A method for preparing refractory composite bricks using waste refractory materials

Abstract

The invention relates to the field of refractory bricks, and in particular to a method for preparing refractory composite bricks by using waste refractory materials. The waste refractory bricks are crushed, ground and screened, and then subjected to pre-magnetic separation and ultrasonic enhanced bio-acid leaching in sequence to prepare low-iron refractory brick blanks; mullite whiskers are introduced into the refractory bricks to in-situ enhance the cordierite-mullite porous structure by controlling the raw material ratio of auxiliary agents, and the formed mullite whiskers are needle-shaped by controlling the amount of coal gangue added to form an interlocking structure; yttrium-doped silicon organic skeletons are used to modify phenolic resins, and the introduction of yttrium-doped organic skeleton modified resins is conducive to the densification of the structure, and can effectively improve the generation of high-silicon amorphous phases in the refractory bricks, thereby improving the alkali corrosion resistance of the refractory bricks; and yttrium oxide and titanium dioxide formed by the yttrium-doped organic skeleton modified resins after sintering effectively improve the density and wear resistance of the refractory bricks.

Description

Technical Field

[0001] The invention relates to the field of refractory bricks, in particular to a method for preparing refractory composite bricks by utilizing waste refractory materials. Background Art

[0002] With the continuous development of industry, the mining of refractory raw materials is increasing year by year, and along with it is the increasing amount of refractory waste. These waste refractory materials not only occupy arable land space, but also seriously pollute the environment, which is not in line with the practice of the current sustainable development concept.

[0003] In recent years, with the promotion of environmental protection concepts and the needs of corporate development, more and more attention has turned to the recycling of waste refractory materials, such as remaking refractory materials into refractory bricks to achieve energy-saving and environmental protection effects. However, if waste refractory bricks are directly used to prepare refractory bricks without treatment, they have poor corrosion resistance and are prone to cracks during the sintering process, thereby reducing the service life of the fired bricks. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing refractory composite bricks using waste refractory materials, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for preparing refractory composite bricks using waste refractory materials comprises the following steps:

[0007] S1: crushing and screening the waste refractory bricks to prepare waste brick slurry, and then pre-magnetic separation to obtain pre-treated waste;

[0008] S2: mixing the pretreated waste with the bio-acid, ultrasonically treating, filtering, and drying to obtain waste brick material;

[0009] S3: Mix kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as an auxiliary agent;

[0010] S4: Mix the waste brick material, additives and yttrium-doped organic framework modified resin to obtain a brick blank, dry and sinter the brick blank to obtain a refractory composite brick.

[0011] Furthermore, the working conditions of the pre-magnetic separation are: the magnetic field strength is 0.5-0.6T, and the diameter of the magnetic rod medium is 1-2mm.

[0012] Furthermore, the working conditions of the ultrasonic treatment are: ultrasonic power of 450W-500W, temperature of 25°C-45°C, stirring speed of 400-500r / min, and time of 10-15min.

[0013] Furthermore, the waste brick slurry is composed of ultrapure water as solvent, wherein the concentration of waste refractory brick powder is 25-35%.

[0014] Furthermore, the preparation of bio-acid includes the following steps: inoculating the strain into an inorganic salt culture medium sterilized at 121°C for 15 minutes, culturing at a pH of 6.7, a temperature of 30°C, and a shaking speed of 200 r / min until the pH reaches 0.9, removing the mycelium and diluting 10 times to obtain bio-acid.

[0015] Furthermore, the bacterial strains are obtained by mixing Aspergillus niger and Thiobacillus ferrooxidans in a mass ratio of 2:1.

[0016] Furthermore, the composition of the brick blank is, by weight: 14-18 parts of waste bricks, 8-11 parts of additives, and 1-2 parts of yttrium-doped organic framework modified resin.

[0017] Furthermore, the weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additive is 14:8:5:10.

[0018] Furthermore, the mass ratio of the sum of the mass of the waste brick material and the additive to the mass of the yttrium-doped organic framework modified resin is 14.5-22.

[0019] Further, the preparation of yttrium-doped organic framework modified resin comprises the following steps:

[0020] 1) isopropyl titanate, yttrium chloride, p-methylphenylacetic acid, N,N-dimethylformamide and methanol are mixed, 2-aminoterephthalic acid is added, the reaction kettle is transferred, the temperature is kept at 150° C. for 22-24 hours, cooled, centrifuged, washed and dried to obtain a yttrium-doped organic framework;

[0021] 2) Mixing and stirring the yttrium-doped organic framework and phenolic resin to obtain the yttrium-doped organic framework modified resin.

[0022] Furthermore, the mass ratio of the yttrium-doped organic framework to the phenolic resin is 1:20.

[0023] Furthermore, the drying working conditions are: 110-120°C for 22-24h.

[0024] Furthermore, the sintering working conditions are: heating to 660°C at 3°C / min, then heating to 1240-1250°C at 6°C / min and keeping at that temperature for 2h.

[0025] Beneficial effects of the present invention:

[0026] The present invention provides a method for preparing refractory composite bricks by using waste refractory materials. The prepared refractory composite bricks have good corrosion resistance, high bending resistance and good wear resistance. The waste refractory materials and coal gangue are used as raw materials to achieve the effects of cost reduction, efficiency improvement, energy saving and environmental protection.

[0027] Low-iron refractory brick blanks are prepared using waste refractory materials. The waste refractory bricks are crushed, ground and sieved, and then subjected to pre-magnetic separation and ultrasonic enhanced bio-acid leaching. By controlling the process parameters of the added magnetic field, ultrasonic wave and bio-acid, bricks containing cobalt, low iron, high aluminum and high silicon are obtained, thereby improving the crack resistance of the refractory bricks.

[0028] Coal gangue is an industrial solid waste generated along with coal during the process of coal mining and coal washing. In order to realize the resource utilization of coal gangue, the present invention uses kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as auxiliary agents, controls the raw material ratio of the auxiliary agents, introduces mullite whiskers into the refractory bricks to in-situ enhance the cordierite-mullite porous structure, and controls the amount of coal gangue added so that the formed mullite whiskers are needle-shaped to form an interlocking structure, thereby effectively improving the volume density and compressive strength of the refractory bricks. However, the introduction of coal gangue is not conducive to the apparent porosity of the refractory bricks.

[0029] In the present invention, phenolic resin is introduced as a binder before sintering, and it also plays the role of a porogen during sintering, so that a good apparent porosity is maintained without adding an additional porogen; however, directly adding phenolic resin and blending it with waste refractory brick powder and additives will cause compatibility problems, and the powder particles will agglomerate, which will easily lead to stress concentration after sintering, thereby affecting the flexural strength of the refractory bricks.

[0030] In the present invention, yttrium-doped organic framework is used to modify phenolic resin, thereby improving its compatibility with waste refractory brick powder and additives, keeping the refractory bricks uniform, and thus improving the crack resistance and wear resistance of the refractory bricks. By making the mass ratio of the sum of the mass of the waste bricks and the additives to the mass ratio of the yttrium-doped organic framework modified resin to be 14.5-22, during sintering, Y 3+ Entering the cordierite lattice, replacing Mg 2+ , and a gap O is generated 2- Defects, Mg 2+ Vacancy defects form lattice distortion, thereby increasing the lattice diffusion rate, which is beneficial to the densification of the structure; and the introduction of yttrium-doped organic skeleton modified resin can effectively increase the production of high-silicon amorphous phase in refractory bricks, allowing it to react with K element to produce high-viscosity glass phase to block the pores, thereby improving the alkali corrosion resistance of refractory bricks; and the yttrium oxide and titanium dioxide formed by the yttrium-doped organic skeleton modified resin after sintering effectively improve the density and wear resistance of refractory bricks. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back, etc., the directional indication is only used to explain a specific posture such as the relative position relationship between the components, the movement status, etc. If the specific posture changes, the directional indication will also change accordingly. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0033] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0034] Embodiment 1: A method for preparing refractory composite bricks using waste refractory materials, comprising the following steps:

[0035] S1: crushing the waste refractory bricks through a 100-mesh sieve, using ultrapure water as a solvent to prepare a waste brick slurry with a concentration of 25%, and then performing pre-magnetic separation to obtain pre-treated waste;

[0036] The working conditions of pre-magnetic separation are: magnetic field intensity of 0.5T, diameter of magnetic bar medium of 1mm, and time of 30min;

[0037] S2: mixing the pretreated waste with the bio-acid, ultrasonically treating, filtering, and drying to obtain waste brick material;

[0038] The mass volume ratio of pretreated waste to bio-acid was 1 g:100 mL;

[0039] The preparation of bio-acid comprises the following steps: inoculating the bacterial strain into an inorganic culture medium sterilized at 121°C for 15 minutes, culturing the culture medium at a pH of 6.7, a temperature of 30°C, and a shaking speed of 200 r / min until the pH reaches 0.9, removing the mycelium and diluting the culture medium by 10 times to obtain the bio-acid;

[0040] The strains are Aspergillus niger and Thiobacillus ferrooxidans mixed in a mass ratio of 2:1;

[0041] S3: Mix kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as an auxiliary agent;

[0042] The weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additive is 14:8:5:10;

[0043] The preparation of yttrium-doped organic framework modified resin comprises the following steps:

[0044] 1) 1mmol isopropyl titanate, 1mmol yttrium chloride, 6mmol p-methylphenylacetic acid, 9mL N,N-dimethylformamide, and 1mL methanol were mixed, 3mmol 2-aminoterephthalic acid was added, the reaction kettle was transferred, and the temperature was kept at 150°C for 22h, cooled, centrifuged, washed, and dried to obtain a yttrium-doped organic framework;

[0045] 2) mixing 1 g of yttrium-doped organic framework and 20 g of phenolic resin to obtain yttrium-doped organic framework modified resin;

[0046] S4: Mixing waste bricks, additives, and yttrium-doped organic framework modified resin to obtain a brick blank, and drying and sintering the brick blank to obtain a refractory composite brick;

[0047] In terms of weight, the composition of the brick blank is: 14 parts of waste bricks, 8 parts of additives, and 1 part of yttrium-doped organic framework modified resin;

[0048] The mass ratio of the sum of the mass of the waste brick material and the additive to the mass of the yttrium-doped organic framework modified resin is 22;

[0049] The working conditions of ultrasonic treatment were as follows: ultrasonic power of 450 W, temperature of 25 °C, stirring speed of 500 r / min, and time of 15 min;

[0050] The working conditions for drying are: keeping at 110°C for 24 hours; the working conditions for sintering are: heating to 660°C at 3°C / min, then heating to 1240°C at 6°C / min and keeping at that for 2 hours.

[0051] Embodiment 2: A method for preparing refractory composite bricks using waste refractory materials, comprising the following steps:

[0052] S1: crush the waste refractory bricks through a 100-mesh sieve, use ultrapure water as a solvent, prepare a waste brick slurry with a concentration of 30%, and then perform pre-magnetic separation to obtain pre-treated waste;

[0053] The working conditions of pre-magnetic separation are: magnetic field intensity of 0.55T, diameter of magnetic bar medium of 1mm, and time of 25min;

[0054] S2: mixing the pretreated waste with the bio-acid, ultrasonically treating, filtering, and drying to obtain waste brick material;

[0055] The mass volume ratio of pretreated waste to bio-acid was 1 g:100 mL;

[0056] The preparation of bio-acid comprises the following steps: inoculating the bacterial strain into an inorganic culture medium sterilized at 121°C for 15 minutes, culturing the culture medium at a pH of 6.7, a temperature of 30°C, and a shaking speed of 200 r / min until the pH reaches 0.9, removing the mycelium and diluting the culture medium by 10 times to obtain the bio-acid;

[0057] The strains are Aspergillus niger and Thiobacillus ferrooxidans mixed in a mass ratio of 2:1;

[0058] S3: Mix kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as an auxiliary agent;

[0059] The weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additive is 14:8:5:10;

[0060] The preparation of yttrium-doped organic framework modified resin comprises the following steps:

[0061] 1) 1mmol isopropyl titanate, 1mmol yttrium chloride, 6mmol p-methylphenylacetic acid, 9mL N,N-dimethylformamide, and 1mL methanol were mixed, 3mmol 2-aminoterephthalic acid was added, the reaction kettle was transferred, and the temperature was kept at 150°C for 23h, cooled, centrifuged, washed, and dried to obtain a yttrium-doped organic framework;

[0062] 2) mixing 1 g of yttrium-doped organic framework and 20 g of phenolic resin to obtain yttrium-doped organic framework modified resin;

[0063] S4: Mixing waste bricks, additives, and yttrium-doped organic framework modified resin to obtain a brick blank, and drying and sintering the brick blank to obtain a refractory composite brick;

[0064] In terms of weight, the composition of the brick blank is: 16 parts of waste brick material, 9 parts of additives, and 1.5 parts of yttrium-doped organic framework modified resin;

[0065] The mass ratio of the sum of the mass of waste bricks and additives to the mass of yttrium-doped organic framework modified resin is 16.7;

[0066] The working conditions of ultrasonic treatment were as follows: ultrasonic power of 48 W, temperature of 35 °C, stirring speed of 450 r / min, and time of 12 min;

[0067] The working conditions for drying are: keeping at 115°C for 23 hours; the working conditions for sintering are: heating to 660°C at 3°C / min, then heating to 1245°C at 6°C / min and keeping at that for 2 hours.

[0068] Embodiment 3: A method for preparing refractory composite bricks using waste refractory materials, comprising the following steps:

[0069] S1: crush the waste refractory bricks through a 100-mesh sieve, use ultrapure water as a solvent, prepare a waste brick slurry with a concentration of 35%, and then perform pre-magnetic separation to obtain pre-treated waste;

[0070] The working conditions of pre-magnetic separation are: magnetic field intensity of 0.6T, diameter of magnetic bar medium of 2mm, and time of 20min;

[0071] S2: mixing the pretreated waste with the bio-acid, ultrasonically treating, filtering, and drying to obtain waste brick material;

[0072] The mass volume ratio of pretreated waste to bio-acid was 1 g:100 mL;

[0073] The preparation of bio-acid comprises the following steps: inoculating the bacterial strain into an inorganic culture medium sterilized at 121°C for 15 minutes, culturing the culture medium at a pH of 6.7, a temperature of 30°C, and a shaking speed of 200 r / min until the pH reaches 0.9, removing the mycelium and diluting the culture medium by 10 times to obtain the bio-acid;

[0074] The strains are Aspergillus niger and Thiobacillus ferrooxidans mixed in a mass ratio of 2:1;

[0075] S3: Mix kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as an auxiliary agent;

[0076] The weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additive is 14:8:5:10;

[0077] The preparation of yttrium-doped organic framework modified resin comprises the following steps:

[0078] 1) 1mmol isopropyl titanate, 1mmol yttrium chloride, 6mmol p-methylphenylacetic acid, 9mL N,N-dimethylformamide, and 1mL methanol were mixed, 3mmol 2-aminoterephthalic acid was added, the reaction kettle was transferred, and the temperature was kept at 150°C for 24h, cooled, centrifuged, washed, and dried to obtain a yttrium-doped organic framework;

[0079] 2) mixing 1 g of yttrium-doped organic framework and 20 g of phenolic resin to obtain yttrium-doped organic framework modified resin;

[0080] S4: Mixing waste bricks, additives, and yttrium-doped organic framework modified resin to obtain a brick blank, and drying and sintering the brick blank to obtain a refractory composite brick;

[0081] In terms of weight, the composition of the brick blank is: 18 parts of waste brick material, 11 parts of additives, and 2 parts of yttrium-doped organic framework modified resin;

[0082] The mass ratio of the sum of the mass of the waste brick material and the additive to the mass of the yttrium-doped organic framework modified resin is 14.5;

[0083] The working conditions of ultrasonic treatment were as follows: ultrasonic power of 500 W, temperature of 45 °C, stirring speed of 400 r / min, and time of 10 min;

[0084] The working conditions for drying are: keeping at 120°C for 22 hours; the working conditions for sintering are: heating to 660°C at 3°C / min, then heating to 1250°C at 6°C / min and keeping for 2 hours.

[0085] Comparative Example 1: Example 3 was used as the control group, without pre-magnetic separation, and other processes were normal.

[0086] Comparative Example 2: Example 3 was used as the control group, no bio-acid was added for ultrasonic treatment, and other processes were normal.

[0087] Comparative Example 3: Taking Example 3 as the control group, the weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additives is 14:7:5:10, and other processes are normal.

[0088] Comparative Example 4: Taking Example 3 as the control group, the yttrium-doped organic skeleton modified resin was replaced by phenolic resin, and the other processes were normal.

[0089] Comparative Example 5: Taking Example 3 as the control group, 18 parts of waste bricks, 11 parts of additives, and 3 parts of yttrium-doped organic skeleton modified resin; the mass ratio of the sum of the mass of the waste bricks and the additives to the mass of the yttrium-doped organic skeleton modified resin is 9.7, and other processes are normal.

[0090] Comparative Example 6: Taking Example 3 as the control group, 18 parts of waste bricks, 11 parts of additives, and 1 part of yttrium-doped organic skeleton modified resin; the mass ratio of the sum of the mass of the waste bricks and the additives to the mass of the yttrium-doped organic skeleton modified resin is 29, and other processes are normal.

[0091] Source of raw materials:

[0092] The main components of waste refractory bricks are: by mass fraction, magnesium 20.1%, copper 16.1%, iron 6.2%, cobalt 0.3%, chromium 0.51%, silver 0.01%, lead 0.31%; coal gangue powder: aluminum oxide 20.5%, iron oxide 5.01%, calcium oxide 1.1%, titanium dioxide 0.85%, potassium oxide 1.72%, magnesium oxide 1.91%, sulfur trioxide 0.51%, and the balance is silicon dioxide; inorganic culture medium BY-P91297: Shanghai Baiyi Biotechnology Co., Ltd.; Aspergillus niger YXJ0028-CMCC(F)98003: Shanghai Yimiao Chemical Technology Co., Ltd. Co., Ltd.; Thiobacillus ferrooxidans XKBio: Shanghai Xuanke Biotechnology Co., Ltd.; kaolin powder (industrial grade): Hubei Chengfeng Chemical Co., Ltd.; talc powder S30618: Shanghai Yuanye Biotechnology Co., Ltd.; aluminum hydroxide powder 21645-51-2: Langfang Pengcai Fine Chemical Co., Ltd.; isopropyl titanate T105735, yttrium chloride Y119238, p-methylphenylacetic acid T100785, N,N-dimethylformamide D111999, 2-aminoterephthalic acid A151463, phenolic resin P195710: Aladdin reagent; methanol, analytical grade: Sinopharm Group reagent.

[0093] Performance test: The performance test of the refractory bricks prepared in Examples 1-3 and Comparative Examples 1-6 was carried out:

[0094] Compressive strength test: refer to GB / T50081-2002 for testing, the size of the refractory brick is 200mm×100mm×60mm, the load is continuously and evenly applied during the test, 0.6MPa per second, the compressive strength f=F / A (F-failure load, N; A-pressure bearing area, mm 2 );

[0095] Thermal shock resistance: Take a sample of 200mm×100mm×60mm, keep it at 1000℃ for 30min, water-cool it, cycle it 3 times, and after cooling, test the flexural strength before and after the cycle, and calculate the flexural strength retention rate;

[0096] Wear resistance test: refer to GB / T12988-2009 for testing, the size of the refractory brick is 200mm×100mm×60mm, standard curing is 7d, and the average wear pit length is measured 5 times to evaluate its wear resistance;

[0097] Crack resistance: Alkali resistance was tested by alkali crucible method. A hole of 50 mm × 25 mm was drilled in 200 mm × 100 mm × 60 mm. 20 g of commercially available chemically pure potassium carbonate was placed in the hole. The temperature was raised to 1000 ° C and kept for 4 hours. After natural cooling, cracks were detected and the crack width was tested. The results are shown in the following table.

[0098]

[0099] The present invention provides a method for preparing refractory composite bricks by using waste refractory materials. The prepared refractory composite bricks have good corrosion resistance, high bending resistance and good wear resistance. The waste refractory materials and coal gangue are used as raw materials to achieve the effects of cost reduction, efficiency improvement, energy saving and environmental protection.

[0100] Example 3 is compared with Comparative Example 1 and Comparative Example 2. Low-iron refractory brick blanks are prepared using waste refractory materials. The waste refractory bricks are crushed, ground and sieved, and then subjected to pre-magnetic separation and ultrasonic enhanced bio-acid leaching. By controlling the process parameters of the added magnetic field, ultrasonic wave and bio-acid, bricks containing cobalt, low iron, high aluminum and high silicon are obtained, thereby improving the crack resistance of the refractory bricks.

[0101] Compare Example 3 with Comparative Example 3. Coal gangue is an industrial solid waste generated along with coal during coal mining and coal washing. In order to realize the resource utilization of coal gangue, the present invention uses kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as auxiliary agents. By controlling the raw material ratio of the auxiliary agents, mullite whiskers are introduced into the refractory bricks to in-situ enhance the cordierite-mullite porous structure. By controlling the amount of coal gangue added, the mullite whiskers formed are needle-shaped to form an interlocking structure, so as to effectively improve the volume density and compressive strength of the refractory bricks. However, the introduction of coal gangue is not conducive to the apparent porosity of the refractory bricks.

[0102] Comparing Example 3 with Comparative Example 4, the present invention uses yttrium-doped organic framework to modify the phenolic resin, thereby improving its compatibility with waste refractory brick powder and additives, keeping the refractory bricks uniform, and thus improving the crack resistance and wear resistance of the refractory bricks.

[0103] By comparing Example 3 with Comparative Examples 5 and 6, the mass ratio of the sum of the mass of the waste brick material and the additive to the mass of the yttrium-doped organic framework modified resin is 14.5-22. 3+ Entering the cordierite lattice, replacing Mg 2+ , and a gap O is generated 2- Defects, Mg 2+ Vacancy defects form lattice distortion, thereby increasing the lattice diffusion rate, which is beneficial to the densification of the structure; it can effectively increase the production of high-silicon amorphous phase in refractory bricks, so that it reacts with K element to produce high-viscosity glass phase to block the pores, thereby improving the alkali corrosion resistance of refractory bricks; and the yttrium oxide and titanium dioxide formed by the yttrium-doped organic skeleton modified resin after sintering effectively improve the density and wear resistance of refractory bricks.

[0104] The above descriptions are only embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the present invention specification under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing refractory composite bricks using waste refractory materials, characterized in that: The following steps are involved: S1: crushing and screening the waste refractory bricks to prepare waste brick slurry, and then pre-magnetic separation to obtain pre-treated waste; S2: mixing the pretreated waste with the bio-acid, ultrasonically treating, filtering, and drying to obtain waste bricks; S3: Mix kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder as an auxiliary agent; S4: Mixing waste bricks, additives, and yttrium-doped organic framework modified resin to obtain a brick blank, and drying and sintering the brick blank to obtain a refractory composite brick; The weight ratio of kaolin powder, coal gangue powder, talcum powder and aluminum hydroxide powder in the additive is 14:8:5:10; The mass ratio of the sum of the mass of the waste brick material and the additive to the mass of the yttrium-doped organic framework modified resin is 14.5-22; The preparation of yttrium-doped organic framework modified resin comprises the following steps: 1) isopropyl titanate, yttrium chloride, p-methylphenylacetic acid, N,N-dimethylformamide and methanol are mixed, 2-aminoterephthalic acid is added, the reaction kettle is transferred, the temperature is kept at 150° C. for 22-24 hours, cooled, centrifuged, washed and dried to obtain a yttrium-doped organic framework; 2) Mixing and stirring the yttrium-doped organic framework and phenolic resin to obtain the yttrium-doped organic framework modified resin.

2. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: The working conditions of pre-magnetic separation are: magnetic field strength is 0.5-0.6T, and the diameter of the magnetic rod medium is 1-2mm.

3. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: The working conditions of ultrasonic treatment are: ultrasonic power of 450-500W, temperature of 25-45°C, stirring speed of 400-500r / min, and time of 10-15min.

4. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: The composition of the waste brick slurry is: ultrapure water is used as a solvent, wherein the concentration of waste refractory brick powder is 25-35%.

5. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: Calculated by weight, the composition of the brick blank is: 14-18 parts of waste bricks, 8-11 parts of additives, and 1-2 parts of yttrium-doped organic skeleton modified resin.

6. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: In the preparation of yttrium-doped organic framework modified resin, the mass ratio of yttrium-doped organic framework to phenolic resin is 1:

20.

7. The method for preparing refractory composite bricks using waste refractory materials according to claim 1, characterized in that: The working conditions for drying are: keeping at 110-120°C for 22-24h; the working conditions for sintering are: heating to 660°C at 3°C / min, then heating to 1240-1250°C at 6°C / min and keeping for 2h.

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