Heat storage ceramic and preparation method thereof

Abstract

The invention relates to heat storage ceramic and a preparation method thereof, and belongs to the technical field of ceramic materials. The method comprises the following steps: obtaining steel slag which does not have magnetism; removing free calcium oxide in the steel slag to obtain a steel slag raw material; preparing the steel slag raw material, kaolin, aluminum oxide and silicon carbide to obtain a wet material; the wet material is subjected to forming treatment and drying treatment, and a component is obtained; the component is sintered, and the heat storage ceramic is obtained; the steel slag without magnetism is adopted, and free calcium oxide in the steel slag is removed, so that the influence of the free calcium oxide on the heat storage ceramic is avoided, the flaws of the heat storage ceramic are reduced, and the steel slag can be massively utilized in the preparation of the heat storage ceramic.

Description

Technical Field

[0001] The present application relates to the technical field of ceramic materials, and in particular to a thermal storage ceramic and a preparation method thereof. Background Art

[0002] Thermal storage ceramics are a material that can efficiently store and release thermal energy. They are widely used in solar power generation, industrial waste heat recovery, building heating and cooling, and other fields, and can improve energy utilization efficiency.

[0003] One of the main components of steel slag is calcium oxide. Most of the calcium oxide forms stable compounds with oxides of silicon, aluminum, iron, magnesium, phosphorus, etc., which can improve the thermal stability of thermal storage ceramics. Usually, steel slag is used as a raw material for thermal storage ceramics to realize resource utilization of steel slag and reduce the production cost of thermal storage ceramics. However, in the existing technical solutions, the amount of steel slag in thermal storage ceramics is low and cannot be used in large quantities. This is because a small part of the calcium oxide in the steel slag is in a free state, and the proportion is uncertain, ranging from 5% to 30%, making the production process difficult to control and easily causing local defects in thermal storage ceramics. Summary of the invention

[0004] The embodiments of the present application provide a thermal storage ceramic and a preparation method thereof, so as to increase the amount of steel slag used in the preparation of the thermal storage ceramic.

[0005] The present application provides a method for preparing a thermal storage ceramic, the method comprising:

[0006] Obtaining steel slag, wherein the steel slag has no magnetism;

[0007] removing free calcium oxide from the steel slag to obtain a steel slag raw material;

[0008] The steel slag raw material, kaolin, alumina and silicon carbide are prepared to obtain a wet material;

[0009] The wet material is subjected to molding and drying to obtain a component;

[0010] The component is sintered to obtain heat storage ceramics.

[0011] As an optional implementation, the sintering process includes a microwave sintering process.

[0012] As an optional embodiment, the maximum temperature of the microwave sintering process is 1200-1400° C.; and / or

[0013] The microwave sintering process is kept at the highest temperature for 2 to 4 hours; and / or

[0014] The heating rate of the microwave sintering process is no higher than 5°C / min.

[0015] As an optional implementation manner, the step of obtaining steel slag includes magnetically separating primary steel slag to remove magnetic substances in the primary steel slag to obtain steel slag.

[0016] As an optional embodiment, the method of removing free calcium oxide in the steel slag includes pickling.

[0017] As an optional embodiment, the pH of the acid solution used for pickling is 0-1; and / or

[0018] The acid solution used for pickling includes hydrochloric acid or sulfuric acid; and / or

[0019] During the pickling process, the volume ratio of the steel slag to the acid solution is 1:(10-20).

[0020] As an optional embodiment, the steel slag comprises, by mass percentage, 35% to 45% CaO, 35% to 45% SiO 2 14%~18%,Al 2 O 3 6%~12%, MgO3%~8%, Fe 2 O 3 18%~24%, P 2 O 5 1% to 3% and MnO 1% to 5%, and unavoidable impurities; and / or

[0021] The kaolin composition by mass percentage includes Al 2 O 3 45%~50%, SiO 2 48% to 52% and oxides 1% to 3%, and unavoidable impurities, wherein the oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 At least one of; and / or

[0022] The purity of the aluminum oxide is above 99%; and / or

[0023] The purity of the silicon carbide is above 99%.

[0024] As an optional embodiment, the wet material includes, by weight, 70-75 parts of steel slag raw material, 10-15 parts of kaolin, 10-15 parts of alumina and 2-4 parts of silicon carbide; and / or

[0025] The steel slag raw material, kaolin, alumina and silicon carbide are all sieved through a 300-mesh sieve.

[0026] As an optional embodiment, the drying temperature is 100° C. to 120° C.; and / or

[0027] The drying time is 4 to 8 hours.

[0028] In a second aspect, an embodiment of the present application provides a thermal storage ceramic, which is prepared by the method provided in the first aspect.

[0029] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0030] The method provided in the embodiment of the present application adopts non-magnetic steel slag and removes free calcium oxide therein, thereby avoiding the influence of free calcium oxide on thermal storage ceramics and reducing the defects of thermal storage ceramics, thereby allowing steel slag to be widely used in the preparation of thermal storage ceramics. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] Figure 1 A flowchart of the method provided in the embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] Unless otherwise specified, the terms used herein should be understood as the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. In the event of a conflict, this specification takes precedence.

[0036] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0037] Figure 1 A flow chart of the method provided in the embodiment of the present application is as follows: Figure 1 As shown, the embodiment of the present application provides a method for preparing a thermal storage ceramic, the method comprising:

[0038] S1. obtaining steel slag, wherein the steel slag is non-magnetic;

[0039] In some embodiments, the steel slag is obtained by magnetically separating the primary steel slag to remove magnetic substances in the primary steel slag to obtain the steel slag. It is understood that the purpose of magnetically separating the primary steel slag is to remove iron-containing magnetic substances to prevent these substances from affecting the performance of the thermal storage ceramic. In other embodiments, other methods can be used to remove the magnetic substances in the primary steel slag, as long as the above-mentioned effects can be achieved.

[0040] S2. removing free calcium oxide from the slag to obtain a slag raw material;

[0041] In some embodiments, the method of removing free calcium oxide in the steel slag includes pickling. It is understandable that pickling can remove free calcium oxide in the steel slag, and the remaining calcium oxide combines with substances such as silicon dioxide to form a relatively stable compound form, and the content is relatively stable and uniform. In other embodiments, other methods can be used to remove free calcium oxide in steel slag, as long as the above-mentioned effect can be achieved.

[0042] Furthermore, the pH of the acid solution used in the pickling process is 0-1; the acid solution used in the pickling process includes hydrochloric acid or sulfuric acid; during the pickling process, the volume ratio of the steel slag to the acid solution is 1:(10-20). The use of the above acid solution can fully remove free calcium oxide and will not react with compounds compounded with calcium oxide.

[0043] Specifically, in this embodiment, the steel slag retained after magnetic separation is pickled to remove free calcium oxide therein. The specific operation is to mix the steel slag with dilute hydrochloric acid or dilute sulfuric acid with a pH value of 0-1 at a solid-liquid volume ratio of 1:10-1:20, react for 10-15 minutes, and then remove the acid. Then, the steel slag is mixed with deionized water at a volume ratio of 1:1-1:2 to neutralize the residual acidity.

[0044] S3. The steel slag raw material, kaolin, alumina and silicon carbide are prepared to obtain a wet material;

[0045] In some embodiments, the steel slag comprises, by mass percentage, 35% to 45% CaO, 35% to 45% SiO 2 14%~18%,Al 2 O 3 6%~12%, MgO3%~8%, Fe 2 O3 18%~24%, P 2 O 5 1% to 3% and MnO1% to 5%, and inevitable impurities; the composition of the kaolin in terms of mass percentage includes Al 2 O 3 45%~50%, SiO 2 48% to 52% and oxides 1% to 3%, and unavoidable impurities, wherein the oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 At least one of the following: the purity of the aluminum oxide is above 99%; the purity of the silicon carbide is above 99%. By limiting the components of each raw material to the above range, it is beneficial to obtain a thermal storage ceramic with better comprehensive performance.

[0046] In some embodiments, the wet material includes 70-75 parts of steel slag raw material, 10-15 parts of kaolin, 10-15 parts of aluminum oxide and 2-4 parts of silicon carbide by weight; by adopting the above ratio, a thermal storage ceramic with good comprehensive performance can be prepared. The steel slag raw material, kaolin, aluminum oxide and silicon carbide are all sieved through a 300 mesh sieve. The particle size of each raw material is within the above range so that each raw material can be mixed relatively evenly.

[0047] S4. The wet material is subjected to molding and drying to obtain a component;

[0048] In some embodiments, the drying process is carried out at a temperature of 100° C. to 120° C. and for a time of 4 to 8 hours.

[0049] Specifically, in this embodiment, the uniformly mixed wet material is placed in a mold to form a thermal storage ceramic green body of a desired shape. The molding pressure needs to be adjusted according to the specific material properties and product requirements to ensure the density and shape stability of the green body. Then, the molded green body is dried in a drying oven to remove moisture from the green body, with a drying time of 4-8 hours and a temperature of 100-120°C.

[0050] S5. Sintering the component to obtain heat storage ceramics.

[0051] In some embodiments, the sintering process includes a microwave sintering process. Compared with the traditional sintering process that relies on heat conduction, the microwave sintering process is beneficial to improving energy utilization efficiency. However, the microwave sintering process has high requirements on the wave absorption capacity and distribution uniformity of the sintered material. Most materials of thermal storage ceramics, including alumina and kaolin, have weak wave absorption capacity, and the microwave sintering process is less applicable to these materials, which leads to the fact that thermal storage ceramics are usually not sintered by the microwave sintering process. The raw materials of this scheme include steel slag and silicon carbide, and the wave absorption properties of steel slag and silicon carbide are relatively good. Therefore, this scheme can be sintered by the microwave sintering process, and the production energy consumption is relatively low. In addition, metallic iron will affect the absorption of microwaves, so the use of non-magnetic steel slag is also beneficial to improve the effect of microwave sintering.

[0052] Furthermore, the maximum temperature of the microwave sintering process is 1200-1400° C.; the holding time of the microwave sintering process at the maximum temperature is 2-4 hours; and the heating rate of the microwave sintering process is not higher than 5° C. / min.

[0053] By controlling the maximum temperature, holding time and heating rate of the microwave sintering process, the preform can be fully sintered with low energy consumption. At the same time, the microwave sintering process can be carried out as smoothly as possible, making the sintering effect more uniform.

[0054] Exemplarily, the maximum temperature of the microwave sintering process can be 1200° C., 1250° C., 1300° C., 1350° C., 1400° C., or any value within the range of 1200 to 1400° C. The holding time of the microwave sintering process at the maximum temperature can be 2 h, 2.5 h, 3 h, 3.5 h, 4 h, or any value within the range of 2 to 4 h.

[0055] This method has at least the following effects:

[0056] 1) By using non-magnetic steel slag and removing the free calcium oxide therein, the influence of free calcium oxide on thermal storage ceramics is avoided, and the defects of thermal storage ceramics are reduced. As a result, steel slag can be used in large quantities in the preparation of thermal storage ceramics, which helps to reduce the environmental impact of industrial waste, improve the recycling rate of resources, and reduce production costs.

[0057] 2) Using steel slag with non-magnetic materials such as metallic iron particles and removing its free calcium oxide not only improves the purity of the raw materials, but also reduces the emission of harmful substances that may be generated in subsequent use, playing a positive role in environmental protection.

[0058] 3) By introducing silicon carbide to form uniform microcracks during the sintering process, the heat conduction path is optimized, the heat conduction resistance is reduced, and the thermal stability and thermal conductivity of the heat storage body are significantly improved. This enables it to have higher thermal energy utilization efficiency in high-temperature thermal energy storage and conversion systems. Through the combination of material combinations and preparation processes, thermal storage ceramics can work stably at high temperatures and effectively alleviate energy losses during thermal energy transmission.

[0059] 4) Microwave sintering technology is used, and raw materials with good microwave absorption performance such as steel slag and silicon carbide are selected. Compared with the traditional sintering method, it not only improves the energy utilization rate, but also makes the heating more uniform. This sintering method helps to obtain a more uniform and dense ceramic structure, thereby improving the thermal stability and compressive strength of the thermal storage ceramic.

[0060] Based on a general inventive concept, an embodiment of the present application further provides a thermal storage ceramic, which is prepared by the method provided above.

[0061] The heat storage ceramic is implemented based on the above method. The specific steps of the method can refer to the above embodiment. Since the heat storage ceramic adopts part or all of the technical solutions of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described one by one here.

[0062] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0063] Example 1

[0064] A heat storage ceramic, the preparation process of which is as follows:

[0065] S1. removing magnetic substances from the primary slag by magnetic separation to obtain slag;

[0066] S2. removing free calcium oxide from the slag by pickling to obtain a slag raw material;

[0067] S3. Mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0068] S4. Adding the wet material to the mold for molding and drying to obtain a component;

[0069] S5. Sintering the components to obtain heat storage ceramics.

[0070] Among them, the wet material includes 70 parts of steel slag raw material, 10 parts of kaolin, 10 parts of alumina, and 2 parts of silicon carbide, calculated by mass.

[0071] The sintering adopts a microwave sintering process, the maximum temperature of the microwave sintering process is 1200° C., the insulation time of the microwave sintering process at the maximum temperature is 2 hours, and the heating rate of the microwave sintering process is 5° C. / min.

[0072] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0073] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0074] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O 3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0075] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0076] Example 2

[0077] A heat storage ceramic, the preparation process of which is as follows:

[0078] S1. removing magnetic substances from the primary slag by magnetic separation to obtain slag;

[0079] S2. removing free calcium oxide from the slag by pickling to obtain a slag raw material;

[0080] S3. Mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0081] S4. Adding the wet material to the mold for molding and drying to obtain a component;

[0082] S5. Sintering the components to obtain heat storage ceramics.

[0083] Among them, the wet material includes 75 parts of steel slag raw material, 15 parts of kaolin, 15 parts of alumina, and 4 parts of silicon carbide, calculated by mass.

[0084] The sintering adopts a microwave sintering process, the maximum temperature of the microwave sintering process is 1400° C., the insulation time of the microwave sintering process at the maximum temperature is 4 hours, and the heating rate of the microwave sintering process is 3° C. / min.

[0085] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0086] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0087] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O 3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0088] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0089] Example 3

[0090] A heat storage ceramic, the preparation process of which is as follows:

[0091] S1. removing magnetic substances from the primary slag by magnetic separation to obtain slag;

[0092] S2. removing free calcium oxide from the slag by pickling to obtain a slag raw material;

[0093] S3. Mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0094] S4. Adding the wet material to the mold for molding and drying to obtain a component;

[0095] S5. Sintering the components to obtain heat storage ceramics.

[0096] Among them, in terms of mass, the wet material includes 73 parts of steel slag raw material, 12 parts of kaolin, 14 parts of alumina, and 3 parts of silicon carbide.

[0097] The sintering adopts a microwave sintering process, the maximum temperature of the microwave sintering process is 1300° C., the insulation time of the microwave sintering process at the maximum temperature is 3 hours, and the heating rate of the microwave sintering process is 4° C. / min.

[0098] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0099] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0100] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O 3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0101] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0102] Comparative Example 1

[0103] A heat storage ceramic, the preparation process of which is as follows:

[0104] S1. removing free calcium oxide from the primary slag by pickling to obtain a slag raw material;

[0105] S2. mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0106] S3. The wet material is added to the mold for molding and drying to obtain a component;

[0107] S4. Sintering the components to obtain heat storage ceramics.

[0108] Among them, the wet material includes 70 parts of steel slag raw material, 10 parts of kaolin, 10 parts of alumina, and 2 parts of silicon carbide, calculated by mass.

[0109] The sintering adopts a microwave sintering process, the maximum temperature of the microwave sintering process is 1200° C., the insulation time of the microwave sintering process at the maximum temperature is 2 hours, and the heating rate of the microwave sintering process is 5° C. / min.

[0110] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0111] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0112] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O 3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0113] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0114] Comparative Example 2

[0115] A heat storage ceramic, the preparation process of which is as follows:

[0116] S1. removing magnetic substances from the primary slag by magnetic separation to obtain slag raw materials;

[0117] S2. mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0118] S3. The wet material is added to the mold for molding and drying to obtain a component;

[0119] S4. Sintering the components to obtain heat storage ceramics.

[0120] Among them, the wet material includes 70 parts of steel slag raw material, 10 parts of kaolin, 10 parts of alumina, and 2 parts of silicon carbide, calculated by mass.

[0121] The sintering adopts a microwave sintering process, the maximum temperature of the microwave sintering process is 1200° C., the insulation time of the microwave sintering process at the maximum temperature is 2 hours, and the heating rate of the microwave sintering process is 5° C. / min.

[0122] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0123] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0124] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O 3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0125] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0126] Comparative Example 3

[0127] A heat storage ceramic, the preparation process of which is as follows:

[0128] S1. removing magnetic substances from the primary slag by magnetic separation to obtain slag;

[0129] S2. removing free calcium oxide from the slag by pickling to obtain a slag raw material;

[0130] S3. Mixing the steel slag raw material, kaolin, alumina, silicon carbide and water to obtain a wet material;

[0131] S4. Adding the wet material to the mold for molding and drying to obtain a component;

[0132] S5. Sintering the components to obtain heat storage ceramics.

[0133] Among them, the wet material includes 70 parts of steel slag raw material, 10 parts of kaolin, 10 parts of alumina, and 2 parts of silicon carbide, calculated by mass.

[0134] The sintering adopts a conventional thermal sintering process, the maximum sintering temperature is 1200° C., the holding time of the conventional thermal sintering process at the maximum temperature is 2 hours, and the heating rate of the conventional thermal sintering process is 5° C. / min.

[0135] The acid solution for pickling is a sulfuric acid solution, and the pH of the sulfuric acid solution is 1.

[0136] The steel slag raw materials, kaolin, alumina and silicon carbide were all sieved through a 300-mesh sieve.

[0137] The composition of steel slag by mass percentage includes CaO40%, SiO 2 16%, Al 2 O3 10%, MgO5%, Fe 2 O 3 20%, P 2 O 5 2%, MnO2%, and impurities.

[0138] The composition of kaolin by mass percentage includes Al 2 O 3 50%、SiO 2 48%, oxides 2%, oxides include MgO, K 2 O、TiO 2 , Fe 2 O 3 .

[0139] The thermal storage ceramics provided in each embodiment and comparative example were tested, and the test results are shown in the following table:

[0140]

[0141] It can be seen from the above table that the thermal storage ceramics prepared by the method provided in the embodiments of the present application have good comprehensive performance, and the performance is not weaker than that of conventional thermal storage ceramics due to the large amount of steel slag used.

[0142] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0143] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present application specification, the terms "including", "comprising", etc. refer to "including but not limited to". Moreover, the terms "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. For the association relationship of more than three associated objects described by "and / or", it means that any one of the three associated objects can exist alone, or any at least two of them can exist at the same time. For example, for A, and / or B, and / or C, it can mean that any one of A, B, and C exists alone, or any two of them exist at the same time, or three of them exist at the same time. In this article, "at least one" means one or more, and "multiple" means two or more. "At least one", "the following at least one (one)" or similar expressions refer to any combination of these items, including any combination of single (one) or plural (one). For example, "at least one (one) of a, b, or c", or "at least one (one) of a, b, and c", can all represent: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, and c can be single or multiple, respectively.

[0144] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing a thermal storage ceramic, characterized in that: The method comprises: Obtaining steel slag, wherein the steel slag has no magnetism; removing free calcium oxide from the steel slag to obtain a steel slag raw material; The steel slag raw material, kaolin, alumina and silicon carbide are prepared to obtain a wet material; The wet material is subjected to molding and drying to obtain a component; The component is sintered to obtain heat storage ceramics.

2. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The sintering process includes a microwave sintering process.

3. The method for preparing the thermal storage ceramic according to claim 2, characterized in that: The maximum temperature of the microwave sintering process is 1200-1400°C; and / or The microwave sintering process is kept at the highest temperature for 2 to 4 hours; and / or The heating rate of the microwave sintering process is no higher than 5°C / min.

4. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The method of obtaining steel slag includes magnetically separating primary steel slag to remove magnetic substances in the primary steel slag to obtain steel slag.

5. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The method of removing free calcium oxide in the steel slag includes pickling.

6. The method for preparing the thermal storage ceramic according to claim 5, characterized in that: The pH of the acid solution used in the pickling is 0 to 1; and / or The acid solution used for pickling includes hydrochloric acid or sulfuric acid; and / or During the pickling process, the volume ratio of the steel slag to the acid solution is 1:(10-20).

7. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The steel slag comprises, by mass percentage, 35% to 45% CaO, 14% to 18% SiO2, 6% to 12% Al2O3, 3% to 8% MgO, 18% to 24% Fe2O3, 1% to 3% P2O5 and 1% to 5% MnO, as well as unavoidable impurities; and / or The kaolin comprises, by mass percentage, 45% to 50% Al2O3, 48% to 52% SiO2 and 1% to 3% oxides, as well as unavoidable impurities, wherein the oxides comprise at least one of MgO, K2O, TiO2 and Fe2O3; and / or The purity of the aluminum oxide is above 99%; and / or The purity of the silicon carbide is above 99%.

8. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The wet material comprises, by weight, 70-75 parts of steel slag raw material, 10-15 parts of kaolin, 10-15 parts of alumina and 2-4 parts of silicon carbide; and / or The steel slag raw material, kaolin, alumina and silicon carbide are all sieved through a 300-mesh sieve.

9. The method for preparing the thermal storage ceramic according to claim 1, characterized in that: The drying temperature is 100°C to 120°C; and / or The drying time is 4 to 8 hours.

10. A thermal storage ceramic, characterized in that: The thermal storage ceramic is prepared by the method according to any one of claims 1 to 9.

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