High-strength adhesive plastic refractory

Abstract

The invention relates to a novel high-strength adhesive plastic refractory which comprises the following components in percentage by mass: 20-60% of granules, 20-45% of fine powder, the balance of additives and 8-30% of an additional binding agent. The critical dimensions of the granules employed vary according to different filling gaps. The critical dimension is less than one third of the filling gap. And the material of the used material corresponds to a bonded object. If the high-strength bonding plastic refractory is bonded with magnesia carbon bricks, the high-strength bonding plastic refractory is made of magnesia carbon. The high-strength bonding plastic refractory is mainly applied to bonding of high-temperature furnace linings, especially steel ladles. When the steel ladle has a weak link and needs to be repaired, after the surface slag steel is removed, a layer of bonding plastic refractory is smeared, and then new bricks are supplemented. Therefore, the new brick and the residual lining are firmly combined by the high-strength adhesive plastic refractory to form a whole. Cracking and stripping are avoided through cyclic maintenance and use, the service life is greatly prolonged, and the unit consumption of refractory materials is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of refractory materials, and relates to a preparation method of a high-strength binder and application thereof. Background Art

[0002] At present, the lining of the refined steel ladle is mainly made of bricks. When it is used offline, the residual steel on the surface of the molten pool lining is cleaned, and the coating material is applied to extend the service life. The slag line and other local parts with serious wear and tear are excavated and repaired, and then baked and put online for use. When the slag line erodes to the safety line again, it is offline, and all working layers are stripped off and replaced with new working layers. The unit consumption of refractory materials in this construction and maintenance method reaches about 3kg / t. In fact, the discarded refractory materials are stripped off at more than 1.5kg / t, exceeding 50%, which is a serious waste of resources. Wasting refractory resources means high energy consumption and high costs.

[0003] Ruitai Magang New Material Technology Co., Ltd. uses high-grade corundum spinel coating material on 300 t ladle, with an adhesion rate of 95%. It can be used 30 to 35 times after one coating, achieving good results. Using coating material to coat the lining is a way to balance erosion and increase service life. However, its corrosion resistance is insufficient. When the coating layer is thin, it will peel off, resulting in uneven ladle conditions, which makes it difficult to judge the ladle. It also does not fundamentally solve the problem of excessive amount of waste refractory materials removed during medium and major repairs.

[0004] Patent 201810610506.2 is "a composite refractory and wear-resistant plastic material", which uses conventional aluminum-silicon refractory raw materials, which are not suitable for refining ladle lining. Its corrosion resistance is insufficient, and conventional silicate binders are used. Silicates generate liquid phases at very low temperatures, which is extremely unfavorable for high temperature resistance and corrosion resistance. Patent 202010538345.8 is "a kind of aluminum silicate refractory plastic material", which is also an aluminum-silicon material and uses clay as a binder. It is difficult to form a bond with the original layer, which will cause peeling or high-temperature shedding. Patent 201511011055.3 is "high-aluminum refractory plastic material", which uses conventional phosphate binders. Although this binder has good viscosity, it is not resistant to high temperatures and cannot meet the requirements of high-temperature adhesion and service life of the ladle. Patent 201310425093.8 is a "hot-repairable refractory plastic", which is also a high-aluminum plastic. It uses high-aluminum cement, which introduces CaO. Although the strength increases, the viscosity and corrosion resistance become worse. If used on a ladle, the risk of peeling increases and the service life is reduced. Patent 202010127849.0 is a "micro-powder-bonded coating for ladle lining and its preparation method and application". This patent is an aluminum-magnesium spinel coating. Micro-powder bonding is used. One advantage of micro-powder bonding is that it can be sintered at high temperature to form a good high-temperature bond. However, there is a lack of bonding between the residual lining and the new lining. Without bonding, it will cause peeling and cracking, resulting in a low service life and failing to achieve the desired service life. Patent 202011337689.9 is an aluminum-magnesium repair material for a ladle, which is a castable repair. The residual lining and the repair material layer are not firmly bonded at high temperature. Temperature fluctuations under high temperatures will cause the tiles to peel off, especially when the remaining thickness of the patching bricks is relatively thin, which makes it easier to peel off, making it difficult to judge the packages and increasing consumption.

[0005] In summary, the current methods for ladle repair include 1) lining by coating, 2) lining by spraying, 3) lining by casting, and 4) lining by patching. The adhesion between the coating material, spraying material, castable material or brick and the residual lining is not good. Existing solutions include: micro powder sintering method, cement binder, aluminum silicate binder, phosphate binder, etc., but the adhesion effect is not good. After adhesion at room temperature, it will fall off or peel off at high temperature. What's worse, when the repair layer is used thinner, it will peel off and become a patch face, which seriously affects the judgment and service life of the ladle. This requires that the transition layer between the residual lining and the patching brick can firmly bond the two, and at the same time it is also resistant to corrosion.

[0006] Based on this, the present application proposes a new type of high-strength bonding plastic material to solve the problems existing in the prior art. Summary of the invention

[0007] The purpose of the present invention is to provide a new type of high-strength bonding plastic material to solve the problem of insufficient bonding to new bricks and residual linings, and at the same time solve the problem of corrosion resistance.

[0008] The specific technical scheme of the present invention is as follows:

[0009] A high-strength bonding plastic material is composed of the following components in parts by mass: 20-60% granular material and 20-45% fine powder, wherein the material of the granular material and the fine powder is the same as the material of the position to be repaired, and the rest is additives, which are composed of three parts: plasticizer, reinforcing agent and recarburizer, and 8-30% carbon binder.

[0010] A preferred solution is that the granular material refers to a particle size not greater than 8 mm, which is determined by the width of the gap to be filled, and the particle size is less than one third of the gap width.

[0011] A preferred solution is that the fine powder has a particle size of ≤0.15 mm, of which particles ≤10 μm account for no less than 5%.

[0012] The preferred solution is that the reinforcing agent is one or more of silicon powder, aluminum powder, chromium powder, titanium powder, nickel powder or short carbon fiber, which mainly plays a reinforcing role and further ensures the high-temperature bonding between the residual lining and the patching bricks.

[0013] A preferred solution is that the plasticizer is one of trioctyl phosphate, dioctyl phthalate or soft clay, which improves the plasticity of the plastic and the construction performance.

[0014] A preferred solution is that the recarburizer is one of colloidal sulfur, paraformaldehyde or hexamethylenetetramine, which increases the residual carbon content of the plastic and improves the high-temperature bonding strength of the plastic.

[0015] The preferred solution is that the carbon binder is phenolic resin, furan resin, asphalt binder or a combination thereof. Curing at low temperature improves low-temperature bonding strength; carbonization at high temperature forms a carbon bond, which improves the high-temperature bonding strength of the plastic and ensures that it does not crack or peel during use.

[0016] The present invention has the following beneficial effects:

[0017] 1. This application selects different high-strength bonding plastic materials according to the different materials of different parts of different ladles to control the different corrosion resistance and thermal expansion, and ensure the basic consistency of the line changes of the residual lining, the new patch bricks and the high-strength bonding plastic. This ensures that when the temperature changes during use, the stress generated between the interfaces is very small, and there will be no cracking and peeling. And because the material is basically the same as the bricks in the same position, coupled with the use of additives and carbon binders, the corrosion resistance will be greatly improved. Therefore, in terms of adhesion, peeling resistance and corrosion resistance, the new high-strength bonding plastic has the same corrosion resistance as the bonded residual lining and new bricks.

[0018] 2. The high-strength adhesive plastic is used for patching and lining high-temperature kilns. When the kiln is used to the safety thickness limit, it is not dismantled, but the lining is patched. That is, the adhesive plastic is applied to the surface of the residual lining, and the patch short bricks are laid inside and squeezed tightly, so that the high-strength adhesive plastic is squeezed into the gap between the residual lining and the short bricks. In this way, the high-strength adhesive plastic firmly bonds the residual lining and the patch short bricks together, and the kiln is used like a new lining. Such unlimited recycling makes the waste refractory materials approach zero, significantly reducing the unit consumption and cost of refractory materials. DETAILED DESCRIPTION

[0019] In order to demonstrate the essential features and significant improvements of the present invention, the following examples are used to further illustrate the implementation methods and effects.

[0020] Embodiment:

[0021] Prepare the ingredients according to the following formula (all raw materials are by mass ratio):

[0022]

[0023] The high-strength bonding plastic is used to bond magnesia carbon bricks and aluminum-magnesia carbon bricks. Taking Example 1 as an example, when used to bond MT-14A magnesia carbon bricks, its granular material and fine powder are mainly composed of fused magnesia sand and -195 graphite, aluminum powder, magnesium aluminum powder, short carbon fiber as reinforcing agent, dioctyl phthalate as plasticizer, colloidal sulfur as carburizer, after curing at 200°C, hot strength test is carried out under the conditions of 1400°C and 3h carbon burial, and its flexural strength can reach 5.5MPa. Some magnesia carbon bricks break at the body, not at the bonding point, so it can be confirmed that the plastic bonding is very strong.

[0024] At the same time, by comparing Example 4 with Comparative Example 3, when used to adhere aluminum-magnesium-carbon bricks, the bonding properties are also improved by adding plasticizers and recarburizers.

[0025] The above are only preferred embodiments of the present invention. It should be pointed out that the present invention is not limited to the above embodiments, and any changes made under the enlightenment of the present invention, which have the same or similar technical solutions as the present invention, shall fall within the protection scope of the present invention.

Claims

1. A high-strength bonding plastic material, characterized in that: The invention is composed of the following components in parts by mass: 20-60% granular material and 20-45% fine powder. The material of the granular material and the fine powder is the same as the material of the position to be repaired. The rest is additives, which are composed of three parts: plasticizer, reinforcing agent and recarburizer, and 8-30% carbon binder.

2. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The granular material refers to a particle size not greater than 8 mm, which is determined by the width of the gap to be filled, and the particle size is less than one third of the gap width.

3. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The fine powder has a particle size of ≤0.15 mm, of which particles ≤10 μm are not less than 5%.

4. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The reinforcing agent is one or more of silicon powder, aluminum powder, chromium powder, titanium powder, nickel powder or carbon fiber.

5. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The plasticizer is one of trioctyl phosphate, dioctyl phthalate or soft clay.

6. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The recarburizer is one of colloidal sulfur, paraformaldehyde or hexamethylenetetramine.

7. A high-strength bonding plastic material as claimed in claim 1, characterized in that: The carbon binder is phenolic resin, furan resin, asphalt binder or a combination thereof.

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