Chloride ion corrosion resistant castable for heat storage combustion device and preparation method of chloride ion corrosion resistant castable

Abstract

The invention discloses a chloridion corrosion resistant castable for a heat storage combustion device and a preparation method of the chloridion corrosion resistant castable. The castable comprises the following components in percentage by mass: 40%-60% of Al2O3 aggregate, 20%-30% of Al2O3 powder, 5%-12% of a chloride ion erosion resistant additive, 3%-8% of an aluminate cement binder, 0.5%-2% of a polycarboxylate dispersant and 4.5%-6% of water. The preparation method comprises the following steps: mixing the refractory aggregate and the powder, adding the chloride ion erosion resistant additive, the binding agent, the dispersing agent and the water, uniformly stirring to prepare slurry with the viscosity of 2000cP-5000cP, casting and molding, naturally curing for 24 hours, demolding, drying for 24 hours at 110 DEG C, and firing for 3 hours at 1300-1500 DEG C to obtain a finished product. Experimental results show that the mass loss rate of the castable is as low as 2.0%-2.5%, the compressive strength reaches 85-92 MPa, the breaking strength is 12-15 MPa, the apparent porosity is 16%-19%, the thermal shock resistance is 25-30 times, and the castable is remarkably superior to a traditional castable, is suitable for a chlorine-containing waste gas treatment environment and can effectively prolong the service life of equipment.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials, in particular to a chloride ion corrosion-resistant castable for a heat storage combustion device and a preparation method thereof. Background Art

[0002] Chloride ions are a common corrosive medium, especially in the fields of chlorine-containing waste gas treatment, chlor-alkali industry, seawater desalination, etc. Chloride ions have a significant corrosive effect on refractory materials, resulting in a decrease in material performance and a shortened service life.

[0003] Regenerative Thermal Oxidation (RTO) is a highly effective purification method for chemical waste gas treatment. Halogen-containing waste gases such as dichloromethane and chloroform are incinerated in RTO to produce HCl. Therefore, RTO requires the use of corrosion-resistant refractory materials to protect the equipment from high temperatures and corrosive media.

[0004] Traditional castables are prone to chemical corrosion and physical peeling in chloride ion environments and cannot meet the requirements of long-term stable operation.

[0005] Therefore, developing a castable that can effectively resist chloride ion corrosion is of great significance to improving the service life and operating efficiency of equipment. Summary of the Invention

[0006] Traditional castables are prone to chemical corrosion and physical peeling in chloride ion environments and cannot meet the requirements of long-term stable operation.

[0007] The present application provides a chloride ion corrosion-resistant casting material for a thermal storage combustion device, which comprises, by mass percentage:

[0008] Al2O3 aggregate: 40% to 60%

[0009] Al2O3 powder: 20% to 30%

[0010] Chloride ion corrosion resistance additive: 5% to 12%

[0011] Binder: 3% to 8%

[0012] Dispersants: 0.5% to 2%

[0013] Water: 4.5% to 6%.

[0014] As an optimal technical solution for a chloride ion corrosion-resistant castable for a thermal storage combustion device, the chloride ion corrosion-resistant additive is a composite oxide including yttrium oxide, cerium oxide and zirconium oxide in a mass ratio of (1 to 3):(1 to 2):(2 to 4).

[0015] As an optimal technical solution for a castable resistant to chloride ion corrosion for a thermal storage combustion device, the binder is aluminate cement.

[0016] As an optimal technical solution for a castable resistant to chloride ion corrosion for a thermal storage combustion device, the dispersant is a polycarboxylate dispersant.

[0017] In addition, the present invention provides a method for preparing a castable resistant to chloride ion corrosion, comprising the following steps:

[0018] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0019] Step S3. Add the anti-chloride ion corrosion additive to the matrix mixture, stir evenly, add the binder and dispersant, continue to stir evenly, add an appropriate amount of water, stir until uniform and free of particles, and obtain a casting slurry.

[0020] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1300°C to 1500°C for 3 hours to obtain a castable product resistant to chloride ion corrosion.

[0021] As a method for preparing a castable resistant to chloride ion corrosion, the viscosity of the castable slurry is 2000 cP to 5000 cP.

[0022] The chloride ion corrosion-resistant castable and preparation method provided by the present invention significantly improve the corrosion resistance of the castable in a chloride ion-containing environment by introducing chloride ion corrosion-resistant additives (yttrium oxide, cerium oxide, and zirconium oxide in a mass ratio of 1:1:2 to 3:2:4), reducing the mass loss rate to 2.0%-2.5% (5.8% in comparison example 1), while also improving the mechanical properties, with the compressive strength reaching 85-92 MPa and the flexural strength reaching 12-15 MPa (70 MPa and 8 MPa, respectively, in comparison example 1), the apparent porosity reduced to 16%-19% (22% in comparison example 1), and the thermal shock stability increased to 25-30 times (15 times in comparison example 1), thereby effectively extending the service life of the thermal storage combustion device in harsh environments, reducing maintenance costs, and improving operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is the XRD pattern of Example 1. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0028] Example 1 A castable resistant to chloride ion corrosion for a thermal storage combustion device and a preparation method thereof, wherein the castable resistant to chloride ion corrosion for a thermal storage combustion device comprises, in terms of mass ratio:

[0029] Al2O3 aggregate: 40%

[0030] Al2O3 powder: 30%

[0031] Anti-chloride ion corrosion additives: yttrium oxide (Y2O3) 1%, cerium oxide (CeO2) 1%, zirconium oxide (ZrO2) 3% (mass ratio is 1:1:3)

[0032] Binder: Aluminate cement 3%

[0033] Dispersant: Polycarboxylate dispersant 0.5%

[0034] Water: 5%.

[0035] A method for preparing a castable material resistant to chloride ion corrosion for a thermal storage combustion device comprises the following steps:

[0036] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0037] Step S3. Add the chloride ion corrosion resistance additive to the matrix mixture and stir evenly. Add the binder and dispersant and continue stirring evenly. Add an appropriate amount of water and stir until the mixture is uniform and free of particles to obtain a casting slurry. The viscosity of the casting slurry is 2000 cP.

[0038] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1300°C for 3 hours to obtain a finished castable product resistant to chloride ion corrosion.

[0039] Example 2 A castable resistant to chloride ion corrosion for a thermal storage combustion device and a preparation method thereof, wherein the castable resistant to chloride ion corrosion for a thermal storage combustion device comprises, in terms of mass ratio:

[0040] Al2O3 aggregate: 50%

[0041] Al2O3 powder: 25%

[0042] Anti-chloride ion corrosion additives: yttrium oxide (Y2O3) 2%, cerium oxide (CeO2) 4%, zirconium oxide (ZrO2) 6% (mass ratio is 1:2:3)

[0043] Binder: Aluminate cement 5.5%

[0044] Dispersant: Polycarboxylate dispersant 1.25%

[0045] Water: 6%.

[0046] A method for preparing a castable material resistant to chloride ion corrosion for a thermal storage combustion device comprises the following steps:

[0047] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0048] Step S3. Add the chloride ion corrosion resistance additive to the matrix mixture and stir evenly. Add the binder and dispersant and continue stirring evenly. Add an appropriate amount of water and stir until the mixture is uniform and free of particles to obtain a casting slurry. The viscosity of the casting slurry is 5000 cP.

[0049] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1400°C for 3 hours to obtain a finished castable product resistant to chloride ion corrosion.

[0050] Example 3 A castable resistant to chloride ion corrosion for a thermal storage combustion device and a preparation method thereof, wherein the castable resistant to chloride ion corrosion for a thermal storage combustion device comprises, in terms of mass ratio:

[0051] Al2O3 aggregate: 60%

[0052] Al2O3 powder: 20%

[0053] Anti-chloride ion corrosion additives: yttrium oxide (Y2O3) 2%, cerium oxide (CeO2) 2%, zirconium oxide (ZrO2) 4% (mass ratio is 1:1:2)

[0054] Binder: Aluminate cement 8%

[0055] Dispersant: Polycarboxylate dispersant 2%

[0056] Water: 4.5%.

[0057] A method for preparing a castable material resistant to chloride ion corrosion for a thermal storage combustion device comprises the following steps:

[0058] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0059] Step S3. Add the chloride ion corrosion resistance additive to the matrix mixture and stir evenly. Add the binder and dispersant and continue stirring evenly. Add an appropriate amount of water and stir until the mixture is uniform and free of particles to obtain a casting slurry. The viscosity of the casting slurry is 2500 cP.

[0060] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1400°C for 3 hours to obtain a finished castable product resistant to chloride ion corrosion.

[0061] Example 4 A castable material for a thermal storage combustion device that is resistant to chloride ion corrosion and a preparation method thereof, wherein the castable material for a thermal storage combustion device that is resistant to chloride ion corrosion comprises, in terms of mass ratio:

[0062] Al2O3 aggregate: 48%

[0063] Al2O3 powder: 25%

[0064] Anti-chloride ion corrosion additives: yttrium oxide (Y2O3) 3%, cerium oxide (CeO2) 2%, zirconium oxide (ZrO2) 4% (mass ratio is 3:2:4)

[0065] Binder: Aluminate cement 5%

[0066] Dispersant: Polycarboxylate dispersant 2%

[0067] Water: 5%.

[0068] A method for preparing a castable material resistant to chloride ion corrosion for a thermal storage combustion device comprises the following steps:

[0069] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0070] Step S3. Add the chloride ion corrosion resistance additive to the matrix mixture and stir evenly. Add the binder and dispersant and continue stirring evenly. Add an appropriate amount of water and stir until the mixture is uniform and free of particles to obtain a casting slurry. The viscosity of the casting slurry is 3000 cP.

[0071] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1350°C for 3 hours to obtain a finished castable product resistant to chloride ion corrosion.

[0072] Example 5 A castable resistant to chloride ion corrosion for a thermal storage combustion device and a preparation method thereof, wherein the castable resistant to chloride ion corrosion for a thermal storage combustion device comprises, in terms of mass ratio:

[0073] Al2O3 aggregate: 50%

[0074] Al2O3 powder: 25%

[0075] Anti-chloride ion corrosion additives: yttrium oxide (Y2O3) 2%, cerium oxide (CeO2) 1%, zirconium oxide (ZrO2) 2% (mass ratio is 2:1:2)

[0076] Binder: aluminate cement 8%

[0077] Dispersant: Polycarboxylate dispersant 2%

[0078] Water: 4.5%.

[0079] A method for preparing a castable material resistant to chloride ion corrosion for a thermal storage combustion device comprises the following steps:

[0080] Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture;

[0081] Step S3. Add the chloride ion corrosion resistance additive to the matrix mixture and stir evenly. Add the binder and dispersant and continue stirring evenly. Add an appropriate amount of water and stir until the mixture is uniform and free of particles to obtain a casting slurry. The viscosity of the casting slurry is 4000 cP.

[0082] Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1400°C for 3 hours to obtain a finished castable product resistant to chloride ion corrosion.

[0083] Control Example

[0084] Comparative Example 1

[0085] The difference between the comparative example 1 and the embodiment 1 is that the anti-chloride ion corrosion additive is replaced by an equal amount of Al2O3 powder.

[0086] Performance testing methods

[0087] 1. Mass loss rate (%)

[0088] Standard: GB / T 17671-2021 Test method for chemical corrosion resistance of refractory materials

[0089] Test method: Place the sample in a high-temperature furnace containing a chloride ion atmosphere and perform 100 thermal cycles. After cleaning and drying, measure the mass change.

[0090] 2. Compressive strength (MPa)

[0091] Standard: GB / T 5072-2008 Test method for compressive strength of refractory materials at room temperature

[0092] Test method: Load the specimen at a rate of 0.5 mm / min on a universal testing machine until it breaks, and calculate the compressive strength.

[0093] 3. Flexural strength (MPa)

[0094] Standard: GB / T 3002-2017 Test method for flexural strength of refractory materials at room temperature.

[0095] Test method: Load the specimen in a three-point bending fixture at a rate of 0.2 mm / min until it breaks, and calculate the flexural strength.

[0096] 4. Apparent porosity (%)

[0097] Standard: GB / T 2997-2015 Test method for apparent porosity and bulk density of refractory materials

[0098] Test method: The dry weight, saturated weight and suspended weight of the sample are measured by vacuum immersion method, and the apparent porosity is calculated.

[0099] 5. Thermal shock stability (times)

[0100] Standard: GB / T 30873-2014 Test method for thermal shock stability of refractory materials;

[0101] Test method: After the sample is kept at 1100℃ for 30 minutes, it is quickly immersed in 20℃ water. Repeat the cycle until obvious cracks appear and record the number of cycles.

[0102]

[0103]

[0104] Combined with Example 1, Figure 1 It can be seen that there are multiple phases in the chloride ion corrosion resistant castable prepared in Example 1, including α-Al2O3 (mainly from Al2O3 aggregate and powder), t-ZrO2 (tetragonal zirconium oxide, derived from ZrO2 in the chloride ion corrosion resistant additive), CeO2 (cerium oxide), Y2O3 (yttrium oxide), and a small amount of composite phases such as Y3Al5O 12 (yttrium aluminum garnet), Ca3(AlO3)3 (calcium aluminate, probably formed by the reaction of aluminate cement with Al2O3 during high-temperature firing), Y-Ce-Al-O, and Y-Ce-Zr-O (solid solutions or composite oxides formed by yttrium oxide, cerium oxide, and Al2O3 or ZrO2 at high temperatures). The formation of these phases indicates that the chloride ion corrosion resistance additives (Y2O3, CeO3, ZrO2) undergo a complex chemical reaction with the matrix material during high-temperature firing (1300°C), forming a stable composite oxide structure. This structure helps improve the corrosion resistance and high-temperature stability of the castable, which is consistent with the low mass loss rate (2.5%), high compressive strength (85MPa), and excellent thermal shock resistance (25 times) demonstrated in the performance test of Example 1.

[0105] Combining Examples 1 to 5, Comparative Example 1, and Table 1, it can be seen that the chloride-resistant castables of Examples 1 to 5 significantly outperformed Comparative Example 1 in terms of mass loss rate, compressive strength, flexural strength, apparent porosity, and thermal shock stability. The mass loss rates of Examples 1 to 5 ranged from 2.0% to 2.5%, significantly lower than the 5.8% of Comparative Example 1, indicating that the chloride-resistant additives (yttrium oxide, cerium oxide, and zirconium oxide) effectively improved the corrosion resistance of the material. The compressive strength and flexural strength ranged from 85-92 MPa and 12-15 MPa, respectively, significantly improving from the 70 MPa and 8 MPa of Comparative Example 1, demonstrating higher mechanical properties. In terms of apparent porosity, Examples 1 to 5 ranged from 16% to 19%, lower than the 22% of Comparative Example 1, indicating a denser material that helps resist chloride ion penetration. In terms of thermal shock stability, the number of cycles (25-30) of Examples 1 to 5 far exceeded the 15 of Comparative Example 1, demonstrating superior stability in high-temperature cycling environments. The introduction of chloride ion corrosion resistance additives significantly enhanced the comprehensive performance of the castable. Example 4 (mass loss rate 2.1%, compressive strength 92 MPa, flexural strength 15 MPa, apparent porosity 16%, thermal shock stability 30 times) performed particularly well, showing the best balance between corrosion resistance and mechanical properties.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. 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 castable material for a thermal storage combustion device resistant to chloride ion corrosion, characterized in that: In terms of mass percentage, it includes: Al2O3 aggregate: 40% to 60% Al2O3 powder: 20% to 30% Chloride ion corrosion resistance additive: 5% to 12% Binder: 3% to 8% Dispersants: 0.5% to 2% Water: 4.5% to 6%.

2. The chloride ion corrosion resistant castable for thermal storage combustion device according to claim 1, characterized in that: The anti-chloride ion corrosion additive is a composite oxide, including yttrium oxide, cerium oxide and zirconium oxide, and the mass ratio thereof is (1 to 3): (1 to 2): (2 to 4).

3. The chloride ion corrosion resistant casting material for thermal storage combustion device according to claim 1, characterized in that: The binder is aluminate cement.

4. The chloride ion corrosion resistant castable for thermal storage combustion device according to claim 1, characterized in that: The dispersant is a polycarboxylate dispersant.

5. The method for preparing a chloride ion corrosion resistant castable according to any of claims 1 to 4, characterized in that: The following steps are involved: Step S1. Weigh the components according to the above mass percentages, mix the refractory aggregate and refractory powder evenly to obtain a matrix mixture; Step S3. Add the anti-chloride ion corrosion additive to the matrix mixture, stir evenly, add the binder and dispersant, continue to stir evenly, add an appropriate amount of water, stir until uniform and free of particles, and obtain a casting slurry. Step S4. Pour the castable slurry into a mold, vibrate and shape it, naturally cure it at room temperature for 24 hours, demould it, dry it at 110°C for 24 hours, and then sinter it at 1300°C to 1500°C for 3 hours to obtain a castable product resistant to chloride ion corrosion.

6. The preparation method according to claim 5, characterized in that The viscosity of the castable slurry is 2000 cP to 5000 cP.

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