Red mud modified anticorrosive paint as well as preparation method and application thereof

Abstract

The invention provides a red mud modified anti-corrosion coating as well as a preparation method and application thereof, and belongs to the technical field of anti-corrosion materials. The red mud modified anticorrosive paint comprises red mud, water-borne epoxy resin, a curing agent and water, the mass ratio of the red mud to the water-borne epoxy resin is 1: (3-10), and the mass ratio of the curing agent to the water-borne epoxy resin is 1: (3-8). According to the invention, the red mud has fine particles and contains various tiny mineral particles, and the hard particles are uniformly dispersed in the epoxy coating, so that the compactness of the epoxy coating can be improved, the permeation path of a corrosive medium can be prolonged, and the physical shielding capability of the epoxy coating can be improved; rigid particles are introduced into the red mud, so that the hardness, rigidity and wear resistance of the epoxy coating can be improved; the alkalinity of the red mud is beneficial for maintaining or repairing a passivation film on the metal surface (the metal can form a stable oxide protection layer in an alkaline environment); part of the aluminum element in the red mud can participate in the corrosion reaction to form an oxide on the metal surface so as to play a role in protecting the metal.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion materials technology, and in particular to a red mud-modified anti-corrosion coating, its preparation method, and its application. Background Technology

[0002] Corrosion prevention is a key concept involving multiple industrial sectors and daily life. It primarily refers to preventing or slowing down the corrosion of materials (such as metals, wood, and concrete) caused by environmental factors (such as humidity, oxygen, and chemicals) through physical, chemical, or electrochemical methods. It mainly includes the following aspects: 1) Corrosion protection of industrial equipment and infrastructure In equipment such as storage tanks, pipelines, and electrolytic cells used in chemical and energy industries, coatings must withstand long-term corrosion from strong acids, strong alkalis, and chemical solvents. Especially in alternating acid-alkali environments, ordinary anti-corrosion coatings are prone to peeling and failure.

[0003] 2) Marine Engineering and Steel Structure Protection Cross-sea bridges, offshore platforms, port machinery, and other facilities face harsh corrosive environments characterized by high salt spray and high humidity. Traditional solvent-based coatings are prone to creating weak points in protection at weld seams and corners, while water-based epoxy systems offer better penetration and coverage.

[0004] 3) Environmentally friendly building corrosion protection Low-VOC coatings are required for urban elevated roads, tunnels, and steel structure buildings. However, existing water-based epoxy coatings have shortcomings in terms of weather resistance and scratch resistance.

[0005] Existing methods for recycling red mud mainly involve using it as an inert admixture in building materials. While this method achieves a certain degree of resource utilization of red mud, its added value is relatively low, and the beneficial components with anti-corrosion properties contained in red mud are not fully developed and utilized. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a red mud-modified anti-corrosion coating, its preparation method, and its application. The red mud-modified anti-corrosion coating provided by this invention has a long-lasting anti-corrosion effect.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a red mud modified anti-corrosion coating, comprising red mud, waterborne epoxy resin, curing agent and water, wherein the mass ratio of red mud to waterborne epoxy resin is 1:3~10, and the mass ratio of curing agent to waterborne epoxy resin is 1:3~8.

[0008] Preferably, the viscosity of the red mud modified anticorrosive coating at 25°C is 50~120 Pa·s.

[0009] Preferably, the mass ratio of water to waterborne epoxy resin is 1:1 to 5.

[0010] Preferably, the mass ratio of the red mud to the water-based epoxy resin is 1:5.

[0011] Preferably, the red mud particle size is less than 100 μm.

[0012] Preferably, the waterborne epoxy resin is added in the form of a waterborne epoxy resin emulsion.

[0013] Preferably, the curing agent includes an amine curing agent.

[0014] This invention also provides a method for preparing the red mud modified anti-corrosion coating described in the above technical solution, comprising the following steps: Red mud, water-based epoxy resin, curing agent and water are mixed to obtain the red mud modified anti-corrosion coating.

[0015] Preferably, the mixing is stirring, and the stirring speed is 600~1500 rpm for 10~20 min.

[0016] The present invention also provides the application of the red mud modified anti-corrosion coating described above in the field of metal corrosion protection, wherein the red mud modified anti-corrosion coating is applied to the surface of the metal and then cured.

[0017] This invention provides a red mud modified anti-corrosion coating, comprising red mud, waterborne epoxy resin, curing agent and water, wherein the mass ratio of red mud to waterborne epoxy resin is 1:3~10, and the mass ratio of curing agent to waterborne epoxy resin is 1:3~8.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, the red mud itself has fine particles and contains various micro-mineral particles (such as iron oxide, silicon dioxide, and aluminum oxide). These hard particles are uniformly dispersed in the epoxy coating, which can increase the density of the epoxy coating, extend the penetration path of corrosive media (water, oxygen, and chloride ions), and thus enhance its physical barrier ability. The introduction of rigid red mud particles can improve the hardness, rigidity, and wear resistance of the epoxy coating. The alkalinity of red mud helps to maintain or repair the passivation film on the metal surface (metals form a stable oxide protective layer in an alkaline environment). Some aluminum elements in red mud can participate in the corrosion reaction, forming oxides on the metal surface and playing a protective role for the metal. This invention utilizes the alkalinity of red mud and the filling effect of solid particles to improve the anti-corrosion performance of water-based epoxy coatings. By controlling the ratio, the anti-corrosion performance of the epoxy coating is significantly improved. Attached Figure Description

[0019] Figure 1 The flowchart below illustrates the preparation and spraying of the red mud-modified anti-corrosion coating according to this invention. Figure 2 The image shows the coating and corrosion-resistant plating formed by the red mud-modified anti-corrosion coating in Example 1. Figure 3 The image shows the coating and corrosion plate formed by the paint in Comparative Example 1. Figure 4 Physical images of the coatings formed in the initial state of Example 1 and Comparative Example 1; Figure 5 The image shows the physical images of the coatings of Example 1 and Comparative Example 1 on day 7. Figure 6 The image shows the actual coatings of Example 1 and Comparative Example 1 on day 15. Figure 7 The image shows the coatings of Example 1 and Comparative Example 1 on day 30. Detailed Implementation

[0020] This invention provides a red mud modified anti-corrosion coating, comprising red mud, waterborne epoxy resin, curing agent and water, wherein the mass ratio of red mud to waterborne epoxy resin is 1:3~10, and the mass ratio of curing agent to waterborne epoxy resin is 1:3~8.

[0021] In this invention, the viscosity of the red mud modified anticorrosive coating at 25°C is preferably 50~120 Pa·s, specifically 50, 60, 70, 80, 90, 100, 110 or 120 Pa·s. If the viscosity is too low, it is not conducive to coating.

[0022] In this invention, the mass ratio of water to waterborne epoxy resin is preferably 1:1 to 5, specifically 1:1, 1:2, 1:3, 1:4 or 1:5. In this invention, the viscosity of the red mud modified anticorrosive coating is preferably adjusted by controlling the amount of water used.

[0023] In this invention, the mass ratio of the red mud to the waterborne epoxy resin can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0024] In this invention, the red mud particle size is preferably less than 100 μm.

[0025] In this invention, the waterborne epoxy resin is preferably added in the form of a waterborne epoxy resin emulsion.

[0026] In this invention, the mass ratio of the curing agent to the waterborne epoxy resin can be specifically 1:3, 1:4, 1:5, 1:6, 1:7 or 1:8.

[0027] In this invention, the curing agent preferably includes an amine curing agent.

[0028] This invention also provides a method for preparing the red mud modified anti-corrosion coating described in the above technical solution, comprising the following steps: Red mud, water-based epoxy resin, curing agent and water are mixed to obtain the red mud modified anti-corrosion coating.

[0029] In this invention, the red mud is preferably dried and ground sequentially before being mixed.

[0030] In this invention, the mixing is stirring, and the stirring speed is preferably 600~1500 rpm, and the stirring time is preferably 10~20 min.

[0031] The present invention preferably involves mixing the red mud and water-based epoxy resin evenly, then adding the curing agent, and finally adding water to adjust the viscosity of the resulting mixture to 50~120 Pa·s (25℃), and stirring with a high-speed disperser to obtain the red mud modified anti-corrosion coating.

[0032] Figure 1 This is a flowchart illustrating the preparation and spraying of the red mud-modified anti-corrosion coating according to the present invention. Figure 1 Waterborne epoxy refers to waterborne epoxy resin.

[0033] The present invention also provides the application of the red mud modified anti-corrosion coating described above in the field of metal corrosion protection, wherein the red mud modified anti-corrosion coating is applied to the surface of the metal and then cured.

[0034] In this invention, the metal is preferably steel.

[0035] In this invention, the coating is preferably applied by spraying.

[0036] The present invention does not have any special limitations on the curing process, and any method known to those skilled in the art can be used.

[0037] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] The salt spray test was conducted in accordance with GB / T 10125-2021 Artificial Atmosphere Corrosion Test - Salt Spray Test.

[0039] Example 1 First, collect red mud from the alumina plant. Then, mix the dried and ground red mud (particle size less than 100 μm) with waterborne epoxy resin (PZ3961-1 waterborne epoxy resin emulsion Huntsman ARALDITE) at a mass ratio of 1:5 and stir until homogeneous. Next, add a curing agent (water-soluble amine curing agent Aradur). ® 3984 (the mass ratio of curing agent and waterborne epoxy resin is 1:3), then deionized water is added, the viscosity of the mixture is adjusted to 100 Pa·s (25℃), and stirred for 10 min using a high-speed disperser to obtain red mud modified anti-corrosion coating.

[0040] The red mud-modified anti-corrosion coating was uniformly sprayed onto the surface of the steel sheet with a thickness of 100 μm and cured at 60℃ for 12 h.

[0041] Figure 2 The image shows the coating and corrosion-resistant pads formed by the red mud modified anti-corrosion coating in Example 1.

[0042] Comparative Example 1 Same as in Example 1, except that no red mud was added to obtain the coating.

[0043] Figure 3 The image shows the coating and corrosion plate formed by the paint in Comparative Example 1.

[0044] Salt spray tests were conducted on the coatings formed in Example 1 and Comparative Example 1. Figure 4 These are physical images of the coatings formed in the initial state of Example 1 and Comparative Example 1. Figure 5 These are physical images of the coatings from Example 1 and Comparative Example 1 on day 7. Figure 6 These are physical images of the coatings from Example 1 and Comparative Example 1 on day 15. Figure 7 The images show the actual coatings of Example 1 and Comparative Example 1 on day 30. As can be seen, the performance of the red mud modified anti-corrosion coating of the present invention is significantly better than that of the ordinary water-based epoxy anti-corrosion coating. The modified coating did not produce obvious rust swelling after 15 days of salt spray testing, and only produced rust swelling after 30 days of salt spray testing. In contrast, the ordinary water-based epoxy anti-corrosion coating produced obvious rust swelling after 7 days, indicating that the red mud modified anti-corrosion coating has obvious anti-corrosion advantages.

[0045] Table 1 shows the raw material ratios and corrosion performance data of the coatings formed in different embodiments and comparative examples. The types of waterborne epoxy resin and curing agent are the same as in Example 1. It can be seen that at a suitable viscosity (80~120 Pa·s), the anti-corrosion performance of the red mud modified coating prepared by adding an appropriate amount of red mud (the mass ratio of red mud to waterborne epoxy resin is 1:3~10) is significantly better than that of the unmodified anti-corrosion coating.

[0046] Table 1. Raw material ratios and corrosion properties of coatings in different embodiments and comparative examples.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A red mud modified anticorrosive coating, characterized by, The red mud, the water-based epoxy resin, the curing agent and water are mixed to obtain the red mud modified anticorrosive paint.

2. The bauxite residue-modified anticorrosive paint according to claim 1, characterized by, The red mud modified anticorrosive paint has a viscosity of 50-120 Pa·s at 25 DEG C.

3. The red mud modified anticorrosive paint according to claim 1 or 2, characterized by, The mass ratio of the water to the water-based epoxy resin is 1:1-5.

4. The bauxite residue modified anticorrosive paint according to claim 1, characterized in that, The mass ratio of the red mud to the water-based epoxy resin is 1:

5.

5. The bauxite residue modified anticorrosive paint according to claim 1, characterized in that, The particle size of the red mud is less than 100 microns.

6. The bauxite residue modified anticorrosive paint according to claim 1, characterized in that, The water-based epoxy resin is added in the form of a water-based epoxy resin emulsion.

7. The bauxite residue modified anticorrosive paint according to claim 1, characterized in that, The curing agent comprises an amine curing agent.

8. The method for preparing the bauxite residue-modified anticorrosive coating according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: The red mud, the water-based epoxy resin, the curing agent and water are mixed to obtain the red mud modified anticorrosive paint.

9. The production method according to claim 8, characterized by, The mixing is stirring, the stirring speed is 600-1500 rpm, and the stirring time is 10-20 min.

10. Use of the red mud modified anticorrosive paint according to any one of claims 1 to 7 in the field of metal anticorrosion, characterized by the fact that, The red mud modified anticorrosive paint is applied to the surface of a metal and then cured.

Images