Production process of special calcium for cigarette paper

Abstract

The invention provides a production process of special calcium for cigarette paper. The process comprises the following steps: step S1, selecting CaO with the content greater than or equal to 54% and Mg0lt; the method comprises the following steps: crushing 1% of limestone, calcining the crushed limestone in a shaft kiln at 900-1000 DEG C to produce calcium oxide and carbon dioxide; s2, calcium oxide meeting the requirements enters a lime slaker according to the ash-water ratio of 1: (4-4.5) to be slaked; the digested coarse pulp is stirred and emulsified in a coarse pulp tank, enters a fine pulp aging tank after being subjected to two times of hydrocyclone separation, sieving and deslagging, and is conveyed into a carbonization tower after being aged; s3, a porous gas distributor is arranged in the carbonization tower, multiple layers of stirring blades are assembled, and the functions of bubble breaking and slurry stirring are achieved; step S4, raising the carbonization reaction temperature to the maximum, then reducing the temperature by 3-5 DEG C, sampling, and dropping a 1% phenolphthalein indicator until the solution is not red, thereby indicating that the carbonization is finished; and step S5, filtering and dehydrating after carbonization, filtering and collecting again after dehydration, conveying to a filter press after collection, carrying out filter pressing to form a cake, and then drying to form the special calcium for the cigarette paper.

Description

Technical Field

[0001] The invention relates to the technical field of production of special calcium for cigarette paper, in particular to a production process of special calcium for cigarette paper. Background Art

[0002] In the past, inorganic fillers such as kaolin, talc, and calcium carbonate were used as fillers for papermaking in order to improve the whiteness, opacity, and printability of paper. As the pH of the wet end of paper machines becomes neutral, light calcium carbonate is increasingly used. In order to improve optical properties such as whiteness and opacity and printability when using it, products with controlled calcium carbonate particle shape and particle size have been developed.

[0003] Calcium carbonate is an important inorganic filler. Due to its low price, wide range of raw materials and non-toxicity, it is widely used as a filler for rubber, plastic, paper, coating, toothpaste, etc. Calcium carbonate is also one of the important raw materials for producing cigarette paper. In addition to fiber raw materials, calcium carbonate accounts for 40% to 50% of cigarette paper. Therefore, the quality of cigarette paper, in addition to fiber raw materials, is directly related to the quality and properties of calcium carbonate. In order to make the tobacco burn fully and reduce the content of harmful substances in cigarettes, the use of high-permeability cigarette paper is a more effective method. The advancement of cigarette production technology also requires cigarette paper to have higher strength to adapt to high-speed cigarette machines, and at the same time puts forward new requirements for the quality of calcium carbonate fillers used in cigarettes.

[0004] The main function of calcium carbonate in cigarette paper is to increase the air permeability of paper, control the burning speed, and improve whiteness and opacity. The so-called high-grade cigarette paper must not only meet the requirements of high air permeability to reduce tar content and reduce harmful substances to the human body, but also meet the requirements of high-speed cigarette making machines for high strength of paper.

[0005] In the prior art, the process for producing light calcium carbonate is relatively backward. The produced calcium carbonate has unstable crystal form and uneven grain size. It is easy to form flake or point distribution in the production process of cigarette paper, which easily covers the space between fibers in the cigarette paper. The uncovered fibers have high air permeability, which easily causes uneven and unstable air permeability. In addition, the paper feels thin and has a poor refractive index, and the appearance of the paper is not beautiful. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a special calcium production process for cigarette paper, which can realize the production of calcium carbonate for cigarette paper and has the characteristics of high retention rate and high opacity.

[0007] The present invention is realized by the following method: a production process of calcium for cigarette paper, the process comprising the following steps:

[0008] Step S1, selecting limestone with a CaO content of ≧54% and MgO<1% for crushing, and calcining the crushed limestone in a vertical kiln at 900-1000°C to produce calcium oxide and carbon dioxide;

[0009] Step S2, the calcium oxide that meets the requirements is fed into a lime digester for digestion at a lime-water ratio of 1:4-4.5; the digested crude pulp is stirred and emulsified in a crude pulp tank, and after two hydrocyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, and after aging, it is transported to a carbonization tower;

[0010] Step S3, a porous gas distributor is installed in the carbonization tower, and a multi-layer stirring blade is equipped, which has the functions of bubble crushing and slurry stirring; a crystal shape control agent and an organic dispersant are added, and the carbon dioxide gas is compressed and transported to the carbonization tower for carbonization; Step S4, the carbonization reaction temperature rises to the highest and then drops by 3-5°C, and a sample is taken. If a 1% phenolphthalein indicator is dripped and no redness occurs, it indicates that the carbonization is completed;

[0011] Step S5, filtering and dehydrating after carbonization, filtering and collecting again after dehydration, conveying to a filter press after collection to filter into cakes, and then drying to form calcium for cigarette paper.

[0012] Furthermore, the step S1 is specifically as follows: limestone with a CaO content of ≧54% and MgO<1% is selected for crushing, and the crushing is processed into a specification of 40-80mm or 20-40mm, and calcined in a vertical kiln at 900-1000°C to produce CaO and CO2; the quality requirements of calcium oxide are: CaO content ≧92%, effective calcium content ≧87%, activity ≧320, and CO2 content ≧32%.

[0013] Furthermore, it includes a vertical kiln, which is connected to a coarse pulp pool via a first discharge pipe, a first motor is provided in the middle of the upper surface of the coarse pulp pool, an output end of the first motor is connected to a first rotating shaft, the first rotating shaft is arranged in the coarse pulp pool, first stirring blades are equidistantly arranged on the first rotating shaft, the right end of the upper surface of the coarse pulp pool is connected to an air pump, a first filter plate is provided at the discharge port of the coarse pulp pool, a second motor is embedded below the first filter plate, a first eccentric wheel for driving the first filter plate to vibrate up and down is provided at the end of the output shaft of the second motor, a screw conveyor is provided below the first filter plate, the screw conveyor is connected to a refined pulp aging pool, a feed port is provided at the lower end of the left side surface of the refined pulp aging pool, and the feed port is connected to the screw conveyor. The discharge port of the rotary conveyor is connected, and a first telescopic cylinder is embedded in the feed port, and a first opening and closing plate for opening and closing the feed port is provided at the end of the telescopic rod of the first telescopic cylinder, and a first mixer is provided in the refined pulp aging tank, and an air outlet pipe is connected to the right end of the upper surface of the refined pulp aging tank, and the refined pulp aging tank is connected to the carbonization tower via the first discharge pipe, and a second mixer is provided on the inner bottom surface of the carbonization tower, and an air inlet pipe is connected to the upper end of the right side surface of the carbonization tower, and the inner bottom surface of the carbonization tower is inclined from left to right, and a discharge port is provided at the lower end of the right side surface of the carbonization tower, and the discharge port is connected to the dehydration bin via the second discharge pipe, and a second telescopic cylinder is embedded in the discharge port, and a second opening and closing plate for opening and closing the discharge port is provided at the end of the telescopic rod of the second telescopic cylinder.

[0014] Furthermore, a partition plate is provided in the middle part of the bottom surface of the dehydration bin, and a flip filter plate is hingedly provided on the partition plate, a fixed block is provided on the upper end of the left side surface of the dehydration bin, and a return spring is provided on the fixed block, and the left end of the flip filter plate is mounted on the return spring, a suction pump is provided on the left end of the bottom surface of the dehydration bin, and a collecting box with an open upper surface is provided on the right end of the bottom surface of the dehydration bin, and a collecting bucket matched with the flip filter plate is provided at the upper end between the right side surface of the dehydration bin and the partition plate, and a second filter plate is provided at the discharge port of the collecting bucket, and the second filter plate corresponds to the feed port of the collecting box, and a third motor is embedded in the right end of the rear surface of the dehydration bin, and a second eccentric wheel for driving the second filter plate to vibrate up and down is provided on the output shaft of the third motor.

[0015] Furthermore, the step S2 is further specified as follows: calcium oxide that meets the requirements is fed into a lime digester for digestion at a ash-water ratio of 1:4-4.5; the temperature of the digestion water is ≥50°C, and the temperature of the digested pulp is ≥90°C; the digested pulp is stirred and emulsified in a pulp tank, and after two cyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, wherein the screening and deslagging includes screening through 180 mesh; the refined pulp concentration is adjusted to 14 Baume; the refined pulp is dynamically stirred and aged for 24 hours; the refined pulp temperature is 35-45°C.

[0016] Further, the step S3 is further specifically as follows: a porous gas distributor is installed in the carbonization tower, a multi-layer stirring blade is installed, the carbonization tower has the functions of bubble crushing and slurry stirring, and a frequency conversion speed regulation is equipped; a crystal shape control agent is prepared: the addition amount is 0.1% of the solid content; an organic dispersant is prepared: the addition amount is 0.3% of the solid content; carbon dioxide gas is compressed, a Roots blower is used, the outlet pressure is ≧50KPa, and the gas transmission rate is 60m / min; refined qualified calcium hydroxide is sent into the carbonization tower through a centrifugal pump Tower, turn on the carbonization tower agitator at 30 rpm, add crystal control agent and organic dispersant with a metering pump, and increase the stirring speed to 110 rpm; start the Roots blower, and pump the CO2 mixed gas into the carbonization tower for carbonization; the carbonization reaction temperature rises to the highest and then drops by 3-5°C, take a sample, and if it does not turn red when dripped with 1% phenolphthalein indicator, it indicates that the carbonization is completed; take a sample of the carbonized slurry, filter and dry it to a moisture content of ≤0.3%, and then pass it through a 120-mesh sieve to detect the sedimentation volume and particle size distribution.

[0017] The beneficial effects of the present invention are as follows: the present invention can achieve product indicators: sedimentation volume ≧3.3, pH value ≦10.0, whiteness ≧95 (R457 blue light whiteness), sieve residue 125um ≦0.005, sieve residue 45um ≦0.05, heavy metal content meets the food grade standard; it has the advantages of high retention rate and high opacity when applied to special paper; in the process of chemical reaction between carbon dioxide and calcium hydroxide, the present invention adds a crystal form control agent and an organic dispersant, so that the produced calcium carbonate crystal form is stable, has a spindle structure, and has a uniform particle size, so that there are channels between the calcium carbonate crystal particles, and air cannot be prevented from passing through, thereby ensuring the uniformity and stability of the air permeability of the cigarette paper, and greatly improving the thick and soft feel of the paper, and the refractive index and air permeability. The technical problems existing in the prior art that the production process of light calcium carbonate is relatively backward, the produced calcium carbonate crystal form is unstable, and the grain size is uneven are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0019] Figure 2 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] See also Figure 1 and Figure 2 As shown, the present invention provides an embodiment: a production process of calcium for cigarette paper, the process comprising the following steps:

[0022] Step S1, selecting limestone with a CaO content of ≧54% and MgO<1% for crushing, and calcining the crushed limestone in a vertical kiln at 900-1000°C to produce calcium oxide and carbon dioxide; selecting limestone with a CaO content of ≧54% and MgO<1% for crushing, and crushing the limestone into a size of 40-80mm or 20-40mm, and calcining the limestone in a vertical kiln at 900-1000°C to produce CaO and CO2; calcium oxide quality requirements: CaO content ≧92%, effective calcium content ≧87%, activity ≧320, CO2 content ≧32%.

[0023] Step S2, the calcium oxide that meets the requirements is fed into a lime digester for digestion at an ash-water ratio of 1:4-4.5; the digested crude pulp is stirred and emulsified in a crude pulp tank, and after two hydrocyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, and after aging, it is transported to a carbonization tower; the calcium oxide that meets the requirements is fed into a lime digester for digestion at an ash-water ratio of 1:4-4.5; the digestion water temperature is ≧50°C, and the digestion crude pulp temperature is ≧90°C; the digested crude pulp is stirred and emulsified in a crude pulp tank, and after two hydrocyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, and the screening and deslagging includes deslagging and sieving through 180 mesh;

[0024] The seminal plasma concentration was adjusted to 14 Baume; the seminal plasma was dynamically stirred and aged for 24 hours; the seminal plasma temperature was 35-45°C.

[0025] Step S3, a porous gas distributor is installed in the carbonization tower, and a multi-layer stirring blade is equipped with a bubble crushing and slurry stirring function; a crystal shape control agent and an organic dispersant are added, and the carbon dioxide gas is compressed and transported to the carbonization tower for carbonization; a porous gas distributor is installed in the carbonization tower, and a multi-layer stirring blade is equipped with a bubble crushing and slurry stirring function, and a frequency conversion speed regulation is equipped; a crystal shape control agent is prepared: the addition amount is 0.1% of the solid content; an organic dispersant is prepared: the addition amount is 0.3% of the solid content; carbon dioxide gas is compressed, using a Roots blower, the outlet pressure is ≧50KPa, and the gas delivery rate is 60m / min; refined qualified calcium hydroxide is used, and it is sent into the carbonization tower through a centrifugal pump, the carbonization tower agitator is turned on at 30 rpm, the metering pump adds the crystal shape control agent and the organic dispersant, and the stirring speed is increased to 110 rpm; the Roots blower is started,

[0026] The mixed gas of CO2 is injected into the carbonization tower for carbonization.

[0027] Step S4, the carbonization reaction temperature rises to the highest and then drops by 3-5°C, sampling is performed, and a 1% phenolphthalein indicator is dripped in and no red color is obtained, indicating that the carbonization is completed; the carbonization reaction temperature rises to the highest and then drops by 3-5°C, sampling is performed, and a 1% phenolphthalein indicator is dripped in and no red color is obtained, indicating that the carbonization is completed; sampling the carbonized slurry, filtering and drying it to a moisture content of ≤0.3%, and then passing it through a 120-mesh sieve to detect the sedimentation volume and particle size distribution.

[0028] Step S5, filtering and dehydrating after carbonization, filtering and collecting again after dehydration, conveying to a filter press after collection to filter into cakes, and then drying to form calcium for cigarette paper.

[0029] The crystal shape control agent and the organic dispersant in the present invention may be sodium chloride, sodium bromide, or sodium citrate, and the organic dispersant may be ethylenediaminetetramethylenephosphonic acid (EDTMPA) or hydroxyethylidene diphosphate (HEDP), but are not limited thereto.

[0030] Please continue reading Figure 2As shown, in one embodiment of the present invention, it includes a vertical kiln 1, which is connected to a rough pulp pool 2 via a first discharge pipe 11, a first motor 21 is provided at the middle of the upper surface of the rough pulp pool 2, an output end of the first motor 21 is connected to a first rotating shaft 22, the first rotating shaft 22 is arranged in the rough pulp pool 2, first stirring blades 23 are arranged at equal distances on the first rotating shaft 22, a vacuum pump 24 is connected to the right end of the upper surface of the rough pulp pool 2, a first filter plate 25 is provided at the discharge port of the rough pulp pool 2, a second motor (not shown) is embedded below the first filter plate 25, a first eccentric wheel 26 for driving the first filter plate 25 to vibrate up and down is provided at the end of the output shaft of the second motor, a screw conveyor 3 is provided below the first filter plate 25, the screw conveyor 3 is connected to a refined pulp aging pool 4, a feed port (not shown) is provided at the lower end of the left side of the refined pulp aging pool 4, the The feed port is connected to the discharge port of the screw conveyor 3, and a first telescopic cylinder 31 is embedded in the feed port. The end of the telescopic rod of the first telescopic cylinder 31 is provided with a first opening and closing plate 32 for opening and closing the feed port. A first mixer 41 is arranged in the refined pulp aging tank 4, and an air outlet pipe 42 is connected to the right end of the upper surface of the refined pulp aging tank 4. The refined pulp aging tank 4 is connected to the carbonization tower 5 via the first discharge pipe 43. A second mixer 51 is arranged on the inner bottom surface of the carbonization tower 5, and an air inlet pipe 52 is connected to the upper end of the right side surface of the carbonization tower 5. The inner bottom surface of the carbonization tower 5 is inclined from left to right, and a discharge port (not shown) is opened at the lower end of the right side surface of the carbonization tower 5. The discharge port is connected to the dehydration bin 6 via the second discharge pipe 53. A second telescopic cylinder 54 is embedded in the discharge port, and a second opening and closing plate 55 for opening and closing the discharge port is arranged at the end of the telescopic rod of the second telescopic cylinder 54. The calcium oxide formed by calcining the vertical kiln 1 is transported to the rough pulp pool 2, and then water is added. The first motor 21 drives the first rotating shaft 22 to rotate, so that the first stirring blade 23 can rotate to achieve uniform stirring and emulsification. Then, it is filtered through the first filter plate 25 and transported to the refined pulp aging pool 4 through the screw conveyor 3. The second motor can drive the first eccentric wheel 26 to rotate to avoid clogging of the first filter plate 25. The first telescopic cylinder 31 can drive the first opening and closing plate 32 to rise and fall to achieve the opening and closing of the feed port. The first mixer 41 is used to stir and mix again, and then it is transported to the carbonization tower 5 for carbonization. The Roots blower is started to inject the mixed gas of CO2 into the carbonization tower for carbonization.

[0031] Please continue reading Figure 2As shown, in one embodiment of the present invention, a partition plate 61 is provided in the middle part of the inner bottom surface of the dehydration bin 6, and a flip filter plate 62 is hingedly provided on the partition plate 61, a fixed block 63 is provided on the upper end of the left side surface of the dehydration bin 6, and a return spring 64 is provided on the fixed block 63, and the left end of the flip filter plate 62 is mounted on the return spring 64, a suction pump 65 is provided on the left end of the inner bottom surface of the dehydration bin 6, and a collecting box body 7 with an open upper surface is provided on the right end of the inner bottom surface of the dehydration bin 6, and a collecting bucket 66 matching the flip filter plate 62 is provided at the upper end between the right side surface of the dehydration bin 6 and the partition plate 61, and a second filter plate 67 is provided at the discharge port of the collecting bucket 66, and the second filter plate 67 corresponds to the feed port of the collecting box body 7, and a third motor (not shown) is embedded at the right end of the inner rear surface of the dehydration bin 6, and a second eccentric wheel 68 for driving the second filter plate 67 to vibrate up and down is provided on the output shaft of the third motor. By flipping the filter plate 62, the cooked pulp after carbonization can be filtered and dehydrated through a large-capacity pool for homogenization (generally 200m / pool is required), so that preliminary dehydration can be carried out. After dehydration, the cooked pulp is flipped into the collecting bucket 66 by flipping the filter plate 62 for re-filtration. After filtration, it enters the collecting box 7 for collection and is transported to the dryer for drying. The second eccentric wheel 68 is driven to rotate by the third motor to realize the up and down vibration of the second filter plate 67, thereby avoiding clogging of the second filter plate 67.

[0032] The hinge arrangement in the present invention is an existing hinge arrangement, which can be clearly understood by those skilled in the art and will not be described in detail here.

[0033] The material extraction pump, air extraction pump, motor, telescopic cylinder, screw conveyor and mixer in the present invention are all prior arts, and those skilled in the art are already well aware of them, so they will not be described in detail here.

[0034] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A process for producing calcium for cigarette paper, characterized in that: The process comprises the following steps: Step S1, selecting limestone with a CaO content of ≧54% and MgO<1% for crushing, and calcining the crushed limestone in a vertical kiln at 900-1000°C to produce calcium oxide and carbon dioxide; Step S2, the calcium oxide that meets the requirements is fed into a lime digester for digestion at a lime-water ratio of 1:4-4.5; the digested crude pulp is stirred and emulsified in a crude pulp tank, and after two hydrocyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, and after aging, it is transported to a carbonization tower; Step S3, a porous gas distributor is installed in the carbonization tower, and a multi-layer stirring blade is equipped with bubble crushing and slurry stirring functions; a crystal shape control agent and an organic dispersant are added, and the carbon dioxide gas is compressed and transported to the carbonization tower for carbonization; Step S4, the carbonization reaction temperature rises to the highest and then drops by 3-5°C, a sample is taken, and a 1% phenolphthalein indicator is dripped in, and if it does not turn red, it indicates that the carbonization is completed; Step S5, filtering and dehydrating after carbonization, filtering and collecting again after dehydration, conveying to a filter press after collection to filter into cakes, and then drying to form calcium for cigarette paper.

2. The process for producing calcium for cigarette paper according to claim 1, characterized in that: The step S1 specifically comprises: selecting limestone with a CaO content of ≧54% and MgO<1% for crushing, crushing into a specification of 40-80mm or 20-40mm, and calcining in a vertical kiln at 900-1000°C to produce CaO and CO2; the quality requirements of calcium oxide are: CaO content ≧92%, effective calcium content ≧87%, activity ≧320, and CO2 content ≧32%.

3. The process for producing calcium for cigarette paper according to claim 1, characterized in that: The invention comprises a vertical kiln, which is connected to a rough pulp pool via a first discharge pipe, a first motor is arranged in the middle of the upper surface of the rough pulp pool, an output end of the first motor is connected to a first rotating shaft, the first rotating shaft is arranged in the rough pulp pool, first stirring blades are arranged at equal distances on the first rotating shaft, an air pump is connected to the right end of the upper surface of the rough pulp pool, a first filter plate is arranged at the discharge port of the rough pulp pool, a second motor is embedded below the first filter plate, a first eccentric wheel for driving the first filter plate to vibrate up and down is arranged at the end of the output shaft of the second motor, a screw conveyor is arranged below the first filter plate, the screw conveyor is connected to a refined pulp aging pool, a feed port is provided at the lower end of the left side of the refined pulp aging pool, and the feed port is connected to the screw conveyor. The discharge port of the machine is connected, a first telescopic cylinder is embedded in the feed port, a first opening and closing plate for opening and closing the feed port is provided at the end of the telescopic rod of the first telescopic cylinder, a first mixer is provided in the refined pulp aging tank, an air outlet pipe is connected to the right end of the upper surface of the refined pulp aging tank, the refined pulp aging tank is connected to the carbonization tower via the first discharge pipe, a second mixer is provided on the inner bottom surface of the carbonization tower, an air inlet pipe is connected to the upper end of the right side surface of the carbonization tower, the inner bottom surface of the carbonization tower is inclined from left to right, a discharge port is provided at the lower end of the right side surface of the carbonization tower, the discharge port is connected to the dehydration bin via the second discharge pipe, a second telescopic cylinder is embedded in the discharge port, a second opening and closing plate for opening and closing the discharge port is provided at the end of the telescopic rod of the second telescopic cylinder.

4. The process for producing calcium for cigarette paper according to claim 3, characterized in that: A partition plate is provided in the middle part of the bottom surface of the dehydration bin, and a flip filter plate is hingedly provided on the partition plate. A fixed block is provided on the upper end of the left side surface of the dehydration bin, and a return spring is provided on the fixed block. The left end of the flip filter plate is mounted on the return spring. A suction pump is provided on the left end of the bottom surface of the dehydration bin, and a collecting box with an open upper surface is provided on the right end of the bottom surface of the dehydration bin. A collecting bucket matched with the flip filter plate is provided at the upper end between the right side surface of the dehydration bin and the partition plate, and a second filter plate is provided at the discharge port of the collecting bucket, and the second filter plate corresponds to the feed port of the collecting box. A third motor is embedded in the right end of the rear surface of the dehydration bin, and a second eccentric wheel for driving the second filter plate to vibrate up and down is provided on the output shaft of the third motor.

5. The process for producing calcium for cigarette paper according to claim 1, characterized in that: The step S2 is further specifically as follows: calcium oxide that meets the requirements is fed into a lime digester for digestion at a lime-water ratio of 1:4-4.5; the temperature of the digestion water is ≥50°C, and the temperature of the digested pulp is ≥90°C; the digested pulp is stirred and emulsified in a pulp tank, and after two hydrocyclone separations, it is screened and deslagging and then fed into a refined pulp aging tank, wherein the screening and deslagging includes screening through 180 mesh; the refined pulp concentration is adjusted to 14 Baume; the refined pulp is dynamically stirred and aged for 24 hours; the refined pulp temperature is 35-45°C.

6. The process for producing calcium for cigarette paper according to claim 1, characterized in that: The step S3 is further specifically as follows: a porous gas distributor is installed in the carbonization tower, and a multi-layer stirring blade is installed, which has the functions of bubble crushing and slurry stirring, and is equipped with variable frequency speed regulation; a crystal shape control agent is prepared: the addition amount is 0.1% of the solid content; an organic dispersant is prepared: the addition amount is 0.3% of the solid content; carbon dioxide gas is compressed, and a Roots blower is used, with an outlet pressure of ≧50KPa and a gas transmission rate of 60m / min; refined qualified calcium hydroxide is sent into the carbonization tower through a centrifugal pump, Turn on the carbonization tower agitator at 30 rpm, add the crystal control agent and organic dispersant with a metering pump, and increase the stirring speed to 110 rpm; start the Roots blower, and pump the CO2 mixed gas into the carbonization tower for carbonization; the carbonization reaction temperature rises to the highest and then drops by 3-5°C, take a sample, and if it does not turn red when dripped with 1% phenolphthalein indicator, it indicates that the carbonization is completed; take a sample of the carbonized slurry, filter and dry it to a moisture content of ≤0.3%, and then pass it through a 120-mesh sieve to detect the sedimentation volume and particle size distribution.

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