KR20200105074A - System for manufacturing Calcium carbonate using supercritical state CO2 and Method of manufacturing Calcium carbonate using the same - Google Patents

Abstract

The present invention relates to a method for preparing calcium carbonate, including the steps of: (A) allowing a controlling unit to supply calcium hydroxide slurry to the inner space of a cylindrical main body through a feed line, heating the slurry to a predetermined temperature, and pressurizing carbon dioxide in the slurry through an injection line to convert the carbon dioxide into a supercritical state; (B) allowing the controlling unit to retain a reaction of dissolving calcium hydroxide in the carbon dioxide converted into a supercritical state for a predetermined time; and (C) allowing the controlling unit to eject the solution containing the supercritical carbon dioxide and calcium hydroxide dissolved therein to a recovery chamber though an ejection line to recover a suspension containing rapidly crystallized carbonate crystals.

Description

System for manufacturing calcium carbonate using supercritical state CO2 and Method of manufacturing Calcium carbonate using the same}

The present invention relates to a system for producing calcium carbonate using supercritical carbon dioxide and a method for producing calcium carbonate using the same.In particular, a system for producing precipitated calcium carbonate by discharging supercritical carbon dioxide and calcium hydroxide slurry, and using the same It relates to a method for producing calcium carbonate.

Calcite products have been continuously increasing in industrial demand over the past decades, and these calcite products are generally classified into heavy calcium carbonate produced by physically direct grinding of crystalline limestone and precipitated calcium carbonate chemically producing limestone. Precipitated calcium carbonate is divided into hard calcium carbonate with an average particle size of 1 to 3 μm and colloid calcium carbonate with an average particle size of 0.02 to 0.15 μm, depending on the basic particle size.

To obtain calcium carbonate, a water-soluble calcium salt and alkali carbonate are reacted, or lime water and carbon dioxide are reacted. Industrially, it is obtained by crushing limestone to make powder, sieving it, or sieving it, or by peeling (an operation that divides the particles according to their size or specific gravity using the difference in speed when solid particles freely settle in the air). This is called heavy calcium carbonate. Alternatively, the precipitate produced by blowing carbon dioxide into lime oil is obtained by filtration, drying, and fine pulverization, which is called hard calcium carbonate (輕質). Or, it is obtained by wet grinding the shells, which are called algae (胡粉).

Calcium carbonate is widely used in industrial fields due to its low cost and low specific gravity. That is, like limestone and marble, it is used as a main raw material for cement, as a raw material for calcium oxide, as a neutralizing agent for iron making and building materials. In addition, ash is used for white pigments and water-based paints, and precipitated calcium carbonate is used for pigments, paints, toothpaste, etc., and is also compounded as a reinforcing agent in rubber.

In the case of heavy calcium carbonate, the shape of the particles is uneven, but in the case of precipitated calcium carbonate, the particle size is very small and even, so it can be used not only in fine chemical industries such as paper, plastic, rubber, etc., but also in stationery, household goods, food and pharmaceutical fields. It is a high value-added material.

Calcium carbonate is widely used as fillers and extender pigments for paper, plastics, paints, etc., with domestic supply of 465,000 tons, 92.8% of demand, and imports of 36,000 tons, accounting for 7.2%, most of which are supplied domestically. Calcium carbonate produced in Korea is mainly a low-cost product, and it is difficult to develop overseas markets due to the high burden of logistics costs when exporting. In addition, limestone, a raw material, is not suitable for manufacturing high-end products, so its competitiveness is somewhat inferior.

In addition, limestone has a low thermal dissociation rate due to its large grain size and dense structure, because the heat transfer power through pores in coarse limestone is low, and carbon dioxide generated as a result of pyrolysis is difficult to escape through the dense structure of limestone.

Particularly, at the interface where the pyrolysis reaction occurs, the partial pressure of carbon dioxide is relatively high, resulting in a slow pyrolysis rate, and due to this problem, the heat treatment must be performed at a high temperature, thereby increasing the manufacturing cost.

In addition, precipitated calcium carbonate prepared using limestone contains a lot of impurities, and there is a problem that the environment is polluted due to carbon dioxide generated during pretreatment of limestone.

Conventionally, there is a growing interest in the technology of forming a carbonate of nanoparticles, but carbonate mineralization using calcium hydroxide has a disadvantage in that the reaction time is somewhat longer due to the low solubility of calcium hydroxide.

Patent Document: Unexamined Patent Publication No. 10-2018-0030900

The present invention was conceived to solve the above problems, and an object of the present invention is to cause a carbonation reaction of a slurry mixed with supercritical carbon dioxide and calcium hydroxide, thereby improving reaction efficiency and shortening the reaction time, and rapid It is to provide a calcium carbonate production system for producing high-quality precipitated calcium carbonate in a short time through crystallization.

Another object of the present invention is to utilize a slurry in which supercritical carbon dioxide and calcium hydroxide are mixed, but the crystal size and mineral homogeneity of precipitated calcium carbonate can be controlled by controlling the reaction time and discharge rate, and high-quality precipitated calcium carbonate It is to provide a method for producing precipitated calcium carbonate that can be prepared.

A system for producing calcium carbonate according to an embodiment of the present invention includes a cylinder; A recovery chamber connected to the discharge pipe of the cylinder; And a control unit connected to and controlling each of the cylinder and the recovery chamber.

In the calcium carbonate production system according to an embodiment of the present invention, the cylinder includes a cylinder body having an inner space; A slurry supply pipe for supplying a calcium hydroxide slurry from an upper side of the cylinder body to the inner space; A heating unit provided on one side of the cylinder body; An observation unit provided on the other side of the cylinder body; The discharge pipe provided under the cylinder body; An injection pipe for injecting carbon dioxide from a lower portion of the cylinder body; A temperature and pressure measuring tube provided under the cylinder body; And a stirrer provided in the inner space of the cylinder body.

In the calcium carbonate production system according to an embodiment of the present invention, the heating unit is provided in the form of a heating belt or a heating jacket including a heating coil.

In the calcium carbonate production system according to an embodiment of the present invention, the discharge pipe is provided in a form in which the cross-sectional area of the end portion becomes narrower in the inner direction of the recovery chamber than the cross-sectional area of the middle portion.

In the calcium carbonate production system according to an embodiment of the present invention, the recovery chamber is characterized in that it is a closed chamber that has a low pressure state lower than atmospheric pressure and maintains a low temperature state lower than room temperature by using a cooler provided at the bottom. .

In addition, in the method for producing calcium carbonate according to another embodiment of the present invention, (A) the controller supplies the calcium hydroxide slurry to the inner space of the cylinder body through the slurry supply pipe, heats the slurry to a predetermined temperature, and through the injection pipe. Converting the carbon dioxide into a supercritical phase by pressing carbon dioxide into the slurry; (B) maintaining, by the control unit, a reaction in which calcium hydroxide is dissolved in carbon dioxide that has changed into the supercritical phase for a predetermined time; And (C) the control unit discharging a solution in which the supercritical carbon dioxide and calcium hydroxide are dissolved into a recovery chamber through a discharge pipe to recover a suspension containing carbonate crystals rapidly crystallized.

In the method for producing calcium carbonate according to another embodiment of the present invention, step (A) includes heating the calcium hydroxide slurry to a temperature higher than 31°C through a heating unit provided on one side of the cylinder body by the control unit (A-1). Step to do; And (A-2) pressurizing, by the control unit, the carbon dioxide at a pressure higher than 74 bar through the injection pipe.

In the method for producing calcium carbonate according to another embodiment of the present invention, step (B) further includes agitating the carbon dioxide and calcium hydroxide slurry changed to the supercritical phase using a stirrer provided in the lower center of the cylinder body. Characterized in that.

In the method for producing calcium carbonate according to another embodiment of the present invention, step (C) includes the supercritical carbon dioxide and calcium hydroxide slurry present in the inner space of the cylinder body through the temperature and pressure measuring tube by the control unit. Detecting temperature and pressure for the mixed solution; (C-2) determining, by the control unit, whether or not to discharge the mixed solution of the supercritical carbon dioxide and calcium hydroxide slurry to the recovery chamber; (C-3) the control unit discharging the mixed solution through the discharge pipe to the recovery chamber at a discharge rate range of 200 to 340 ml/second; And (C-4) collecting, by the control unit, the carbon dioxide gas introduced into the recovery chamber through a collection tube.

In the method for producing calcium carbonate according to another embodiment of the present invention, the recovery chamber is characterized in that it is a closed chamber that has a low pressure state lower than atmospheric pressure and maintains a low temperature state lower than room temperature by using a cooler provided at the bottom. .

Features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to this, terms or words used in the present specification and claims are conventional and should not be interpreted in a dictionary meaning, and the concept of terms is appropriately defined in order for the inventor to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

The system for producing calcium carbonate according to an embodiment of the present invention has an effect of improving reaction efficiency by using supercritical carbon dioxide and a high concentration calcium solution, and producing precipitated calcium carbonate in a short time through discharge.

In the method for producing calcium carbonate according to an embodiment of the present invention, the particle size can be easily adjusted through the control of the reaction time, and thus particulate calcium carbonate can be produced in a short time.

1 is a block diagram of a system in which a method for producing calcium carbonate according to an embodiment of the present invention is performed.
2 is an image of a cylinder in which a method for producing calcium carbonate according to an embodiment of the present invention is performed.
3 is a flow chart for explaining a method for producing calcium carbonate according to an embodiment of the present invention.
4 is a graph of the amount of carbonate produced according to an embodiment of the present invention.
Figure 5 is a graph showing the content of more than homogeneous carbonate prepared according to an embodiment of the present invention.
6 is SEM images of carbonates prepared according to the first embodiment of the present invention.
7 is SEM images of carbonates prepared according to a second embodiment of the present invention.
8 is SEM images of carbonates prepared according to a third embodiment of the present invention.
9 is a graph showing the distribution by particle size of carbonates prepared according to an embodiment of the present invention.

Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In adding reference numerals to elements of each drawing in the present specification, it should be noted that, even though they are indicated on different drawings, only the same elements are to have the same number as possible. In addition, terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram of a system in which a method for producing calcium carbonate is performed according to an embodiment of the present invention, and FIG. 2 is an image of a cylinder in which a method for producing calcium carbonate is performed according to an embodiment of the present invention.

The system in which the method for producing calcium carbonate is performed according to an embodiment of the present invention includes a cylinder 100 for producing calcium carbonate and a recovery chamber 200 connected to the discharge pipe 150 of the cylinder 100, as shown in FIG. ) And a control unit (not shown) for overall control of the system.

Specifically, the cylinder 100 is a cylinder that maintains a constant temperature and high pressure, and includes an upper opening and closing portion 110, a cylinder body portion 120 having an inner space, and an inner space from the upper side of the cylinder body 120, for example, calcium hydroxide. The slurry supply pipe 125 for supplying the slurry, the heating part 130 provided on one side of the cylinder body 120, the observation part 140 provided on the other side of the cylinder body 120, and the cylinder body 120 The discharge pipe 150 provided at the lower part of the cylinder body 120, the injection pipe 160 for injecting carbon dioxide from the lower part of the cylinder body 120, the temperature and pressure measuring pipe 170 provided in the lower part of the cylinder body 120, and optional It includes a stirrer 180 provided in the inner space of the cylinder body 120.

The cylinder body 120 is made of a metal material, is formed in various cylindrical shapes such as a cylindrical shape, a square cylinder shape, etc., and may have a sealed inner space.

The heating unit 130 is provided on one side of the cylinder body 120 in the form of, for example, a heating belt including a heating coil or a heating jacket, and heats the cylinder body 120 under the control of the controller.

The observation unit 140 includes a window made of a transparent material such as tempered glass or tempered plastic on the other side of the cylinder body 120 and is provided so that the user can observe the reaction situation in the inner space.

The discharge pipe 150 is a metal pipe injected from the cylinder body 120 into the recovery chamber 200 as shown in FIGS. 1 and 2, and is in the interior direction of the recovery chamber 200 rather than the cross-sectional area of the middle part. It is provided in the form of narrowing the cross-sectional area of the distal end. Here, the discharge pipe 150 may be separately equipped with a detachable discharge port (not shown) having a narrow cross-sectional area at the distal end.

As the distal end of the discharge pipe 150 is formed in a form with a narrow cross-sectional area, the mixture of carbon dioxide and calcium hydroxide slurry in a supercritical state may rapidly crystallize as carbonate in the process of being discharged to the recovery chamber 200 at a predetermined discharge rate. have.

The agitator 180 is selectively provided in the lower center of the inner space of the cylinder body 120 and operates so that calcium hydroxide is easily dissolved in the carbon dioxide that has changed into a supercritical phase, and this operation is performed through the discharge pipe 150. It may be carried out until the mixture of the calcium hydroxide slurry is all discharged.

The recovery chamber 200 is a closed chamber having a low temperature and low pressure state connected to the discharge pipe 150, and has a low pressure state that is lower than atmospheric pressure and maintains a low temperature state lower than room temperature by using a cooler 210 provided at the bottom. It can be a closed chamber. This recovery chamber 200 includes a discharge pipe 221 provided on a lower side and a collection pipe 222 provided on an upper one side, and sends the calcium carbonate suspension to a separate storage container through the discharge pipe 221 for storage, or Alternatively, carbon dioxide gas introduced into the recovery chamber 200 through the collection pipe 222 may be collected and stored in a separate storage container.

The control unit is individually connected to each component of the system configured as described above and controls the overall, for example, heating the cylinder body 120 through the heating unit 130, injecting carbon dioxide through the injection pipe 160, and temperature The temperature and pressure of the inner space of the cylinder body 120 is detected through the pressure measuring pipe 170, and through the discharge pipe 150 using the temperature and pressure information detected through the temperature pressure measuring pipe 170. It is determined whether or not the mixture of carbon dioxide and calcium hydroxide slurry is to be discharged to the recovery chamber 200, and the carbon dioxide gas introduced into the recovery chamber 200 is collected through the collection pipe 222 in the process of discharging to the recovery chamber 200. It is stored in a separate storage container, and the calcium carbonate suspension can be sent to a separate storage container through the discharge pipe 221 and stored.

In the system according to the embodiment of the present invention configured as described above, the calcium hydroxide slurry injected into the inner space of the cylinder body 120 is heated to a predetermined temperature by heating the heating unit 130, and carbon dioxide through the injection pipe 160 Is injected at a predetermined pressure to convert carbon dioxide into a supercritical phase.

The mixture in which calcium hydroxide is dissolved in carbon dioxide that has changed into a supercritical phase is discharged to the recovery chamber 200 in a low temperature and low pressure state through the discharge pipe 150 to rapidly crystallize carbonate.

Accordingly, the carbonation reaction efficiency of the slurry is improved, the reaction time is shortened, and high-quality precipitated calcium carbonate can be produced in a short time through rapid crystallization through discharge.

Hereinafter, a method for producing calcium carbonate according to an embodiment of the present invention will be described with reference to FIGS. 3 to 9. 3 is a flow chart for explaining a method of producing calcium carbonate according to an embodiment of the present invention, FIG. 4 is a graph of the amount of carbonate produced according to an embodiment of the present invention, and FIG. 5 is It is a graph showing the more homogeneous content of the prepared carbonate, FIG. 6 is an SEM image of a carbonate prepared according to the first embodiment of the present invention, and FIG. 7 is an SEM image of a carbonate prepared according to the second embodiment of the present invention. 8 are SEM images of a carbonate prepared according to a third embodiment of the present invention, and FIG. 9 is a graph showing a distribution of carbonates prepared according to an embodiment of the present invention by particle size.

In the method for producing calcium carbonate according to an embodiment of the present invention, first, a calcium hydroxide slurry is supplied to the inner space of the cylinder body 120 through the slurry supply pipe 125, and the slurry is heated to a predetermined temperature, and the injection pipe 160 ) Through injection of carbon dioxide and pressurization (S310).

Specifically, the control unit (i) supplying the calcium hydroxide slurry to the inner space of the cylinder body 120 through the slurry supply pipe 125, (ii) the cylinder body 120 through the heating unit 130 Heating the calcium hydroxide slurry to 31° C. or higher, and (iii) injecting carbon dioxide into the calcium hydroxide slurry at 74 bar or higher through the injection pipe 160 to pressurize the calcium hydroxide slurry.

These heating and pressurization conditions are the minimum temperature and pressure range at which carbon dioxide turns into a supercritical phase, and the range of heating and pressurization is according to the desired homogeneity and crystal size at a temperature of 31°C or higher and a pressure of 74 bar or higher to form supercritical carbon dioxide. Adjustable.

After performing the process of heating and pressurization, the control unit maintains the reaction for a predetermined time so that calcium hydroxide is dissolved in carbon dioxide that has turned into a supercritical phase in the inner space of the cylinder body 120 (S320).

This dissolution reaction process is performed for, for example, 30 minutes or more so that calcium hydroxide can be easily dissolved in carbon dioxide that has changed into a supercritical phase while the above-described heating and pressurizing conditions are maintained, and the homogeneity and crystal size are adjusted according to the control of the reaction time. Can be adjusted. In this case, a process of stirring the carbon dioxide and calcium hydroxide slurry changed to the supercritical phase may be additionally performed using the stirrer 180 so that calcium hydroxide can be more easily dissolved in the carbon dioxide changed to the supercritical phase.

After maintaining the dissolution reaction process, the controller discharges a solution in which the supercritical carbon dioxide and calcium hydroxide slurry are mixed to the recovery chamber 200 through the discharge pipe 150 to recover a suspension containing carbonate crystals that have undergone rapid crystallization ( S330).

Specifically, the control unit detects the temperature and pressure of a solution in which the supercritical carbon dioxide and calcium hydroxide slurry present in the inner space of the cylinder body 120 are mixed through the temperature pressure measuring tube 170.

With reference to the temperature and pressure information and the above-described dissolution reaction time, the control unit determines whether to discharge a mixture of carbon dioxide and calcium hydroxide slurry to the recovery chamber 200 through the discharge pipe 150. For example, after a dissolution reaction time of 30 minutes or more has elapsed while a temperature of 31°C or higher and a pressure of 74 bar or higher are maintained, the control unit discharges a mixture of carbon dioxide and calcium hydroxide slurry to the recovery chamber 200 through the discharge pipe 150 do.

At this time, as the mixture of carbon dioxide and calcium hydroxide slurry is discharged to the recovery chamber 200 having a low temperature and low pressure at a discharge rate range of, for example, 200 to 340 ml/sec, a suspension containing carbonate crystals in which the carbonate is rapidly crystallized is returned to the recovery chamber ( 200). Here, the discharge rate range is one of the factors that determine the crystal grain size of the carbonate that is rapidly crystallized, and if it is out of the discharge rate range, rapid crystallization of the carbonate does not occur or production cost increases.

In addition, as the recovery chamber 200 has a low-temperature and low-pressure state, the mixture of carbon dioxide and calcium hydroxide slurry in a state in which a temperature of 31°C or higher and a pressure of 74 bar or higher is maintained is relatively low temperature and low pressure. Crystallization takes place. In this case, as the temperature difference and the atmospheric pressure difference of the recovery chamber 200 are larger, the rapid crystallization of carbonate becomes finer, so that the crystal grain size of the carbonate can be obtained finer.

In this process of discharging to the recovery chamber 200, the control unit collects the carbon dioxide gas introduced into the recovery chamber 200 through the collection pipe 222 and stores it in a separate storage container. Thereafter, the carbon dioxide gas stored in a separate storage container may be injected through the injection pipe 160 in the heating and pressurizing step (S310) to be reused.

At the same time, the control unit may send and store the calcium carbonate suspension to a separate storage container through the discharge pipe 221.

In the method for producing calcium carbonate according to an embodiment of the present invention including such a process, the particle size of the carbonate can be easily adjusted through the reaction time, the temperature difference and the air pressure difference of the recovery chamber 200, and the discharge rate. Can be manufactured.

Hereinafter, control of the particle size of the carbonate may be examined through examples in which the reaction time and heating and pressurizing conditions are different.

[First Example]

In the first embodiment, a supercritical carbon dioxide and 1M calcium hydroxide (Ca(OH) ₂ ) slurry solution was discharged at a temperature of 35°C and a pressure of 75 bar. A 1M calcium hydroxide slurry solution was prepared and 500 mL was injected into the cylinder body 120.

After the injection, the cylinder body 120 was heated up to 35°C using the heating unit 130, and after the heating was completed, carbon dioxide was injected to a pressure of 75 bar through the injection pipe 160 to make carbon dioxide into a supercritical phase.

Thereafter, a temperature of 35°C and a pressure of 75 bar are maintained, and a reaction time of 30 minutes, 1 hour, 2 hours 30 minutes, and 4 hours is passed, and then the supercritical state through the discharge pipe 150 of the cylinder body 120 The mixture of carbon dioxide and calcium hydroxide slurry was discharged into the recovery chamber 200.

The discharged solution was collected through the discharge pipe 221 and separated into a solid phase and a liquid phase after centrifugation, and the separated solid phase was dried and pulverized again to perform XRD, TGA, SEM-EDX, and FT-R analysis.

[Second Example]

Proceed in the same manner as in the first embodiment, but the temperature was raised to 50°C by varying the temperature and pressure, and carbon dioxide was injected to a pressure of 90 bar to obtain a supercritical phase. The reaction time and analysis method are the same.

[Third Example]

Proceeding in the same manner as in the first embodiment, the temperature was raised to 80°C by varying the temperature and pressure, and carbon dioxide was injected to a pressure of 120 bar to obtain a supercritical phase. The reaction time and analysis method are the same.

As a result of the analysis of these examples, as shown in FIG. 4, the carbonate obtaining efficiency was the highest in the analysis result after 1 hour reaction, and in the case of [Example 2] at 50° C. and 90 bar, after 1 hour reaction It showed a carbonate yield efficiency of 93%.

This result is a result that exceeds the result of up to 85% of the carbonate acquisition efficiency using calcium hydroxide slurry in the conventional research results.

It can be seen that the content of vaterite is high in the analysis result of [Example 1] at 35° C. and 75 bar shown in FIG. 5A, and the analysis result of [Example 2] at 50° C. and 90 bar shown in FIG. 5B In the result of [Example 3] at 80° C. and 120 bar shown in FIG. 5C, the content of Calcite was highest when reacting for 1 hour, and in the case of [Example 2], Aragonite was around 1 hour. It can be seen that the content of and vaterite increases.

In particular, in the analysis result of the [Third Example] shown in FIG. 5C, it can be seen that the content of the homogeneous or higher likewise changes with time, but the width is relatively small. These results indicate that carbonates of different homogeneity can be obtained depending on temperature, pressure conditions, and reaction time, and can be adjusted according to the use.

6 is an SEM image of a carbonate prepared according to the first embodiment of the present invention, FIG. 6A is an SEM image of a carbonate prepared through a reaction time of 30 minutes, and FIG. 6B is a reaction time prepared through a reaction time of 1 hour. It is an SEM image of carbonate, FIG. 6C is an SEM image of carbonate produced through a reaction time of 2 hours and 30 minutes, and FIG. 6D is an SEM image of carbonate produced through reaction time of 4 hours.

Through the SEM images of FIG. 6, it can be seen that vaterite in a round shape than the crystal phase for the calcite particles shown in FIGS. 7 and 8 was precipitated. In addition, it can be seen that particles relatively smaller than the particles of FIGS. 7 and 8 are formed by agglomeration.

Referring to FIG. 7B, it can be seen that the size of the particles in the reaction for 1 hour is even and the crystallinity is good. Referring to FIGS. 7C and 7D, the size of the particles becomes various and the crystal size is also relatively large. .

Referring to FIG. 8B, the size of the particles is relatively largest when reacting for 1 hour, and the results of the reaction time of 2 hours and 30 minutes in FIG. 8C and the reaction time of 4 hours in FIG. 8D show that the smaller crystals are evenly formed as time passes. I can.

Accordingly, comparing the analysis results of FIGS. 7 and 8, it can be seen that the size of the carbonate crystal decreases as a whole when the temperature and pressure conditions are high, and this means that the larger the difference between the temperature and pressure that changes during the discharging process, the smaller the fine particles. It indicates that the carbonate of the particles can be obtained.

As shown in the graph, as shown in Fig. 9A, in the first embodiment under the condition of 35°C and 75 bar, particles of about 40 nm occupy the largest specific gravity, and the specific gravity of the fine particles is the highest on average.

On the other hand, in the result graph of the second embodiment of FIG. 9B and the graph of the third embodiment of FIG. 9C, it can be seen that as the temperature and pressure increase, the specific gravity of the ultrafine particles of 40 nm changes to a greater extent depending on the conditions.

Therefore, in the aspect that it is a useful technique to make carbonate particles of 500 nm or less in the formation of particles of carbonate crystals, the method for producing calcium carbonate according to an embodiment of the present invention has a specific gravity of carbonate crystal particles of about 100 nm or less, which is 90% or more. Can produce calcium.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiments are for the purpose of explanation and not limitation.

In addition, those skilled in the art of the present invention will understand that various implementations are possible within the scope of the technical idea of the present invention.

100: cylinder 110: upper opening and closing part
120: cylinder body 125: slurry supply pipe
130: heating unit 140: observation unit
150: discharge pipe 160: injection pipe
170: temperature and pressure measuring tube 180: stirrer
200: recovery chamber 210: cooler
221: discharge pipe 222: collection pipe

Claims (10)

cylinder;
A recovery chamber connected to the discharge pipe of the cylinder; And
A control unit connected to each of the cylinder and the recovery chamber to control;
Calcium carbonate production system comprising a.
The method of claim 1,
The cylinder is
A cylinder body portion having an inner space;
A slurry supply pipe for supplying a calcium hydroxide slurry from an upper side of the cylinder body to the inner space;
A heating unit provided on one side of the cylinder body;
An observation unit provided on the other side of the cylinder body;
The discharge pipe provided under the cylinder body;
An injection pipe for injecting carbon dioxide from a lower portion of the cylinder body;
A temperature and pressure measuring tube provided under the cylinder body; And
A stirrer provided in the inner space of the cylinder body;
Calcium carbonate production system comprising a.
The method of claim 2,
The heating unit is a calcium carbonate production system, characterized in that provided in the form of a heating belt or a heating jacket including a heating coil.
The method of claim 2,
The discharge pipe is a calcium carbonate production system, characterized in that provided in a form in which the cross-sectional area of the end portion becomes narrower in the inner direction of the recovery chamber than the cross-sectional area of the middle portion.
The method of claim 1,
The recovery chamber is a closed-type chamber that has a low pressure state lower than atmospheric pressure and maintains a low temperature state lower than room temperature by using a cooler provided at the bottom.
(A) The control unit supplies calcium hydroxide slurry to the inner space of the cylinder body through a slurry supply pipe, heats the slurry to a predetermined temperature, and converts the carbon dioxide into a supercritical phase by pressurizing carbon dioxide to the slurry through an injection pipe. step;
(B) maintaining, by the control unit, a reaction in which calcium hydroxide is dissolved in carbon dioxide that has changed into the supercritical phase for a predetermined time; And
(C) the control unit discharging the solution in which the supercritical carbon dioxide and the calcium hydroxide are dissolved into a recovery chamber through a discharge pipe to recover a suspension containing carbonate crystals having rapid crystallization;
Calcium carbonate production method comprising a.
The method of claim 6,
Step (A)
(A-1) heating the calcium hydroxide slurry to a temperature higher than 31° C. through a heating unit provided on one side of the cylinder body by the control unit; And
(A-2) the control unit pressurizing the carbon dioxide at a pressure higher than 74 bar through the injection pipe;
Calcium carbonate production method, characterized in that it further comprises.
The method of claim 6,
The step (B) further comprises the step of stirring the carbon dioxide and calcium hydroxide slurry changed into the supercritical phase using a stirrer provided in the lower center of the cylinder body.
The method of claim 6,
Step (C)
(C-1) detecting, by the controller, a temperature and pressure of a solution in which supercritical carbon dioxide and calcium hydroxide slurry present in the inner space of the cylinder body are mixed through a temperature pressure measuring tube;
(C-2) determining, by the control unit, whether or not to discharge the mixed solution of the supercritical carbon dioxide and calcium hydroxide slurry to the recovery chamber;
(C-3) the control unit discharging the mixed solution through the discharge pipe to the recovery chamber at a discharge rate range of 200 to 340 ml/second; And
(C-4) collecting, by the control unit, the carbon dioxide gas introduced into the recovery chamber through a collection tube;
Calcium carbonate production method, characterized in that it further comprises.
The method of claim 6,
The recovery chamber is a method of manufacturing calcium carbonate, characterized in that the inside of the recovery chamber has a low pressure state lower than atmospheric pressure and is a closed chamber that maintains a low temperature state lower than room temperature by using a cooler provided at the bottom.

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