CN116332553A - Cementing microsphere and preparation method and application thereof - Google Patents

Abstract

The invention provides a cemented microsphere and its preparation method and application. The cemented microsphere provided by the invention comprises an outer shell layer and a repair inner core, wherein the outer shell layer is wrapped with a dense fiber membrane, and the repair inner core layer includes a carbonized gel material and a carbon dioxide source. When the cemented microspheres are cured by carbon dioxide, the temperature of the system rises, the water evaporates, and the inner layer of the product generates stress; the fiber film is destroyed, and the carbonized gelling material inside the cemented microspheres reacts with carbon dioxide to form calcium carbonate crystal nuclei and have cementation properties. The effective C‑S‑H gel can repair the cracks and prevent the product from cracking; the excess carbon dioxide can also react with the carbonized gelling material inside the product to increase the degree of carbonization of the product.

Description

A kind of cemented microsphere and its preparation method and application

technical field

The invention belongs to the technical field of carbon mineralization reaction products, and relates to a cemented microsphere and its preparation method and application, in particular to a cemented microsphere, its preparation method, and a product and application for carbon mineralization reaction.

Background technique

In recent years, technologies and researches on the absorption, capture and utilization of carbon dioxide have been increasing; in the construction industry, materials rich in calcium silicate phase or calcium hydroxide can form a calcite-containing structure under carbon dioxide carbonation curing. Carbonized products. For example, Chinese patent CN114163205 discloses adding slag and reinforcing agent solution to steel slag to prepare building material products; Chinese patent CN115108784 discloses a kind of thiourea slag carbonized brick and its preparation method. Aggregate is mixed, and admixture or aqueous solution is added, and the strength of MU10 or more can be reached after carbonization and curing after compression molding; Chinese patent CN113998933 discloses a calcium silicate board and its preparation method, by adding iron oxide green to silicate two Calcium is carbonized in a vacuum _CO2 environment to form a high-strength calcium silicate board. However, the carbonization reaction is an exothermic reaction. During the curing process, a large amount of heat will be released, which will increase the temperature in the body system, and then cause the surface water to evaporate. When the surface moisture content drops below the saturation point, the surface layer of the product begins to shrink. , but at this time the water content of the inner layer of the product is still above saturation. The shrinkage of the surface layer of the product is restricted by the inner layer and cannot shrink freely, so stress is generated inside the product, the surface layer is pulled, and the inner layer is compressed, which in turn causes the product to crack. Moreover, after the carbon dioxide reacts with the carbonized cementitious material, the generated calcium carbonate will hinder the further entry of carbon dioxide, the inner cementitious material is difficult to carbonize, and the mechanical strength of the product decreases accordingly.

Although there are also some technical solutions that have carried out corresponding research, such as Chinese patent CN112645736, the combination of modified silica microspheres and modified composite fibers is used to make the modified silica microspheres adhere to the surface of the modified composite fibers. The good connection performance between composite fiber and cement makes lightweight concrete have good crack resistance, but the modified silica microspheres can only be used in the hydration reaction of poured concrete, which has certain limitations .

Therefore, how to find a more suitable way to solve the problems of product cracking and insufficient carbonization in the carbonization reaction in the above-mentioned prior art, and the current situation that the solution is relatively scarce, has become a problem for many front-line researchers and R&D-oriented researchers in the industry. One of the focuses of widespread attention of technology companies.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide a cemented microsphere and a preparation method thereof. The cemented microspheres provided by the invention can solve the problems of cracking and low carbonization degree of carbon mineralization reaction products during carbonization maintenance, and have low production cost, simple process and mild conditions, which are beneficial to realize industrial scale production and application.

The invention provides a cemented microsphere, which includes a fiber membrane, a carbonized gel material and a carbon dioxide source wrapped in the fiber membrane.

Preferably, the cemented microspheres have a core-shell structure;

The cemented microspheres use the fiber membrane as the shell, and the carbonized gelling material and the carbon dioxide source as the core;

The thickness of the fiber membrane is 200-600 μm;

The particle size of the cemented microspheres is 1-5 mm.

Preferably, the mass ratio of the fiber membrane to the carbonized cementitious material is (1-5): (100-200);

The mass ratio of the carbonized gelling material to the carbon dioxide source is (5-15):1;

The fiber membrane is a dense fiber membrane;

The material of the fiber membrane includes one or more of polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose and polyacrylamide.

Preferably, the carbonized cementitious material comprises a calcium silicate-rich phase and/or a calcium hydroxide-rich material;

The material rich in calcium silicate phase includes one or more of steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate and tricalcium disilicate;

The calcium hydroxide-rich material includes one or more of red mud, carbide slag and thiourea slag;

The carbon dioxide source comprises dry ice and/or capsules of carbon dioxide-containing gas;

The carbon dioxide-containing gas includes industrial tail gas containing carbon dioxide;

The industrial tail gas containing carbon dioxide includes one or more of the tail gas of thermal power plant, rubber factory tail gas, kiln tail gas, cement factory tail gas, paint factory tail gas and thiourea tail gas;

The shell components of the capsules include gelatin and glycerin.

The invention provides a method for preparing cemented microspheres, comprising the following steps:

1) mixing the carbonized cementitious material with a carbon dioxide source at low temperature to obtain a mixture;

2) The mixture obtained in the above steps is placed in the cellulose solution, so that the cellulose wraps the mixture to obtain cemented microspheres.

Preferably, the low-temperature mixing method includes low-temperature and slow-speed stirring and mixing;

The speed of the low temperature mixing is 30～60rpm;

The temperature of the low temperature mixing is -50～20°C;

The time for the low-temperature mixing is 1-10 minutes.

Preferably, the mass ratio of the carbonized gelling material to the carbon dioxide source is (5-15):1;

The time for placing is 1 to 20 minutes.

The present invention provides a product for carbon mineralization reaction, including the cemented microspheres described in any one of the above technical solutions or the cemented microspheres prepared by the preparation method described in any one of the above technical solutions.

Preferably, the product also includes a matrix material and water;

The matrix material includes steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate and tricalcium disilicate, furnace slag, carbide slag, thiourea slag, quartz sand tailing One or more of ore and fly ash;

In the product, the mass content of the matrix material is 50% to 80%;

In the product, the mass content of cemented microspheres is 5% to 30%;

In the product, the mass content of water is 8% to 20%;

The product is obtained by mixing cemented microspheres, matrix material and water, and then pressing;

The pressing pressure is 5-30 MPa.

The present invention also provides the cemented microspheres described in any one of the above technical solutions, the cemented microspheres prepared by the preparation method described in any one of the above technical solutions, or the products described in any one of the above technical solutions in the field of building materials Application in carbonation conservation.

The invention provides a cemented microsphere, which includes a fiber membrane, a carbonized gel material and a carbon dioxide source wrapped in the fiber membrane. Compared with the prior art, the present invention provides a cemented microsphere with a specific structure and composition, including an outer shell and a repaired inner core, the outer shell is a dense fiber membrane, and the inner repair includes a carbonized cementitious material and a carbon dioxide source . When carbon dioxide is curing carbonized products, the temperature of the system rises, the water evaporates, and the inner layer of the product generates stress; the fiber film is destroyed, and the carbonized gelling material inside the cemented microspheres reacts with carbon dioxide to form calcium carbonate crystal nuclei and C-S-H condensation with cementation. Glue, and then repair the cracks and prevent the product from cracking; the excess carbon dioxide can also react with the carbonized gelling material inside the product to increase the degree of carbonization of the product.

When the cemented microspheres provided by the present invention are applied to carbonization curing, the carbonization reaction releases heat, which increases the temperature of the system, and the dry ice particles are heated and gasified to form carbon dioxide gas, which is filled in the interior of the microspheres; when the temperature rises, the surface moisture of the product is heated and evaporated , when the surface moisture content drops below the saturation point, the surface layer of the product begins to shrink, but at this time the moisture content of the adjacent inner layer of the product is still above the saturation point, and no shrinkage occurs. The shrinkage of the product surface layer is limited by the inner layer. It cannot shrink freely, so stress is generated inside the product, which in turn causes cracking of the product. The carbon dioxide filling the inside of the microspheres creates an outward expansion pressure on the fiber membrane; the fiber membrane ruptures after being subjected to the pulling force of the outer crack and the outward pressure. At the same time, the carbon dioxide reacts with the gel material of the cemented microsphere repair layer to generate Calcite with crystal nucleation and C-S-H gel with bonding effect to repair cracks. In addition, each cemented microsphere can also be used as a "small supply station" for the carbonization reaction. Excess carbon dioxide reacts with the carbonized gelling material in the cemented microsphere and then continues to diffuse, and the carbonized gelled material in the carbonized product outside the cemented microsphere Further reaction to increase the degree of carbonization of the product.

The cemented microspheres provided by the invention, the calcium carbonate and C-S-H produced by the reaction of the fiber membrane of the cemented microsphere shell layer and the carbonized gelling material, play the role of crystal nucleus, connection and bonding, and can be effectively repaired during the maintenance process of the carbonization process The carbon dioxide inside the cemented microspheres can further react with the gelling material in the product, increasing the degree of carbonization of the product, thereby improving the mechanical properties of the prepared product, and the production cost is low, the process is simple, and the conditions are mild. , which is conducive to the realization of industrial scale production and application.

Experimental results show that, using the cemented microspheres provided by the present invention, the building material products formed by carbonization can significantly improve the compressive strength and degree of carbonization, the highest increase is 17.15MPa and 5.55%, respectively, and the performance is improved by about 27%. For cementitious materials, without adding dry ice, there is no obvious improvement in performance. At the same time, changing the type of carbonized cementitious material and the ratio of carbon dioxide source can also help to improve the compressive strength and degree of carbonization.

Description of drawings

Fig. 1 is a schematic diagram of the reaction mechanism of cemented microspheres provided by the present invention in carbonization curing.

Detailed ways

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the invention.

All raw materials in the present invention have no particular limitation on their sources, they can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

The purity of all raw materials in the present invention is not particularly limited, and the present invention preferably adopts industrial purity or conventional purity requirements in the field of carbon mineralization reaction product preparation.

All raw materials of the present invention, their grades and abbreviations belong to the conventional grades and abbreviations in this field, and each grade and abbreviation are all clear and definite in the field of its related use. Those skilled in the art can according to the grades, abbreviations and corresponding uses, It can be purchased from commercial sources or prepared by conventional methods.

The invention provides a cemented microsphere, which includes a fiber membrane, a carbonized gel material and a carbon dioxide source wrapped in the fiber membrane.

In the present invention, the cemented microspheres preferably have a core-shell structure.

In the present invention, the cemented microspheres preferably use the fiber membrane as the shell, and the carbonized cementitious material and the carbon dioxide source as the core.

In the present invention, the thickness of the fiber membrane is preferably 200-600 μm, more preferably 250-550 μm, more preferably 300-500 μm, more preferably 350-450 μm.

In the present invention, the particle size of the cemented microspheres is preferably 1-5 mm, more preferably 1.5-4.5 mm, more preferably 2-4 mm, more preferably 2.5-3.5 mm.

In the present invention, the mass ratio of the fiber membrane to the carbonized cementitious material is preferably (1-5): (100-200), more preferably (2-4): (100-200), and more preferably ( 1~5): (140~160).

In the present invention, the mass ratio of the carbonized gelling material to the carbon dioxide source is preferably (5-15):1, more preferably (7-13):1, more preferably (9-11):1.

In the present invention, the fibrous membrane is preferably a dense fibrous membrane.

In the present invention, the material of the fiber membrane preferably includes one or more of polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose and polyacrylamide, more preferably polyvinyl alcohol, carboxymethyl cellulose Cellulose, hydroxyethylcellulose or polyacrylamide.

In the present invention, the carbonized cementitious material preferably includes a calcium silicate-rich phase and/or a calcium hydroxide-rich material, more preferably a calcium silicate-rich phase or a calcium hydroxide-rich material.

In the present invention, the material rich in calcium silicate phase preferably includes steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate and tricalcium disilicate One or more, more preferably steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate or tricalcium disilicate.

In the present invention, the calcium hydroxide-rich material preferably includes one or more of red mud, carbide slag and thiourea slag, more preferably red mud, carbide slag or thiourea slag.

In the present invention, the carbon dioxide source preferably comprises dry ice and/or capsules containing carbon dioxide gas, more preferably dry ice or capsules containing carbon dioxide gas.

In the present invention, the carbon dioxide-containing gas preferably includes industrial tail gas containing carbon dioxide.

In the present invention, the industrial tail gas containing carbon dioxide preferably includes one or more of thermal power plant tail gas, rubber factory tail gas, kiln tail gas, cement factory tail gas, paint factory tail gas and thiourea tail gas, more preferably thermal power plant tail gas, rubber factory tail gas Factory tail gas, kiln tail gas, cement factory tail gas, paint factory tail gas or thiourea tail gas.

In the present invention, the shell components of the capsule preferably include gelatin and glycerin.

When the carbon dioxide source used in the present invention is industrial tail gas containing carbon dioxide, the industrial tail gas containing carbon dioxide can be placed in a gas capsule, stirred evenly with the carbonized gelling material, then wrapped in a fiber solution, and the gas capsule can be mixed with the gas capsule for a short time at room temperature Contact with an aqueous solution of cellulose does not dissolve the capsules. During carbonization curing, after the fiber membrane is heated and ruptured, the water generated by the reaction of the carbonized gelling material and the external carbon dioxide enters the interior of the cemented microspheres. In addition, the ambient temperature rises during the carbonization reaction, and the gelatin in the shell of the gas capsule is dissolved in hot water, thereby Carbon dioxide gas is released.

The present invention is a complete and refined overall technical solution, which can better ensure the structure, composition and characteristics of cemented microspheres, and better improve the degree of carbonization and mechanical properties of carbon mineralized products. The above cemented microspheres specifically include the following structures:

A cemented microsphere includes an outer shell layer and a repair layer, the outer shell layer is a dense fiber membrane, and the repair layer includes a carbonized gel material and a carbon dioxide source.

Specifically, the dense fiber membrane includes one or more of polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, and polyacrylamide.

Specifically, the carbonized cementitious material is a material rich in calcium silicate phase or calcium hydroxide.

Specifically, the materials rich in calcium silicate phase components include steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate, and tricalcium disilicate one or more.

Specifically, the calcium hydroxide-rich material includes one or more of red mud, carbide slag, and thiourea slag.

Specifically, the carbon dioxide source includes dry ice or capsules containing carbon dioxide gas. Wherein, the gas containing carbon dioxide includes industrial tail gas containing carbon dioxide.

Specifically, the carbon dioxide-containing gas preferably includes industrial tail gas containing carbon dioxide.

Specifically, the industrial tail gas containing carbon dioxide includes one or more of tail gas from thermal power plants, rubber factory tail gas, kiln tail gas, cement factory tail gas, paint factory tail gas, and thiourea tail gas.

Specifically, the shell components of the capsule preferably include gelatin and glycerin.

The invention provides a method for preparing cemented microspheres, comprising the following steps:

1) mixing the carbonized cementitious material with a carbon dioxide source at low temperature to obtain a mixture;

2) The mixture obtained in the above steps is placed in the cellulose solution, so that the cellulose wraps the mixture to obtain cemented microspheres.

In the present invention, firstly, the carbonized cementitious material is mixed with a carbon dioxide source at low temperature to obtain a mixture.

In the present invention, the low-temperature mixing method preferably includes low-temperature and slow-speed stirring and mixing.

In the present invention, the speed of the low-temperature mixing is preferably 30-60 rpm, more preferably 35-55 rpm, more preferably 40-50 rpm.

In the present invention, the temperature of the low-temperature mixing is preferably -50 to 20°C, more preferably -40 to 10°C, more preferably -30 to 0°C, more preferably -20 to -10°C.

In the present invention, the time for the low-temperature mixing is preferably 1-10 min, more preferably 3-8 min, and more preferably 5-6 min.

In the present invention, the mass ratio of the carbonized gelling material to the carbon dioxide source is preferably (5-15):1, more preferably (7-13):1, more preferably (9-11):1.

Finally, in the present invention, the mixture obtained in the above steps is placed in the cellulose solution, so that the cellulose wraps the mixture to obtain cemented microspheres.

In the present invention, the standing time is preferably 1-20 min, more preferably 3-18 min, more preferably 5-15 min, more preferably 8-12 min.

The present invention is a complete and refined overall technical solution, which can better ensure the structure, composition and characteristics of cemented microspheres, and better improve the degree of carbonization and mechanical properties of carbon mineralized products. The preparation method of the above cemented microspheres can specifically include The following steps:

A preparation method of cemented microspheres, comprising the following steps:

Stir the carbonized cementitious material and dry ice particles at low temperature and slowly to form a mixture of carbonized cementitious material and dry ice particles;

The mixture is soaked in the cellulose solution, so that the cellulose solution completely wraps the mixture of the carbonized cementitious material and the dry ice particles, and forms a dense fiber film on the surface of the mixture.

Specifically, in the mixture, the mass ratio of the carbonized cementitious material to the dry ice is 5-15:1.

Specifically, the low temperature and slow speed stirring, the stirring rate is 30-60 rpm, the stirring temperature is -50°C-20°C, and the stirring time is 1min-10min.

Specifically, the wrapping time is 1min-20min.

The present invention provides a product (carbon mineralization product) for carbon mineralization reaction, including the cemented microspheres prepared by any one of the above technical solutions or the cemented microspheres prepared by the preparation method described in any one of the above technical solutions. Microspheres.

In the present invention, the article preferably also includes a base material and water.

In the present invention, the matrix material preferably includes steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate and tricalcium disilicate, furnace slag, carbide slag, sulfur One or more of urea slag, quartz sand tailings and fly ash, more preferably steel slag, magnesium slag, cement, β-dicalcium silicate, γ-dicalcium silicate, monocalcium silicate and disilicate Tricalcium acid, furnace slag, carbide slag, thiourea slag, quartz sand tailings or fly ash.

In the present invention, in the product, the mass content of the matrix material is preferably 50%-80%, more preferably 55%-75%, more preferably 60%-70%.

In the present invention, in the product, the mass content of cemented microspheres is preferably 5%-30%, more preferably 10%-25%, more preferably 15%-20%.

In the present invention, in the product, the mass content of water is preferably 8%-20%, more preferably 10%-18%, more preferably 12%-16%.

In the present invention, the product is preferably obtained by mixing cemented microspheres, matrix material and water, and then pressing.

In the present invention, the pressing pressure is preferably 5-30 MPa, more preferably 10-25 MPa, more preferably 15-20 MPa.

In the present invention, the cemented microspheres are located everywhere in the carbon mineralized product, and the carbon mineralization reaction is carried out, and the cemented microspheres only exist in the non-carbon mineralized area. Concretely, the cemented microspheres are located in the carbon mineralized products, and along with the carbon mineralization process of the products used for carbon mineralization, the cemented microspheres are integrated with the carbon mineralized products along with the carbon mineralized process, and the non-carbon mineralized In the area of , there are cemented microspheres.

Referring to Fig. 1, Fig. 1 is a schematic diagram of the reaction mechanism of the cemented microspheres provided by the present invention in carbonization curing. Among them, 1-carbonized area in the carbonized product, 2-fiber film, 3-carbonized cementitious material and dry ice mixture, 4-uncarbonized area in the carbonized product.

The present invention provides the cemented microspheres described in any one of the above technical solutions, the cemented microspheres prepared by the preparation method described in any one of the above technical solutions, or the products described in any one of the above technical solutions in the field of building materials application in chemical maintenance.

Specifically, the application may be the application in the maintenance process of carbonized products in the field of building materials.

The above content of the present invention provides a cemented microsphere and its preparation method, products and applications for carbon mineralization reaction. The cemented microsphere with specific structure and composition provided by the invention comprises an outer shell layer and a repair inner core, the outer shell layer is wrapped with a dense fiber membrane, and the inner repair layer includes carbonized cementitious material and a carbon dioxide source. When carbon dioxide is curing carbonized products, the temperature of the system rises, the water evaporates, and the inner layer of the product generates stress; the fiber film is destroyed, and the carbonized gelling material inside the cemented microspheres reacts with carbon dioxide to form calcium carbonate crystal nuclei and C-S-H condensation with cementation. Glue, and then repair the cracks and prevent the product from cracking; the excess carbon dioxide can also react with the carbonized gelling material inside the product to increase the degree of carbonization of the product.

When the cemented microspheres provided by the present invention are applied to carbonization curing, the carbonization reaction releases heat, which increases the temperature of the system, and the dry ice particles are heated and gasified to form carbon dioxide gas, which is filled in the interior of the microspheres; when the temperature rises, the surface moisture of the product is heated and evaporated , when the surface moisture content drops below the saturation point, the surface layer of the product begins to shrink, but at this time the moisture content of the adjacent inner layer of the product is still above the saturation point, and no shrinkage occurs. The shrinkage of the product surface layer is limited by the inner layer. It cannot shrink freely, so stress is generated inside the product, which in turn causes cracking of the product. The carbon dioxide filling the inside of the microspheres creates an outward expansion pressure on the fiber membrane; the fiber membrane ruptures after being subjected to the pulling force of the outer crack and the outward pressure. At the same time, the carbon dioxide reacts with the gel material of the cemented microsphere repair layer to generate Calcite with crystal nucleation and C-S-H gel with bonding effect to repair cracks. In addition, each cemented microsphere can also be used as a "small supply station" for the carbonization reaction. Excess carbon dioxide reacts with the carbonized gelling material in the cemented microsphere and continues to diffuse, and the carbonized gelled material in the carbonized product outside the cemented microsphere Further reaction to increase the degree of carbonization of the product.

The cemented microspheres provided by the invention, the calcium carbonate and C-S-H produced by the reaction of the fiber membrane of the cemented microsphere shell layer and the carbonized gelling material, play the role of crystal nucleus, connection and bonding, and can be effectively repaired during the maintenance process of the carbonization process The carbon dioxide inside the cemented microspheres can further react with the gelling material in the product, increasing the degree of carbonization of the product, thereby improving the mechanical properties of the prepared product, and the production cost is low, the process is simple, and the conditions are mild. , which is conducive to the realization of industrial scale production and application.

Experimental results show that, using the cemented microspheres provided by the present invention, the building material products formed by carbonization can significantly improve the compressive strength and degree of carbonization, the highest increase is 17.15MPa and 5.55%, respectively, and the performance is improved by about 27%. For cementitious materials, without adding dry ice, there is no obvious improvement in performance. At the same time, changing the type of carbonized cementitious material and the ratio of carbon dioxide source can also help to improve the compressive strength and degree of carbonization.

In order to further illustrate the present invention, a kind of cemented microsphere provided by the present invention and its preparation method and application are described in detail below in conjunction with the examples, but it should be understood that these examples are implemented on the premise of the technical solution of the present invention. The detailed implementation and specific operation process are only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following examples.

The source of the selected raw material of embodiment and comparative example is consistent.

Example 1 (steel slag: different proportions of dry ice particles 1)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of steel slag and 4 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious material and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Embodiment 2 (steel slag: different proportions of dry ice particles 2)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of steel slag and 8 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious material and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Embodiment 3 (add cemented microsphere ratio 1)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of steel slag and 8 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious material and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 22 parts of cemented microspheres, mix them evenly, and press them into a carbonized product of 10cm×10cm×2cm under a pressure of 20MPa, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Embodiment 4 (add cemented microsphere ratio 2)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of steel slag and 8 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious material and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 66 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Example 5 (different carbonized cementitious materials 1)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of γ-C ₂ S and 8 parts of dry ice particles at a temperature of -10°C and a rotation speed of 30 rpm to form a mixture of carbonized gelling material and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Example 6 (different carbonized cementitious material 2)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of carbide slag and 8 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious materials and dry ice particles;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Example 7 (different fiber membranes)

Stir 40 parts of carbide slag and 8 parts of dry ice particles evenly at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized cementitious material and dry ice particles;

Soak the mixture in the carboxymethylcellulose solution for 10 minutes, so that the carboxymethylcellulose solution completely wraps the mixture of carbonized cementitious material and dry ice particles, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Embodiment 8 (when carbon dioxide source is gas)

Inject carbon dioxide gas into the carbon dioxide gas capsule, stir 40 parts of steel slag and 8 parts of carbon dioxide gas capsule at a temperature of -10°C and a speed of 30 rpm to form a mixture of carbonized gelling material and gas capsule;

Soak the mixture in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the mixture of the carbonized gelling material and the gas capsule, forming a dense fiber film on the surface of the mixture;

Take 200 parts of steel slag, 48 parts of water, and 22 parts of cemented microspheres, mix them evenly, and press them into a carbonized product of 10cm×10cm×2cm under a pressure of 20MPa, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Comparative example 1 (without adding cemented microspheres)

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Comparative example 2 (only adding carbonized cementitious material)

A cemented microsphere and its preparation method and application, the steps are as follows:

Stir 40 parts of steel slag evenly at a temperature of -10°C and a speed of 30 rpm;

Soak the steel slag in the polyvinyl alcohol cellulose solution for 10 minutes, so that the polyvinyl alcohol cellulose solution completely wraps the steel slag and forms a dense fiber film on the surface;

Take 200 parts of steel slag, 48 parts of water, and 44 parts of cemented microspheres, mix them evenly, and press them under a pressure of 20 MPa to form a carbonized product of 10 cm × 10 cm × 2 cm, and place them in a carbonization device for carbonization. Carbonization conditions: carbon dioxide concentration 10%, carbon dioxide pressure 0.2 MPa, carbonization temperature 50°C, carbonization time 20h.

Performance Testing

1. Compressive strength test

The compressive strength of the samples was tested using a SANS universal testing machine.

2. Carbonation degree test

计算钙离子的碳化程度，再计算出镁离子的碳化程度，相加即得该块制品的碳化程度；再计算其他区域的碳化程度，取平均值。After the product is cut into pieces, crushed, and ground, the mass m1 is obtained, and the mass m2 is obtained by placing it in a muffle furnace at 500°C for 2 hours, and then calcined at 1000°C for 2 hours to obtain the mass m3. After performing XRF test, the percentage content A of sample CaO and MgO is obtained, through the formula

Calculate the degree of carbonization of calcium ions, then calculate the degree of carbonization of magnesium ions, add up to get the degree of carbonization of the block product; then calculate the degree of carbonization of other regions, and take the average value.

The above test results are shown in Table 1. Table 1 shows the performance data of the carbonized products prepared in the examples and comparative examples of the present invention after carbonization.

Table 1

A kind of cemented microsphere provided by the present invention and its preparation method, products for carbon mineralization reaction, and application have been introduced in detail above. In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The above The description of the embodiment is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables anyone skilled in the art to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims (10)

1. A cementitious microsphere, wherein the cementitious microsphere comprises a fibrous membrane and a carbonized gelling material and a carbon dioxide source encased within the fibrous membrane.

2. The cementitious microsphere of claim 1, wherein the cementitious microsphere has a core-shell structure;

the cementing microsphere takes a fiber membrane as a shell layer, and carbonized cementing materials and carbon dioxide as cores;

the thickness of the fiber film is 200-600 mu m;

the granularity of the cementing microsphere is 1-5 mm.

3. The cementitious microsphere of claim 1, wherein the mass ratio of fibrous membrane to carbonized cementitious material is (1-5): (100-200);

the mass ratio of the carbonized cementing material to the carbon dioxide source is (5-15): 1, a step of;

the fiber membrane is a compact fiber membrane;

the fiber membrane is made of one or more of polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose and polyacrylamide.

4. The cementitious microsphere of claim 1, wherein the carbonized cementitious material comprises a calcium silicate-rich phase and/or calcium hydroxide-rich material;

the material rich in the calcium silicate phase comprises one or more of steel slag, magnesium slag, cement, beta-dicalcium silicate, gamma-dicalcium silicate, monocalcium silicate and tricalcium silicate;

the calcium hydroxide-rich material comprises one or more of red mud, carbide slag and thiourea slag;

the carbon dioxide source comprises dry ice and/or capsules containing carbon dioxide gas;

the carbon dioxide-containing gas comprises an industrial tail gas containing carbon dioxide;

the industrial tail gas containing carbon dioxide comprises one or more of tail gas of a thermal power plant, tail gas of a rubber plant, tail gas of a kiln, tail gas of a cement plant, tail gas of a paint plant and tail gas of thiourea;

the shell components of the capsule comprise gelatin and glycerin.

5. A method for preparing a cementitious microsphere, comprising the steps of:

1) Mixing the carbonized cementing material with a carbon dioxide source at a low temperature to obtain a mixture;

2) And (3) placing the mixture obtained in the steps into a cellulose solution to enable the cellulose to wrap the mixture, thereby obtaining the cementing microsphere.

6. The method according to claim 5, wherein the low-temperature mixing mode comprises low-temperature slow stirring mixing;

the low-temperature mixing speed is 30-60 rpm;

the temperature of the low-temperature mixing is-50-20 ℃;

the low-temperature mixing time is 1-10 min.

7. The method according to claim 6, wherein the mass ratio of the carbonized gelling material to the carbon dioxide source is (5 to 15): 1, a step of;

the time for the placing is 1-20 min.

8. An article for use in a carbon mineralization reaction comprising the cementitious microsphere of any one of claims 1 to 4 or the cementitious microsphere prepared by the method of any one of claims 5 to 7.

9. The article of claim 8, further comprising a matrix material and water;

the matrix material comprises one or more of steel slag, magnesium slag, cement, beta-dicalcium silicate, gamma-dicalcium silicate, monocalcium silicate and tricalcium silicate, slag, carbide slag, thiourea slag, quartz sand tailings and fly ash;

in the product, the mass content of the matrix material is 50% -80%;

in the product, the mass content of the cementing microsphere is 5-30%;

in the product, the mass content of water is 8% -20%;

the product is obtained by mixing the cementing microsphere, a matrix material and water and then pressing;

the pressing pressure is 5-30 MPa.

10. Use of the cementitious microsphere according to any one of claims 1 to 4, the cementitious microsphere prepared by the method of any one of claims 5 to 7 or the article according to any one of claims 8 to 9 in carbonation curing in the construction field.

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