Wear-resistant corrosion-resistant refractory material for hazardous waste incinerator and preparation method thereof

Abstract

The application discloses a kind of hazardous waste incinerator wear-resistant corrosion-resistant refractory and preparation method, belong to refractory technical field, the application includes the following weight parts count raw material composition: 80-100 parts high-alumina aggregate, 15-20 parts composite aerogel, 10-15 parts high-temperature binder, 9-15 parts auxiliary material;The application is prepared by obtaining composite silicon nitride fiber and activated silicon nitride fiber, the latter is cooperated with nanocrystalline liquid to prepare composite aerogel, and both are simultaneously used as high-temperature binder skeleton, nanocrystalline liquid is used as the additive of high-alumina bauxite high-temperature calcination material crystal type defect repair, finally by high-alumina aggregate, composite aerogel, high-temperature binder and auxiliary material are mixed, and a kind of wear-resistant, high mechanical strength and acid-resistant light weight heat-insulating wear-resistant corrosion-resistant refractory is prepared.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, specifically to a wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators and its preparation method. Background Technology

[0002] The development of wear-resistant lightweight refractory materials for hazardous waste incinerators has evolved from traditional refractory bricks to continuous optimization of high-performance composite materials. In the early days, incinerators mainly used high-density refractory bricks. Although they had good refractoriness, their large weight, poor wear resistance, and insufficient thermal shock resistance made them unable to cope with the complex operating conditions of high temperature, high corrosion, and high erosion in incinerators, leading to rapid material wear and increased maintenance costs. As the processing capacity of incinerators increased, lightweight refractory materials were gradually applied to furnace linings. In the mid-20th century, high-alumina and silica lightweight materials were used to achieve weight reduction and improved thermal insulation performance, but the wear resistance and chemical corrosion resistance of these materials still need to be improved.

[0003] The prior art CN108975887A discloses a refractory material comprising the following components by weight: 75-90 parts alumina, 20-29 parts silicon dioxide, 4-6 parts nano alumina, 1-5 parts metal toughening agent, and 3-5 parts pore-forming agent. The metal toughening agent includes metal powder or metal alloy powder. Utilizing the excellent high-temperature resistance of the alumina-silica system, the addition of nano alumina, metal toughening agent, and pore-forming agent lowers the sintering temperature, resulting in high toughness, enhanced insulation effect, and reduced production costs.

[0004] However, the aforementioned patent uses starch adhesive as a pore-forming agent to improve the thermal shock resistance of materials by bonding and creating pores. However, starch adhesive has poor thermal stability, and the pore structure generated by pyrolysis is unstable and prone to detachment, which means that the wear resistance of the material needs to be further improved. In addition, the material introduces a large amount of high-density high-temperature resistant materials and metal materials, which means that the material's lightweight needs to be further improved. The excessive weight places high demands on the adhesive, which in turn means that the performance of functional adhesive materials needs to be further improved.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators and its preparation method, in order to solve the technical problem that the wear resistance and lightweight properties of existing refractory materials need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solution: a wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators, comprising the following raw material components by weight: 80-100 parts high-alumina aggregate, 15-20 parts composite aerogel, 10-15 parts high-temperature binder, and 9-15 parts auxiliary materials.

[0008] The preparation method of composite aerogel includes the following steps:

[0009] A1. Add alumina powder and deionized water to a magnetically stirred reactor. Stir at room temperature for 10-15 minutes, then add ethylenediaminetetraacetic acid to the reactor. Raise the temperature of the reactor to 40-60℃ and keep it at that temperature for 1-2 hours to obtain a nanocrystalline liquid.

[0010] The reaction principle for preparing nanocrystalline liquid is as follows: under acidic catalysis, alumina powder undergoes hydrolysis to obtain active structures, and finally nanocrystalline liquid is prepared.

[0011] A2. After adding the nanocrystalline liquid and activated silicon nitride fiber into the inner liner of the reactor, seal the inner liner of the reactor with a lid and then add it into a stainless steel hydrothermal reactor. Transfer the stainless steel hydrothermal reactor to the inside of an oven, raise the oven temperature to 220-240℃, keep it at the temperature for 4-5 hours, and then process it to obtain a composite gel.

[0012] The reaction principle for preparing composite gels is as follows: as the reaction proceeds, the active structure in the system undergoes a condensation reaction, eventually forming an Al-O-Al structure. Subsequently, the various chain segments in the system aggregate, cross-link, and combine with each other, becoming increasingly abundant and the molecular weight increasing. Finally, when the critical point of gel formation is reached, a gel is formed. The internal three-dimensional network structure is gradually perfected by the aggregation and cross-linking between particles, and the composite gel is finally obtained through gel aging.

[0013] A3. The composite aerogel is obtained by two-step post-processing of the composite gel.

[0014] Furthermore, the excipients include water glass, boron nitride micro powder, and steel fiber, with a ratio of 3-5g:3-5g:3-5g. In step A1, the stirring speed of the magnetic stirring vessel is 60-80 rpm, and the ratio of alumina powder, deionized water, and ethylenediaminetetraacetic acid is 3-4g:30-40mL:1-2mL. In step A2, the ratio of nanocrystalline liquid and activated silicon nitride fiber is 5-6mL:1-2g. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, remove the inner liner of the reaction vessel and open the seal, transfer the inner liner of the reaction vessel to a constant temperature drying oven, raise the temperature of the constant temperature drying oven to 80-90℃, and maintain the temperature for 1-2 hours to obtain the composite gel.

[0015] Further, in step A3, the two post-processing operations are as follows: the composite gel is soaked in ethanol and left to stand for 12-16 hours. After soaking three times, the composite gel is transferred to a high-pressure reactor. After the temperature of the high-pressure reactor is raised to 40-50°C, carbon dioxide gas is introduced into the high-pressure reactor and the pressure is controlled at 12 MPa. The reactor is treated at constant temperature and pressure for 2-3 hours to obtain the composite aerogel.

[0016] Furthermore, the preparation method of activated silicon nitride fibers includes the following steps:

[0017] B1. Silicon monoxide is loaded into a graphite crucible, a graphite sheet is placed on top of the crucible, and the crucible is wrapped with graphite paper. The crucible is then transferred to a high-temperature furnace. After heat treatment, the fibers attached to the graphite sheet are collected to obtain composite silicon nitride fibers.

[0018] The reaction equation for preparing silicon nitride fibers is:

[0019] 3SiO(g)+3C(s)+3N2(g)→Si3N4(s)+3CO(g)

[0020] 6SiO(g)+4N2(g)→Si3N4(s)+3CO(g)

[0021] The reaction principle for preparing silicon nitride fibers is as follows: after silicon oxide sublimates at high temperature, it reacts with carbon and nitrogen gas, and finally silicon nitride fibers are prepared on the surface of graphite sheets.

[0022] B2. Add composite silicon nitride fiber and 98.0 wt% sulfuric acid to a reaction vessel at a temperature of 0-5℃, keep warm and stir for 10-15 min, then add sodium chlorate to the reaction vessel, keep the temperature of the reaction vessel at 0-5℃ and react for 2-4 h, and then perform post-treatment to obtain activated silicon nitride fiber.

[0023] The principle of preparing activated silicon nitride fibers is as follows: the partial sulfation reaction of multilayer graphene makes the graphene structure more active, creating conditions for oxidation reaction. Sodium chlorate decomposes under acidic conditions to generate chloric acid and oxygen. The strong oxidizing effect of chloric acid can oxidize the carbon layer of graphene to produce graphene oxide, which contains various oxygen functional groups, such as epoxy groups, carboxyl groups and hydroxyl groups.

[0024] Further, in step B1, the heat treatment operation is as follows: after nitrogen gas is introduced into the high-temperature furnace, the temperature is raised to 1800-2000℃ at a heating rate of 6-8℃ / min, and the reaction is held at this temperature for 1-2 hours. Then, it is naturally cooled to room temperature to complete the heat treatment operation. In step B2, the ratio of composite silicon nitride fiber, 98.0wt% sulfuric acid and sodium chlorate is 5-6g:50-60mL:3-5g. The post-treatment includes: after the reaction is completed, after the temperature of the reaction vessel is raised to room temperature, the pH of the reaction system is adjusted to 7 using acetic acid. The reaction liquid is filtered to collect the filter cake. The filter cake is washed 3-5 times with anhydrous ethanol and deionized water. The filter cake is then transferred to a drying oven at 60℃ and vacuum dried to constant weight to obtain activated silicon nitride fiber.

[0025] Furthermore, the preparation method of the high-temperature adhesive includes the following steps:

[0026] C1. 2,4,6,8-Tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 3-(methacryloyloxy)propyltrimethoxysilane, epoxy vinyl resin, chloroplatinic acid hexahydrate and N,N-dimethylformamide are added to a reaction vessel. The temperature of the reaction vessel is raised to 40-50℃ and the reaction is maintained for 1-2 hours. The composite resin is obtained after post-treatment.

[0027] The reaction principle for preparing the composite resin is as follows: under the initiation of a catalyst, the silane-hydrogen bonds on 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane undergo a hydrosilylation reaction with the double bonds on 3-(methacryloyloxy)propyltrimethoxysilane and epoxy vinyl resin, and finally the composite resin is prepared.

[0028] C2. Add composite resin, organosilicon resin and N,N-dimethylformamide to the reaction vessel. After the temperature of the reaction vessel is reduced to 0-5℃, add saturated sodium hydroxide solution dropwise to the reaction vessel. After keeping the reaction at this temperature for 1-2 hours, adjust the pH of the system to 7 using glacial acetic acid. The adhesive precursor is then obtained through post-treatment.

[0029] The reaction principle for preparing adhesive precursors is as follows: under alkaline conditions, the silane coupling agent component in the composite resin undergoes hydrolysis and crosslinks with the siloxane structure in the organosilicon resin to obtain the adhesive precursor.

[0030] C3. After uniformly mixing the adhesive precursor, composite silicon nitride fiber and activated silicon nitride fiber, add them to a twin-screw extruder and extrude to obtain a high-temperature adhesive.

[0031] Further, in step C1, the ratio of 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 3-(methacryloyloxy)propyltrimethoxysilane, epoxy vinyl resin, chloroplatinic acid hexahydrate, and N,N-dimethylformamide is 8-10 g: 3-4 g: 10-15 g: 0.1-0.2 g: 80-100 mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at a temperature of 80-90℃, and remove the solvent under reduced pressure to obtain the composite resin.

[0032] Furthermore, in step C2, the ratio of composite resin, organosilicon resin, N,N-dimethylformamide and saturated sodium hydroxide solution is 3-4g:5-8g:30-40mL:0.1-0.2mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator at a temperature of 80-90℃, remove the solvent under reduced pressure, and obtain the adhesive precursor.

[0033] Furthermore, in step C3, the ratio of the binder precursor, composite silicon nitride fiber, and activated silicon nitride fiber is 8-10g:1g:1g, and the pressure of the twin-screw extruder is set to 40-60 Bar.

[0034] Furthermore, the preparation method of high-alumina aggregate is as follows: after crushing high-alumina bauxite through a 400-600 mesh sieve, it is mixed with nanocrystalline liquid and then transferred to a tube furnace for calcination to obtain high-alumina aggregate.

[0035] Furthermore, the ratio of high-alumina bauxite to nanocrystalline liquid is 2-3g:1mL. The calcination operation is as follows: after nitrogen protection is introduced into the tube furnace, the tube furnace is heated to 1350-1600℃ at a heating rate of 5-8℃ / min, and the reaction is held at this temperature for 4-6 hours. The mixture is then naturally cooled to room temperature to obtain high-alumina aggregate.

[0036] This invention also proposes a method for preparing wear-resistant and corrosion-resistant refractory materials for hazardous waste incinerators, comprising the following steps: adding high-alumina aggregate, boron nitride micro powder and steel fiber into a twin-screw extruder; gradually adding composite aerogel, high-temperature binder and water glass to the mixture during stirring; setting the pressure of the twin-screw extruder to 80-100 bar; and obtaining the wear-resistant and corrosion-resistant refractory material after twin-screw extrusion.

[0037] The present invention has the following beneficial effects:

[0038] 1. This invention involves preparing composite silicon nitride fibers and activated silicon nitride fibers. The activated silicon nitride fibers are then synergistically combined with nanocrystalline liquid obtained from alumina hydrolysis to prepare a composite aerogel. After the composite aerogel fills the material structure, the material's own weight is significantly reduced, thereby alleviating the burden on the incinerator structure. The porous structure of the aerogel also reduces the material's thermal conductivity, thereby reducing heat loss and improving the thermal efficiency of the incinerator. Furthermore, the reduced weight of the porous aerogel material and the material itself further enhances the material's thermal shock resistance. The composite silicon nitride fibers act as a supporting skeleton at high temperatures, and the active groups on the activated silicon nitride fibers react with the resin components of the high-temperature adhesive at high temperatures, preventing further shrinkage of the high-temperature adhesive and ultimately significantly improving the material's thermal shock resistance. The nano-alumina particles in the nanocrystalline liquid fill the defects in the crystal structure of the calcined product during the calcination of high-alumina bauxite, ultimately making the final high-alumina aggregate structure stable, thereby significantly improving the material's acid resistance, mechanical properties, and thermal shock resistance.

[0039] 2. This invention overcomes the shortcomings of low mechanical properties of aerogel materials by preparing activated silicon nitride fibers as the skeleton structure of alumina aerogel. Furthermore, the alumina and silicon nitride components significantly improve the high-temperature resistance of the composite aerogel. Utilizing the extremely low thermal conductivity of aerogel, the thermal conductivity of the composite aerogel material is significantly reduced, enabling it to more effectively insulate heat, reduce heat loss, and improve the thermal efficiency of the incinerator. The thermal stability and low coefficient of thermal expansion of the composite aerogel, when used in combination with other materials, help reduce the thermal stress caused by temperature fluctuations within the material, thereby reducing crack formation and improving the material's thermal shock resistance.

[0040] 3. This invention involves selecting cyclic siloxanes as the crosslinking structure, adding them with silane coupling agents and epoxy vinyl resins to ultimately prepare a composite resin. The stability of the cyclic structure is combined with the high viscosity of the epoxy vinyl resin, and a silane coupling agent is used as a crosslinking agent to crosslink with organosilicon resin and dope with composite silicon nitride fibers and activated silicon nitride fibers to obtain a corrosion-resistant and wear-resistant high-temperature adhesive. This high-temperature adhesive effectively improves the initial mechanical strength of refractory materials, maintains structural stability during manufacturing and installation, prevents damage or cracking caused by stress or external forces at high temperatures, and effectively reduces thermal stress caused by drastic temperature changes. By providing uniform bonding between refractory materials, they help disperse thermal stress, thereby enhancing the material's thermal shock resistance. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The epoxy vinyl resin used in this invention was purchased from Guiyang Jinhua Heng Chemical Co., Ltd.

[0043] The silicone resin used in this invention was purchased from Changzhou Jianuo Silicone Co., Ltd., with product number FJN-1152.

[0044] Example 1

[0045] This embodiment provides a method for preparing activated silicon nitride fibers for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, including the following steps:

[0046] Step 1: Preparation of activated silicon nitride fibers

[0047] Weigh 100.0g of silicon monoxide and place it in a graphite crucible. Place a graphite sheet on top of the crucible, wrap the crucible with graphite paper, and then transfer the crucible to a high-temperature furnace. After introducing nitrogen into the furnace, heat it to 1800℃ at a rate of 6℃ / min. After holding the reaction at this temperature for 1 hour, allow it to cool naturally to room temperature. Collect the fibers attached to the graphite sheet to obtain composite silicon nitride fibers.

[0048] Step 2: Preparation of activated silicon nitride fibers

[0049] Weigh 500.0g of composite silicon nitride fiber and 5.0L of 98.0wt% sulfuric acid and add them to a reactor at 5℃. After stirring for 10min, add 300.0g of sodium chlorate to the reactor and maintain the reactor temperature at 5℃ for 2h. After the reaction is complete, wait for the reactor temperature to rise to room temperature, adjust the pH of the reaction system to 7 with acetic acid, filter the reaction liquid and collect the filter cake. Wash the filter cake three times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 60℃ and vacuum dry it to constant weight to obtain activated silicon nitride fiber.

[0050] Example 2

[0051] This embodiment provides a method for preparing activated silicon nitride fibers for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, including the following steps:

[0052] Step 1: Preparation of activated silicon nitride fibers

[0053] Weigh 100.0g of silicon monoxide and place it into a graphite crucible. Place a graphite sheet on top of the crucible, wrap the crucible with graphite paper, and then transfer the crucible to a high-temperature furnace. After introducing nitrogen into the furnace, heat it to 2000℃ at a rate of 8℃ / min. Hold the temperature for 2 hours and then allow it to cool naturally to room temperature. Collect the fibers attached to the graphite sheet to obtain composite silicon nitride fibers.

[0054] Step 2: Preparation of activated silicon nitride fibers

[0055] Weigh 600.0g of composite silicon nitride fiber and 6.0L of 98.0wt% sulfuric acid and add them to a reactor at 0℃. After stirring for 15min, add 500.0g of sodium chlorate to the reactor and keep the reactor temperature at 0℃ for 4h. After the reaction is complete, wait for the reactor temperature to rise to room temperature, adjust the pH of the reaction system to 7 with acetic acid, filter the reaction liquid and collect the filter cake. Wash the filter cake 5 times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 60℃ and vacuum dry it to constant weight to obtain activated silicon nitride fiber.

[0056] Example 3

[0057] This embodiment provides a method for preparing activated silicon nitride fibers for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, including the following steps:

[0058] Step 1: Preparation of activated silicon nitride fibers

[0059] Weigh 100.0g of silicon monoxide and place it in a graphite crucible. Place a graphite sheet on top of the crucible, wrap the crucible with graphite paper, and then transfer the crucible to a high-temperature furnace. After introducing nitrogen into the furnace, heat it to 1900℃ at a rate of 7℃ / min. Hold the temperature for 2 hours and then allow it to cool naturally to room temperature. Collect the fibers attached to the graphite sheet to obtain composite silicon nitride fibers.

[0060] Step 2: Preparation of activated silicon nitride fibers

[0061] Weigh 550.0g of composite silicon nitride fiber and 5.5L of 98.0wt% sulfuric acid and add them to a reaction vessel at 3℃. After stirring for 12min, add 400.0g of sodium chlorate to the reaction vessel and maintain the temperature at 3℃ for 3h. After the reaction is complete, wait for the temperature of the reaction vessel to rise to room temperature, adjust the pH of the reaction system to 7 with acetic acid, filter the reaction liquid and collect the filter cake. Wash the filter cake 4 times with anhydrous ethanol and deionized water, and then transfer the filter cake to a drying oven at 60℃ and vacuum dry it to constant weight to obtain activated silicon nitride fiber.

[0062] Example 4

[0063] This embodiment provides a method for preparing a high-temperature adhesive for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, comprising the following steps:

[0064] Step ①: Preparation of composite resin

[0065] Weigh out 800.0g of 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 300.0g of 3-(methacryloyloxy)propyltrimethoxysilane, 1.0kg of epoxy vinyl resin, 10.0g of chloroplatinic acid hexahydrate, and 8.0L of N,N-dimethylformamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 50℃ and keep it at that temperature for 2 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, and then transfer the reaction solution to a rotary evaporator at 80℃ to remove the solvent under reduced pressure to obtain the composite resin.

[0066] Step 2: Preparation of adhesive precursor

[0067] Weigh out 300.0g of composite resin, 500.0g of organosilicon resin and 3.0L of N,N-dimethylformamide and add them to the reaction vessel. After the temperature of the reaction vessel is reduced to 5℃, add 10.0mL of saturated sodium hydroxide solution dropwise to the reaction vessel. After keeping the reaction vessel at this temperature for 1h, adjust the pH of the system to 7 using glacial acetic acid. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, then transfer the reaction solution to a rotary evaporator at 80℃ to remove the solvent under reduced pressure, and obtain the adhesive precursor.

[0068] Step 3: Preparation of high-temperature adhesive

[0069] Weigh out 800.0g of adhesive precursor, 100.0g of composite silicon nitride fiber prepared in Example 1 and 100.0g of activated silicon nitride fiber prepared in Example 1, mix them evenly and add them to a twin-screw extruder. Set the pressure of the twin-screw extruder to 40 Bar and extrude to obtain a high-temperature adhesive.

[0070] Example 5

[0071] This embodiment provides a method for preparing a high-temperature adhesive for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, comprising the following steps:

[0072] Step ①: Preparation of composite resin

[0073] Weigh out 1.0 kg of 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 400.0 g of 3-(methacryloyloxy)propyltrimethoxysilane, 1.5 kg of epoxy vinyl resin, 20.0 g of chloroplatinic acid hexahydrate, and 10.0 L of N,N-dimethylformamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 50°C and maintain the temperature for 2 hours. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, and transfer the reaction solution to a rotary evaporator at 90°C to remove the solvent under reduced pressure to obtain the composite resin.

[0074] Step 2: Preparation of adhesive precursor

[0075] Weigh out 400.0g of composite resin, 800.0g of organosilicon resin and 4.0L of N,N-dimethylformamide and add them to the reaction vessel. After the temperature of the reaction vessel is lowered to 0℃, add 20.0mL of saturated sodium hydroxide solution dropwise to the reaction vessel. After keeping the reaction vessel at this temperature for 2 hours, adjust the pH of the system to 7 using glacial acetic acid. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, then transfer the reaction solution to a rotary evaporator at 90℃ to remove the solvent under reduced pressure, and obtain the adhesive precursor.

[0076] Step 3: Preparation of high-temperature adhesive

[0077] Weigh out 1.0 kg of adhesive precursor, 100.0 g of composite silicon nitride fiber prepared in Example 2 and 100.0 g of activated silicon nitride fiber prepared in Example 2, mix them evenly and add them to a twin-screw extruder. Set the pressure of the twin-screw extruder to 60 Bar and extrude to obtain a high-temperature adhesive.

[0078] Example 6

[0079] This embodiment provides a method for preparing a high-temperature adhesive for wear-resistant and corrosion-resistant refractory materials used in hazardous waste incinerators, comprising the following steps:

[0080] Step ①: Preparation of composite resin

[0081] Weigh out 900.0g of 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 350.0g of 3-(methacryloyloxy)propyltrimethoxysilane, 1.2kg of epoxy vinyl resin, 15.0g of chloroplatinic acid hexahydrate, and 9.0L of N,N-dimethylformamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 45℃ and maintain the temperature for 2 hours. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, and transfer the reaction solution to a rotary evaporator at 85℃ to remove the solvent under reduced pressure to obtain the composite resin.

[0082] Step 2: Preparation of adhesive precursor

[0083] Weigh out 350.0g of composite resin, 650.0g of organosilicon resin and 3.5L of N,N-dimethylformamide and add them to the reaction vessel. After the temperature of the reaction vessel is reduced to 3℃, add 15.0mL of saturated sodium hydroxide solution dropwise to the reaction vessel. After keeping the reaction vessel at this temperature for 2h, adjust the pH of the system to 7 using glacial acetic acid. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, then transfer the reaction solution to a rotary evaporator at 85℃ to remove the solvent under reduced pressure, and obtain the adhesive precursor.

[0084] Step 3: Preparation of high-temperature adhesive

[0085] Weigh out 900.0g of adhesive precursor, 100.0g of composite silicon nitride fiber prepared in Example 3 and 100.0g of activated silicon nitride fiber prepared in Example 3, mix them evenly and add them to a twin-screw extruder. Set the pressure of the twin-screw extruder to 50 Bar and extrude to obtain a high-temperature adhesive.

[0086] Example 7

[0087] This embodiment provides a method for preparing composite aerogel for wear-resistant, corrosion-resistant, and refractory materials used in hazardous waste incinerators, including the following steps:

[0088] Step 1: Preparation of nanocrystalline liquid

[0089] Weigh 300.0g of alumina powder and 3.0L of deionized water and add them to a magnetically stirred reactor. Stir at 60rpm for 10min at room temperature. Then add 100.0mL of ethylenediaminetetraacetic acid to the reactor. Heat the reactor to 40℃ and stir for 1h to obtain nanocrystalline liquid.

[0090] Step 2: Preparation of composite gel

[0091] Weigh out 500.0 mL of nanocrystalline liquid and 200.0 g of activated silicon nitride fiber prepared in Example 1, add them to the inner liner of the reactor, seal the inner liner of the reactor with a lid, and then add it to a stainless steel hydrothermal reactor. Transfer the stainless steel hydrothermal reactor to the inside of an oven, raise the oven temperature to 220°C, and keep it at that temperature for 4 hours. After the reaction is complete, wait for the reactor temperature to drop to room temperature, remove the inner liner of the reactor and open the lid, transfer the inner liner of the reactor to a constant temperature drying oven, raise the temperature of the constant temperature drying oven to 80°C, and keep it at that temperature for 1 hour to obtain the composite gel.

[0092] Step 3: Preparation of composite aerogel

[0093] Weigh out 1.0 kg of composite gel and soak it in ethanol. Let it stand for 12 h. Repeat the soaking process three times. Then transfer the composite gel to a high-pressure reactor. After the temperature of the high-pressure reactor is raised to 40℃, carbon dioxide gas is introduced into the high-pressure reactor and the pressure is controlled at 12 MPa. The reactor is treated at constant temperature and pressure for 2 h to obtain composite aerogel.

[0094] Example 8

[0095] This embodiment provides a method for preparing composite aerogel for wear-resistant, corrosion-resistant, and refractory materials used in hazardous waste incinerators, including the following steps:

[0096] Step 1: Preparation of nanocrystalline liquid

[0097] Weigh 400.0g of alumina powder and 4.0L of deionized water and add them to a magnetically stirred reactor. Stir at 80rpm for 15min at room temperature. Then add 200.0mL of ethylenediaminetetraacetic acid to the reactor. Heat the reactor to 60℃ and stir for 2h to obtain nanocrystalline liquid.

[0098] Step 2: Preparation of composite gel

[0099] Weigh out 600.0 mL of nanocrystalline liquid and 200.0 g of activated silicon nitride fiber prepared in Example 2, add them to the inner liner of the reactor, seal the inner liner with a lid, and then add it to a stainless steel hydrothermal reactor. Transfer the stainless steel hydrothermal reactor to an oven, raise the oven temperature to 240°C, and keep it at that temperature for 5 hours. After the reaction is complete, wait for the reactor temperature to drop to room temperature, remove the inner liner of the reactor and open the lid, then transfer the inner liner of the reactor to a constant temperature drying oven. Raise the temperature of the constant temperature drying oven to 90°C and keep it at that temperature for 2 hours to obtain the composite gel.

[0100] Step 3: Preparation of composite aerogel

[0101] Weigh out 1.0 kg of composite gel and soak it in ethanol. Let it stand for 16 h. Repeat the soaking process three times. Then transfer the composite gel to a high-pressure reactor. After the temperature of the high-pressure reactor is raised to 50℃, carbon dioxide gas is introduced into the high-pressure reactor and the pressure is controlled at 12 MPa. The reactor is treated at constant temperature and pressure for 3 h to obtain composite aerogel.

[0102] Example 9

[0103] This embodiment provides a method for preparing composite aerogel for wear-resistant, corrosion-resistant, and refractory materials used in hazardous waste incinerators, including the following steps:

[0104] Step 1: Preparation of nanocrystalline liquid

[0105] Weigh 350.0g of alumina powder and 3.5L of deionized water and add them to a magnetically stirred reactor. Stir at 70rpm for 12min at room temperature. Then add 150.0mL of ethylenediaminetetraacetic acid to the reactor. Heat the reactor to 50℃ and stir for 2h to obtain nanocrystalline liquid.

[0106] Step 2: Preparation of composite gel

[0107] Weigh out 550.0 mL of nanocrystalline liquid and 150.0 g of activated silicon nitride fiber prepared in Example 3, add them to the inner liner of the reactor, seal the inner liner with a lid, and then add it to a stainless steel hydrothermal reactor. Transfer the stainless steel hydrothermal reactor to an oven, raise the oven temperature to 230°C, and keep it at that temperature for 5 hours. After the reaction is complete, wait for the reactor temperature to drop to room temperature, remove the inner liner of the reactor and open the lid, then transfer the inner liner of the reactor to a constant temperature drying oven. Raise the temperature of the constant temperature drying oven to 85°C and keep it at that temperature for 2 hours to obtain the composite gel.

[0108] Step 3: Preparation of composite aerogel

[0109] Weigh out 1.0 kg of composite gel and soak it in ethanol. Let it stand for 14 h. Repeat the soaking process three times. Then transfer the composite gel to a high-pressure reactor. After the temperature of the high-pressure reactor is raised to 45℃, carbon dioxide gas is introduced into the high-pressure reactor and the pressure is controlled at 12 MPa. The reactor is treated at constant temperature and pressure for 3 h to obtain composite aerogel.

[0110] Example 10

[0111] This embodiment provides a method for preparing wear-resistant and corrosion-resistant refractory materials for hazardous waste incinerators, including the following steps:

[0112] S1. Preparation of high-alumina aggregate

[0113] Weigh out 200.0g of high-alumina bauxite, crush it through a 600-mesh sieve, mix it with 100.0mL of the nanocrystalline liquid prepared in Example 7, and transfer it to a tube furnace. After purging with nitrogen, heat the tube furnace to 1350℃ at a heating rate of 5℃ / min, hold the reaction at that temperature for 4h, and then let it cool naturally to room temperature to obtain high-alumina aggregate.

[0114] S2. Preparation of wear-resistant and corrosion-resistant refractory materials

[0115] Weigh out 800.0g of high-alumina aggregate, 30.0g of boron nitride micro powder and 30.0g of steel fiber and add them to a twin-screw extruder. During the stirring process, gradually add 150.0g of the composite aerogel prepared in Example 7, 100.0g of the high-temperature adhesive prepared in Example 4 and 30.0g of water glass to the mixture. Set the pressure of the twin-screw extruder to 80 bar. After twin-screw extrusion, a wear-resistant and corrosion-resistant refractory material is obtained.

[0116] Example 11

[0117] This embodiment provides a method for preparing wear-resistant and corrosion-resistant refractory materials for hazardous waste incinerators, including the following steps:

[0118] S1. Preparation of high-alumina aggregate

[0119] Weigh out 300.0g of high-alumina bauxite, crush it through a 400-mesh sieve, mix it with 100.0mL of the nanocrystalline liquid prepared in Example 8, and transfer it to a tube furnace. After purging with nitrogen, heat the tube furnace to 1600℃ at a heating rate of 8℃ / min, hold the reaction at that temperature for 6h, and then let it cool naturally to room temperature to obtain high-alumina aggregate.

[0120] S2. Preparation of wear-resistant and corrosion-resistant refractory materials

[0121] Weigh out 1.0 kg of high-alumina aggregate, 50.0 g of boron nitride micro powder, and 50.0 g of steel fiber and add them to a twin-screw extruder. During the stirring process, gradually add 200.0 g of the composite aerogel prepared in Example 8, 150.0 g of the high-temperature adhesive prepared in Example 5, and 50.0 g of water glass to the mixture. Set the pressure of the twin-screw extruder to 100 bar. After twin-screw extrusion, a wear-resistant, corrosion-resistant, and refractory material is obtained.

[0122] Example 12

[0123] This embodiment provides a method for preparing wear-resistant and corrosion-resistant refractory materials for hazardous waste incinerators, including the following steps:

[0124] S1. Preparation of high-alumina aggregate

[0125] Weigh out 250.0g of high-alumina bauxite, crush it through a 500-mesh sieve, mix it with 100.0mL of the nanocrystalline liquid prepared in Example 9, and transfer it to a tube furnace. After purging with nitrogen, heat the tube furnace to 1500℃ at a heating rate of 6℃ / min, hold the reaction at that temperature for 6h, and then let it cool naturally to room temperature to obtain high-alumina aggregate.

[0126] S2. Preparation of wear-resistant and corrosion-resistant refractory materials

[0127] Weigh out 900.0g of high-alumina aggregate, 40.0g of boron nitride micro powder and 40.0g of steel fiber and add them to a twin-screw extruder. During the stirring process, gradually add 180.0g of the composite aerogel prepared in Example 9, 120.0g of the high-temperature adhesive prepared in Example 6 and 40.0g of water glass to the mixture. Set the pressure of the twin-screw extruder to 90 bar. After twin-screw extrusion, a wear-resistant and corrosion-resistant refractory material is obtained.

[0128] Comparative Example 1

[0129] The difference between this comparative example and Example 12 is that, in the preparation process of the composite aerogel used in step S2, the composite silicon nitride fiber prepared in Example 3 is used to replace the activated silicon nitride fiber prepared in Example 3 in an equal amount.

[0130] Comparative Example 2

[0131] The difference between this comparative example and Example 12 is that, in the preparation process of the high-temperature adhesive used in step S2, the composite silicon nitride fiber prepared in Example 3 and the activated silicon nitride fiber prepared in Example 3 are omitted.

[0132] Comparative Example 3

[0133] The difference between this comparative example and Example 12 is that, in step S1, the use of nanocrystalline liquid is omitted.

[0134] Comparative Example 4

[0135] The difference between this comparative example and Example 12 is that, in step S2, silicon nitride fibers are used to replace the composite aerogel in equal amounts.

[0136] Performance testing:

[0137] The wear-resistant and corrosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 were tested for room temperature wear resistance, room temperature flexural strength, room temperature compressive strength, thermal shock resistance (1000℃ / water cooling), bulk density, and thermal conductivity in accordance with the standard GB / T 23294-2021 "Wear-resistant Refractory Materials".

[0138] The acid resistance of the wear-resistant and corrosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested according to the standard GB / T 17601-2023 "Test Method for Acid Resistance of Refractory Materials". The specific data are shown in Table 1.

[0139] Table 1 - Performance test data of each sample

[0140] Data Analysis:

[0141] Based on the comparative analysis of the data in Table 1 above, the wear-resistant and corrosion-resistant refractory material prepared by this invention has a room temperature wear resistance of 3.8 cm. 3 Flexural strength at room temperature: 17.0 MPa; Compressive strength at room temperature: 125.4 MPa; Thermal shock resistance (1000℃ / water cooling): 34 cycles; Bulk density: 2.48 g / cm³ 3 And its acid resistance is 99.8%;

[0142] By comparing the data of Example 12 and Comparative Example 1, it can be found that the mechanical properties, thermal shock resistance and acid resistance of the material are significantly reduced. This indicates that the large number of active functional groups on the surface of the activated silicon nitride fiber promotes the cross-linking of the composite aerogel and the high-temperature adhesive during the bonding process with the high-temperature adhesive, which ultimately makes the structure of the material more compact and significantly improves the mechanical properties and acid resistance of the material.

[0143] By comparing the data of Example 12 and Comparative Example 2, it can be found that the thermal shock resistance of the material is significantly reduced, indicating that the composite silicon nitride fiber acts as a supporting skeleton at high temperature. The active groups on the activated silicon nitride fiber react with the resin component of the high-temperature adhesive at high temperature, preventing further shrinkage of the high-temperature adhesive and ultimately significantly improving the thermal shock resistance of the material.

[0144] By comparing the data of Example 12 and Comparative Example 3, it can be found that the mechanical properties and thermal shock resistance of the material are significantly reduced. This indicates that the nano-alumina particles in the nanocrystalline liquid fill the defects of the crystal form of the calcined product during the calcination of high-alumina bauxite, which ultimately makes the structure of the final high-alumina aggregate stable, thereby significantly improving the mechanical properties and thermal shock resistance of the material.

[0145] By comparing the data of Example 12 and Comparative Example 4, it can be found that the thermal shock resistance and density of the material are significantly reduced, while the thermal conductivity is significantly increased. This indicates that after the composite aerogel fills the material structure, the material's own weight is significantly reduced, thereby reducing the burden on the incinerator structure. The porous structure of the aerogel also reduces the thermal conductivity of the material, thereby reducing heat loss and improving the thermal efficiency of the incinerator. Furthermore, the porous structure of the aerogel and the reduction in the material's own weight further enhance the material's thermal shock resistance.

[0146] This invention describes the preparation of composite silicon nitride fibers and activated silicon nitride fibers. The latter is used in conjunction with nanocrystalline liquid to prepare composite aerogel. Both fibers serve as a high-temperature adhesive skeleton to enhance the high-temperature resistance of the adhesive. The nanocrystalline liquid also acts as an additive to repair crystal defects in high-alumina bauxite during high-temperature calcination. Finally, a lightweight, heat-insulating, wear-resistant, and corrosion-resistant refractory material with high mechanical strength and acid resistance is prepared by mixing high-alumina aggregate, composite aerogel, high-temperature adhesive, and auxiliary materials.

[0147] The above are merely examples and descriptions of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which shall fall within the protection scope of the present invention.

Claims

1. A wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators, characterized in that, It comprises the following raw materials in parts by weight: 80-100 parts high-alumina aggregate, 15-20 parts composite aerogel, 10-15 parts high-temperature adhesive, and 9-15 parts auxiliary materials. The preparation method of composite aerogel includes the following steps: A1. Add alumina powder and deionized water to a magnetically stirred reactor. Stir at room temperature for 10-15 minutes, then add ethylenediaminetetraacetic acid to the reactor. Raise the temperature of the reactor to 40-60℃ and keep it at that temperature for 1-2 hours to obtain a nanocrystalline liquid. A2. After adding the nanocrystalline liquid and activated silicon nitride fiber into the inner liner of the reactor, seal the inner liner of the reactor with a lid and then add it into a stainless steel hydrothermal reactor. Transfer the stainless steel hydrothermal reactor to the inside of an oven, raise the oven temperature to 220-240℃, keep it at the temperature for 4-5 hours, and then process it to obtain a composite gel. A3. Composite aerogel is obtained by two-step post-processing of the composite gel; The auxiliary materials include water glass, boron nitride micro powder and steel fiber, and the ratio of water glass, boron nitride micro powder and steel fiber is 3-5g:3-5g:3-5g; The method for preparing the activated silicon nitride fiber includes the following steps: B1. Silicon monoxide is loaded into a graphite crucible, a graphite sheet is placed on top of the crucible, and the crucible is wrapped with graphite paper. The crucible is then transferred to a high-temperature furnace. After heat treatment, the fibers attached to the graphite sheet are collected to obtain composite silicon nitride fibers. B2. Add composite silicon nitride fiber and 98.0 wt% sulfuric acid to a reaction vessel at a temperature of 0-5℃, keep warm and stir for 10-15 min, then add sodium chlorate to the reaction vessel, keep the temperature of the reaction vessel at 0-5℃ and react for 2-4 h, and then perform post-treatment to obtain activated silicon nitride fiber. The preparation method of the high-temperature adhesive includes the following steps: C1. 2,4,6,8-Tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 3-(methacryloyloxy)propyltrimethoxysilane, epoxy vinyl resin, chloroplatinic acid hexahydrate and N,N-dimethylformamide are added to a reaction vessel. The temperature of the reaction vessel is raised to 40-50℃ and the reaction is maintained for 1-2 hours. The composite resin is obtained after post-treatment. C2. Add composite resin, organosilicon resin and N,N-dimethylformamide to the reaction vessel. After the temperature of the reaction vessel is reduced to 0-5℃, add saturated sodium hydroxide solution dropwise to the reaction vessel. After keeping the reaction at this temperature for 1-2 hours, adjust the pH of the system to 7 using glacial acetic acid. The adhesive precursor is then obtained through post-treatment. C3. After uniformly mixing the adhesive precursor, composite silicon nitride fiber and activated silicon nitride fiber, add them to a twin-screw extruder and melt extrude to obtain a high-temperature adhesive.

2. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 1, characterized in that, In step A1, the stirring speed of the magnetic stirring vessel is 60-80 rpm, and the ratio of alumina powder, deionized water and ethylenediaminetetraacetic acid is 3-4 g: 30-40 mL: 1-2 mL; in step A2, the ratio of nanocrystalline liquid and activated silicon nitride fiber is 5-6 mL: 1-2 g.

3. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 1, characterized in that, In step A3, the two post-processing steps are as follows: the composite gel is soaked in ethanol and left to stand for 12-16 hours. After soaking three times, the composite gel is transferred to a high-pressure reactor. After the temperature of the high-pressure reactor is raised to 40-50°C, carbon dioxide gas is introduced into the high-pressure reactor and the pressure is controlled at 12 MPa. The reactor is treated at constant temperature and pressure for 2-3 hours to obtain the composite aerogel.

4. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 1, characterized in that, In step B1, the heat treatment operation is as follows: after nitrogen gas is introduced into the high-temperature furnace, the temperature is raised to 1800-2000℃ at a heating rate of 6-8℃ / min, and the reaction is held at this temperature for 1-2 hours. Then, the temperature is naturally cooled to room temperature to complete the heat treatment operation. In step B2, the ratio of composite silicon nitride fiber, 98.0wt% sulfuric acid and sodium chlorate is 5-6g:50-60mL:3-5g.

5. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 1, characterized in that, In step C1, the ratio of 2,4,6,8-tetramethyl-2-[3-(epoxyethylene methoxy)propyl]cyclotetrasiloxane, 3-(methacryloyloxy)propyltrimethoxysilane, epoxy vinyl resin, chloroplatinic acid hexahydrate, and N,N-dimethylformamide is 8-10g:3-4g:10-15g:0.1-0.2g:80-100mL; in step C2, the ratio of composite resin, organosilicon resin, N,N-dimethylformamide, and saturated sodium hydroxide solution is 3-4g:5-8g:30-40mL:0.1-0.2mL; in step C3, the ratio of adhesive precursor, composite silicon nitride fiber, and activated silicon nitride fiber is 8-10g:1g:1g.

6. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 1, characterized in that, The preparation method of the high-alumina aggregate is as follows: after crushing the high-alumina bauxite through a 400-600 mesh sieve, it is mixed with nanocrystalline liquid and then transferred to a tube furnace for calcination to obtain the high-alumina aggregate.

7. The wear-resistant and corrosion-resistant refractory material for hazardous waste incinerators according to claim 6, characterized in that, The ratio of high-alumina bauxite to nanocrystalline liquid is 2-3g:1mL. The calcination operation is as follows: after nitrogen protection is introduced into the tube furnace, the temperature of the tube furnace is raised to 1350-1600℃ at a heating rate of 5-8℃ / min, and the reaction is held at the temperature for 4-6 hours. The mixture is then naturally cooled to room temperature to obtain high-alumina aggregate.

8. A method for preparing a wear-resistant and corrosion-resistant refractory material for a hazardous waste incinerator as described in any one of claims 1-7, characterized in that, Includes the following steps: High-alumina aggregate, boron nitride micro powder, and steel fiber are added to a twin-screw extruder. During the mixing process, composite aerogel, high-temperature binder, and water glass are gradually added to the mixture. The pressure of the twin-screw extruder is set to 80-100 bar. After twin-screw extrusion, wear-resistant and corrosion-resistant refractory material is obtained.

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