A composite material based on waste electrical porcelain and its preparation method and application

Abstract

The present invention discloses a composite material based on waste electrical porcelain, a preparation method, and an application thereof. The material comprises waste electrical porcelain, fly ash, a potassium source, and alumina. Based on 100wt% of the waste electrical porcelain, fly ash, potassium source, and alumina, the weight of the waste electrical porcelain is 45wt% to 80wt%, the weight of the fly ash is 5wt% to 40wt%, the weight of the potassium source is 2wt% to 20wt%, and the weight of the alumina is 0.5wt% to 15wt%. The composite material based on waste electrical porcelain of the present invention has high mechanical strength (for example, high flexural strength) and can be used under high temperature conditions. In high-temperature and high-strength environments, it can serve as a supporting component, such as a load-bearing and pressure-bearing component of a kiln.

Description

Technical Field

[0001] The present invention belongs to the field of inorganic materials, and in particular relates to a composite material based on waste electrical porcelain, and specifically relates to a composite material based on waste electrical porcelain, and a preparation method and application thereof. Background Art

[0002] Refractory materials generally refer to inorganic, non-metallic materials with a refractoriness above 1580°C. They include natural ores and various products manufactured through specific processes to meet specific requirements. They possess specific high-temperature mechanical properties and excellent volume stability, making them essential for various high-temperature equipment. Refractory materials are a key component of my country's industrial development, primarily used in the steel, building materials, nonferrous metals, and chemical industries. They are a key pillar supporting my country's rapid economic growth. However, since refractory raw materials are consumables, the possibility of their depletion must be considered.

[0003] At the same time, the ceramic industry is developing rapidly. Insulators are a type of ceramic used in power systems, primarily for supporting and insulating components. Due to their demanding operating conditions, the manufacturing process for insulators requires a more rigorous and precise process. Consequently, waste insulators inherently offer advantages such as heat and high-temperature resistance. Therefore, finding the best way to fully utilize waste insulators has become a research topic for many technicians.

[0004] Chinese patent CN115710138A discloses a method for preparing high-temperature-resistant, lightweight thermal insulation materials from waste electrical porcelain, relating to the fields of comprehensive solid waste utilization and thermal insulation materials. The method involves adding water to a slurry made from waste electrical porcelain, bauxite, and clay. Cetyltrimethylammonium bromide (CTAB) is used as a foaming agent, along with a foam stabilizer. The slurry is then poured into a mold using a casting process. The mold is then removed, dried, and sintered at high temperature to produce the material.

[0005] Chinese patent CN115745585A discloses a method for preparing low-aluminum mullite refractory bricks using waste electrical porcelain. The method first uses waste electrical porcelain of different particle sizes as raw materials, water glass solution as a binder, and aluminum ash and clay as coating materials. The ingredients are mixed evenly in a certain proportion and naturally dried at room temperature for 90 minutes; then the materials are weighed and placed in a mold, and a sample is obtained under the conditions of dry pressing at 15MPa and holding pressure for 60 seconds.

[0006] However, the prior art does not involve the use of waste electrical porcelain and fly ash to prepare a composite material based on waste electrical porcelain. Summary of the Invention

[0007] To overcome the problems existing in the prior art, the present invention provides a composite material based on waste electrical porcelain, its preparation method, and its application. This invention utilizes waste electrical porcelain as the primary raw material to prepare the composite material, addressing the issue of solid waste recycling while also conserving mineral resources. The present invention also utilizes fly ash as the primary additive, providing a new approach for the high-value utilization of coal-based solid waste in my country. Due to its high mechanical strength (e.g., high flexural strength), the composite material based on waste electrical porcelain can be used in high-temperature environments. In such environments, it can serve as a supporting component, such as the load-bearing and pressure-bearing components of kilns. Overall, this approach achieves resource recovery and reuse of industrial and coal-based solid waste, reduces environmental pollution, and increases economic value at a low cost, meeting industry needs.

[0008] One of the objects of the present invention is to provide a composite material based on waste electrical porcelain, which contains waste electrical porcelain, fly ash, a potassium source and alumina.

[0009] In a preferred embodiment, the potassium source is selected from potassium feldspar.

[0010] In a preferred embodiment, based on the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the weight of the waste electrical porcelain is 45wt%~80wt%, the weight of the fly ash is 5~40wt%, the weight of the potassium source is 2~20wt%, and the weight of the alumina is 0.5~15wt%.

[0011] For example, taking the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the waste electrical porcelain accounts for 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt% or 80wt%, the fly ash accounts for 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%, the potassium source accounts for 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt% or 20wt%, and the alumina accounts for 0.5wt%, 1wt%, 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt% or 15wt%.

[0012] In a further preferred embodiment, based on the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the weight of the waste electrical porcelain is 60wt%~70wt%, the weight of the fly ash is 15~25wt%, the weight of the potassium source is 5~15wt%, and the weight of the alumina is 1~10wt%.

[0013] In a preferred embodiment, the particle size of the waste electrical porcelain is less than 5 mm, preferably less than 1 mm.

[0014] In a further preferred embodiment, the waste electrical porcelain comprises a mixture of three particle sizes, wherein the three particle sizes are respectively less than 74 μm, 74 μm to 0.3 mm, and 0.3 to 0.6 mm.

[0015] Among them, the inventors found in experiments that the combination of the above three particle sizes has the best effect.

[0016] In a further preferred embodiment, the weight ratio of waste electrical porcelain smaller than 74 μm, waste electrical porcelain from 74 μm to 0.3 mm, and waste electrical porcelain from 0.3 to 0.6 mm is (10 to 60): (10 to 20): (10 to 20), preferably (25 to 45): (12 to 18): (12 to 18).

[0017] For example, the weight ratio of waste electrical porcelain less than 74μm, waste electrical porcelain from 74μm to 0.3mm, and waste electrical porcelain from 0.3 to 0.6mm is (10, 15, 20, 25, 30, 35, 40, 45, 50, 55 or 60):(10, 12, 14, 16, 18 or 20):(10, 12, 14, 16, 18 or 20).

[0018] In a preferred embodiment, the composite material based on waste electrical porcelain further contains a binder.

[0019] In a further preferred embodiment, the binder is selected from at least one of PVA and water glass, preferably PVA (polyvinyl alcohol).

[0020] In a further preferred embodiment, based on 100wt% of the waste electrical porcelain, fly ash, potassium source and alumina, the weight of the binder is 0.5~15wt%, preferably 1~10wt%, for example, 0.5wt%, 1wt%, 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt% or 15wt%.

[0021] The second object of the present invention is to provide a method for preparing a composite material based on waste electrical porcelain, which is preferably used to prepare the composite material based on waste electrical porcelain described in one of the objects of the present invention. The preparation method comprises: mixing the raw materials including the waste electrical porcelain, the fly ash, the potassium source, the alumina and the optional binder, stirring evenly, pressing into shape, drying, and sintering to obtain the composite material based on waste electrical porcelain.

[0022] In a preferred embodiment, based on the total amount of the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the amount of the waste electrical porcelain is 45wt%~80wt%, the amount of the fly ash is 5~40wt%, the amount of the potassium source is 2~20wt%, and the amount of the alumina is 0.5~15wt%.

[0023] For example, based on the total amount of the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the amount of the waste electrical porcelain is 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt% or 80wt%, the amount of the fly ash is 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%, the amount of the potassium source is 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt% or 20wt%, and the amount of alumina is 0.5wt%, 1wt%, 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt% or 15wt%.

[0024] In a further preferred embodiment, based on the total amount of the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the amount of the waste electrical porcelain is 60wt%~70wt%, the amount of the fly ash is 15~25wt%, the amount of the potassium source is 5~15wt%, and the amount of the alumina is 1~10wt%.

[0025] In a preferred embodiment, based on the total amount of the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the amount of the binder is 0.5~15wt%, preferably 1~10wt%, for example, 0.5wt%, 1wt%, 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt% or 15wt%.

[0026] In a preferred embodiment, the compression molding conditions include: a pressure of 2 to 18 MPa, and a holding pressure of 20 to 200 seconds.

[0027] In a further preferred embodiment, the compression molding conditions include: a pressure of 5 to 15 MPa, and a holding pressure of 30 to 100 seconds.

[0028] For example, the conditions for the compression molding include: a pressure of 2 MPa, 4 MPa, 6 MPa, 8 MPa, 10 MPa, 12 MPa, 14 MPa, 16 MPa or 18 MPa, and holding the pressure for 20 seconds, 40 seconds, 60 seconds, 80 seconds, 100 seconds, 120 seconds, 140 seconds, 160 seconds, 180 seconds or 200 seconds.

[0029] The present invention does not require high pressure pressing to obtain a material with excellent performance. Preferably, the pressing is a semi-dry pressing method.

[0030] In a preferred embodiment, the drying conditions include: a temperature of 50-150° C. and a time of 5-50 hours.

[0031] In a further preferred embodiment, the drying conditions include: a temperature of 80-130° C. and a time of 10-40 hours.

[0032] For example, the drying conditions include: a temperature of 50°C, 60°C, 80°C, 100°C, 120°C, 140°C or 150°C, and a time of 5h, 10h, 15h, 20h, 25h, 30h, 35h or 40h.

[0033] In a preferred embodiment, the sintering comprises: gradually heating from room temperature to T1 for sintering, T1 = 1300-1600°C; then gradually cooling from T1 to T2, T2 = 500-1000°C; and finally naturally cooling from T2.

[0034] For example, T1=1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃ or 1600℃; T2=500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃ or 1000℃.

[0035] In a further preferred embodiment, the sintering comprises: gradually raising the temperature from room temperature to T1 for sintering, T1 = 1400-1600°C; then gradually lowering the temperature from T1 to T2, T2 = 600-1000°C; and finally naturally cooling from T2.

[0036] In a further preferred embodiment, the sintering comprises: gradually raising the temperature from room temperature to T1 for sintering, T1 = 1400-1500°C; then gradually lowering the temperature from T1 to T2, T2 = 700-900°C; and finally naturally cooling from T2.

[0037] In a preferred embodiment, multiple insulation steps are performed during the heating process of sintering, and the insulation time is 20 to 200 minutes, for example, 20 minutes, 40 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, 140 minutes, 160 minutes, 180 minutes or 200 minutes.

[0038] In a preferred embodiment, the sintering includes: heating the temperature to T0 at a heating rate of 1 to 10 ° C / min for sintering, T0 = 700 to 1200 ° C, and keeping the temperature for 3 to 7 times (preferably 4 to 6 times) during the heating process (preferably keeping the temperature for 10 to 80 minutes); then continuing to heat the temperature to T1 at a heating rate of 0.5 to 8 ° C / min, and keeping the temperature for 1 to 5 times (preferably 2 to 4 times) during the heating process (preferably keeping the temperature for 20 to 150 minutes); keeping the temperature at T1 (preferably keeping the temperature for 60 to 200 minutes), then cooling the temperature to T2 at a cooling rate of 1 to 10 ° C / min, and finally cooling naturally.

[0039] For example, the sintering includes: heating the temperature to T0 at a heating rate of 1°C / min, 2°C / min, 4°C / min, 6°C / min, 8°C / min or 10°C / min for sintering, T0 = 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C, and keeping the temperature for 3, 4, 5, 6 or 7 times during the heating process (preferably keeping the temperature for 10min, 20min, 30min, 40min, 50min, 60min, 70min or 80min); and then continuing to heat the temperature at a heating rate of 0.5°C / min, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 8°C / min or 10°C / min, wherein T0 = 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C. min, 7 ° C / min or 8 ° C / min to T1, and keep warm once, twice, three times, four times or five times during the heating process (preferably for 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, 140 min or 150 min); keep warm at T1 (preferably for 60 min, 80 min, 100 min, 120 min, 140 min, 160 min, 180 min or 200 min), then cool to T2 at a cooling rate of 1 ° C / min, 2 ° C / min, 4 ° C / min, 6 ° C / min, 8 ° C / min or 10 ° C / min, and finally cool naturally.

[0040] In a further preferred embodiment, the sintering includes: the sintering system is heated to T0 at a heating rate of 3-8°C / min, T0=800-950°C, and during the heating process, the sintering temperature is respectively at 50-150°C (for example, 60°C, 80°C, 100°C, 120°C or 140°C), 250-350°C (for example, 260°C, 280°C, 300°C, 320°C or 340°C), 450-550°C (for example, 460°C, 480°C, 500°C, 520°C or 540°C), 650-750°C (for example, 660°C, 680°C, 700°C, 750°C) The sintering temperature is preferably 00℃, 720℃ or 740℃), 850~900℃ (for example, 850℃, 860℃, 880℃ or 900℃), and kept at this temperature for 20~60min; then the temperature is continued to be raised at a heating rate of 1~5℃ / min to T1. During this heating process, the temperature is kept at 980~1020℃ (for example, 980℃, 1000℃ or 1020℃), 1080~1120℃ (for example, 1080℃, 1100℃ or 1120℃), and 1180~1220℃ (for example, 1180℃, 1200℃ or 1220℃) for 40~120min. When the sintering temperature reaches T1, it is kept at this temperature for 80~150min, then the temperature is reduced to T2 at a rate of 3~8℃ / min, and finally cooled naturally.

[0041] The endpoints and any values of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and a separate point value, and the separate point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be considered as specifically disclosed in this article.

[0042] Compared with the prior art, the present invention has the following beneficial effects: (1) the composite material based on waste electrical porcelain of the present invention has beneficial flexural strength; (2) the surface of the composite material based on waste electrical porcelain of the present invention is glossy and has no obvious granularity; (3) the composite material based on waste electrical porcelain of the present invention is mainly composed of mullite in the physical phase and has fire resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Example 3 ( Figure 1 B) and Comparative Example 1 ( Figure 1 A) SEM image of the obtained sample.

[0044] Figure 2 The XRD patterns of Example 3 and Examples 5-6 are shown. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0046] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0047] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the scope of protection of the present invention.

[0048] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0049] According to the national standard GB / T 3810.3-2016, the boiling method and the Archimedes drainage method were used, and the open and closed porosity of the sample was measured by a density balance. According to the national standard GB / T 38978-2020, the three-point bending method was used, and the flexural strength test of all fired samples was carried out using a universal material testing machine.

[0050] The raw materials included scrap electrical porcelain of varying particle sizes (0-74µm, 74µm-0.3mm, and 0.3mm-0.6mm, from Shandong Laiwu Porcelain Insulator Co., Ltd., China), fly ash (average particle size 600µm, from Hebei Province, China), and potassium feldspar (average particle size 600µm, from Shandong Province, China). Polyvinyl alcohol (PVA) (Aladdin, China) served as a binder. The chemical compositions of the main components of the scrap electrical porcelain (from Zibo Tengyun Economic and Trade Co., Ltd.) are shown in Tables 1 and 2.

[0051] Table 1: Main components of waste electrical porcelain

[0052]

[0053] Table 2: Main components of fly ash

[0054]

[0055] [Example 1]

[0056] 1.665g of 0-74μm [200 mesh] waste electrical porcelain, 0.555g of 74μm -0.3mm waste electrical porcelain, 0.555g of 0.3mm-0.6mm waste electrical porcelain, 0.37g fly ash, 0.37g potassium feldspar, 0.185g alumina and 0.185g binder PVA were mixed to obtain a mixture. The mixture was then pressed into a cylindrical mold with a specification of Φ 15 × h 15 mm and a rectangular compact (45 mm × 6 mm × 6 mm) using a semi-dry pressing method in a mold at a pressure of 10 MPa for 60 seconds. The mold was placed in a drying oven at 100°C and dried for 24 hours. The sintering system was sintered at 5° per minute to 900°C (T0), with the temperature maintained at 100°C, 300°C, 500°C, 700°C and 900°C for 40 minutes. When the sintering temperature is higher than 900°C, sinter at 3°C / min to a final temperature of 1440°C (T1), then hold at 1000°C, 1100°C, and 1200°C for 60 min. When the sintering temperature reaches 1440°C, hold for 120 min, then reduce the temperature to 800°C at 5°C / min (T2), and finally cool naturally.

[0057] The sample has a flexural strength of 57 MPa. XRD analysis of the sample shows that the main phase of the sample is mullite, indicating a relatively high content of mullite, proving that the sample is fire-resistant. Due to the high melting point of mullite, the resulting material has good high-temperature resistance.

[0058] [Example 2]

[0059] The process of Example 1 was repeated except that the raw materials were: 1.295 g of 0-74 μm scrap electrical porcelain, 0.555 g of 74 μm -0.3 mm scrap electrical porcelain, 0.555 g of 0.3 mm -0.6 mm scrap electrical porcelain, 0.74 g of fly ash, 0.37 g of potassium feldspar, 0.185 g of aluminum oxide, and 0.185 g of PVA binder. All other conditions remained unchanged.

[0060] The sample's flexural strength is 77.3 MPa. XRD analysis of the sample reveals that the main phase is mullite, indicating a relatively high mullite content, demonstrating the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material exhibits excellent high-temperature resistance.

[0061] [Example 3]

[0062] The process of Example 1 was repeated except that the raw materials were: 0.925 g of 0-74 μm scrap electrical porcelain, 0.555 g of 74 μm-0.3 mm scrap electrical porcelain, 0.555 g of 0.3 mm-0.6 mm scrap electrical porcelain, 1.11 g of fly ash, 0.37 g of potassium feldspar, 0.185 g of aluminum oxide, and 0.185 g of PVA binder. All other conditions remained unchanged.

[0063] The sample's flexural strength is 65.4 MPa. XRD analysis of the sample shows that the main phase of the sample is mullite, indicating a relatively high content of mullite, proving the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material possesses good high-temperature resistance.

[0064] [Example 4]

[0065] The process of Example 1 was repeated except that the raw materials were: 0.555 g of 0-74 μm scrap electrical porcelain, 0.555 g of 74 μm-0.3 mm scrap electrical porcelain, 0.555 g of 0.3 mm-0.6 mm scrap electrical porcelain, 1.48 g of fly ash, 0.37 g of potassium feldspar, 0.185 g of aluminum oxide, and 0.185 g of PVA binder. Other conditions remained unchanged.

[0066] The sample's flexural strength is 73.6 MPa. XRD analysis of the sample shows that the main phase of the sample is mullite, indicating a relatively high content of mullite, proving the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material possesses excellent high-temperature resistance.

[0067] [Example 5]

[0068] The process of Example 3 was repeated, except for the following sintering procedures: sintering was performed at 5°C / min to 900°C, with 40-min holds at 100°C, 300°C, 500°C, 700°C, and 900°C. When the sintering temperature exceeded 900°C (T0), sintering was performed at 3°C / min to the final temperature T1 (1540°C), with 60-min holds at 1000°C, 1100°C, and 1200°C. When the sintering temperature reached 1540°C, it was held for 120 min, then reduced to 800°C (T2) at 5°C / min, followed by natural cooling.

[0069] The sample's flexural strength is 61.9 MPa. XRD analysis of the sample reveals that the main phase is mullite, indicating a relatively high mullite content, demonstrating the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material exhibits excellent high-temperature resistance.

[0070] [Example 6]

[0071] The process of Example 3 was repeated, except for the following sintering procedures: sintering was performed at 5°C / min to 900°C, with 40-min holds at 100°C, 300°C, 500°C, 700°C, and 900°C. When the sintering temperature exceeded 900°C (T0), sintering was performed at 3°C / min to the final temperature T1 (1340°C), with 60-min holds at 1000°C, 1100°C, and 1200°C. When the sintering temperature reached 1340°C, it was held for 120 min, then reduced at 5°C / min to 800°C (T2), followed by natural cooling.

[0072] The sample's flexural strength is 52.1 MPa. XRD analysis of the sample reveals that the main phase is mullite, indicating a relatively high mullite content, demonstrating the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material exhibits excellent high-temperature resistance.

[0073] [Example 7]

[0074] 1.093g of 0-74μm scrap electrical porcelain, 0.656g of 74μm -0.3mm scrap electrical porcelain, 0.656g of 0.3mm-0.6mm scrap electrical porcelain, 0.74g of fly ash, 0.37g of potassium feldspar, 0.185g of aluminum oxide, and 0.185g of PVA binder were used. The resulting mixture was semi-dry pressed in a mold at 6MPa for 100 seconds to form cylindrical briquettes (Ø15 x h15mm) and rectangular briquettes (45mm x 6mm x 6mm). The briquettes were then dried in a drying oven at 100°C for 24 hours. The sintering process was performed at 3°C / min to 800°C (T0), with 60min holding times at 80°C, 250°C, 450°C, 650°C, and 800°C. When the sintering temperature is higher than 800°C, sinter at a rate of 1°C per minute to the final temperature T1 (1400°C), and then hold at 1000°C, 1100°C, and 1200°C for 80 minutes. When the sintering temperature reaches 1400°C, hold it for 150 minutes, then reduce it to 700°C (T2) at a rate of 3°C per minute, and finally cool naturally.

[0075] The sample's flexural strength is 50.49 MPa. XRD analysis of the sample shows that the main phase of the sample is mullite, indicating a relatively high content of mullite, proving the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material possesses excellent high-temperature resistance.

[0076] [Example 8]

[0077] The process of Example 1 was repeated, except that the raw materials were: 0.7568g of 0-74μm scrap electrical porcelain, 0.4541g of 74μm-0.3mm scrap electrical porcelain, 0.4541g of 0.3mm-0.6mm scrap electrical porcelain, 1.48g of fly ash, 0.37g of potassium feldspar, 0.185g of aluminum oxide, and 0.185g of PVA binder. Other conditions remained unchanged. The resulting mixture was semi-dry pressed in a mold at a pressure of 18 MPa for 30 seconds to form a cylindrical mold with dimensions of Φ15 × 15 mm and a rectangular compact (45 mm × 6 mm × 6 mm). The compact was then placed in a drying oven at 100°C and dried for 24 hours. The sintering process was performed at a rate of 8°C / min to 950°C (T0), with 30-min holding times at 120°C, 350°C, 550°C, 750°C, and 900°C. When the sintering temperature is higher than 900°C, sinter at 5°C / min to the final temperature T1 (1500°C), and then hold at 1000°C, 1100°C, and 1200°C for 40 minutes. When the sintering temperature reaches 1500°C, hold it for 80 minutes, then reduce it to 900°C (T2) at 8°C / min, and finally cool naturally.

[0078] The sample's flexural strength is 56.56 MPa. XRD analysis of the sample reveals that the main phase is mullite, indicating a relatively high mullite content, demonstrating the sample's fire resistance. Furthermore, due to the high melting point of mullite, the resulting material exhibits excellent high-temperature resistance.

[0079] [Comparative Example 1]

[0080] The process of Example 1 was repeated, except for the following sintering procedures: sintering was performed at 5°C / min to 900°C, with 40-min holds at 100°C, 300°C, 500°C, 700°C, and 900°C. When the sintering temperature exceeded 900°C, sintering was performed at 3°C / min to the final temperature T1 (1140°C), followed by a 60-min hold at 1000°C. When the sintering temperature reached 1140°C, the temperature was held for 120 min, then reduced at 5°C / min to 800°C (T2), followed by natural cooling.

[0081] The flexural strength of the sample is 43.8 MPa.

[0082] [Comparative Example 2]

[0083] The process of Example 3 was repeated, except that an equal amount of fly ash was used to replace the waste electrical porcelain. The results showed that:

[0084] The sample showed obvious overburning during the sintering process, with many pores appearing on the surface and bulges around it. The morphology of the sample could not be guaranteed and the flexural strength could not be measured.

[0085] [Test Example 1]

[0086] The samples obtained in Example 3, Example 6, Example 5 and Comparative Example 1 were analyzed (observed with the naked eye): the sizes of the sintered bodies of Comparative Example 1 and Example 6 were not significantly different from those of the green bodies, but the fired samples had obvious granularity; the fired sample of Example 3 had significantly lower granularity than that of Example 6 and Comparative Example 1, and had a certain gloss; and the sample of Example 5 had slight deformation after firing, but the glossiness did not change much.

[0087] [Test Example 2]

[0088] For Example 3 ( Figure 1 B) and Comparative Example 1 ( Figure 1 The sample obtained in (A) was subjected to SEM examination, and the results were as follows Figure 1 shown.

[0089] Compared with Example 3: The surface of the sample in Comparative Example 1 is relatively rough. As the temperature increases, the surface smoothness of the sample increases and it transforms into ceramicization. The overall pore size of the sample gradually decreases. At the final temperature of 1140°C, the surface of the sample is relatively rough and has a larger unbonded surface.

[0090] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A composite material based on waste electrical porcelain, comprising waste electrical porcelain, fly ash, a potassium source and alumina, wherein the waste electrical porcelain, fly ash, potassium source and alumina are 100 wt %, wherein: The weight of the waste electrical porcelain is 45wt%~80wt%, the weight of the fly ash is 15~40wt%, the weight of the potassium source is 2~20wt%, and the weight of the alumina is 0.5~15wt%; the waste electrical porcelain includes a mixture of three particle sizes, and the three particle sizes are respectively less than 74μm, 74μm~0.3mm, and 0.3~0.6mm. The weight ratio of waste electrical porcelain less than 74μm, waste electrical porcelain 74μm~0.3mm, and waste electrical porcelain 0.3~0.6mm is (10~60):(10~20):(10~20).

2. The composite material based on waste electrical porcelain according to claim 1, characterized in that: The potassium source is selected from potassium feldspar.

3. The composite material based on waste electrical porcelain according to claim 1, characterized in that: Taking the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the weight of the waste electrical porcelain is 60wt%~70wt%, the weight of the fly ash is 15~25wt%, the weight of the potassium source is 5~15wt%, and the weight of the alumina is 1~10wt%.

4. The composite material based on waste electrical porcelain according to any one of claims 1 to 3, characterized in that: The composite material based on waste electrical porcelain further contains a binder.

5. The composite material based on waste electrical porcelain according to claim 4, characterized in that: The binder is selected from at least one of PVA and water glass.

6. The composite material based on waste electrical porcelain according to claim 4, characterized in that: Based on 100 wt% of the waste electrical porcelain, fly ash, potassium source and alumina, the weight of the binder is 0.5-15 wt%.

7. The composite material based on waste electrical porcelain according to claim 4, characterized in that: Based on 100 wt% of the waste electrical porcelain, fly ash, potassium source and alumina, the weight of the binder is 1-10 wt%.

8. A method for preparing a composite material based on waste electrical porcelain, for preparing the composite material according to any one of claims 1 to 7, the method comprising: The raw materials including the waste electrical porcelain, the fly ash, the potassium source, the alumina and the optional binder are mixed, stirred evenly, pressed into shape, dried and sintered to obtain the composite material based on waste electrical porcelain; based on the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the weight of the waste electrical porcelain is 45wt%~80wt%, the weight of the fly ash is 15~40wt%, the weight of the potassium source is 2~20wt%, and the weight of the alumina is 0.5~15wt%; the waste electrical porcelain includes a mixture of three particle sizes, and the three particle sizes are respectively less than 74μm, 74μm~0.3mm, and 0.3~0.6mm, and the weight ratio of the waste electrical porcelain less than 74μm, the waste electrical porcelain 74μm~0.3mm and the waste electrical porcelain 0.3~0.6mm is (10~60):(10~20):(10~20).

9. The preparation method according to claim 8, characterized in that Based on the total amount of the waste electrical porcelain, fly ash, potassium source and alumina as 100wt%, the amount of the waste electrical porcelain is 60wt%~70wt%, the amount of the fly ash is 15~25wt%, the amount of the potassium source is 5~15wt%, and the amount of the alumina is 1~10wt%.

10. The preparation method according to claim 8, characterized in that The total amount of the waste electrical porcelain, fly ash, potassium source and alumina is 100wt%, wherein the amount of the binder is 0.5-15wt%.

11. The preparation method according to claim 10, characterized in that: The total amount of the waste electrical porcelain, fly ash, potassium source and alumina is 100wt%, wherein the amount of the binder is 1-10wt%.

12. The preparation method according to claim 8, characterized in that The compression molding conditions include: a pressure of 2 to 18 MPa, and a holding pressure of 20 to 200 seconds; and / or, The drying conditions include: a temperature of 50-150° C. and a drying time of 5-50 hours.

13. The preparation method according to claim 8, characterized in that The compression molding conditions include: a pressure of 5 to 15 MPa, holding pressure for 30 to 100 seconds; and / or, The drying conditions include: a temperature of 80-130° C. and a drying time of 10-40 hours.

14. The preparation method according to any one of claims 8 to 13, characterized in that: The sintering includes: gradually raising the temperature from room temperature to T1 for sintering, then gradually lowering the temperature from T1 to T2, and finally naturally cooling from T2; wherein T1 = 1300-1600°C.

15. The preparation method according to claim 14, characterized in that T1=1400~1600℃; T2=500~1000℃.

16. The preparation method according to claim 14, characterized in that T2=600~1000℃。 17. The preparation method according to claim 14, characterized in that The sintering process includes: heating the temperature to T0 at a heating rate of 1-10°C / min for sintering, where T0 = 700-1200°C, and performing 3-7 heat preservation steps during the heating process; then heating the temperature to T1 at a heating rate of 0.5-8°C / min, and performing 1-5 heat preservation steps during the heating process; maintaining the temperature at T1, then cooling the temperature to T2 at a cooling rate of 1-10°C / min, and finally cooling naturally.

18. The preparation method according to claim 17, characterized in that The sintering process includes: heating the temperature to T0 at a heating rate of 1-10°C / min for sintering, where T0 = 700-1200°C, and performing 4-6 heat preservation steps for 10-80 minutes during the heating process; then heating the temperature to T1 at a heating rate of 0.5-8°C / min, and performing 2-4 heat preservation steps for 20-150 minutes during the heating process; and maintaining the temperature at T1 for 60-200 minutes, followed by cooling the temperature to T2 at a cooling rate of 1-10°C / min, and finally cooling naturally.

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