Preparation of zro2-doped cma material and method for integrated regulation of structure and function thereof

Abstract

This invention discloses a method for preparing ZrO2-doped CMA materials and integrating their structure and function control. The method includes the following steps: S1, mixing alumina, calcium oxide, and magnesium oxide sources in a set ratio to obtain a mixed source material, adding zirconium dioxide as an additive to the mixed raw material to obtain a raw material mixture; wherein the particle sizes of the alumina, calcium oxide, and magnesium oxide sources are similar, and the mass ratio of zirconium dioxide to the mixed source material is no more than 4 wt%; S2, stirring and mixing the raw material mixture, adding a water binder to obtain a homogeneous mixture; wherein the mass ratio of water to the raw material mixture is 5-50%; S3, pressing the homogeneous mixture under a pressure of 80-120 MPa to obtain a green body; S4, firing the green body in an air atmosphere at 1650-1750℃ to obtain ZrO2-doped CMA materials. By controlling the ZrO2 doping amount, firing temperature, and holding time, the C2M2A content in the CMA material can be controlled. 14 The phase content is controlled between 80% and 100%.

Description

Technical Field

[0001] This invention belongs to the field of refractory materials technology, specifically relating to ZrO2-doped CMA materials and their integrated structural and functional control method. Background Technology

[0002] To achieve energy conservation and emission reduction in the steelmaking process, the lining material of industrial furnaces typically consists of multiple layers. The working layer uses heavy materials, while the insulation layer uses porous insulation materials. The working layer is in direct contact with molten steel, and its performance and application directly affect the efficiency and safety of steel production. This requires the working layer refractory material to possess excellent high-temperature resistance, stability, thermal shock resistance, and slag erosion resistance. The insulation layer uses porous insulation materials to reduce heat loss from the furnace body, ensure uniform temperature distribution, and prevent structural damage. Due to the differences in properties between different layers, cracks and detachment can easily occur during use. Using materials with similar compositions for the working layer and insulation layer of the furnace body ensures that the industrial furnace operates safely and stably while maintaining efficient thermal insulation performance, thereby reducing heat loss and heat storage loss to achieve energy conservation.

[0003] Al2O3-MgO-CaO ternary refractory materials possess excellent structural and functional properties, making them a research hotspot in green high-temperature refractory materials. Among these, the aluminum-rich fraction of the Al2O3-MgO-CaO ternary system contains typical high-melting-point compounds such as magnesium aluminum spinel (MgAl2O4, abbreviated as MA) and calcium hexaaluminate (CaAl2O4). 12 O 19 CA6 (Alternative Carbon) possesses advantages such as high melting point, strong stability, strong thermal shock resistance, and low wettability to molten metal / slag, making it widely used in the steel, petrochemical, and aluminum industries. However, due to the significant differences in the stability regions and crystallization habits of CA6 and MA, synthesizing dense CA6 / MA multiphase materials is relatively difficult, greatly limiting the integrated design and application of industrial furnaces and kilns based on CA6 / MA multiphase materials.

[0004] Ca2Mg2Al 28 O 46 (abbreviated as C2M2A) 14 ) and CaMg2Al 16 O 27(Abbreviated as CM2A8) collectively referred to as CMA, is a limited solid solution of MgO in CA6, possessing the excellent properties of both MA and CA6. It has been initially applied in clean steel smelting, high-temperature alloy melting, and other fields. However, the current preparation process of CMA materials is complex and costly, severely limiting its industrial application. On the one hand, the raw materials used to produce CMA are mainly alumina, calcium, and magnesium sources. The uniformity of the mixture of these three raw materials determines the physical properties and purity of the prepared CMA material. The preparation of CMA materials usually adopts a wet mixing method. However, wet mixing requires first uniformly mixing Al2O3, CaCO3, and MgCO3 powders, then drying, pulverizing, and pressing them into a green body. This greatly increases the preparation process and cost. Moreover, due to differences in powder density and particle size, the mixed powder obtained by wet mixing is also prone to stratification during the drying process.

[0005] On the other hand, CMA materials can be prepared by methods such as electrofusion, hot pressing and two-step sintering. Although these methods can produce relatively dense CMA materials, they all have disadvantages such as complex processes, long production cycles and high energy consumption, making it difficult to achieve industrial-scale preparation.

[0006] One-step sintering can effectively reduce the preparation process and production costs, and has been widely used in the industrial preparation of refractory materials. However, it is still difficult to achieve integrated control of the structure and function of CMA materials, which greatly limits its large-scale application in the field of industrial furnace lining. Summary of the Invention

[0007] In view of this, some embodiments disclose a method for preparing ZrO2-doped CMA materials and for integrated control of their structure and function, including the following steps:

[0008] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed raw material. Zirconia additive is added to the mixed raw material and a mixer is used to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is not greater than 4%, and the mixing time of the mixer is 1 to 6 hours.

[0009] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5-50%;

[0010] S3. The uniformly mixed material is pressed into shape under a pressure of 80-120MPa to obtain a green body;

[0011] S4. The green body is fired in air at 1650–1750°C for 3–10 hours to obtain ZrO2-doped CMA material; the ZrO2-doped CMA material contains only C2M2A. 14In the CM2A8 phase, Zr ions are uniformly distributed within the CMA grains; in ZrO2-doped CMA materials, C2M2A... 14 The phase content is controlled at 80-100%, and the bulk density of ZrO2-doped CMA is controlled at 2.0-3.17 g / cm³. 3 The porosity is controlled between 45.5% and 10.4%, the water absorption rate is between 20.8% and 3.4%, and the melting point is increased by more than 10℃.

[0012] Furthermore, in some embodiments of the ZrO2-doped CMA material preparation and its integrated structure-function control method, in step S1, the average particle size of the alumina source is not greater than 56 μm, the average particle size of the magnesium oxide source is not greater than 56 μm, the average particle size of the calcium oxide source is not greater than 56 μm, and the average particle size of the zirconium dioxide is not greater than 6 μm.

[0013] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgO. The mass ratio of Al2O3, CaCO3, and MgO is 83.56–85.29:11.72–11.75:4.72–2.96.

[0014] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating structure and function control. In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgO. The mass ratio of Al2O3, CaO, and MgO is 88.83–89.94:6.94:4.23–3.12.

[0015] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is Mg(OH)2. The mass ratio of Al2O3, CaO, and Mg(OH)2 is 86.18–88.70: 6.78–6.85: 7.04–4.45.

[0016] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating structure and function control. In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgCO3. The mass ratio of Al2O3, CaO, and MgCO3 is 83.56–86.98: 6.57–6.71: 9.87–6.31.

[0017] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgCO3. The mass ratio of Al2O3, CaCO3, and MgCO3 is 79.47–82.62: 11.14–11.38: 9.39–6.00.

[0018] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is Mg(OH)2. The mass ratio of Al2O3, CaCO3, and Mg(OH)2 is 81.83–84.18: 11.48–11:60: 6.69–4.22.

[0019] On the other hand, some embodiments disclose ZrO2-doped CMA materials, obtained by a method for preparing ZrO2-doped CMA materials and integrating their structure and function. These ZrO2-doped CMA materials contain only C2M2A. 14 In the CM2A8 phase, Zr ions are uniformly distributed within the CMA grains; in ZrO2-doped CMA materials, C2M2A... 14 The phase content is 80-100%, and the bulk density of ZrO2-doped CMA is 2.0-3.17 g / cm³. 3 Between these values, the porosity is between 45.5% and 10.4%, the water absorption rate is between 20.8% and 3.4%, and the melting point is increased by more than 10°C.

[0020] Some embodiments disclose ZrO2-doped CMA materials, which are used as refractory materials, wherein C2M2A 14 ZrO2-doped CMA materials with relatively high phase content are used as heat insulation materials for industrial furnaces, C2M2A 14 ZrO2-doped CMA materials with relatively low phase content are used as working layer materials in industrial furnaces.

[0021] The present invention discloses a method for preparing ZrO2-doped CMA materials and integrating their structure and function. This method employs a one-step sintering process to prepare ZrO2-doped CMA materials with tunable performance, resulting in a short production cycle and low production cost. The CMA materials contain only C2M2A. 14 By controlling the ZrO2 doping amount, sintering temperature, and holding time, the C2M2A phase in CMA materials can be controlled. 14 With the phase content controlled between 80-100%, Zr ions are uniformly distributed within the CMA grains, and the bulk density of CMA can be achieved in the range of 2.0–3.17 g / cm³. 3The porosity can be controlled between 45.5% and 10.4%, the water absorption between 20.8% and 3.4%, and the melting point can be increased by more than 10℃. ZrO2-doped CMA can be used to prepare high-performance refractory materials. By controlling the C2M2A content in ZrO2-doped CMA materials... 14 Precise control of phase content enables integrated regulation of the structure and function of CMA materials, resulting in refractory materials of different densities. Through the combined use of CMA materials of different densities, they can be applied to different parts of industrial boiler bodies. The ZrO2-doped CMA material preparation and its integrated structural and functional regulation method disclosed in this invention have good application prospects in the industrial preparation of CMA materials and the field of refractory materials. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the preparation process of the ZrO2-doped CMA material disclosed in Example 1;

[0023] Figure 2 The XRD pattern of the CMA material with a ZrO2 doping content of 1.5 wt% disclosed in Example 2;

[0024] Figure 3 The XRD pattern of the CMA material with a ZrO2 doping content of 1.3 wt% disclosed in Example 3;

[0025] Figure 4 SEM image of the CMA surface disclosed in Comparative Example 1;

[0026] Figure 5 SEM image of the CMA surface disclosed in Example 4;

[0027] Figure 6 The XRD pattern of the CMA surface disclosed in Example 4;

[0028] Figure 7 SEM image of the CMA surface disclosed in Example 5;

[0029] Figure 8 The XRD pattern of the CMA surface disclosed in Example 5;

[0030] Figure 9 This is a cross-sectional surface scan image of the ZrO2-doped CMA (1.5 wt% ZrO2) material in Example 2. Detailed Implementation

[0031] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in these embodiments of the invention, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in these embodiments is merely for describing particular implementations and is not intended to limit the scope of the disclosure of these embodiments.

[0032] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain; other experimental methods and technical means not specifically noted in the embodiments of this invention refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0033] The terms “basic” and “approximately” used in this document are to describe small fluctuations. For example, they can mean less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or expressed in range format in this document are used for convenience and brevity only, and should therefore be flexibly interpreted to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0034] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0035] To better illustrate the content of this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the invention can be practiced even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail, in order to highlight the main points of the invention.

[0036] Without conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of the present invention.

[0037] C2M2A 14 With a hexagonal plate / plate morphology, CM2A8 exhibits an equiaxed morphology, and the difference in grain morphology further affects the physical properties of the prepared samples. The reaction process for CMA formation follows the route CA6→C2M2A. 14 →CM2A8, inevitably in the preparation of C2M2A 14 The process generates the CM2A8 phase. By controlling the content of the two phases and utilizing their different grain morphologies, the physical properties of the prepared samples can be adjusted, thereby achieving integrated control of the structure and function of CMA materials. The ZrO2-doped CMA materials with different densities prepared can be used in combination and applied to different parts of industrial boiler bodies.

[0038] The technical solution provided by this invention is based on the synergistic control of ZrO2 doping, firing temperature, and holding time to regulate the phase content in CMA materials. By adjusting the amount of ZrO2 added to the raw materials, the firing temperature, and the holding time, the phase composition and physical properties of the prepared ZrO2-doped CMA materials can be controlled, resulting in ZrO2-doped CMA materials with different densities. These ZrO2-doped CMA materials with different densities can be used in combination. As refractory materials with different properties, ZrO2-doped CMA materials can be applied to different parts of industrial boiler furnaces. By adjusting the phases in ZrO2-doped CMA, the application of ZrO2-doped CMA materials in different fields can also be met.

[0039] In some embodiments, the method for preparing ZrO2-doped CMA materials and integrating their structure and function control includes the following steps:

[0040] S1. Alumina source, calcium oxide source, and magnesium oxide source are mixed in a set ratio to obtain a mixed source material. Zirconia additive is added to the mixed raw material, and the mixture is uniformly mixed using a mixer to obtain a raw material mixture. The particle sizes of the alumina source, calcium oxide source, and magnesium oxide source are similar, and the mass ratio of zirconium dioxide to the mixed source material is no more than 4%. The mixing time in the mixer is 1-6 hours. Typically, the doped Zr atoms replace the positions of Al atoms and integrate into C2M2Al. 14 In the CM2A8 grains, it can increase the grain thickness in the ZrO2-doped CMA material, thereby reducing the porosity inside the sample, increasing the sample density, and promoting the densification of the product.

[0041] Generally, the uniformity of the mixture of the three raw materials, namely alumina source, calcium oxide source and magnesium oxide source, determines the purity of the prepared CMA material. Uneven mixing of raw materials may lead to element enrichment in some areas, which may not conform to the optimal atomic ratio of CMA, thus producing impurity phases such as calcium dialuminate, calcium hexaaluminate and magnesium aluminum spinel, resulting in an impure final CMA sample. Therefore, it is necessary to thoroughly stir and mix the raw material mixture to obtain a uniform mixture.

[0042] Generally, the alumina source is industrial alumina, activated alumina, or calcined alumina; the calcium oxide source is calcium oxide or calcium carbonate; and the magnesium oxide source is magnesium oxide, magnesium hydroxide, or magnesium carbonate. Typically, the particle size of the alumina, magnesium, and calcium sources significantly affects the physical properties and purity of the prepared CMA. Excessive differences in particle size among the three raw materials can lead to segregation during mixing, thus affecting the purity of the synthesized CMA. Therefore, the particle sizes of the three raw materials are usually comparable, with similar particle size distribution ranges. For example, the average particle size of the alumina source is no greater than 56 μm, the average particle size of the magnesium oxide source is no greater than 56 μm, and the average particle size of the calcium oxide source is no greater than 56 μm. Simultaneously, the particle size of zirconium oxide should be smaller than that of the alumina, calcium oxide, or magnesium oxide sources; for example, the average particle size of ZrO2 is no greater than 6 μm.

[0043] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5-50%;

[0044] Generally, the amount of water added determines the uniformity of its dispersion in the mixed powder. Too little or too much water will cause water to accumulate in some areas. During the drying process, the water will evaporate when heated, creating pores in those areas and affecting the physical properties of the prepared CMA. Too little water may cause the mixed powder to separate or fail to form during the pressing process. Generally, the mass ratio of water to raw material mixture is 5-50%.

[0045] S3. The uniformly mixed material is pressed into shape under a pressure of 80-120MPa to obtain a green body;

[0046] Typically, homogeneous mixtures can be formed under the pressure of a press. The pressure of the press has a significant impact on the quality of the green body after forming. Excessive pressure may cause delamination inside the green body, affecting the physical properties of the prepared CMA; insufficient pressure may make it difficult to form the green body. The suitable pressure range is 80–120 MPa.

[0047] S4. The green body is fired in air at 1650–1750°C for 3–10 hours to obtain ZrO2-doped CMA material. ZrO2-doped CMA material contains only C2M2A. 14In the CM2A8 phase, Zr ions are uniformly distributed within the CMA grains; the CMA material contains C2M2A... 14 The phase content is controlled at 80-100%, and the bulk density of CMA is controlled at 2.0-3.17 g / cm³. 3 The porosity is controlled between 45.5% and 10.4%, the water absorption rate is between 20.8% and 3.4%, and the melting point is increased by more than 10℃.

[0048] Generally, the sintering temperature of ZrO2-doped CMA materials has a significant impact on the product's properties. Too low a sintering temperature or too short a holding time may result in incomplete reaction within the product, affecting the purity and physical properties of the prepared ZrO2-doped CMA. Conversely, too high a sintering temperature or too long a holding time may lead to excessively large grains in the prepared ZrO2-doped CMA, thus impacting its further applications. Therefore, under the condition of keeping the ZrO2 addition amount constant, adjusting the sintering temperature and holding time can regulate the C2M2A content in the product. 14 The content of the phase and the physical properties of the sample, increasing the firing temperature or extending the holding time can inhibit C2M2A in CMA. 14 The formation of the phase enables the preparation of high-density CMA materials, which can be applied to the working layer of industrial furnace linings.

[0049] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgO. The mass ratio of Al2O3, CaCO3, and MgO is 83.56–85.29:11.72–11.75:4.72–2.96. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaCO3, and MgO. During the reaction, CaCO3 decomposes to produce CO2, which may create pores inside the sample, thus increasing the porosity and reducing the material density. The ZrO2-doped CMA materials prepared by this method can be applied to the production of ZrO2-doped CMA fine powder and industrial furnace lining insulation layers.

[0050] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgO. The mass ratio of Al2O3, CaO, and MgO is 88.83–89.94:6.94:4.23–3.12. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaO, and MgO as raw materials. During the reaction, the raw materials do not decompose, resulting in ZrO2-doped CMA materials with low porosity and high density. These materials can be applied to the production of ZrO2-doped CMA aggregates and working layer materials for industrial furnace linings.

[0051] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is Mg(OH)2. The mass ratio of Al2O3, CaO, and Mg(OH)2 is 86.18–88.70:6.78–6.85:7.04–4.45. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaO, and Mg(OH)2 as raw materials. During the reaction, Mg(OH)2 decomposes to produce H2O, which may generate pores and cracks inside the sample, thereby increasing the porosity and reducing the gas density of the ZrO2-doped CMA material. The presence of cracks facilitates the breakage of the ZrO2-doped CMA material. The ZrO2-doped CMA material prepared by this method can be applied to the production of ZrO2-doped CMA fine powder and industrial furnace lining insulation layers.

[0052] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgCO3. The mass ratio of Al2O3, CaO, and MgCO3 is 83.56–86.98: 6.57–6.71: 9.87–6.31. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaO, and MgCO3 as raw materials. During the reaction, MgCO3 decomposes to produce CO2, which may create pores inside the sample, thereby increasing the porosity and reducing the density of the ZrO2-doped CMA material. The ZrO2-doped CMA material prepared by this method can be applied to the production of ZrO2-doped CMA fine powder and industrial furnace lining insulation layers.

[0053] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgCO3. The mass ratio of Al2O3, CaCO3, and MgCO3 is 79.47–82.62:11.14–11.38:9.39–6.00. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaCO3, and MgCO3 as raw materials. During the reaction, CaCO3 and MgCO3 decompose to produce CO2, which may create pores inside the sample, thereby increasing the porosity and reducing the gas density of the ZrO2-doped CMA material. The ZrO2-doped CMA material prepared by this method can be applied to the production of ZrO2-doped CMA fine powder and industrial furnace lining insulation layers.

[0054] Some embodiments disclose a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is Mg(OH)2. The mass ratio of Al2O3, CaCO3, and Mg(OH)2 is 81.83–84.18:11.48–11:60:6.69–4.22. Generally, ZrO2-doped CMA materials are prepared directly using Al2O3, CaCO3, and Mg(OH)2 as raw materials. During the reaction, CaCO3 and Mg(OH)2 decompose to produce CO2 and H2O, which may generate pores and cracks inside the sample, thereby increasing the porosity and reducing the density of the CMA material. The presence of cracks facilitates the breakage of the ZrO2-doped CMA material. The ZrO2-doped CMA material prepared by this method can be applied to the production of ZrO2-doped CMA fine powder and industrial furnace lining insulation layers.

[0055] Some embodiments disclose ZrO2-doped CMA materials, which are obtained by a method for preparing ZrO2-doped CMA materials and integrating their structure and function. The ZrO2-doped CMA materials contain only C2M2A. 14 In the CM2A8 phase, Zr ions are uniformly distributed within the CMA grains; in ZrO2-doped CMA materials, C2M2A... 14 The phase content is 80-100%, and the bulk density of ZrO2-doped CMA is 2.0-3.17 g / cm³. 3 Between these values, the porosity is between 45.5% and 10.4%, the water absorption rate is between 20.8% and 3.4%, and the melting point is increased by more than 10°C.

[0056] Some embodiments disclose ZrO2-doped CMA materials, which are used as refractory materials, wherein C2M2A 14 ZrO2-doped CMA materials with relatively high phase content are used as heat insulation materials for industrial furnaces, C2M2A14 ZrO2-doped CMA materials with relatively low phase content are used as working layer materials in industrial furnaces. Typically, when ZrO2-doped CMA materials are used as refractory materials, C2M2A... 14 The content of the phase can be controlled between 80% and 100%, allowing for the precise preparation of C2M2A based on the required refractory material properties. 14 The content of different phases will affect the content of C2M2A. 14 Refractory materials with varying phase contents are combined to construct the structure of industrial boiler furnaces; generally, in the structure of industrial boiler furnaces, ZrO2-doped CMA materials, used as insulation layers, contain C2M2A. 14 The content of phase A is higher than that of C2M2A in the working layer material. 14 Phase content; for example, C2M2A 14 ZrO2-doped CMA materials with a phase content between 95% and 100% can be used as heat insulation materials for industrial furnaces; C2M2A 14 ZrO2-doped CMA materials with a phase content between 80% and 90% can be used as working layer materials for industrial furnaces.

[0057] Some embodiments disclose the application of ZrO2-doped CMA materials. ZrO2-doped CMA materials can be used to prepare ZrO2-doped CMA dense refractory finished products, porous refractory finished products, aggregates and fine powders. The aggregates and fine powders can be further used to prepare CMA crucibles, added as additives to magnesia-carbon refractory materials, or used as surface materials of shells.

[0058] The technical details are further illustrated below with reference to the embodiments.

[0059] Example 1

[0060] In Example 1, as Figure 1 As shown, the method for preparing ZrO2-doped CMA materials and its integrated structure-function regulation includes the following steps:

[0061] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed source material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly by a mixer to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is not greater than 4%, and the mixing time of the mixer is 1-6 hours.

[0062] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5-50%;

[0063] S3. The uniformly mixed material is pressed into shape under a pressure of 80-120MPa to obtain a green body;

[0064] S4. The green body is fired in air at 1650-1750℃ and held for 3-10 hours to obtain ZrO2-doped CMA material.

[0065] Example 2

[0066] In Example 2, the method for preparing ZrO2-doped CMA materials and integrating their structure and function control includes the following steps:

[0067] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed source material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly using a mixer to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is 1.5%, and the mixing time of the mixer is 1 hour.

[0068] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5%;

[0069] S3. The uniformly mixed material is pressed into a shape under a pressure of 120MPa to obtain a green body;

[0070] S4. The green body is fired in air at 1700℃ and held for 6 hours to obtain ZrO2-doped CMA material.

[0071] Figure 2 The XRD pattern of the CMA material with a ZrO2 doping content of 1.5 wt% disclosed in Example 2 is shown. Figure 6 This is a cross-sectional surface scan image of the CMA material with a ZrO2 doping content of 1.5 wt% in Example 2.

[0072] Example 3

[0073] In Example 3, the method for preparing ZrO2-doped CMA materials and integrating their structure and function control includes the following steps:

[0074] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed raw material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly using a mixer to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is 1.3%, and the mixing time of the mixer is 2 hours.

[0075] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5%;

[0076] S3. The uniformly mixed material is pressed into shape under a pressure of 100MPa to obtain a green body;

[0077] S4. The green body is fired in air at 1650℃ and held for 3 hours to obtain ZrO2-doped CMA material.

[0078] Figure 3 The image shows the XRD pattern of the CMA material with a ZrO2 doping content of 1.3 wt% disclosed in Example 3.

[0079] Example 4

[0080] In Example 4, the method for preparing ZrO2-doped CMA materials and integrating their structure and function control includes the following steps:

[0081] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed source material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly by a mixer to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is 1.3%, and the mixing time of the mixer is 2 hours.

[0082] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5%;

[0083] S3. The uniformly mixed material is pressed into shape under a pressure of 100MPa to obtain a green body;

[0084] S4. The green body is fired in air at 1750°C and held for 10 hours to obtain ZrO2-doped CMA material.

[0085] Figure 5 The image shows a SEM image of the CMA material with a ZrO2 doping content of 1.3 wt% disclosed in Example 4.

[0086] Figure 6 The XRD pattern of the CMA material with a ZrO2 doping content of 1.3 wt% disclosed in Example 4 shows that, based on the phase content calculated by the RIR method, the C2M2A content in the ZrO2 doped CMA material obtained in Example 4 is... 14 The phase content is 80%, the CM2A8 phase content is 20%, the internal grains are equiaxed, and the bulk density of the sample measured by Archimedes' displacement method is 3.15 g / cm³. 3 With a porosity of 10.76% and a water absorption rate of 3.25%, the high-density ZrO2-doped CMA material prepared by this method can be used as the working layer of the furnace body.

[0087] Example 5

[0088] In Example 5, the method for preparing ZrO2-doped CMA materials and integrating their structure and function control includes the following steps:

[0089] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed source material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly using a mixer to obtain raw material mixture. The particle size of alumina source, calcium oxide source and magnesium oxide source is similar, the mass ratio of zirconium dioxide to mixed source material is 2.5%, and the mixing time of the mixer is 5 hours.

[0090] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5%;

[0091] S3. The uniformly mixed material is pressed into shape under a pressure of 100MPa to obtain a green body;

[0092] S4. The green body is fired in air at 1680℃ and held for 6 hours to obtain ZrO2-doped CMA material.

[0093] Figure 7 The image shows a SEM image of the CMA material with a ZrO2 doping content of 2.5 wt% disclosed in Example 5.

[0094] Figure 8 The XRD pattern of the CMA material with a ZrO2 doping content of 2.5 wt% disclosed in Example 5 shows that the ZrO2 doped CMA material prepared in Example 5 contains only C2M2A. 14 The phase has plate-like internal grains and contains abundant porosity. The bulk density of the sample, measured by the Archimedes displacement method, is 2.11 g / cm³. 3 With a porosity of 43.5% and a water absorption rate of 18.84%, the porous CMA material prepared under these conditions can be used as a heat insulation layer for furnace bodies.

[0095] Comparative Example 1

[0096] In Comparative Example 1, the industrial preparation method of CMA material includes the following steps:

[0097] S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain mixed source material, and then mixed evenly with a mixer to obtain raw material mixture; wherein, the particle size of alumina source, calcium oxide source and magnesium oxide source is similar, and the mixing time of the mixer is 1 hour;

[0098] S2. The raw material mixture is stirred and mixed, and water binder is added to obtain a homogeneous mixture; wherein, the mass ratio of water to the raw material mixture is 5%;

[0099] S3. The uniformly mixed material is pressed into a shape under a pressure of 120MPa to obtain a green body;

[0100] S4. The green body is fired in air at 1700℃ and held for 6 hours to obtain CMA material.

[0101] Figure 9 SEM images of the CMA surface disclosed in Comparative Example 1 are shown. Figure 9 As shown, the internal grains of the CMA material prepared without ZrO2 are in the form of thin plates and have a certain porosity.

[0102] The technical solutions and technical details disclosed in the embodiments of this invention are merely illustrative of the inventive concept of this invention and do not constitute a limitation on the technical solutions of the embodiments of this invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of this invention have the same inventive concept as this invention and are within the protection scope of the claims of this invention.

Claims

1. A method for preparing ZrO2-doped CMA materials with integrated structure and function control, characterized in that, Including the following steps: S1. Alumina source, calcium oxide source and magnesium oxide source are mixed in a set ratio to obtain a mixed source material. Zirconia additive is added to the mixed raw material and the mixture is mixed evenly using a mixer to obtain a raw material mixture. The mass ratio of zirconium dioxide to the mixed source material is not greater than 4wt%, and the mixing time of the mixer is 1 to 6 hours. S2. The raw material mixture is stirred and mixed, and a water binder is added to obtain a homogeneous mixture; wherein the mass ratio of water to the raw material mixture is 5-50%. S3. The uniformly mixed material is pressed into shape under a pressure of 80-120MPa to obtain a green body; S4. The green body is fired in air at 1650-1750℃ and held for 3-10 hours to obtain ZrO2-doped CMA material. The ZrO2-doped CMA material contains only C2M2A. 14 Phases with CM2A8, or containing only C2M2A 14 Phase; Zr ions are uniformly distributed in CMA grains; C2M2A in the ZrO2-doped CMA material 14 The content of the phase is controlled at 80-100%; the volume density of the ZrO2-doped CMA is controlled at 2.0-3.17 g / cm³. 3 The porosity is controlled between 10.4% and 45.5%, and the water absorption rate is controlled between 3.4% and 20.8%.

2. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the average particle size of the alumina source is no greater than 56 μm, the average particle size of the magnesium oxide source is no greater than 56 μm, the average particle size of the calcium oxide source is no greater than 56 μm, and the average particle size of the zirconium dioxide is no greater than 6 μm.

3. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgO; Among them, Al2O 3、 The mass ratio of CaCO3 to MgO is 83.56~85.29: 11.72~11.75: 2.96~4.

72.

4. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgO, wherein the mass ratio of Al2O3, CaO, and MgO is 88.83~89.94:6.94:3.12~4.

23.

5. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is Mg(OH)2, wherein the mass ratio of Al2O3, CaO, and Mg(OH)2 is 86.18~88.70:6.78~6.85:4.45~7.

04.

6. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaO, and the magnesium oxide source is MgCO3, wherein the mass ratio of Al2O3, CaO, and MgCO3 is 83.56~86.98: 6.57~6.71: 6.31~9.

87.

7. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is MgCO3, wherein the mass ratio of Al2O3, CaCO3, and MgCO3 is 79.47~82.62:11.14~11.38:6.00~9.

39.

8. The method for integrated structural and functional control of ZrO2-doped CMA materials according to claim 1, characterized in that, In step S1, the alumina source is Al2O3, the calcium oxide source is CaCO3, and the magnesium oxide source is Mg(OH)2, wherein the mass ratio of Al2O3, CaCO3, and Mg(OH)2 is 81.83~84.18:11.48~11:60:4.22~6.

69.

9. A ZrO2-doped CMA material, characterized in that, The ZrO2-doped CMA material is prepared by the integrated structure-function control method according to any one of claims 1 to 8, wherein the CMA material contains only C2M2A. 14 Phases with CM2A8, or containing only C2M2A 14 Phase; Zr ions are uniformly distributed in CMA grains; C2M2A in the CMA material 14 The phase content is 80-100%, and the bulk density of CMA is 2.0-3.17 g / cm³. 3 The porosity ranges from 10.4% to 45.5%, and the water absorption rate ranges from 3.4% to 20.8%.

10. The ZrO2-doped CMA material according to claim 9, characterized in that, ZrO2-doped CMA materials are used as refractory materials, in which C2M2A 14 ZrO2-doped CMA materials with a phase content between 95% and 100% are used as heat insulation materials for industrial furnaces. 14 ZrO2-doped CMA materials with a phase content between 80% and 90% are used as working layer materials in industrial furnaces.

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