the product was sampled and analyzed, the shape of the product was mostly rod-like, and a small amount was cube-like and plate-like triangle-like, see fig. 11, and the length of the rod-like was less than 1.2 μm.
The XRD pattern of the powder sample is shown in figure 12. The first characteristic peak of aragonite appeared at 26.16, 2 θ, and the peak area integral of the first characteristic peak of calcite at 29.38, calculated as the ratio of calcite crystalline phases Xc was 16.15%, indicating that the calcium carbonate sample had about 83.85% aragonite crystalline phase calcium carbonate. In the SEM photograph (FIG. 11), it can be seen that the rod-like or columnar crystals are aragonitic calcium carbonate, and the remainder is calcitic crystalline calcium carbonate.
BET5.19m of product powder2(iv)/g, oil absorption of 49.20gDOP/00g, free base content of 0.049 wt%.
Example 6
The same procedure and operating conditions as in example 5, except that the temperature of the calcium hydroxide raw material was changed to 48.5 ℃; the temperature in the first-stage reactor is measured to be 60.9-61.5 ℃, and the temperature in the second-stage reactor is measured to be 61.3-61.8 ℃.
After reaching the stable operation condition, the product was sampled and analyzed, the shape of the product was mostly rod-like, and the rest was cube-like and sheet-like triangle, see fig. 13, the length of the rod-like was less than 1.2 μm.
The XRD pattern of the powder sample is shown in figure 14. The first characteristic peak of aragonite appeared at 26.16, 2 θ, and the peak area integral of the first characteristic peak of calcite at 29.38, calculated as the ratio of calcite crystalline phases Xc was 43.39%, indicating that the calcium carbonate sample had about 56.61% aragonite crystalline phase calcium carbonate. In the SEM photograph (FIG. 13), it can be seen that the rod-like or columnar crystals are aragonitic calcium carbonate, and the remainder is calcitic crystalline calcium carbonate.
BET3.87m of product powder2(ii) oil absorption of 55.80g DOP/00g, free base content of 0.046 wt%.
Example 7
The same procedure and operating conditions as in example 5, except that the temperature of the calcium hydroxide raw material was changed to 43.4 ℃; the temperature in the first-stage reactor is 57.2-57.8 ℃, and the temperature in the second-stage reactor is 57.5-57.9 ℃.
After stable operating conditions were reached, the product was sampled and analyzed, the morphology of which was mostly rod-shaped, the remainder being cuboidal and platelet-triangular, see fig. 15, the length of the rod being less than 1.3 microns.
The XRD pattern of the powder sample is shown in figure 16. The first characteristic peak of aragonite appeared at 26.16, 2 θ, and the peak area integral of the first characteristic peak of calcite at 29.38, calculated as the ratio of calcite crystalline phases Xc was 28.74%, indicating that there was about 71.24% aragonite crystalline phase calcium carbonate in the calcium carbonate sample. In the SEM photograph (FIG. 15), it can be seen that the rod-like or columnar crystals are aragonitic calcium carbonate, and the remainder is calcitic crystalline calcium carbonate.
BET4.12m of the product powder2(ii) an oil absorption value of 48.20gDOP/00g, and a free base content of 0.038 wt%.
Example 8
The same procedure and operating conditions as in example 1 were used except that the temperature of the calcium hydroxide raw material was changed to 41 deg.C, the gas flow rate was changed to 5L/min, and the carbon dioxide content in the gas was 40V%. The operation temperature in the first-stage reactor is measured to be 55.1-55.6 ℃, and the operation temperature in the second-stage reactor is measured to be 55.6-55.8 ℃.
After stable operating conditions were achieved, the product was sampled and analyzed, and the morphology was mostly cubic and slightly triangular, see fig. 17.
The laser particle size distribution is shown in figure 18, D50.425μm，D502.685μm，D978.556μm。
BET3.21m of the product powder2The oil absorption value is 40.80gDOP/00g, and the free alkali content is 0.031 wt%.
Example 9
The same procedure and operating conditions as in example 8 were used, except that the concentration of the calcium hydroxide raw material was changed to 0.40 mol/L. The operation temperature in the first-stage reactor is measured to be 55.0-55.3 ℃, and the operation temperature in the second-stage reactor is measured to be 55.4-55.6 ℃.
After stable operating conditions were achieved, the product was sampled and analyzed, and the morphology was mostly cubic and slightly triangular, see fig. 19.
The laser particle size distribution is shown in figure 20, D50.419μm，D501.963μm，D975.551μm。
BET4.66m of the product powder2(iv)/g, oil absorption of 40.51gDOP/00g, free base content of 0.039 wt%.
Example 10
The same procedure and operating conditions as in example 4 were used except that the temperature of the calcium hydroxide raw material was changed to 50.5 and the gas flow rate was changed to 6L/min. The operation temperature in the first-stage reactor is measured to be 66.0-66.3 ℃, and the operation temperature in the second-stage reactor is measured to be 66.3-66.6 ℃.
After stable operating conditions were achieved, the product was sampled and analyzed, and the morphology was mostly cubic and slightly triangular, see fig. 21.
The laser particle size distribution is shown in figure 22, D50.808μm，D501.933μm，D975.238μm。
BET3.51m of the product powder2(ii) an oil absorption value of 40.32g DOP/00g and a free base content of 0.037 wt%.
Example 11
Three stirred carbonation reaction vessels with an operation volume of 3.0L were connected according to the flow of FIG. 1 and operated as follows. The concentration of the calcium hydroxide emulsion is 1.80mol/L, the calcium hydroxide emulsion is continuously supplied by a peristaltic pump, the supply speed is set to be 100.0ml/min, the temperature is 56.0-56.1 ℃, and the calcium hydroxide emulsion is introduced to the position of the same level of a stirring blade of the reactor through a conduit; introducing carbonic acid gas into the first-stage stirring type reaction kettle from the bottom of the reactor, wherein the flow rate is 5.0L/min, the volume content of carbon dioxide in the calcium carbonate gas is 40V%, and the balance is air; the stirring speed of the reactor is 1200rpm, and the temperature in the first-stage reaction kettle after the steady state is 65.2-65.4 ℃.
Feeding the material overflowing from the first-stage reaction kettle into a second-stage stirring reaction kettle A, starting stirring (1200rpm) after the material is fed to the liquid level of about 1L, and introducing the carbonic acid gas with the same concentration, wherein the flow rate of the carbonic acid gas is 4.0L/min; after 23 minutes (from the beginning of feeding, the same applies below), the operation volume of 3.0L is reached, the feeding three-way valve is switched to the second-stage stirring reaction kettle B, the reaction kettle B starts feeding, and the reaction kettle B operates according to the same procedure of the reaction kettle A; and (3) continuously introducing air into the reaction kettle A until the pH value is reduced to 6.5, introducing the air for 4min, measuring the temperature in the reaction kettle A to be 65.5-65.7 ℃, stopping introducing the air, discharging the material from the bottom of the reaction kettle after 2min, and taking 58min after the material is discharged from the three-way valve, wherein the reactor A is ready for the next round of operation.
From the row material sample of second grade reation kettle A and B, use EDTA complex method analysis titration total calcium ion concentration, when total calcium ion concentration relative deviation is less than 2% in two batches of row materials, can judge that continuous operation system has reached stable operating condition, later from row material sample of second grade stirred tank reactor A, suction filtration, dry in 105 ℃ drying cabinet to the moisture content is less than 0.2 wt%, be used for the test and the analysis.
SEM photograph shows that the product is in an agglomerated state (figure 23), the agglomerate is 4 microns at most, and the agglomerate is composed of a small amount of partial triangles and a large amount of spindles with the length of 1-2 microns.
BET of the product powder was 5.04m2(ii) a DOP oil absorption of 66.78g/100g and a free base content of 0.045 wt%.
Example 12
According to the same reaction kettle and the same flow of the embodiment 11, except that the feeding speed of the calcium hydroxide of the first-stage reaction kettle is changed to 50mL/min, the temperature in the first-stage reaction kettle after the steady state is measured to be 63.6-63.7 ℃.
The SEM photograph shows that the secondary product is in an agglomerated state composed of needle-like spindles (FIG. 24), and contains a small amount of scalenohedral.
Of the product powderBET of 5.49m2(ii) a DOP oil absorption of 50.09g/100g and a free base content of 0.045 wt%.
Example 13
According to the same reaction kettle and the same flow of the embodiment 11, different operation conditions are that the temperature of calcium hydroxide in the first-stage reaction kettle is changed to 35.4 ℃, the concentration of the calcium hydroxide is changed to 0.60mol/L, the temperature in the first-stage reaction kettle after the steady state is measured to be 45.4-45.5 ℃, and the temperature in the second-stage reaction kettle is measured to be 45.9-46.0 ℃.
SEM pictures show that the secondary products are mostly cubes of 1-2 microns, see FIG. 25.
BET of the product powder was 2.34m2(ii)/g, DOP oil absorption value of 51.80g/100g, free base content of 0.020 wt%.
Example 14
According to the same reaction kettle and the same flow of the embodiment 12, the different operation conditions are that the calcium hydroxide temperature of the first-stage reaction kettle is 36.7 ℃, the calcium hydroxide concentration is changed to 0.80mol/L, the temperature in the first-stage reaction kettle after the steady state is measured to be 45.8-45.9 ℃, and the temperature in the second-stage reaction kettle is measured to be 46.2-46.3 ℃.
SEM pictures show most hedgehog aggregates as secondary products, see fig. 26. The magnified SEM shows that the agglomerates are composed of rod-like crystals with a small amount of scalenohedral, see FIG. 27.
BET of the product powder was 6.06m2(ii)/g, DOP oil absorption value of 47.40g/100g, free base content of 0.049 wt%.
Taking 50g of filter cake, adding 30g of water, stirring to form paste, adding 50g of zirconia balls with the diameter of 2.5mm, putting into a 150mL glass beaker, stirring and grinding for 20min, filtering and separating the zirconia balls by using a screen, performing suction filtration by using qualitative filter paper to obtain the filter cake, putting the filter cake into a 105 ℃ oven, drying until the water content is less than 0.2 wt%, and performing dry powder test SEM (shown in figure 28), wherein most of the filter cake is aragonite-type columnar body.
Claims (7)
1. The two-stage series method for producing micron-sized calcium carbonate by the carbonization method with the liquid phase as the continuous phase is characterized by comprising two-stage series reactors, and the solid suspension liquid of each stage reactor continuously enters and exitsThe calcium hydroxide raw material is continuously fed from a primary reactor, calcium carbonate precipitation suspension is discharged from a secondary reactor, and carbonic acid gas raw materials are continuously supplied to the primary reactor and the secondary reactor respectively, the secondary reactor consists of two reactors operated alternately, and one secondary reactor receives the effluent of the primary reactor to carry out carbonization operation; the other secondary reactor performs the operations of degassing and discharging the calcium carbonate suspension, the operating conditions of each secondary reactor are adjusted and controlled according to the technical indexes of crystal form, morphology and particle size of the target micron-sized calcium carbonate product, and the operating conditions comprise average retention time tau, operating temperature T, calcium hydroxide feeding concentration C0And the supply amount of carbon dioxide Q, Q having molCO unit2/min。
2. The two-stage series connection method for producing micron-sized calcium carbonate by the carbonization method with the continuous liquid phase according to claim 1, wherein the volume concentration of carbon dioxide in the carbonic acid gas is 25-100V%.
3. The two-stage series-connection method for producing micron-sized calcium carbonate by the carbonization method with the continuous liquid phase according to claim 2 is characterized in that the carbonic acid gas is kiln gas collected by lime calcination, and the volume concentration of carbon dioxide is 25-48V%.
4. The two-stage series process for producing micron-sized calcium carbonate according to claim 1, wherein the reactor is any one of a stirred carbonization reactor, a bubble column and a circulating jet carbonization reactor, the upper part of the first-stage reactor is provided with an overflow port, the supply point of calcium hydroxide raw material is arranged in the region with the highest mixing intensity, and the carbon dioxide is supplied into the reactor from the bottom of the reactor.
5. The two-stage series-connected process for producing micron-sized calcium carbonate according to claim 1, wherein the operating volume is V1The operating conditions of the first reactor of (2) are: tau is1＝20～60min，T1＝55～70℃，C0＝0.6～2.0mol/L，Q10.4 to 1.0, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a Operating volume V2The two secondary reactors A and B are operated alternately under the following operating conditions: v2≤V1，T2＝58～75℃，Q2/V20.02-0.04 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1min，V1And V2Has a unit of L to obtain micron-sized spindle-shaped calcium carbonate products, and the weight average particle diameter D of the particles50The content of free calcium oxide is less than 0.05 wt% in the range of 1-6 μm.
6. The two-stage series-connected process for producing micron-sized calcium carbonate according to claim 1, wherein the operating volume is V1The operating conditions of the first reactor of (2) are: tau is1＝25～60min，T1＝35～70℃，C0＝0.4～1.2mol/1，Q11.1 to 1.5, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a (ii) a Operating volume V2The two secondary reactors A and B are operated alternately under the following operating conditions: v2≤V1，T2＝35～70℃，Q/V20.01-0.03 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1min, obtaining the micron-sized cubic calcium carbonate product with the weight average particle diameter D of the particles501.1-4.5 μm, D97 is less than or equal to 9 μm, and the content of free calcium oxide is 0.05%.
7. Two-stage series connection for producing micron-sized calcium carbonate by carbonization with continuous liquid phase according to claim 1Method, characterized in that the operating volume is V1The operating conditions of the first reactor of (2) are: tau is1＝25～60min，T1＝45～70℃，C0＝0.4～1.6mol/1，Q11.1 to 3.4, wherein Q1Is a first-stage reactor CO2Supply rate molCO2Min, A is the calcium hydroxide supply rate molCa (OH)2Min, i.e. A ═ C0*V1/τ1(ii) a Operating volume V2The two secondary reactors A and B are operated alternately under the following operating conditions: v2≤V1，T2＝45～70℃，Q/V20.01-0.03 mol/(min.L), and the feeding and carbonizing time is 10+ tau1min, degassing and discharging for 20min, wherein the total operation time of a single reaction kettle is less than or equal to 2 tau1And min, obtaining precipitated calcium carbonate containing columnar aragonite crystal forms, wherein the aragonite crystal form content of the product is more than 55 wt%, and the rest is cubic calcium carbonate with calcite crystal form, and the content of free calcium oxide is less than 0.05 wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910849885.5A CN110627100B (en) | 2019-09-09 | 2019-09-09 | Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910849885.5A CN110627100B (en) | 2019-09-09 | 2019-09-09 | Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110627100A true CN110627100A (en) | 2019-12-31 |
| CN110627100B CN110627100B (en) | 2022-04-01 |
Family
ID=68970941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910849885.5A Active CN110627100B (en) | 2019-09-09 | 2019-09-09 | Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110627100B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111558606A (en) * | 2020-06-05 | 2020-08-21 | 瀜矿环保科技(上海)有限公司 | Hydrometallurgical multistage reaction and separation system based on carbon dioxide |
| CN117205733A (en) * | 2023-08-03 | 2023-12-12 | 南京工业大学 | Rapid treatment of steel slag and capture of CO using micro-interface strengthening technique 2 Is a method of (2) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020172636A1 (en) * | 1999-09-09 | 2002-11-21 | Christoph Nover | Process for the continuous production of precipitated calcium carbonate |
| US20100135891A1 (en) * | 2007-04-20 | 2010-06-03 | Omya Development Ag | Process for production of pcc |
| CN108928844A (en) * | 2018-08-01 | 2018-12-04 | 建德华明科技有限公司 | The preparation method of regularity calcite |
| CN109824076A (en) * | 2019-02-28 | 2019-05-31 | 广西大学 | Bubble chamber film method prepares calcium carbonate technique and its application |
-
2019
- 2019-09-09 CN CN201910849885.5A patent/CN110627100B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020172636A1 (en) * | 1999-09-09 | 2002-11-21 | Christoph Nover | Process for the continuous production of precipitated calcium carbonate |
| US20100135891A1 (en) * | 2007-04-20 | 2010-06-03 | Omya Development Ag | Process for production of pcc |
| CN108928844A (en) * | 2018-08-01 | 2018-12-04 | 建德华明科技有限公司 | The preparation method of regularity calcite |
| CN109824076A (en) * | 2019-02-28 | 2019-05-31 | 广西大学 | Bubble chamber film method prepares calcium carbonate technique and its application |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111558606A (en) * | 2020-06-05 | 2020-08-21 | 瀜矿环保科技(上海)有限公司 | Hydrometallurgical multistage reaction and separation system based on carbon dioxide |
| CN117205733A (en) * | 2023-08-03 | 2023-12-12 | 南京工业大学 | Rapid treatment of steel slag and capture of CO using micro-interface strengthening technique 2 Is a method of (2) |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110627100B (en) | 2022-04-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| NO342585B1 (en) | Process for the preparation of powdered Ni, Co mixed hydroxide | |
| CN110627100B (en) | Two-stage series method for producing micron-sized calcium carbonate by carbonization method with liquid phase as continuous phase | |
| EP0153228B1 (en) | Cerium dioxide with morphological characteristics, and process for its preparation | |
| EP0153227B1 (en) | Cerium dioxide with morphological characteristics, and process for its preparation | |
| US5064628A (en) | Novel ceric oxides and preparation thereof | |
| CN108928844B (en) | Preparation method of regular cubic calcium carbonate | |
| KR20100007871A (en) | Process for production of pcc | |
| CN108083312B (en) | A kind of carbonization reactor and preparation small particle, polymolecularity, low oil factor nanometer calcium carbonate method | |
| US9352976B2 (en) | Methods for preparing trimanganese tetroxide with low bet specific surface area, methods for controlling particle size of trimanganese tetroxide and trimanganese tetroxide product | |
| CN107486561B (en) | Method for preparing and separating silver nanowires at large scale and normal pressure | |
| KR20140129111A (en) | Method for producing mixed carbonates which can contain hydroxide(s) | |
| CN109289756B (en) | Porous manganese-based lithium ion sieve adsorbent and preparation method thereof | |
| CN109179471B (en) | Preparation method of light calcium carbonate with anti-sedimentation property | |
| CN110589862B (en) | Multistage series method for producing nano-grade calcium carbonate by carbonization method with liquid phase as continuous phase | |
| CN110407220B (en) | Rapid preparation method of SAPO-34 molecular sieve with large specific surface area | |
| CN108321426B (en) | Preparation method and equipment of single-particle-morphology lithium nickel manganese cobalt oxide material | |
| CN109279656A (en) | The mesoporous ball-type Mn of micro-nano2O3Preparation method | |
| CN109266871A (en) | The preparation method of submicron order scandium oxide | |
| CN107961776B (en) | Preparation method of mesoporous material with three-dimensional Ti-Sr oxide skeleton structure | |
| US11329284B2 (en) | Fine and ultrafine powders and nanopowders of lithium metal oxides for battery applications | |
| CN112978773B (en) | High-performance aluminum oxide material and preparation method thereof | |
| CN109289757B (en) | Hexagonal dendritic manganese lithium ion sieve adsorbent and preparation method thereof | |
| WO2019079227A1 (en) | Multi-batch process for generating precipitated calcium carbonate | |
| JP5747648B2 (en) | Method for producing high purity silica powder | |
| CN115010154A (en) | Superfine aluminum hydroxide seed crystal and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |