Coating capable of effectively preventing steam explosion of molten aluminum and preparation method of coating

Abstract

The invention relates to a coating capable of effectively preventing steam explosion of molten aluminum and a preparation method thereof, and the coating capable of effectively preventing steam explosion of molten aluminum is prepared from the following raw materials by weight: 10%-30% of moisture-cured epoxy resin, 5%-20% of super absorbent resin, 2%-10% of calcium salt, 5%-10% of hexagonal boron nitride, 0.5%-2% of a WD-40 lubricant, 0.2%-1% of a dispersant, a defoaming agent and white oil, and performing ball milling. The inorganic calcium salt and the hexagonal boron nitride are used as fillers to be filled in the coating and form an organic-inorganic composite coating with the matrix resin, so that the coating has the advantages of good toughness of an organic material and extremely high hardness, strength, impact resistance, wear resistance, heat resistance and the like of an inorganic material. The coating provided by the invention adopts a white oil system, does not volatilize harmful substances in the use process, is clean and environment-friendly, and has good adhesiveness, excellent construction performance and good molten aluminum steam explosion prevention effect.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and particularly relates to a coating capable of effectively preventing molten aluminum from steam explosion and a preparation method thereof. Background Art

[0002] Aluminum alloy deep-well casting is a high-risk process in the aluminum processing industry. In recent years, explosions caused by the contact between high-temperature molten aluminum and water have frequently occurred, resulting in serious casualties and property damage. This is because when hot molten aluminum comes into contact with water, it instantly vaporizes, producing large amounts of water vapor. Simultaneously, the aluminum and water react to form hydrogen. The flammability of hydrogen can trigger explosions when exposed to ignition sources (such as static electricity or high temperatures) in confined or semi-confined spaces. Studies have found that certain surfaces, such as rusted steel, plaster, and lime, can promote explosions. Other surfaces, such as polished steel and aluminum, and those covered with organic coatings, are inert to explosions, thereby suppressing them.

[0003] Therefore, in deep-well casting, applying an effective coating can effectively prevent steam explosions. However, a single organic coating is not heat-resistant and lacks strength, so an organic-inorganic composite coating is a more ideal coating material. Furthermore, since moisture is almost the only source of steam, trapping it within the coating is a good way to prevent steam generation. Water-absorbing resins and calcium salts are ideal materials for this purpose. However, single water-absorbing resins and calcium salts have high surface activity and limited high-temperature resistance, making them insufficient for coatings that prevent steam explosions in molten aluminum.

[0004] The earliest research work originated from the Alcoa Laboratory of the American Aluminum Alliance. Long et al. concluded that the greater the mass of the aluminum liquid and the higher the temperature, the greater the possibility and intensity of the explosion (Metal Progress, 1957, 71, 107-112). Subsequently, Hess et al. divided the explosion of high-temperature molten aluminum liquid into soft explosion, violent explosion and violent explosion according to the power of the explosion of high-temperature molten aluminum liquid in contact with water (Metal Progress, 969, 95, 93-100). Liu et al. proposed a new thermal fragmentation model when studying the relationship between steam explosion structure and fragmentation mechanism (Nuclear Engineering & Design, 2002, 216, 121-137). Zhou et al. found that film boiling occurs at the moment of contact between high-temperature molten aluminum liquid and water. The impact generated by the violent vaporization of water produces disturbances in the water and expands rapidly. After 40ms, film boiling transitions to nucleate boiling until explosion splashing occurs (Experimental Mechanics, 2021, 36, 114-121). However, most research has focused on the causes and mechanisms of explosions, with little coverage of effective methods for preventing vapor explosions in molten metals, particularly molten aluminum. Perhaps due to technical confidentiality, patents for coatings that prevent vapor explosions in molten aluminum have not been published.

[0005] Hexagonal boron nitride's layered structure enables it to maintain excellent lubricity even at high temperatures, similar to graphite but with enhanced oxidation resistance. It is chemically stable, non-reactive with molten aluminum, and forms a barrier to prevent adhesion, isolating it from oxygen and corrosive media. Therefore, combining a superabsorbent resin, calcium salt, and hexagonal boron nitride is expected to yield a coating that effectively protects against molten aluminum vapor explosions. Summary of the Invention

[0006] In response to the current state of steam explosion prevention in molten aluminum and the existing problems in the prior art, the present invention provides a coating that effectively prevents steam explosions in molten aluminum. The coating utilizes a white oil system, which emits no harmful substances during use, making it clean and environmentally friendly. Furthermore, the addition of a highly absorbent resin and calcium salt imparts exceptional water absorption, trapping moisture within the coating as much as possible. Furthermore, the addition of hexagonal boron nitride not only improves the coating's heat resistance but also provides improved insulation against molten aluminum, further reducing the likelihood of steam explosions in molten aluminum.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A coating for effectively preventing molten aluminum from steam explosion comprises the following components in the following weight ratios: 10%-30% of moisture-curing epoxy resin, 5%-20% of highly absorbent resin, 2%-10% of calcium salt, 5%-10% of hexagonal boron nitride, 0.5%-2% of WD-40 lubricant, 0.2%-1% of dispersant, and the balance of white oil.

[0009] Furthermore, the coating that effectively prevents molten aluminum from steam explosion includes the following components in the following weight ratios: 10% moisture-curing epoxy resin, 20% super absorbent resin, 2% calcium salt, 5% hexagonal boron nitride, 0.5% WD-40 lubricant, 0.2% dispersant, and the balance white oil.

[0010] Furthermore, the coating that effectively prevents molten aluminum from steam explosion also includes a defoaming agent.

[0011] Furthermore, the moisture-curing epoxy resin is any one of a silane-modified epoxy resin, a polyurethane-modified epoxy resin, a ketimine latent-curing epoxy resin or an aldimine latent-curing epoxy resin.

[0012] Furthermore, the super absorbent resin is sodium acrylate resin, methyl ethyl acrylate resin or styrene-butadiene-styrene resin.

[0013] Furthermore, the calcium salt is calcium chloride, calcium sulfate or calcium phosphate compound.

[0014] The present invention also provides a method for preparing the coating that effectively prevents molten aluminum from steam explosion, comprising the following steps: adding raw materials, moisture-curing epoxy resin, highly absorbent resin, WD-40 lubricant, dispersant, calcium salt, hexagonal boron nitride, and white oil, according to weight ratio, into a ball mill and ball-milling.

[0015] Furthermore, the method for preparing the coating for effectively preventing molten aluminum from steam explosion according to the present invention comprises the following steps: adding raw materials, moisture-curing epoxy resin, super absorbent resin, WD-40 lubricant, dispersant, defoamer, calcium salt, hexagonal boron nitride and white oil, into a ball mill according to weight ratio, and ball milling.

[0016] Furthermore, the amount of defoaming agent is added so that there is no foaming when the sensory organ is sensed.

[0017] Furthermore, the ball-to-material ratio of the ball milling is 10:(0.2-1), and the ball milling time is 4-8 hours.

[0018] Beneficial effects of the present invention:

[0019] 1. Environmental performance: The coating of the present invention adopts a white oil system, and no harmful substances are volatilized during use, which meets environmental protection requirements and has no adverse effects on the environment and the health of operators.

[0020] 2. Super strong water absorption capacity: The addition of super absorbent resin and calcium salt gives the coating super strong water absorption capacity, which can seal the water inside the coating as much as possible, thereby reducing the chance of water contact with molten aluminum and effectively reducing the risk of steam explosion.

[0021] 3. High temperature resistance: The addition of hexagonal boron nitride not only improves the temperature resistance of the coating, enabling it to remain stable in high temperature environments, but also enhances the aluminum liquid insulation performance of the coating, further reducing the possibility of steam explosion of molten aluminum. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to specific examples. It should be understood that the following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention, and that those skilled in the art may make non-essential improvements and adjustments based on the contents of the above invention.

[0023] Example 1

[0024] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratio: 10% silane-modified epoxy resin, 20% sodium acrylate resin, 2% calcium chloride, 5% hexagonal boron nitride, 0.5% WD-40 lubricant, 0.2% dispersant, defoaming agent (add as needed, stop adding when no bubbles are observed), and the balance is white oil.

[0025] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 8 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0026] Example 2

[0027] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratio: 30% polyurethane-modified epoxy resin, 5% ethyl methyl acrylate resin, 2% calcium sulfate, 6% hexagonal boron nitride, 0.8% WD-40 lubricant, 0.3% dispersant, defoaming agent (add as needed, stop adding when no bubbles are observed), and the balance is white oil.

[0028] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 6 hours at a ball-to-material ratio of 10:0.5 to produce a coating that prevents molten aluminum from steam explosion.

[0029] Example 3

[0030] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratios: 15% ketimine latent-curing epoxy resin, 10% styrene-butadiene-styrene resin, 10% calcium phosphate, 7% hexagonal boron nitride, 1% WD-40 lubricant, 0.5% dispersant, and a defoaming agent (add as needed, stopping when no bubbles are observed), with the remainder being white oil.

[0031] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 4 hours at a ball-to-material ratio of 10:0.2 to produce a coating that can prevent molten aluminum from steam explosion.

[0032] Example 4

[0033] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratio: 20% silane-modified epoxy resin, 10% sodium acrylate resin, 5% calcium chloride, 7% hexagonal boron nitride, 1.2% WD-40 lubricant, 0.6% dispersant, defoaming agent (add as needed, stop adding when no bubbles are observed), and the balance is white oil.

[0034] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 4 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0035] Example 5

[0036] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratios: 15% polyurethane-modified epoxy resin, 5% ethyl methyl acrylate resin, 5% calcium sulfate, 8% hexagonal boron nitride, 1.6% WD-40 lubricant, 0.8% dispersant, and defoaming agent (add as needed, stop adding when no bubbles are observed), with the remainder being white oil.

[0037] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 6 hours at a ball-to-material ratio of 10:0.2 to produce a coating that prevents molten aluminum from steam explosion.

[0038] Example 6

[0039] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratios: 10% ketimine latent-curing epoxy resin, 10% styrene-butadiene-styrene resin, 10% calcium phosphate, 9% hexagonal boron nitride, 1.8% WD-40 lubricant, 0.7% dispersant, and defoaming agent (add as needed, stopping when no bubbles are observed), with the remainder being white oil.

[0040] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 8 hours at a ball-to-material ratio of 10:0.5 to produce a coating that can prevent molten aluminum from steam explosion.

[0041] Example 7

[0042] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratio: 30% silane-modified epoxy resin, 5% sodium acrylate resin, 10% calcium chloride, 8% hexagonal boron nitride, 1.9% WD-40 lubricant, 0.9% dispersant, defoaming agent (add as needed, stop adding when no bubbles are observed), and the balance is white oil.

[0043] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 6 hours at a ball-to-material ratio of 10:0.2 to produce a coating that prevents molten aluminum from steam explosion.

[0044] Example 8

[0045] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratio: 15% polyurethane-modified epoxy resin, 10% ethyl methyl acrylate resin, 10% calcium sulfate, 9% hexagonal boron nitride, 2% WD-40 lubricant, 0.9% dispersant, defoaming agent (add as needed, stop adding when no bubbles are observed), and the balance is white oil.

[0046] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 5 hours at a ball-to-material ratio of 10:0.5 to produce a coating that can prevent molten aluminum from steam explosion.

[0047] Example 9

[0048] The coating of this embodiment, which effectively prevents molten aluminum from steam explosion, is made of the following raw materials in the following weight ratios: 15% ketimine latent-curing epoxy resin, 10% styrene-butadiene-styrene resin, 10% calcium phosphate, 10% hexagonal boron nitride, 2% WD-40 lubricant, 1.0% dispersant, and defoaming agent (add as needed, stopping when no bubbles are observed), with the remainder being white oil.

[0049] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 7 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0050] Comparative Example 1 (relative to Example 1, without adding hexagonal boron nitride)

[0051] The coating of this comparative example, which is effective in preventing the steam explosion of molten aluminum, is made of the following raw materials in the following weight ratio: 10% silane-modified epoxy resin, 20% sodium acrylate resin, 2% calcium chloride, 0.5% WD-40 lubricant, 0.2% dispersant, defoaming agent (appropriate amount, stop adding when no bubbles are observed), and the balance is white oil.

[0052] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 8 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0053] Comparative Example 2 (relative to Example 1, without adding super absorbent resin, i.e., sodium acrylate resin)

[0054] The coating of this comparative example, which is effective in preventing the steam explosion of molten aluminum, is made of the following raw materials in the following weight ratio: 30% silane-modified epoxy resin, 2% calcium chloride, 5% hexagonal boron nitride, 0.5% WD-40 lubricant, 0.2% dispersant, defoaming agent (appropriate amount, stop adding when no bubbles are observed), and the balance is white oil.

[0055] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 8 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0056] Comparative Example 3 (relative to Example 1, without adding calcium salt)

[0057] The coating of this comparative example, which is effective in preventing the steam explosion of molten aluminum, is made of the following raw materials in the following weight ratio: 10% silane-modified epoxy resin, 20% sodium acrylate resin, 5% hexagonal boron nitride, 0.5% WD-40 lubricant, 0.2% dispersant, defoaming agent (appropriate amount, stop adding when no bubbles are observed), and the balance is white oil.

[0058] After the above raw materials are mixed according to the weight ratio, they are ball-milled for 8 hours at a ball-to-material ratio of 10:1 to produce a coating that can prevent molten aluminum from steam explosion.

[0059] The coatings obtained from the above 9 embodiments and 3 comparative examples were subjected to comparative tests on relevant small-scale experimental equipment to test their anti-splash performance, durability, explosion-proof performance and external impact resistance. The specific experimental comparison results are shown in the following table.

[0060]

[0061]

[0062] By the above comparative test, it is shown that: under the same experimental conditions, the coating obtained in the embodiment has advantages such as good anti-splashing performance, durability, explosion-proof performance and resistance to external impact. This is mainly because the addition of inorganic calcium salt improves the high temperature resistance of coating, the addition of hexagonal boron nitride improves the lubricity and molten aluminum liquid repellency of coating, and the addition of super absorbent resin not only seals moisture but also strengthens the film-forming property and construction performance of coating. More importantly, inorganic calcium salt and hexagonal boron nitride are filled in coating as filler, and form organic-inorganic composite coating with matrix resin (moisture curing resin and super absorbent resin), so that coating has the advantages such as good toughness of organic material and high hardness, strength, impact resistance, wear resistance and heat resistance of inorganic material.

[0063] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A coating that effectively prevents steam explosion of molten aluminum, characterized in that: The invention comprises the following components in the following weight ratios: 10%-30% of moisture-curing epoxy resin, 5%-20% of highly absorbent resin, 2%-10% of calcium salt, 5%-10% of hexagonal boron nitride, 0.5%-2% of WD-40 lubricant, 0.2%-1% of dispersant and the balance of white oil.

2. The coating for effectively preventing steam explosion of molten aluminum according to claim 1, characterized in that: The invention comprises the following components in the following weight ratios: 10% of moisture-curing epoxy resin, 20% of highly absorbent resin, 2% of calcium salt, 5% of hexagonal boron nitride, 0.5% of WD-40 lubricant, 0.2% of dispersant, and the balance of white oil.

3. The coating for effectively preventing steam explosion of molten aluminum according to claim 1 or 2, characterized in that: Also includes defoaming agents.

4. The coating for effectively preventing steam explosion of molten aluminum according to claim 1, characterized in that: The moisture-curing epoxy resin is any one of a silane-modified epoxy resin, a polyurethane-modified epoxy resin, a ketimine latent-curing epoxy resin or an aldimine latent-curing epoxy resin.

5. The coating for effectively preventing steam explosion of molten aluminum according to claim 1, characterized in that: The highly absorbent resin is any one of sodium acrylate resin, methyl ethyl acrylate resin or styrene-butadiene-styrene resin.

6. The coating for effectively preventing steam explosion of molten aluminum according to claim 1, characterized in that: The calcium salt is calcium chloride, calcium sulfate or calcium phosphate compound.

7. The method for preparing a coating for effectively preventing steam explosion of molten aluminum according to claim 1, characterized in that The method comprises the following steps: adding raw materials, moisture-curing epoxy resin, highly absorbent resin, WD-40 lubricant, dispersant, calcium salt, hexagonal boron nitride and white oil into a ball mill according to weight ratio, and then ball-milling the mixture.

8. The method for preparing a coating for effectively preventing steam explosion of molten aluminum according to claim 3, characterized in that The method comprises the following steps: adding raw materials, moisture-curing epoxy resin, highly absorbent resin, WD-40 lubricant, dispersant, defoamer, calcium salt, hexagonal boron nitride and white oil into a ball mill according to weight ratio, and then ball-milling the mixture.

9. The method for preparing a coating for effectively preventing steam explosion of molten aluminum according to claim 8, characterized in that: The amount of defoamer should be added based on the absence of bubbles.

10. The method for preparing a coating that effectively prevents steam explosion of molten aluminum according to claim 7 or 8, characterized in that: The ball-to-material ratio of ball milling is 10:(0.2~1), and the ball milling time is 4~8h.

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