A special thermal insulation material resistant to high temperature and corrosion and its preparation method

Abstract

The present invention provides a special thermal insulation material that is resistant to high temperatures and corrosion, and a preparation method thereof. The material comprises, by weight, 50 to 80 parts of an organic binder sol, 70 to 120 parts of a powder, and 20 to 30 parts of an additive. The first step is to dissolve a desired amount of an organic binder in an organic solvent to form the organic binder sol. The second step is to stir a desired amount of the powder and the organic binder sol to form a wet material, adding a desired amount of the additive while stirring and stirring uniformly. The third step is to place the uniformly stirred wet material into a mold for compression molding, drying, initial setting, and hardening, followed by demolding. The material is kept below 120°C during the drying process for a period of 3 to 12 hours. The fourth step is to obtain a molded material after demolding, and then sinter the molded material at 300 to 600°C for a period of 3 to 8 hours to form a finished product. The thermal insulation material prepared by the present invention has high temperature resistance and corrosion resistance, and can withstand high temperatures of 950°C to 1500°C, so that the thermal insulation material of the present invention can be used in high temperature melt environments with corrosive and oxidizing atmospheres such as metal smelting.

Description

Technical Field

[0001] The present invention relates to the field of high-temperature resistant and corrosion-resistant thermal insulation materials, and in particular to a high-temperature resistant and corrosion-resistant special thermal insulation material and a preparation method thereof. Background Art

[0002] With the rapid development of my country's electrolytic aluminum industry, the per-unit output of electrolytic cells has grown, leading to a growing demand for alumina as a covering material for carbon anodes. However, since alumina is a bulk material, it easily forms a crust after a period of use. This crust must be crushed before reuse, increasing labor intensity. After a certain period of service (typically 30 to 40 days), the anode (carbon anode) needs to be replaced by removing the butts and replacing them with new ones. The anode is considered the heart of electrolytic aluminum production, directly impacting various production indicators. Anode replacement is a major and labor-intensive task in the production process. It involves removing the anode, breaking the crust, removing the butts, scooping out the blocks, installing a new anode, covering the anode, and cleaning the butts.

[0003] Since the working environment is around 950°C and the electrolyte is exposed to the air, the heat dissipation is extremely large, and the flue gas (including F flue gas) in the electrolytic cell is discharged into the working environment, resulting in a poor working environment for the workers. In addition, the workload of replacing the anode is large, and each anode replacement takes about 30 minutes. Secondly, since the carbon anode is covered with bulk alumina, a large amount of alumina blocks (crusts) and bulk materials fall into the electrolytic cell during the process of removing the residual anodes. They are generally fished out manually or by a multi-functional overhead crane grab. During the fishing process, the aluminum liquid and electrolyte at the bottom of the electrolytic cell are severely stirred, which greatly affects the current efficiency of electrolytic production and brings out the electrolyte. In addition, when covering with new materials (bulk alumina), alumina materials will also be brought into the electrolytic cell, resulting in a large amount of precipitation at the bottom of the electrolytic cell, seriously affecting electrolytic production. Summary of the Invention

[0004] The present invention is based on at least one of the above technical problems and proposes a special thermal insulation material that is resistant to high temperature and corrosion and a preparation method thereof.

[0005] A special thermal insulation material that is resistant to high temperature and corrosion, comprising 50 to 80 parts by mass of an organic binder sol, 70 to 120 parts by mass of a powder, and 20 to 30 parts by mass of an additive.

[0006] Furthermore, the powder is a mixture of silicon oxide, aluminum nitride and alumina, wherein, by weight, the weight of silicon oxide is 10 to 30 parts, the weight of alumina powder is 50 to 80 parts, and the weight of aluminum nitride is 10 to 50 parts.

[0007] Furthermore, the auxiliary agent is a combination of a high-temperature adhesive and a hardener, wherein, by weight, the weight of the high-temperature adhesive is 10 to 20 parts, and the weight of the hardener is 5 to 10 parts.

[0008] A method for preparing a special thermal insulation material that is resistant to high temperatures and corrosion, comprising the following steps:

[0009] The first step is to dissolve a required amount of an organic binder in an organic solvent to prepare the organic binder sol;

[0010] The second step is to mix the required amount of powder and the required amount of organic binder sol to form a wet material, and add the required amount of additives while stirring and stir evenly;

[0011] The third step is to put the mixed wet material into the mold for pressing and forming, drying and initial setting, and demoulding after hardening. The temperature during the drying process is below 120°C for 3-12 hours.

[0012] The fourth step is to obtain the molding material after demoulding, and then sinter the molding material into a finished product at a temperature of 300-600°C, and the sintering time is 3-8 hours.

[0013] Furthermore, in the third step, the drying method is step-by-step constant temperature drying.

[0014] Furthermore, in the fourth step, the sintering method is furnace step constant temperature sintering.

[0015] The invention discloses a method for using a special thermal insulation material that is resistant to high temperature and corrosion, and the special thermal insulation material is applied on a carbon anode to cover the carbon anode and exposed high-temperature cryolite electrolyte melt, thereby forming a thermal insulation and sealing material covering the anode surface in electrolytic aluminum production.

[0016] Beneficial effects: The special thermal insulation material prepared by the present invention has high temperature resistance and corrosion resistance, and can withstand high temperatures of 950°C to 1500°C, so that the special thermal insulation material resistant to high temperature and corrosion of the present invention can be used in high-temperature melt environments with corrosive and oxidizing atmospheres such as metal smelting. DETAILED DESCRIPTION

[0017] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0018] Example 1

[0019] A special thermal insulation material that is resistant to high temperatures and corrosion, comprising, by weight, 50-80 parts of an organic binder sol, 70-120 parts of a powder, and 20-30 parts of an additive. The powder is a mixture of silicon oxide, aluminum nitride, and aluminum oxide, with the silicon oxide accounting for 10-30 parts, the aluminum oxide powder for 50-80 parts, and the aluminum nitride for 10-50 parts. The additive is a combination of a high-temperature binder and a hardener, with the high-temperature binder accounting for 10-20 parts and the hardener for 5-10 parts.

[0020] The organic binder sol is preferably an epoxy resin sol.

[0021] The special thermal insulation material is prepared according to the following method: first, dissolving a required amount of an organic binder in an organic solvent to prepare an organic binder sol; second, stirring a required amount of powder containing silicon oxide, aluminum nitride and aluminum oxide and a required amount of epoxy resin sol to prepare a wet material, adding a required amount of an auxiliary agent while stirring, and stirring the wet material with the auxiliary agent evenly; third, placing the evenly stirred wet material into a mold for pressing and molding, and then drying it at below 120°C (3-12 hours) for initial setting and hardening before demoulding; fourth, obtaining a molding material after demoulding, and then sintering it at a temperature of 300-600°C to form a finished product, and the sintering time is 3-8 hours.

[0022] In this embodiment, the high-temperature and corrosion-resistant special insulation material exhibits high-temperature and corrosion resistance, capable of withstanding temperatures ranging from 950°C to 1500°C. This allows the material to be used in high-temperature melt environments with corrosive and oxidizing atmospheres, such as metal smelting. The additive is a commonly known agent that promotes bonding, curing, and strengthening of the main material.

[0023] Example 2:

[0024] As an optimization of the above embodiment, the powder containing metallic aluminum and aluminum oxide is a combination of metallic aluminum powder and aluminum oxide powder. When the powder containing silicon oxide, aluminum nitride and aluminum oxide is combined, the weight proportion of silicon oxide powder is 10 to 20 parts, the weight proportion of aluminum oxide powder is 50 to 80 parts, and the weight proportion of aluminum nitride powder is 10 to 50 parts.

[0025] Example 3:

[0026] As an optimization of the above embodiment, the auxiliary agent is a combination of a binder and a hardener. When the auxiliary agent is a combination of a binder and a hardener, the weight percentage of the binder is 5 to 20 parts, and the weight percentage of the hardener is 5 to 10 parts. The binder is a conventionally known and commonly used binder.

[0027] In this embodiment, the hardener may be replaced by a coagulant, which is a known and commonly used coagulant that promotes the coagulation of wet materials and slurry.

[0028] Example 4:

[0029] In the first step, a required amount of organic binder is dissolved in an organic solvent to prepare an organic binder sol;

[0030] The second step is to mix the required amount of powder containing silicon oxide, aluminum nitride and aluminum oxide and the required amount of epoxy resin sol to form a wet material, and add the required amount of additives while stirring, and stir the wet material with the additives evenly;

[0031] The third step is to put the evenly mixed wet material into the mold for pressing and then drying it at below 120℃ (3-12 hours) for initial setting and hardening before demoulding. The drying method is step-by-step constant temperature drying.

[0032] The fourth step is to obtain the molding material after demoulding, and then sinter it into the finished product at a temperature of 300-600℃. The sintering time is 3-8 hours, and the sintering method is the furnace step constant temperature sintering.

[0033] Embodiment 5:

[0034] This special thermal insulation material, which is resistant to high temperatures and corrosion, comprises, by weight, 80 parts of a uniform mixture of an organic binder (using epoxy resin as an example) and an ethylene glycol diluent, 20 parts by weight of silicon oxide powder, 80 parts by weight of aluminum oxide powder, 20 parts by weight of aluminum nitride powder, 10 parts by weight of aluminum dihydrogen phosphate powder additive, 5 parts by weight of a hardener, and 5 parts by weight of a coagulant. The special thermal insulation material is prepared by the following method: first, dissolving the required amount of organic binder in an organic solvent to form an organic binder sol; second, mixing the required amounts of powders containing silicon oxide, aluminum nitride, and aluminum oxide with the required amount of epoxy resin sol to form a wet material, adding the required amount of additives while stirring, and stirring the wet material to form a uniform mixture; third, placing the uniformly mixed wet material into a mold for compression molding, then drying at below 120°C for 12 hours for initial setting and hardening before demolding; and fourth, demolding the resulting molded material, which is then sintered at 600°C for 8 hours to form a finished product. The carbon anode insulation cover plate described in this embodiment can withstand high temperatures of 1000°C to 1100°C.

[0035] Example 6:

[0036] The special thermal insulation material resistant to high temperature and corrosion comprises, by weight, 80 parts of a uniform mixture of an organic binder (taking epoxy resin as an example) and an ethylene glycol diluent, 120 parts of aluminum ash produced by electrolytic aluminum or aluminum processing and casting, 10 parts of aluminum dihydrogen phosphate powder additive, 5 parts of a hardener, and 5 parts of a coagulant. The special thermal insulation material is obtained by the following method: a first step of dissolving a required amount of an organic binder in an organic solvent to prepare an organic binder sol; a second step of stirring a required amount of a powder mainly containing silicon oxide, aluminum nitride, and aluminum oxide with a required amount of an epoxy resin sol to prepare a wet material, adding a required amount of an additive while stirring, and stirring the wet material with the additive evenly; a third step of placing the evenly stirred wet material into a mold for compression molding, and then drying it at below 120°C for 12 hours for initial setting and hardening before demolding; a fourth step of obtaining a molding material after demolding, and then sintering it at 600°C for 8 hours to form a finished product. The carbon anode insulation cover plate described in this embodiment can withstand high temperatures of 1300°C to 1500°C.

[0037] Embodiment seven:

[0038] The special thermal insulation material resistant to high temperature and corrosion comprises, by weight, 80 parts of a uniform mixture of an organic binder (taking epoxy resin as an example) and an ethylene glycol diluent, 100 parts by weight of aluminum ash produced by electrolytic aluminum or aluminum processing, 20 parts by weight of floating beads, 10 parts of aluminum dihydrogen phosphate powder additive, 5 parts of a hardener, and 5 parts of a coagulant. The special thermal insulation material is obtained by the following method: a first step of dissolving a required amount of an organic binder in an organic solvent to prepare an organic binder sol; a second step of stirring a required amount of a powder mainly containing silicon oxide, aluminum nitride, and aluminum oxide with a required amount of an epoxy resin sol to prepare a wet material, adding a required amount of an additive while stirring, and stirring the wet material with the additive evenly; a third step of placing the evenly stirred wet material into a mold for compression molding, and then drying it at below 120°C for 12 hours for initial setting and hardening before demolding it; a fourth step of obtaining a molding material after demolding, and then sintering it at 600°C for 8 hours to form a finished product. The carbon anode insulation cover plate described in this embodiment can withstand high temperatures of 1300°C.

[0039] Embodiment 8:

[0040] The special thermal insulation material resistant to high temperature and corrosion comprises, by weight, 80 parts of a uniform mixture of an organic binder (taking epoxy resin as an example) and an ethylene glycol diluent, 100 parts by weight of aluminum ash produced by electrolytic aluminum or aluminum processing, 20 parts by weight of fly ash from a power plant, 10 parts by weight of an aluminum dihydrogen phosphate powder additive, 5 parts of a hardener, and 5 parts of a coagulant. The special thermal insulation material is obtained by the following method: a first step of dissolving a required amount of the organic binder in an organic solvent to prepare an organic binder sol; a second step of stirring a required amount of a powder mainly containing silicon oxide, aluminum nitride, and aluminum oxide with a required amount of an epoxy resin sol to prepare a wet material, adding a required amount of an additive while stirring, and stirring the wet material with the additive evenly; a third step of placing the evenly stirred wet material into a mold for compression molding, and then drying it at below 120°C for 12 hours for initial setting and hardening before demoulding; and a fourth step of obtaining a molding material after demoulding, and then sintering it at 600°C for 8 hours to form a finished product. The carbon anode insulation cover plate described in this embodiment can withstand high temperatures of 1400°C.

[0041] Embodiment 9:

[0042] The method of using the high-temperature and corrosion-resistant special thermal insulation material described in the above embodiment is carried out as follows: the special thermal insulation material resistant to high temperature and corrosion replaces the existing alumina covering material, is laid on the carbon anode and covers the carbon anode and the exposed high-temperature cryolite electrolyte melt, forming one of the anode surface covering insulation and sealing materials for electrolytic aluminum production.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A special thermal insulation material that is resistant to high temperature and corrosion, characterized in that: The composition is as follows: 50 to 80 parts by weight of organic binder sol, 70 to 120 parts by weight of powder, and 20 to 30 parts by weight of additive; the powder is a mixture of silicon oxide, aluminum nitride, and aluminum oxide, wherein, as follows: the weight of silicon oxide is 10 to 30 parts, the weight of aluminum oxide powder is 50 to 80 parts, and the weight of aluminum nitride is 10 to 50 parts; The preparation steps of the high temperature and corrosion resistant special thermal insulation material include: The first step is to dissolve a required amount of an organic binder in an organic solvent to prepare the organic binder sol; The second step is to mix the required amount of powder and the required amount of organic binder sol to form a wet material, and add the required amount of additives while stirring and stir evenly; The third step is to put the mixed wet material into the mold for pressing and forming, drying and initial setting, and demoulding after hardening. The temperature during the drying process is below 120°C for 3-12 hours. The fourth step is to obtain the molding material after demoulding, and then sinter the molding material into a finished product at a temperature of 300-600°C, and the sintering time is 3-8 hours.

2. The high temperature and corrosion resistant special thermal insulation material according to claim 1, characterized in that: The auxiliary agent is a combination of a high-temperature adhesive and a hardener, wherein, by weight, the high-temperature adhesive accounts for 10 to 20 parts, and the hardener accounts for 5 to 10 parts.

3. The method for preparing a high-temperature and corrosion-resistant special thermal insulation material according to claim 1 or 2, comprising the steps of: The first step is to dissolve a required amount of an organic binder in an organic solvent to prepare the organic binder sol; The second step is to mix the required amount of powder and the required amount of organic binder sol to form a wet material, and add the required amount of additives while stirring and stir evenly; The third step is to put the mixed wet material into the mold for pressing and forming, drying and initial setting, and demoulding after hardening. The temperature during the drying process is below 120°C for 3-12 hours. The fourth step is to obtain the molding material after demoulding, and then sinter the molding material into a finished product at a temperature of 300-600°C, and the sintering time is 3-8 hours.

4. The method for preparing the high temperature and corrosion resistant special thermal insulation material according to claim 3, characterized in that: In the third step, the drying method is step-by-step constant temperature drying.

5. The method for preparing the high temperature and corrosion resistant special thermal insulation material according to claim 3, characterized in that: In the fourth step, the sintering method is furnace step constant temperature sintering.

6. The method for using the high temperature and corrosion resistant special thermal insulation material according to any one of claims 1 to 2, characterized in that: The special thermal insulation material is laid on the carbon anode and covers the carbon anode and the exposed high-temperature cryolite electrolyte melt to form the thermal insulation and sealing material covering the anode surface in the electrolytic aluminum production.