Coke oven body grouting sealing material and preparation method thereof

Abstract

The invention discloses a grouting sealing material for a coke oven body and a preparation method of the grouting sealing material. The grouting sealing material comprises silica powder, clinker rhombolite, high bauxite powder, corundum, a binding agent and an additive. The preparation method comprises the following steps: mixing and stirring the silica powder, clinker rhombolite, high-alumina bauxite powder and corundum in proportion, and uniformly mixing; then adding a binding agent and continuously stirring to ensure that the binding agent uniformly wraps the raw material particles; adding the admixture according to the proportion, and stirring until the admixture is fully dispersed; and finally, adding a proper amount of diluent according to use conditions, and uniformly stirring to obtain the finished grouting sealing material. The grouting sealing material and the preparation method thereof overcome the defects of traditional coke oven body grouting in the aspects of high temperature resistance, chemical erosion resistance, adhesive property and the like, can keep good performance under the high-temperature and complex chemical environment of a coke oven, and are better in comprehensive performance and lower in cost compared with a coke oven body grouting sealing material in the prior art. The sealing effect and the service life of the coke oven can be obviously improved, and the maintenance frequency and the maintenance cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials, and in particular to a coke oven body grouting sealing material and a preparation method thereof. Background Art

[0002] During the production and operation of coke ovens, the coke oven body is subjected to high temperatures, chemical corrosion, and mechanical vibrations for a long time. Under such complex working conditions, the internal refractory materials of key parts of the furnace body, such as brick gas pipelines, the gap between the protective plate and the furnace head, and the furnace roof area, are easily damaged. Specifically, some refractory materials are missing or cracks and gaps appear. These problems seriously undermine the structural integrity of the coke oven body, resulting in a decrease in the sealing performance of the furnace body, which seriously affects the production efficiency and energy utilization efficiency of the coke oven. As a key link in the daily maintenance of coke ovens, coke oven body grouting plays a decisive role in restoring the structural stability of the coke oven and improving the sealing of the furnace body. The quality of the grouting sealing material largely determines the ultimate effect of the furnace body grouting.

[0003] Traditional coke oven grouting materials often use a basic formula of low-temperature silica fireclay (or clay fireclay) combined with water glass. This traditional grouting material is relatively low-cost and widely available, making it suitable for temporary sealing and repair work. However, due to its poor high-temperature resistance, it is prone to hardening and cracking after high-temperature sintering, resulting in a short service life. To address this issue with traditional grouting materials, existing technologies have been dedicated to improving grouting and sealing materials with high-temperature stability. Chinese patent document CN111484272A discloses a coke oven burner grouting material and its manufacturing method. This grouting material, based on a liquid phenolic resin matrix, is combined with silica powder, mullite powder, clay refractory mortar, and other fillers, and silane coupling agents and polydimethylsiloxane as additives. It can be used to fill gaps between coke oven protective plates and the furnace body. While this grouting material exhibits good high-temperature stability and fluidity, it suffers from relatively high material costs. Furthermore, it suffers from poor durability and difficulty maintaining stable performance in environments subject to long-term chemical attack. Chinese patent document CN107445633A discloses a liquid grouting material, preparation method and use method for hot repair of cracks in coke oven walls, a grouting material composed of water glass, mullite, refractory clay, quartz sand and dispersant, and related preparation and use methods. The raw materials of the grouting material have the characteristics of low cost, easy acquisition and environmental protection. However, under working conditions facing high-intensity mechanical stress, its bonding strength performance is poor and it cannot effectively meet the actual use requirements in the long term. Chinese patent document CN118834696A discloses a grouting penetration sealing method for coke oven brick gas ducts, a slurry with magnesium phosphate cement, sodium tripolyphosphate dispersant, water reducer, suspending agent, sepiolite, sodium silicate, granular material, perlite and the like as main components. Among them, magnesium phosphate cement is a mixture of dead-burned magnesium oxide and monoammonium phosphate in a specific mass ratio. It can achieve a good sealing effect through grouting penetration. However, this grouting material also has the problem of poor long-term chemical stability and is prone to aging and deterioration during use. At the same time, its sealing and filling effect for relatively fine cracks needs to be further improved.

[0004] In view of the many shortcomings of the grouting sealing materials in the above-mentioned existing technologies, it is urgent to develop a high-performance furnace body grouting sealing material with excellent thermal stability, good corrosion resistance and better comprehensive performance, so as to improve the furnace body grouting effect and better ensure the long-term stable operation of the coke oven. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a coke oven body grouting sealant and a preparation method thereof. The grouting sealant and the preparation method thereof overcome the defects of traditional coke oven body grouting in terms of high temperature resistance, chemical corrosion resistance, and bonding performance, and can maintain good performance under the high temperature and complex chemical environment of the coke oven. Compared with the coke oven body grouting sealant in the prior art, the comprehensive performance is better, which can significantly improve the sealing effect and service life of the coke oven and reduce maintenance frequency and maintenance costs.

[0006] In order to solve the above technical problems, the coke oven body grouting sealing material of the present invention includes, by mass fraction, 38% to 44% of silicon micropowder, 18% to 22% of clinker quartz, 13% to 17% of high-alumina bauxite powder, 10% to 14% of corundum, 8% to 12% of binder, and 1% to 3% of admixture.

[0007] Furthermore, the binder is aluminum dihydrogen phosphate.

[0008] Furthermore, the components of the admixture are calculated by mass fraction as follows: Water-retaining agent CMC 20~25% Sintering agent borax 20-25% Binder bentonite 50-60% Diluent: 45-50% aqueous solution of aluminum dihydrogen phosphate.

[0009] A method for preparing the above-mentioned coke oven body grouting and sealing material comprises: mixing silicon micropowder, clinker quartz, high-alumina bauxite powder and corundum in proportion, stirring in a mixer for 30 to 40 minutes to uniformly mix them; then adding a binder, continuing to stir for 20 to 30 minutes to ensure that the binder uniformly wraps the raw material particles; then adding an admixture in proportion, stirring for 15 to 20 minutes to fully disperse them; finally, adding an appropriate amount of diluent according to the use conditions, and stirring evenly to obtain a finished grouting and sealing material.

[0010] Furthermore, during the stirring process, the stirring speed is controlled to be 500-800 rpm and the temperature is maintained at 20-30° C. to ensure the uniformity and stability of the material. Since the coke oven body grouting sealant and its preparation method of the present invention adopt the above-mentioned technical solution, that is, the grouting sealant includes silicon micropowder, clinker quartz, high-alumina bauxite powder, corundum, a binder and an admixture. The preparation method is to mix silicon micropowder, clinker quartz, high-alumina bauxite powder and corundum in proportion and stir them to make them evenly mixed; then add the binder and continue stirring to ensure that the binder evenly wraps the raw material particles; then add the admixture in proportion and stir until it is fully dispersed; finally, add an appropriate amount of diluent according to the working conditions, stir evenly to obtain the finished grouting sealant. The present grouting sealant and its preparation method overcome the defects of traditional coke oven body grouting in terms of high temperature resistance, chemical corrosion resistance, and bonding performance, and can maintain good performance under the high temperature and complex chemical environment of the coke oven. Compared with the coke oven body grouting sealant of the prior art, it has better comprehensive performance, can significantly improve the sealing effect and service life of the coke oven, and reduce the maintenance frequency and maintenance cost. DETAILED DESCRIPTION

[0011] The coke oven body grouting sealing material of the present invention comprises, by mass fraction, 38% to 44% of silicon micropowder, 18% to 22% of clinker quartz, 13% to 17% of high-alumina bauxite powder, 10% to 14% of corundum, 8% to 12% of binder, and 1% to 3% of admixture.

[0012] Preferably, the binder is aluminum dihydrogen phosphate.

[0013] Aluminum dihydrogen phosphate can react chemically with other raw materials at high temperatures to form strong chemical bonds, which can enhance the bonding strength of the overall material. At a high temperature of 1000°C, aluminum dihydrogen phosphate reacts with silicon micropowder, high-alumina bauxite powder, etc. to form a mullite-aluminum phosphate composite phase, which can effectively improve the bonding strength of this sealing material.

[0014] Preferably, the components of the admixture are calculated by mass fraction as follows: Water-retaining agent CMC 20~25% Sintering agent borax 20-25% Binder bentonite 50-60% Diluent: 45-50% aqueous solution of aluminum dihydrogen phosphate.

[0015] The water-retaining agent CMC is carboxymethyl cellulose. The diluent ratio is determined according to different working conditions, which can adjust the flow properties and curing effect of the overall material to ensure the construction performance of the grouting and sealing material.

[0016] A method for preparing the above-mentioned coke oven body grouting and sealing material comprises: mixing silicon micropowder, clinker quartz, high-alumina bauxite powder and corundum in proportion, stirring in a mixer for 30 to 40 minutes to uniformly mix them; then adding a binder, continuing to stir for 20 to 30 minutes to ensure that the binder uniformly wraps the raw material particles; then adding an admixture in proportion, stirring for 15 to 20 minutes to fully disperse them; finally, adding an appropriate amount of diluent according to the use conditions, and stirring evenly to obtain a finished grouting and sealing material.

[0017] Preferably, during the stirring process, the stirring speed is controlled to be 500-800 rpm and the temperature is maintained at 20-30° C. to ensure the uniformity and stability of the material.

[0018] This grouting sealant is made of microsilica powder, clinker quartz, high-alumina bauxite powder and corundum as the main raw materials. Microsilica powder can effectively fill tiny pores and improve the density of the sealant due to its fine particle size and large specific surface area. Compared with ordinary quartz powder, microsilica powder can form a more stable crystal phase structure at high temperatures. At a high temperature of 1000℃, the crystal phase transformation of ordinary quartz powder will cause a volume change of about 10%, while that of microsilica powder is only 2-3%, which effectively enhances the high-temperature resistance of the sealant. Clinker quartz has been calcined at high temperature and has a stable structure. Its thermal expansion coefficient is (0.5-0.8)×10⁻ at (0-1000℃). 6 / °C, far lower than typical quartz materials, effectively resisting high-temperature deformation. High-alumina bauxite powder and corundum not only have high melting points but also exhibit excellent corrosion resistance. The alumina content of high-alumina bauxite powder is as high as 60-80%, which forms a stable mullite phase at high temperatures, enhancing the material's high-temperature stability. Corundum's high hardness and strong chemical stability make it resistant to corrosion from chemicals found in coke ovens.

[0019] Compared with the prior art, the present invention has the following technical effects: (1) Excellent high temperature resistance: The main raw materials are silicon micropowder, clinker quartz, high alumina bauxite powder and corundum, all of which have good high temperature resistance. Silicon micropowder can form a stable crystal structure at high temperature, which enhances the high temperature resistance of the sealing material; clinker quartz has a stable structure after high temperature calcination and can effectively resist high temperature deformation; high alumina bauxite powder and corundum have high melting points and can still maintain good physical properties in high temperature environment, making the sealing material not easy to soften, deform or decompose in the high temperature environment of the coke oven, and can play a long-term and stable sealing role.

[0020] (2) Good sealing performance: The fine particle size of silicon micropowder can fill the tiny pores inside the sealing material and between the sealing material and the furnace body, reducing the gas leakage channel, improving the density of the sealing material, and enhancing the sealing effect. The binder aluminum dihydrogen phosphate will react chemically with other raw materials at high temperatures to form a strong chemical bond, tightly combining the raw materials together, further improving the integrity and sealing performance of the sealing material. In addition, bentonite as a binder can enhance the adhesion between the sealing material and the furnace body, ensuring that the sealing material and the furnace body are tightly fitted, and preventing gaps that may cause gas leakage.

[0021] (3) High chemical stability: High-alumina bauxite powder and corundum have strong resistance to chemical erosion and can effectively resist the erosion of chemicals such as gas and tar in coke ovens. In a long-term chemical erosion environment, the components of the sealing material are not easily deteriorated by chemical reactions, thus ensuring the stable performance of the sealing material and extending its service life.

[0022] (4) Good construction performance: The diluent is an aqueous solution of aluminum dihydrogen phosphate, and its 45-50% ratio can effectively adjust the fluidity of the sealing material, so that it can be smoothly filled into the fine gaps of the furnace body during construction, and will not flow due to excessive fluidity, ensuring the accuracy and uniformity of construction. The presence of the water-retaining agent CMC can prevent the water in the sealing material from evaporating too quickly during construction, ensuring the uniformity and plasticity of the material, facilitating construction operations, ensuring that the sealing material can fully fill the gaps, and improving construction quality.

[0023] (5) Good sintering performance: Borax is used as a sintering agent, which can promote the sintering reaction between the raw materials at high temperatures, making the sealing material more dense. During the operation of the coke oven, the internal structure of the sealing material becomes more compact due to the high temperature, further improving its sealing performance and bonding strength.

[0024] The effects of the present invention are further described below in conjunction with specific embodiments. The grouting sealant, calculated by mass fraction, includes 41% silicon micropowder, 20% clinker rhombohedron, 15% high-alumina bauxite powder, 12% corundum, 10% aluminum dihydrogen phosphate (binder), 2% admixtures (of which the water-retaining agent CMC accounts for 22% of the admixture mass fraction, the sintering agent borax accounts for 22%, and the binder bentonite accounts for 56%), and 48% aluminum dihydrogen phosphate aqueous solution (diluent).

[0025] First, mix the main raw materials according to the mass ratio and stir for 30 minutes to make the raw materials preliminarily mixed. Then add the binder and pre-mixed admixtures and continue stirring for 15 minutes. Finally, add the diluent and stir for 10 minutes until a uniform grouting sealant with appropriate fluidity and consistency is formed. The performance indicators of the obtained grouting sealant are as follows: Based on the above factors and example analysis, the high-performance coke oven body grouting and sealing material prepared by the present invention has excellent comprehensive performance, can meet the high temperature and chemical medium corrosion environment of the coke oven body, and has good construction performance during use, which can significantly improve the sealing effect of the coke oven.

[0026] In terms of raw material selection, although the present invention mainly uses silicon micropowder, clinker quartz, high-alumina bauxite powder and corundum as the main raw materials, in certain special cases, if there are special requirements for a certain performance of the sealant, it is possible to consider replacing some of the raw materials. For example, when there are higher requirements for the thermal shock resistance of the sealant, you can try to replace some of the clinker quartz with kyanite. Kyanite will undergo a crystal transformation at high temperatures and absorb a certain amount of heat, thereby improving the thermal shock resistance of the sealant. However, the amount of kyanite added needs to be strictly controlled, generally not exceeding 30% of the original amount of clinker quartz, otherwise it may affect the high-temperature stability of the sealant.

[0027] Regarding binders, in addition to aluminum dihydrogen phosphate, some cost-sensitive applications and relatively low operating temperatures (no more than 1200°C) may consider using water glass as a partial replacement for aluminum dihydrogen phosphate. However, the replacement ratio should not exceed 50% of the original aluminum dihydrogen phosphate. Water glass is relatively low-cost and can reduce sealant costs to a certain extent, but its high-temperature resistance is inferior to that of aluminum dihydrogen phosphate. Excessive use will affect the sealant's bond strength at high temperatures.

[0028] Regarding admixtures, the water-retaining agent CMC can be partially replaced with polyacrylamide, with the replacement ratio ranging from 20% to 30%. Polyacrylamide also has certain water-retention properties and, in some cases, can enhance the thickening effect of the sealant, helping to improve its resistance to flow during application. However, the addition of polyacrylamide can affect the curing speed of the sealant, requiring corresponding adjustments to the application process.

Claims

1. A coke oven body grouting sealant, characterized by: Calculated by mass fraction, it includes 38% to 44% silicon micropowder, 18% to 22% clinker quartz, 13% to 17% high alumina powder, 10% to 14% corundum, 8% to 12% binder, and 1% to 3% admixture.

2. The coke oven body grouting and sealing material according to claim 1, characterized in that: The binder is aluminum dihydrogen phosphate.

3. The coke oven body grouting and sealing material according to claim 1, characterized in that: The components of the admixture are calculated by mass fraction as follows: Water-retaining agent CMC 20~25% Sintering agent borax 20-25% Binder bentonite 50-60% Diluent: 45-50% aluminum dihydrogen phosphate aqueous solution.

4. A method for preparing a coke oven body grouting sealant according to any one of claims 1 to 3, characterized in that: Mix silicon micropowder, clinker quartz, high-alumina bauxite powder and corundum in proportion, stir in a mixer for 30 to 40 minutes to mix them evenly; then add the binder and continue stirring for 20 to 30 minutes to ensure that the binder evenly wraps the raw material particles; then add the admixture in proportion and stir for 15 to 20 minutes to fully disperse it; finally, add an appropriate amount of diluent according to the working conditions, stir evenly to obtain the finished grouting sealant.

5. The method for preparing a coke oven body grouting sealant according to claim 4, characterized in that: During the stirring process, the stirring speed is controlled at 500-800 rpm and the temperature is maintained at 20-30°C to ensure the uniformity and stability of the material.

Images