A binder suitable for refractory materials and its preparation process and application

Abstract

The present application relates to the technical field of binder, especially to a binder suitable for refractory material and its preparation process and application. The binder suitable for refractory material is prepared from the following raw materials in parts by weight: 30-40 parts of dispersible sulfonated starch ether, 20-30 parts of naphthalene sulfonate sodium formaldehyde condensate, 3-5 parts of hydroxypropyl methyl cellulose, 5-10 parts of sodium bentonite, 3-5 parts of fumed silica and 1-3 parts of polyvinyl alcohol. The main raw material of the binder of the present application is also added with dispersible sulfonated starch ether prepared from the following raw materials and preparation process. When the dispersible sulfonated starch ether is used together with the above-mentioned raw materials, firstly, the strength of the refractory material product can be improved; secondly, when the binder is added to the refractory material for molding, the cracking of thick-gauge refractory material during drying or sintering can be avoided, and the refractory material product prepared has fewer cracks at the edges and corners.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and in particular to an adhesive suitable for refractory materials, its preparation process, and its application. Background Technology

[0002] Refractory materials refer to the process of processing raw materials such as refractory silica into finished products of specified size and shape with the help of external force and molds. In recent years, with the continuous development of new energy vehicles and energy storage technologies, upstream positive and negative electrode material production enterprises and non-ferrous metal enterprises such as lithium carbonate, cobalt, and nickel have used a large number of refractory materials as carriers in the production processes of purification, smelting, and roasting. With the continuous development of refractory materials, the requirements for refractory materials in various fields are also constantly increasing. The refractory materials after molding should meet the following requirements: (1) the shape, size and precision meet the design requirements; (2) the structure is uniform and dense, and there are no cracks on the surface and inside; (3) it has sufficient mechanical strength; (4) it meets the expected physical performance requirements.

[0003] However, traditional organic binders are often used in the molding of refractory materials. Traditional organic binders have the characteristics of poor dispersibility, low density of the pressed products during molding, large dosage and high cost. Furthermore, during drying or firing, traditional organic binders melt, decompose and volatilize in large quantities in the refractory materials, which can easily lead to deformation and cracking of the refractory materials and reduce their mechanical strength, thus affecting the final quality of the refractory materials. Summary of the Invention

[0004] The main objective of this invention is to provide a binder suitable for refractory materials, its preparation process, and its application, aiming to improve the technical problems of existing refractory materials using traditional organic binders, which are prone to deformation, cracking, and low mechanical strength.

[0005] To achieve the above objectives, the present invention proposes a binder suitable for refractory materials, which, by weight, comprises the following raw materials: 30-40 parts of dispersible sulfonated starch ether, 20-30 parts of sodium naphthalene sulfonate formaldehyde condensate, 3-5 parts of hydroxypropyl methylcellulose, 5-10 parts of sodium bentonite, 3-5 parts of fumed silica, and 1-3 parts of polyvinyl alcohol.

[0006] The raw materials for preparing the binder in this scheme include conventional fumed silica, hydroxypropyl methylcellulose, and polyvinyl alcohol, and also introduce special sodium naphthalene sulfonate formaldehyde condensate and sodium bentonite. Sodium naphthalene sulfonate formaldehyde condensate is often used as a water-reducing agent in cement, and this scheme uses it as the main raw material for the binder. The introduction of sodium bentonite can improve the plasticity and strength of refractory materials. In addition, the main raw material for the binder in this scheme also includes dispersible sulfonated starch ether. The dispersible sulfonated starch ether is prepared using the following raw materials and preparation process. When the dispersible sulfonated starch ether is used in combination with the above raw materials, firstly, it can improve the strength of refractory products; secondly, when this binder is added to refractory materials for molding, it can also prevent cracking of thick refractory materials during drying / firing, resulting in fewer cracks at the edges and corners of finished products such as thick refractory bricks / refractory saggers.

[0007] Furthermore, the binder obtained by this method has good adaptability in various types of refractory materials and can be used in conjunction with other additives in refractory materials.

[0008] Preferably, the dispersible sulfonated starch ether is prepared from the following raw materials in parts by weight: 25-35 parts corn starch, 5-10 parts cassava starch, 5-10 parts dextrin, 5-8 parts sodium lignosulfonate, 2-4 parts caustic soda, 6-8 parts methanol, and 6-8 parts chloroacetic acid.

[0009] Preferably, the preparation steps of the dispersible sulfonated starch ether include: mixing and homogenizing the corn starch, the cassava starch, the dextrin, and the sodium lignin sulfonate in a device for 25-35 minutes according to the specified ratio to obtain a first mixture;

[0010] Add the caustic soda flakes to the first mixture and stir until uniform. While stirring, add the methanol and carry out the alkalization reaction in a water bath. After reacting for 35-45 minutes, the second mixture is obtained.

[0011] The chloroacetic acid is added to the second mixture for etherification. During etherification, the temperature is raised to 75-80°C, and the reaction is carried out for 60-70 minutes. After cooling to room temperature, the mixture is passed through a 60-mesh vibrating sieve to obtain the dispersible sulfonated starch ether. The room temperature in this method is approximately 25-30°C.

[0012] This method uses methanol as a solvent and employs sodium lignosulfonate to sulfonate corn starch, cassava starch, and dextrin. During the preparation process, sodium hydroxide flakes are added to promote the alkalization reaction of corn starch, cassava starch, dextrin, and sodium lignosulfonate. Then, chloroacetic acid is used to etherify the above mixture. The resulting dispersible sulfonated starch ether, when added to the raw materials for refractory material preparation, allows for a more complete reaction of the refractory material, resulting in a more uniform and dense internal structure, further improving the strength of the refractory material, and reducing cracking.

[0013] Preferably, the water bath temperature is 33-38℃. The optimal temperature for the alkalization reaction is 33-38℃. At temperatures below or above this range, the alkalization reaction efficiency is low, and the quality of the obtained product is poor.

[0014] Preferably, the sodium naphthalene sulfonate formaldehyde condensate has a pH value of 7.6-7.8, and by mass percentage, the sodium sulfate content is 18.5-19.5%, the chloride ion content is 0.18-0.5%, and the surface tension is approximately 72 mN / m. The sodium naphthalene sulfonate formaldehyde condensate has good dispersing properties, which can make the refractory raw materials more homogenized during stirring, aging, and other processes, reducing the likelihood of agglomeration. It also facilitates air release during molding, resulting in high density of the finished product, improved strength of the refractory material, and enhanced other mechanical properties.

[0015] Preferably, the viscosity of the hydroxypropyl methylcellulose is 40,000-60,000 mPa·s. -1 (Measured by NDJ-1 type viscometer), the hydroxypropyl methylcellulose is a cold-soluble type with a pH value of 6-7; and the methoxy content in the hydroxypropyl methylcellulose is 25-30%, and the hydroxypropoxy content is 10-13%. When the parameters of hydroxypropyl methylcellulose are limited to the above range, the bonding strength of the binder can be improved, and the crack resistance of the refractory material can also be improved.

[0016] Preferably, the particle size range of the sodium naphthalene sulfonate formaldehyde condensate and the hydroxypropyl methylcellulose is 180-380 μm, the particle size range of the sodium bentonite is 80-150 μm, the particle size range of the fumed silica is 5-45 nm, and the particle size range of the polyvinyl alcohol is 100-150 μm.

[0017] Preferably, the bulk density of the fumed silica is 200-400 g / dm³. 3 The pore volume is 0.1-1 cm³. 3 / g. Fumed silica is a microparticle inorganic material. As an excellent performance modifier, fumed silica prevents sedimentation of refractory materials during homogenization and aging processes. It also has good dispersing properties, increasing the flowability of refractory raw materials and improving phenomena such as inconsistent size, uneven thickness, bulging, and delamination caused by insufficient flowability of homogenized powder during molding. When the fumed silica in this scheme is limited to the above parameters, the resulting binder has good quality.

[0018] In addition, the present invention also proposes a preparation process for a binder suitable for refractory materials as described in any of the above claims, comprising the following steps: according to the formula, the dispersible sulfonated starch ether, the sodium naphthalene sulfonate formaldehyde condensate, the hydroxypropyl methylcellulose, the sodium bentonite, the fumed silica, and the polyvinyl alcohol are added to a ball mill and dry ball-milled to 38-58 μm; then the ball-milled raw materials are placed in a pulverizing device and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0019] The binder undergoes two crushing processes during preparation. The first ball milling process yields a mixture with a particle size of 38-58 μm, while the second pulverization process yields a mixture with a particle size of 13-23 μm. This smaller particle size increases the specific surface area of ​​the binder, making it easier to add to refractory materials. This results in better strength for the refractory materials and also helps prevent them from cracking easily.

[0020] In addition, the present invention also proposes the application of a binder suitable for refractory materials as described in any of the above claims in the preparation of refractory materials.

[0021] Compared with existing technologies, the binder for refractory materials of the present invention has the following beneficial effects: It introduces a special sodium naphthalene sulfonate formaldehyde condensate and sodium bentonite. The sodium naphthalene sulfonate formaldehyde condensate is often used as a water-reducing agent in cement, and this invention uses it as the main raw material of the binder. The introduction of sodium bentonite can improve the plasticity and strength of the refractory material. Furthermore, the main raw material of the binder in this invention also includes dispersible sulfonated starch ether. The dispersible sulfonated starch ether is prepared using the following raw materials and preparation process. When the dispersible sulfonated starch ether is used in combination with the above raw materials, firstly, it can improve the strength of the refractory product; secondly, when this binder is added to the refractory material for molding, it can also prevent cracking of thick refractory materials during drying / firing, resulting in fewer cracks at the edges and corners of finished products such as thick refractory bricks / refractory saggers. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a picture of a qualified finished refractory support plate after firing.

[0024] Figure 2 This is a photograph of a refractory support plate that cracked after firing.

[0025] Figure 3 The image shows a qualified finished product of refractory kiln furniture after firing.

[0026] Figure 4 The image shows actual refractory kiln furniture that cracked after firing.

[0027] Figure 5 A photograph of a qualified refractory sagger after firing.

[0028] Figure 6 This is a photograph of a refractory sagger that cracked after firing.

[0029] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0032] A process for preparing a binder suitable for refractory materials includes the following steps:

[0033] By weight, 30-40 parts of the dispersible sulfonated starch ether, 20-30 parts of the sodium naphthalene sulfonate formaldehyde condensate, 3-5 parts of the hydroxypropyl methylcellulose, 5-10 parts of the sodium bentonite, 3-5 parts of the fumed silica, and 1-3 parts of the polyvinyl alcohol are sequentially added to a high-alumina ball mill and dry-milled to 38-58 μm. The ball-milled raw materials are then placed in an air-jet mill and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0034] The sodium naphthalene sulfonate formaldehyde condensate has a pH of 7.6-7.8, and by mass percentage, contains 18.5-19.5% sodium sulfate and 0.18-0.5% chloride ions; the hydroxypropyl methylcellulose has a viscosity of 40,000-60,000 mPa·s. -1The pH value is 6-7; the particle size range of the sodium naphthalenesulfonate formaldehyde condensate and the hydroxypropyl methylcellulose is 180-380 μm, the particle size range of the sodium bentonite is 80-150 μm, the particle size range of the fumed silica is 5-45 nm, and the particle size range of the polyvinyl alcohol is 100-150 μm; the methoxy group content of the hydroxypropyl methylcellulose is 25-30%, and the hydroxypropoxy group content is 10-13%; the bulk density of the fumed silica is 200-400 g / dm³. 3 The pore volume is 0.1-1 cm³. 3 / g.

[0035] The preparation of the dispersible sulfonated starch ether includes the following steps:

[0036] By weight, 25-35 parts of the corn starch, 5-10 parts of the cassava starch, 5-10 parts of the dextrin, and 5-8 parts of the sodium lignosulfonate are placed in a mixing kneader and mixed and homogenized for 25-35 minutes to obtain the first mixture.

[0037] Add 2-4 parts of the caustic soda flakes to the first mixture and stir until uniform. While stirring, add 6-8 parts of the methanol and carry out the alkalization reaction in a water bath at 33-38°C. After reacting for 35-45 minutes, the second mixture is obtained.

[0038] Add 6-8 parts of the chloroacetic acid to the second mixture for etherification. During etherification, the temperature is raised to 75-80°C, and the reaction is carried out for 60-70 minutes. After cooling to room temperature, the mixture is sieved to obtain the dispersible sulfonated starch ether.

[0039] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0040] Example 1

[0041] The preparation of dispersible sulfonated starch ether includes the following steps: 26 parts by weight of corn starch, 5 parts by weight of cassava starch, 6 parts by weight of dextrin, and 6 parts by weight of sodium lignosulfonate are mixed and homogenized in a mixing kneader for 30 minutes to obtain a first mixture; 4 parts by weight of caustic soda are added to the first mixture and stirred evenly, while 7 parts by weight of methanol are added, and an alkalization reaction is carried out in a water bath at 35°C for 40 minutes to obtain a second mixture; 6 parts by weight of chloroacetic acid are added to the second mixture for etherification, the temperature is raised to 80°C during etherification, the reaction is carried out for 65 minutes, and then cooled to room temperature. After sieving, the dispersible sulfonated starch ether is obtained.

[0042] The preparation process of the binder suitable for refractory materials includes the following steps: by weight, 38 parts of dispersible sulfonated starch ether, 23 parts of sodium naphthalene sulfonate formaldehyde condensate, 3 parts of hydroxypropyl methylcellulose, 6 parts of sodium bentonite, 5 parts of fumed silica, and 3 parts of polyvinyl alcohol are sequentially added to a high-alumina ball mill and dry-milled to 38-58 μm. Then, the ball-milled raw materials are placed in an air-jet mill and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0043] The binder obtained in Example 1 was used in the following three different refractory materials:

[0044] 1. Refractory support plate A, comprising the following raw materials by weight percentage: cordierite powder 25%, mullite powder 22%, corundum powder 13%, kaolin 26%, alumina micro powder 6%, silica micro powder 5%, binder 2%, flux (glass powder) 1%; specifications are 500×400×25mm (length×width×thickness).

[0045] 2. Refractory kiln furniture B (perforated brick), comprising the following raw materials by weight percentage: cordierite powder 24%, mullite powder 25%, high-alumina bauxite 6%, kaolin 28%, calcined bauxite 7%, alumina micro powder 8%, binder 2%; specifications are 230×120×80mm (length×width×thickness).

[0046] 3. Refractory sagger C, comprising the following raw materials by weight percentage: pyrophyllite 8%, kaolin 18%, high-alumina bauxite 6.5%, alumina micro powder 5%, silica micro powder 6%, mullite powder 32%, cordierite 23%, binder 1%, flux (glass powder) 0.5%; dimensions are 330×25mm (diameter×thickness).

[0047] This comparative example uses a conventional binder from the prior art, with the following specific components: 48% dextrin and 52% sodium carboxymethyl cellulose.

[0048] The performance test results of the above three refractory materials after using the binder in Example 1 are shown in the table below:

[0049]

[0050] The test results in the table above show that the dry strength of the refractory material is improved compared to before the addition of the binder. The strength improvement effect is better than that of the conventional binder in Comparative Example 1. Furthermore, after adding the binder of this scheme, no obvious cracks were observed on the surface, edges, and corners of the three different refractory materials, even though the thickness of the products was relatively large. The performance of the products was relatively stable.

[0051] Example 2

[0052] The preparation of dispersible sulfonated starch ether includes the following steps: 30 parts by weight of corn starch, 10 parts by weight of cassava starch, 8 parts by weight of dextrin, and 8 parts by weight of sodium lignosulfonate are mixed and homogenized in a mixing kneader for 30 minutes to obtain a first mixture; 3 parts by weight of caustic soda are added to the first mixture and stirred evenly, while 6 parts by weight of methanol are added, and an alkalization reaction is carried out in a water bath at 35°C for 40 minutes to obtain a second mixture; 7 parts by weight of chloroacetic acid are added to the second mixture for etherification, the temperature is raised to 85°C during etherification, the reaction is carried out for 65 minutes, and then cooled to room temperature. After sieving, the dispersible sulfonated starch ether is obtained.

[0053] The preparation process of the binder suitable for refractory materials includes the following steps: by weight, 40 parts of dispersible sulfonated starch ether, 25 parts of sodium naphthalene sulfonate formaldehyde condensate, 4 parts of hydroxypropyl methylcellulose (cold-melting type), 9 parts of sodium bentonite, 3 parts of fumed silica, and 2 parts of polyvinyl alcohol are sequentially added to a high-alumina ball mill and dry-milled to 38-58 μm. Then, the ball-milled raw materials are placed in an air-jet mill and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0054] Example 3

[0055] The preparation of dispersible sulfonated starch ether includes the following steps: 32 parts by weight of corn starch, 8 parts by weight of cassava starch, 10 parts by weight of dextrin, and 7 parts by weight of sodium lignosulfonate are mixed and homogenized in a mixing kneader for 30 minutes to obtain a first mixture; 2 parts by weight of caustic soda are added to the first mixture and stirred evenly, while 8 parts by weight of methanol are added, and an alkalization reaction is carried out in a water bath at 35°C for 40 minutes to obtain a second mixture; 7 parts by weight of chloroacetic acid are added to the second mixture for etherification, the temperature is raised to 78°C during etherification, the reaction is carried out for 65 minutes, and then cooled to room temperature. After sieving, the dispersible sulfonated starch ether is obtained.

[0056] The preparation process of the binder suitable for refractory materials includes the following steps: by weight, 34 parts of dispersible sulfonated starch ether, 30 parts of sodium naphthalene sulfonate formaldehyde condensate, 5 parts of hydroxypropyl methylcellulose (cold-melting type), 10 parts of sodium bentonite, 4 parts of fumed silica, and 1 part of polyvinyl alcohol are sequentially added to a high-alumina ball mill and dry-milled to 38-58 μm. Then, the ball-milled raw materials are placed in an air-jet mill and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0057] Comparative Example 2

[0058] In this comparative example, all preparation steps and parameters are the same as in Example 2, except that no dispersible sulfonated starch ether is added.

[0059] Comparative Example 3

[0060] In this comparative example, all preparation steps and parameters are the same as in Example 2, except that the dispersible sulfonated starch ether is replaced with conventional sodium carboxymethyl starch.

[0061] Comparative Example 4

[0062] In this comparative example, all preparation steps and parameters are the same as in Example 2, except that sodium naphthalene sulfonate formaldehyde condensate is replaced with sodium tripolyphosphate.

[0063] Comparative Example 5

[0064] In this comparative example, all preparation steps and parameters are the same as in Example 2, except that only dry ball milling is performed, and no second airflow pulverizer pulverization is performed (no secondary crushing).

[0065] The binders obtained in Examples 2-3 and Comparative Examples 2-5 were used in the above-mentioned refractory materials, and the performance of the refractory materials was tested. The test results are shown in the table below:

[0066]

[0067] As can be seen from the test results of Examples 2-3 in the table above, the binder obtained by this scheme can significantly improve the strength of refractory materials when used in refractory materials, and can ensure that the products do not crack.

[0068] The test results of Comparative Examples 2-3 show that the strength decreased when dispersible sulfonated starch ether was not added or when it was replaced with commercially available sodium carboxymethyl starch. Furthermore, the prepared refractory materials exhibited various defects, affecting their normal use. Comparative Example 2 showed reduced strength and greater breakage during molding, making molding more difficult. The test results of Comparative Example 4 show that replacing sodium naphthalenesulfonate formaldehyde condensate with sodium tripolyphosphate also reduced strength, and the product exhibited long cracks, affecting the service life of the refractory material. The test results of Comparative Example 5 show that without a subsequent second pulverization, the obtained binder particles were too large, resulting in a significant decrease in product strength and numerous cracks. The finished product was prone to disintegration and could not be used as a refractory material in production.

[0069] Example 4

[0070] The preparation steps and parameters in this embodiment are the same as in Example 2, except that the pH value of the sodium naphthalenesulfonate formaldehyde condensate is different, as detailed in the table below:

[0071]

[0072] The main difference between Example 2 and Examples 4-1 to 4-3 is that the chloride ion content is different (the sodium sulfate content and pH value are similar); the main difference between Example 2 and Examples 4-4 to 4-6 is that the sodium sulfate content is different (the chloride ion content and pH value are similar).

[0073] The adhesive obtained in Example 4 was used in a refractory support plate, and the performance of the refractory material was tested. The test results are shown in the table below:

[0074]

[0075] As can be seen from the test results of Example 4 in the table above, the adjustment of pH value and molecular weight of sodium naphthalene sulfonate formaldehyde condensate in this scheme will affect the performance of the binder. The preferred pH value of this scheme is 7.6-7.8, the sodium sulfate content is 18.5-19.5%, and the chloride ion content is controlled as low as possible, limited to below 0.5%. When the binder is used in refractory materials, the strength of the refractory materials is improved and the quality of the finished refractory materials is high.

[0076] In Example 4-4, the "center crack" is caused by the different unit pressure of the press on the center and the four sides of the refractory support plate during the pressing process. The pressure at the center is relatively smaller and the thickness is thinner. Therefore, the strength at the center is lower than that at the four sides, making it relatively easier to crack.

[0077] Example 5

[0078] The preparation steps and parameters in this embodiment are the same as in Example 2, except that the content of hydroxypropyl methylcellulose groups is different, as detailed in the table below:

[0079]

[0080] The adhesive obtained in Example 5 was used in a refractory support plate, and the performance of the refractory material was tested. The test results are shown in the table below:

[0081]

[0082] As can be seen from the test results of Example 5 in the table above, the selection of hydroxypropyl methylcellulose in this scheme will also affect the performance of the binder. The preferred methoxy content in hydroxypropyl methylcellulose is 25-30%, and the hydroxypropoxy content is 10-13%. After the binder is used in refractory materials, the overall performance of the refractory materials is better.

[0083] Example 6

[0084] The preparation steps and parameters in this embodiment are the same as in Example 2, except that the particle size of each raw material is different, as detailed in the table below:

[0085]

[0086] The binder obtained in Example 6 was used in a refractory support plate, and the performance of the refractory material was tested. The test results are shown in the table below:

[0087]

[0088] The test results of Example 6 show that when the particle size range of sodium naphthalene sulfonate formaldehyde condensate and hydroxypropyl methylcellulose is 180-380 μm, the particle size range of sodium bentonite is 80-150 μm, the particle size range of fumed silica is 5-45 nm, and the particle size range of polyvinyl alcohol is 100-150 μm, the obtained binders all have good quality and can effectively improve strength.

[0089] Example 7

[0090] The preparation of dispersible sulfonated starch ether includes the following steps: 30 parts by weight of corn starch, 9 parts by weight of cassava starch, 10 parts by weight of dextrin, and 7 parts by weight of sodium lignosulfonate are mixed and homogenized in a mixing kneader for 30 minutes to obtain a first mixture; 3 parts by weight of caustic soda are added to the first mixture and stirred evenly, while 7 parts by weight of methanol are added, and an alkalization reaction is carried out in a water bath at 35°C for 40 minutes to obtain a second mixture; 7 parts by weight of chloroacetic acid are added to the second mixture for etherification, the temperature is raised to 80°C during etherification, the reaction is carried out for 60 minutes, and then cooled to room temperature. After passing through a 60-mesh sieve, the dispersible sulfonated starch ether is obtained.

[0091] The preparation process of the binder suitable for refractory materials includes the following steps: by weight, 35 parts of dispersible sulfonated starch ether, 27 parts of sodium naphthalene sulfonate formaldehyde condensate, 5 parts of hydroxypropyl methylcellulose, 8 parts of sodium bentonite, 4 parts of fumed silica, and 2 parts of polyvinyl alcohol are sequentially added to a high-alumina ball mill and dry-milled to 38-58 μm. Then, the ball-milled raw materials are placed in an air-jet mill and pulverized to 13-23 μm to obtain the binder suitable for refractory materials.

[0092] The sodium naphthalene sulfonate formaldehyde condensate has a pH of 7.65; by mass percentage, the sodium sulfate content in the sodium naphthalene sulfonate formaldehyde condensate is 18%, and the chloride ion content is 0.25%; the viscosity of hydroxypropyl methylcellulose is 48,000 mPa·s. -1The pH value is 6.2; and the methoxy group content of the hydroxypropyl methylcellulose is 28%, and the hydroxypropoxy group content is 12%; the particle size range of the sodium naphthalene sulfonate formaldehyde condensate is 200-320 μm, the particle size range of the hydroxypropyl methylcellulose is 200-280 μm, the particle size range of the sodium bentonite is 100-130 μm, the particle size range of the fumed silica is 20-35 nm, and the particle size range of the polyvinyl alcohol is 120-130 μm; the bulk density of the fumed silica is 320 g / dm³. 3 The pore volume is 0.65 cm³. 3 / g.

[0093] The binder obtained in Example 7 was used in refractory material A, and the performance of the refractory material was tested. The test results are shown in the table below:

[0094]

[0095] The test results of Example 7 show that by optimizing parameters such as sodium naphthalene sulfonate formaldehyde condensate and hydroxypropyl methylcellulose, and limiting the particle size range of all raw materials, the binder obtained by this scheme has good quality, the refractory material obtained is not easy to crack, and the strength of the refractory material obtained is significantly improved compared with that without the addition of binder.

[0096] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A preparation process for a binder suitable for refractory materials, characterized in that, Dispersible sulfonated starch ether, sodium naphthalene sulfonate formaldehyde condensate, hydroxypropyl methylcellulose, sodium bentonite, fumed silica and polyvinyl alcohol are added to a ball mill and dry ball milled to 38-58 μm. The ball-milled raw material is then placed in a pulverizing device and pulverized to 13-23 μm to obtain the binder suitable for refractory materials. The binder suitable for refractory materials, by weight, is prepared from the following raw materials: 30-40 parts of the dispersible sulfonated starch ether, 20-30 parts of the sodium naphthalene sulfonate formaldehyde condensate, 3-5 parts of the hydroxypropyl methylcellulose, 5-10 parts of the sodium bentonite, 3-5 parts of the fumed silica, and 1-3 parts of the polyvinyl alcohol; the dispersible sulfonated starch ether is prepared from the following raw materials: 25-35 parts of corn starch, 5-10 parts of cassava starch, 5-10 parts of dextrin, 5-8 parts of sodium lignosulfonate, 2-4 parts of caustic soda flakes, 6-8 parts of methanol, and 6-8 parts of chloroacetic acid; the pH value of the sodium naphthalene sulfonate formaldehyde condensate is 7.6-7.8; by mass percentage, the sodium sulfate content in the sodium naphthalene sulfonate formaldehyde condensate is 18.5-19.5%, and the chloride ion content is 0.18-0.5%.

2. The preparation process of a binder suitable for refractory materials according to claim 1, characterized in that, The preparation steps of the dispersible sulfonated starch ether include: According to the formula, the corn starch, the cassava starch, the dextrin, and the sodium lignin sulfonate are placed in the equipment and mixed and homogenized for 25-35 minutes to obtain the first mixture; Add the caustic soda flakes to the first mixture and stir until uniform. While stirring, add the methanol and carry out the alkalization reaction in a water bath. After reacting for 35-45 minutes, the second mixture is obtained. The chloroacetic acid is added to the second mixture for etherification. During etherification, the temperature is raised to 75-80°C, and after reacting for 60-70 minutes, it is cooled to room temperature. After passing through a 60-mesh sieve, the dispersible sulfonated starch ether is obtained.

3. The preparation process of a binder suitable for refractory materials according to claim 2, characterized in that, The water bath temperature is 33-38℃.

4. The preparation process of a binder suitable for refractory materials according to claim 1, characterized in that, The viscosity of the hydroxypropyl methylcellulose is 40,000-60,000 mPa·s. -1 The pH value is 6-7; and the methoxy content in the hydroxypropyl methylcellulose is 25-30%, and the hydroxypropoxy content is 10-13%.

5. The preparation process of a binder suitable for refractory materials according to claim 1, characterized in that, The particle size range of the sodium naphthalenesulfonate formaldehyde condensate and the hydroxypropyl methylcellulose is 180-380 μm, the particle size range of the sodium bentonite is 80-150 μm, the particle size range of the fumed silica is 5-45 nm, and the particle size range of the polyvinyl alcohol is 100-150 μm.

6. The preparation process of the binder suitable for refractory materials according to claim 1, characterized in that, The bulk density of the fumed silica is 200-400 g / dm³. 3 The pore volume is 0.1-1 cm³. 3 / g.

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