Method for the controlled preparation of solid spherical calcite from a dicalcium silicate powder material

Abstract

The application discloses a method for controllably preparing solid spherical calcite from a di-calcium silicate powder material, and comprises the following steps: S1, mixing calcium carbide slag, sandstone and a fluxing agent to obtain raw material; S2, mixing the raw material with a solvent and pressing into a green body; S3, grinding the calcined green body to obtain clinker powder; S4, adding triethanolamine aqueous solution into the clinker powder to obtain a suspension; S5, introducing carbon dioxide gas into the suspension to perform a carbonization reaction, and obtaining a mixed liquid; and S6, performing solid-liquid separation on the mixed liquid, and then washing and drying, so as to obtain the solid spherical calcite. The application utilizes the double regulation and control mechanism of triethanolamine in the silicate wet carbonization process, realizes accurate regulation and control of the micro-morphology of calcium carbonate, and obtains the solid spherical calcite with smooth surface and compact structure.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, and in particular to a method for the controllable preparation of solid spherical calcite from dicalcium silicate powder material. Background Technology

[0002] With the acceleration of industrialization, the stockpiles of bulk industrial solid waste such as calcium carbide slag and mine tailings are increasing daily, not only occupying land but also causing serious environmental pollution. Meanwhile, the carbon emission problems of the cement and other building materials industries urgently need to be addressed. Utilizing calcium-rich solid waste for CO2 mineralization and sequestration to generate stable carbonates is an effective way to achieve carbon emission reduction targets and high-value utilization of solid waste.

[0003] Traditional mineralization technologies often focus on the CO2 solidification amount and mechanical properties of the products, neglecting the high-value utilization of the mineralized products. Calcium carbonate, as an important inorganic chemical product, has its application value directly determined by its morphology and particle size. Spherical calcium carbonate, due to its large specific surface area, good flowability, and excellent dispersibility, has broad application prospects in rubber, plastics, and papermaking. However, current methods for preparing spherical calcium carbonate mostly use pure chemical reagents as raw materials (such as CaCl2 and Na2CO3), resulting in high costs. Utilizing silicate minerals (such as dicalcium silicate, C2S) for carbonation to prepare calcium carbonate is a low-cost route, but the silicate carbonation process is accompanied by the formation of amorphous silica (silica gel), and Ca... 2+ The limited dissolution rate results in products that are usually irregular lumps or agglomerates, making it difficult to obtain spherical calcite with regular morphology.

[0004] Therefore, developing a technology that can effectively stimulate the activity of C2S in solid waste and precisely control the morphology of carbonization products is of great significance for the high-value utilization of solid waste. Summary of the Invention

[0005] In view of this, this application provides a method for controllably preparing solid spherical calcite from dicalcium silicate powder material, which solves the problem of how to obtain solid spherical calcite with regular morphology using solid waste materials.

[0006] To achieve the above technical objectives, this application adopts the following technical solution: In a first aspect, this application provides a method for the controllable preparation of solid spherical calcite from dicalcium silicate powder material, comprising the following steps: S1. Mix carbide slag, sandstone and flux to obtain raw meal; S2. Mix the raw materials with the solvent and press them into a blank; S3. After calcining the green body, grind it to obtain clinker powder; S4. Add triethanolamine aqueous solution to clinker powder to obtain a suspension; S5. Carbon dioxide gas is introduced into the suspension to carry out a carbonization reaction, resulting in a mixed liquid; S6. After solid-liquid separation of the mixture, wash and dry to obtain solid spherical calcite.

[0007] Preferably, the concentration of the triethanolamine aqueous solution is 0.1-5.0 g / L.

[0008] Preferably, the liquid-to-solid mass ratio in the suspension is 10-30:1.

[0009] Preferably, in step S5, the flow rate of carbon dioxide gas is 0.1-1.0 L / min, the reaction pressure is 0.1-0.5 MPa, and the carbonization reaction time is 5-60 min.

[0010] Preferably, the raw material has a calcium-to-silicon ratio (C / S) of 1.2-2.5:1, a silicon content (SM) of 2.0-4.0:1, and an aluminum content (IM) of 1.0-3.0:1.

[0011] Preferably, in step S3, the calcination temperature is 1150-1450℃, and the heating rate is 5-15℃ / min.

[0012] Preferably, the carbide slag includes calcium oxide and sodium, potassium and aluminum impurities, wherein the calcium oxide content is greater than or equal to 60 wt%; and the particle size of the carbide slag is 5-200 μm.

[0013] Preferably, the sandstone includes silica and sodium, potassium and aluminum impurities, wherein the silica content is greater than or equal to 60 wt%; and the sandstone grain size is 5-200 μm.

[0014] Preferably, the flux is iron(III) oxide; the amount of flux used is 0.5-5 wt% of the raw material.

[0015] Secondly, this application provides a solid spherical calcite.

[0016] The beneficial effects of this application are as follows: This invention fully utilizes the compositional characteristics of carbide slag and sandstone, by introducing a flux and utilizing the alkali metal ions (Na+) naturally present in the solid waste. + K + Al 3+ This method enables low-temperature sintering of calcium silicate clinker. The lattice distortion effect caused by impurity ions entering the crystal lattice allows the clinker to achieve excellent carbon mineralization activity at lower temperatures, significantly reducing production energy consumption. This results in the construction of a solid waste-based calcium silicate clinker system with low energy consumption and high carbon mineralization activity.

[0017] This invention utilizes the dual regulatory mechanism of triethanolamine in the wet carbonization process of silicates. The hydroxyl groups in the triethanolamine molecule form unstable chelates with calcium ions on the clinker surface, accelerating the release of calcium ions from the silicate into the liquid phase. This creates extremely high local supersaturation in the early stages of the reaction, promoting calcium carbonate nucleation. Simultaneously, the triethanolamine molecule inhibits the normal growth of specific crystal faces through chemisorption, forcing the crystal to change its natural rhombohedral growth habit and instead undergo isotropic stacking or radial spheroidal growth. Ultimately, it self-assembles to form solid spherical calcite with a smooth surface and dense structure, achieving precise control over the microstructure of calcium carbonate.

[0018] The spherical calcite prepared by this invention has a uniform particle size distribution and good dispersibility, and can be used as a functional material in industries such as plastics, rubber, and adhesives, showing promising prospects for high-value applications. Simultaneously, this process can consume large quantities of bulk industrial solid waste such as carbide slag and sandstone, and permanently seal carbon dioxide, effectively solving the problems of uncontrollable morphology and low added value of existing solid waste mineralization products. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0020] Figure 1 The X-ray diffraction patterns of the wet carbonization products of Examples 1-2 and Comparative Example 1 are shown below. Figure 2 Fourier transform infrared spectra of the wet carbonization products of Examples 1-2 and Comparative Example 1; Figure 3 The images show the microstructure of the wet carbonization products of Examples 1-2 and Comparative Example 1. Detailed Implementation

[0021] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0022] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0025] Unless otherwise explicitly defined and specified herein, all technical and scientific terms used in this application shall have the generally accepted meanings understood by one of ordinary skill in the field of chemical and chemical materials technology (including but not limited to polymer chemistry, inorganic chemistry, organic synthesis, catalysis chemistry, materials processing, and chemical unit operations) based on their professional knowledge and conventional practice. The use of any terminology herein is intended to describe the specific embodiments of this application in the clearest and most accurate manner, so as to fully disclose the technical solution. Such use shall not in any way be construed as a limitation on the scope of the claims, nor does it imply the exclusion of equivalent technical solutions that could be reasonably known by one of skill in the art based on the concept of this application.

[0026] The terms "comprising," "including," "having," "containing," and any grammatical variations or similar expressions used in the specification and claims of this application are all open-ended and non-exhaustive descriptive terms. Their purpose is to explicitly describe the existence of technical features, components, steps, or parts, while explicitly allowing and covering the possibility that other features, components, steps, parts, or any combinations thereof not explicitly listed may exist or be added to the technical solution, as long as such additions do not destroy the integrity and inventiveness of the original technical solution.

[0027] When the terms "embodiments," "some embodiments," or "specific embodiments" are mentioned in the specification, they refer to examples that, in conjunction with the specific parameters, materials, steps, and results described in that section, constitute one or a group of examples for implementing the technical solutions of this application. These embodiments are used for full disclosure and illustrative purposes, not for exhaustive enumeration. Those skilled in the art should understand that, without departing from the overall inventive concept of this application, the various technical features disclosed in different embodiments can be combined, substituted, modified, or deleted to form other implementation methods that are not listed one by one in the specification but also fall within the protection scope of this application.

[0028] Unless otherwise expressly specified and limited, all terms related to chemical process operations, material preparation, processing and analytical testing involved in this application shall be interpreted in the broadest sense based on the conventional understanding of those skilled in the art.

[0029] Regarding performance testing and structural characterization, all testing and characterization methods involved in this application, unless otherwise specified, refer to conventional methods known in the art. Specific testing conditions may be selected and adjusted according to the sample properties and relevant national standards, international standards, or industry-standard methods. Test items may include mechanical properties (such as tensile, bending, and impact strength), thermal properties (such as DSC and TGA analysis), and chemical stability (such as solvent resistance and acid / alkali corrosion resistance). Structural characterization methods may include FT-IR, NMR, XRD, SEM, TEM, and BET. All test results should be understood to be within the allowable range of conventional experimental errors.

[0030] Regarding numerical values ​​and ranges, all parameter ranges expressed in this application in the form of "from a certain value to a certain value" should be understood as explicitly disclosing the endpoints of the range, each specific numerical point between the endpoints, and all sub-ranges formed by any two numerical points within the range. For example, "30℃ to 80℃" discloses 30, 31, ..., 80℃, as well as sub-ranges such as 30-50℃, 45-70℃, etc. When a numerical value is preceded by "about," "approximately," or similar words, it indicates that the numerical value is allowed to have reasonable errors recognized in the art under the measurement or control conditions, which can generally be understood as the deviation allowed by relevant standards or a normal fluctuation range of ±5% or ±10%.

[0031] This application provides a method for the controllable preparation of solid spherical calcite from dicalcium silicate powder material, comprising the following steps: S1. Mix carbide slag, sandstone and flux to obtain raw meal; S2. Mix the raw materials with the solvent and press them into a blank; S3. After calcining the green body, grind it to obtain clinker powder; S4. Add triethanolamine aqueous solution to clinker powder to obtain a suspension; S5. Carbon dioxide gas is introduced into the suspension to carry out a carbonization reaction, resulting in a mixed liquid; S6. After solid-liquid separation of the mixture, wash and dry to obtain solid spherical calcite.

[0032] In this application, triethanolamine (TEA) is utilized for dual regulation in the wet carbonization process of silicates. The hydroxyl groups in the TEA molecule form unstable chelates with calcium ions on the clinker surface, accelerating the Ca2+ oxidation process. 2+The release from silicates into the liquid phase creates extremely high local supersaturation in the early stages of the reaction, promoting calcium carbonate nucleation. Furthermore, TEA molecules reduce and inhibit the normal growth of specific crystal faces through chemical adsorption, forcing the crystals to change their natural rhombohedral growth habit and instead undergo isotropic stacking or radial spheroid growth, ultimately self-assembling to form solid spherical calcite with a smooth surface and dense structure, thus solving the problem of uncontrollable morphology of solid waste mineralization products.

[0033] In some embodiments, the concentration of the triethanolamine aqueous solution is 0.1-5.0 g / L.

[0034] In this embodiment, the concentration range allows TEA to maintain a suitable concentration in the solution, ensuring that its hydroxyl groups effectively chelate with calcium ions to promote dissolution, and ensuring that TEA molecules specifically chemisorb onto the prism crystal faces of the calcium carbonate crystal nucleus to inhibit normal growth, thereby inducing isotropic stacking to form a solid sphere.

[0035] In some embodiments, the liquid-to-solid mass ratio in the suspension is 10-30:1.

[0036] In this embodiment, the liquid-to-solid ratio range ensures that the reaction system has sufficient liquid phase medium, which is conducive to the uniform dissolution of calcium ions in the clinker and the diffusion and mass transfer of carbon dioxide gas, providing a stable liquid phase environment for the isotropic growth and self-assembly of calcium carbonate crystals.

[0037] In some embodiments, in step S5, the flow rate of carbon dioxide gas is 0.1-1.0 L / min, the reaction pressure is 0.1-0.5 MPa, and the carbonization reaction time is 5-60 min.

[0038] In this embodiment, the flow rate and pressure conditions can prevent excessively rapid carbon dioxide mass transfer from causing uneven local supersaturation and affecting the morphology, while ensuring sufficient reaction time for the carbonization reaction to proceed fully and generate a stable calcite crystal phase, thereby obtaining a solid spherical product with a regular morphology.

[0039] In some embodiments, the calcium-to-silicon ratio (C / S) of the raw material is 1.2-2.5:1, the silicon content (SM) is 2.0-4.0:1, and the aluminum content (IM) is 1.0-3.0:1.

[0040] In some embodiments, in step S3, the calcination temperature is 1150-1450°C, and the heating rate is 5-15°C / min.

[0041] In some embodiments, the carbide slag includes calcium oxide and sodium, potassium and aluminum impurities, wherein the calcium oxide content is greater than or equal to 60 wt%; and the particle size of the carbide slag is 5-200 μm.

[0042] In some embodiments, the sandstone includes silica and sodium, potassium and aluminum impurities, wherein the silica content is greater than or equal to 60 wt%; and the sandstone has a grain size of 5-200 μm.

[0043] In some embodiments, the flux is iron(III) oxide; the amount of flux used is 0.5-5 wt% of the raw material.

[0044] Specifically, the method for controllably preparing solid spherical calcite from dicalcium silicate powder includes the following steps: S1. Dry the calcium carbide slag at 40-105℃; grind the siliceous sandstone in a ball mill for 1-5 minutes, wash away surface clay impurities with water, and control the particle size of the raw material to be 5-200μm; mix the raw materials according to a calcium-silicon ratio (C / S) of 1.2-2.5, and control the silicon content (SM) to be 2.0-4.0 and the aluminum content (IM) to be 1.0-3.0; weigh the treated calcium carbide slag and sandstone, and add 0.5-5% of the total mass of raw materials as a flux, and mix evenly to obtain the raw materials; S2. The raw material obtained in step S1 is mixed with one of anhydrous ethanol, deionized water, and isopropanol, and then pressed into a green body under a pressure of 10.0-100.0 MPa. S3. Place the billet in a high-temperature furnace and heat it to 1150-1450℃ at a heating rate of 5-15℃ / min. After holding at this temperature for 1-6 hours, cool it (the cooling method can be one or more of furnace cooling, rapid cooling, and semi-rapid cooling). Grind the cooled clinker using a ball mill to obtain a powder material (clinker powder) with dicalcium silicate as the main mineral phase. S4. Prepare a triethanolamine (TEA) aqueous solution with a concentration of 0.1-5.0 g / L; add the clinker powder obtained in step S3 to the TEA solution, control the liquid-solid mass ratio to be 10-30, and stir to form a suspension; S5. Introduce 99% pure carbon dioxide gas into the suspension, control the gas flow rate at 0.1-1.0 L / min, the reaction pressure at 0.1-0.5 MPa, and the carbonization reaction time at 5-60 min to obtain a mixed liquid; S6. After the reaction is complete, the suspension is separated into solid and liquid components using a centrifuge. The solid product is washed with anhydrous ethanol and dried to obtain solid spherical calcite powder.

[0045] This application provides a solid spherical calcite.

[0046] The following specific embodiments further illustrate this solution.

[0047] Example 1 A method for the controlled preparation of solid spherical calcite from dicalcium silicate powder material includes the following steps: S1. Dry the calcium carbide slag at 105℃; grind the siliceous sandstone in a ball mill for 2 minutes and wash away the clay impurities on the surface with water; weigh 69.2 parts of calcium carbide slag, 29.2 parts of sandstone, and 1.6 parts of flux ferric oxide, place them in a V-type mixer and mix at a speed of 90 r / min for 6 hours to obtain raw meal for calcination; the calcium-silicon ratio of the raw meal is 2.0.

[0048] S2. The raw material obtained in step S1 is mixed with anhydrous ethanol at a mass ratio of 5:1 and then pressed into a green body under a pressure of 30MPa. S3. The billet is placed in a muffle furnace for calcination at a heating rate of 10℃ / min and a firing temperature of 1350℃. After holding at the temperature for 3 hours, it is cooled in the furnace. The cooled clinker is then ground in a ball mill to obtain a powder material with dicalcium silicate as the main mineral phase. S4. Prepare a triethanolamine aqueous solution with a concentration of 1 g / L; add the clinker powder obtained in step S3 to the triethanolamine solution, with a liquid-to-solid mass ratio of 20, and stir to form a suspension; S5. Introduce carbon dioxide gas with a purity of 99% into the suspension at a flow rate of 0.1 L / min to carry out the carbonization reaction for 5 min. S6. After the reaction is complete, the suspension is separated into solid and liquid components using a centrifuge. The solid product is washed with anhydrous ethanol and dried to obtain solid spherical calcite powder.

[0049] Example 2 A method for the controlled preparation of solid spherical calcite from dicalcium silicate powder material includes the following steps: S1. Dry the calcium carbide slag at 105℃; grind the siliceous sandstone in a ball mill for 2 minutes and wash away the clay impurities on the surface with water; weigh 69.2 parts of calcium carbide slag, 29.2 parts of sandstone, and 1.6 parts of flux ferric oxide, place them in a V-type mixer and mix at a speed of 90 r / min for 6 hours to obtain raw meal for calcination; the calcium-silicon ratio of the raw meal is 2.0.

[0050] S2. The raw material obtained in step S1 is mixed with anhydrous ethanol at a mass ratio of 5:1 and then pressed into a green body under a pressure of 30MPa. S3. The billet is placed in a muffle furnace for calcination at a heating rate of 10℃ / min and a firing temperature of 1350℃. After holding at the temperature for 3 hours, it is cooled in the furnace. The cooled clinker is then ground in a ball mill to obtain a powder material with dicalcium silicate as the main mineral phase. S4. Prepare a triethanolamine aqueous solution with a concentration of 1 g / L; add the clinker powder obtained in step S3 to the triethanolamine solution, with a liquid-to-solid mass ratio of 20, and stir to form a suspension; S5. Introduce carbon dioxide gas with a purity of 99% into the suspension at a flow rate of 0.1 L / min to carry out the carbonization reaction for 15 min. S6. After the reaction is complete, the suspension is separated into solid and liquid components using a centrifuge. The solid product is washed with anhydrous ethanol and dried to obtain solid spherical calcite powder.

[0051] Comparative Example 1 A method for processing calcite includes the following steps: S1. Dry the calcium carbide slag at 105℃; grind the siliceous sandstone in a ball mill for 2 minutes, and wash away the clay impurities on the surface with water; weigh 69.2 parts of calcium carbide slag, 29.2 parts of sandstone, and 1.6 parts of flux ferric oxide, and place them in a V-type mixer to mix at a speed of 90 r / min for 6 hours to obtain raw meal for calcination; S2. The raw material obtained in step S1 is mixed with anhydrous ethanol at a mass ratio of 5:1 and then pressed into a green body under a pressure of 30MPa. S3. The billet is placed in a muffle furnace for calcination at a heating rate of 10℃ / min and a firing temperature of 1350℃. After holding at the temperature for 3 hours, it is cooled in the furnace. The cooled clinker is then ground in a ball mill to obtain a powder material with dicalcium silicate as the main mineral phase. S4. Add the clinker powder obtained in step S3 to the aqueous solution, with a liquid-to-solid mass ratio of 20, and stir to form a suspension; S5. Introduce carbon dioxide gas with a purity of 99% into the suspension at a flow rate of 0.1 L / min to carry out the carbonization reaction for 15 min. S6. After the reaction is complete, the suspension is separated into solid and liquid phases using a centrifuge. The solid product is washed with anhydrous ethanol and dried to obtain calcite powder.

[0052] Comparative Example 2 A method for carbonizing calcite is the same as Comparative Example 1, except that the carbonization time is 5 minutes.

[0053] Testing and Evaluation The products obtained from different embodiments and comparative examples were identified and tested.

[0054] Figure 1 X-ray diffraction (XRD) patterns of the products obtained in Examples 1-2 and Comparative Example 1 are shown. The analysis results indicate that with increasing carbon mineralization time, the amount of calcite formed in the system increases, while the calcite content decreases. The introduction of TEA significantly promotes calcite formation and accelerates the carbon mineralization reaction of dicalcium silicate, further demonstrating that TEA has a significant promoting effect on the carbon mineralization activity of silicate clinker systems.

[0055] Figure 2 The Fourier transform infrared (FTIR) spectra of the products obtained in Examples 1-2 and Comparative Example 1 are shown. The results indicate that in the solid waste-based silicate clinker system, TEA significantly alters the kinetic pathway of calcium carbonate crystallization, effectively suppresses the formation of metastable crystalline phases (such as aragonite), and induces the product to rapidly transform into the thermodynamically stable calcite crystal form, effectively enhancing the carbon mineralization activity of the clinker and solving the problem of uncontrollable product crystal form.

[0056] Figure 3 The microstructure comparison images of the products obtained in Examples 1-2 and Comparative Example 1 are shown. Figure 3 (a) is the product of wet carbonization for 5 min in Comparative Example 2. Figure 3 (b) is the product of wet carbonization for 15 min in Comparative Example 1. Figure 3 (c) shows the EDS energy spectra at points (1-5). Figure 3 (d) is the EDS energy spectrum at point 1. Figure 3 (e) is the wet carbonization product of Example 1. Figure 3 (f) is the wet carbonization product of Example 2. Figure 3 (g) shows the EDS energy spectra at points (6-10). Figure 3 (h) is the EDS energy spectrum at point 10; from Figure 3 As can be seen, the product obtained in Comparative Example 1 exhibits a chaotic and disordered mixed morphology, with a large number of needle-like and irregularly plate-like crystals stacked in its microstructure. Furthermore, the boundaries of the transition zone between product particles are blurred, and EDS analysis shows that the Ca / Si ratio in this region is distributed between 3.0 and 3.5. After the introduction of TEA, the microstructure of the product undergoes a fundamental change, with well-formed solid spherical particles mainly distributed in the field of view. These spherical particles are formed by the dense stacking of fine crystals through spheroidal growth. EDS analysis shows that the Ca / Si ratio on the surface of the spherical particles is increased, higher than that of Comparative Example 1, confirming that the spherical particles formed by TEA are high-purity calcium carbonate. TEA effectively promotes the phase separation of calcium carbonate and the byproduct silica gel, enabling calcium carbonate to independently nucleate and grow into dense spheres.

[0057] The results showed that the calcite micro powder prepared by this method was in the form of precisely packed spheres, and that triethanolamine significantly improved the carbon mineralization activity of calcium silicate clinker and accelerated the formation of calcium carbonate.

[0058] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controllably preparing solid spherical calcite from dicalcium silicate powder, characterized in that, Includes the following steps: S1. Mix carbide slag, sandstone and flux to obtain raw meal; S2. The raw material is mixed with a solvent and pressed into a blank; S3. After calcining the green body, grind it to obtain clinker powder; S4. Add triethanolamine aqueous solution to the clinker powder to obtain a suspension; S5. Carbon dioxide gas is introduced into the suspension to carry out a carbonization reaction, resulting in a mixed liquid; S6. After solid-liquid separation of the mixture, wash and dry to obtain the solid spherical calcite.

2. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The concentration of the triethanolamine aqueous solution is 0.1-5.0 g / L.

3. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The liquid-to-solid mass ratio in the suspension is 10-30:

1.

4. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, In step S5, the flow rate of the carbon dioxide gas is 0.1-1.0 L / min, the reaction pressure is 0.1-0.5 MPa, and the carbonization reaction time is 5-60 min.

5. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The raw material has a calcium-to-silicon ratio (C / S) of 1.2-2.5:1, a silicon content (SM) of 2.0-4.0:1, and an aluminum content (IM) of 1.0-3.0:

1.

6. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, In step S3, the calcination temperature is 1150-1450℃, and the heating rate is 5-15℃ / min.

7. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The carbide slag includes calcium oxide and sodium, potassium and aluminum impurities, wherein the content of calcium oxide is greater than or equal to 60 wt%; the particle size of the carbide slag is 5-200 μm.

8. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The sandstone includes silicon dioxide and sodium, potassium and aluminum impurities, wherein the content of silicon dioxide is greater than or equal to 60 wt%; the grain size of the sandstone is 5-200 μm.

9. The method for controllably preparing solid spherical calcite from dicalcium silicate powder material according to claim 1, characterized in that, The flux is iron(III) oxide; the amount of flux used is 0.5-5 wt% of the raw material.

10. A solid spherical calcite obtained by the method as described in any one of claims 1-9.

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