A release agent for preventing adhesion between the fetal membrane and the working layer of the tundish

Abstract

The present invention belongs to the technical field of refractory materials, and particularly relates to a mold release agent for preventing adhesion between the mold and the working layer of the tundish working layer. The mass percentages of the components of the mold release agent are as follows: talcum powder 50%, graphite 44%, surfactant 4%, dispersant 2%; the MgO content in the talcum powder is ≥32%, the SiO2 content is ≥63.5%, and the talcum powder is a mixture of talcum powder particles with different particle sizes; the C content in the graphite is ≥80.5%, and the graphite is a mixture of graphite particles with different particle sizes; the surfactant is sodium hexametaphosphate, and the surfactant is a mixture of surfactant particles with different particle sizes; the dispersant is MF water glass, the SiO2 content in the dispersant is ≥66.2%, and the dispersant is a mixture of dispersant particles with different particle sizes. The mold release agent provided by the present invention is particularly suitable for the construction of tundish dry mix, and can simultaneously meet the mold release treatment of both hot and cold pressing processes, with a mold release rate reaching 100%.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory materials, and particularly relates to a demoulding agent for preventing adhesion between the formwork and the working layer of the tundish working layer. Background Art

[0002] The lining of the tundish is composed of three parts: a thermal insulation layer, a permanent layer, and a working layer. Among them, the working layer is in direct contact with molten steel and is the basis for protecting the normal use of the tundish. The previously used coating and gunning material working layers have the advantages of relatively long service life and no pollution to molten steel, etc., but 20%-30% of water needs to be added during construction, and there are deficiencies such as complex maintenance of spraying or stirring equipment and long curing time of the working layer.

[0003] In order to combine the advantages of insulating boards and gunning materials, the dry material working layer of the tundish is used as the working layer material of the continuous casting tundish, which has the advantages of no pollution to molten steel, long service life, simple process, convenient maintenance, easy ladle turnover and cleaning, and high operation efficiency. Therefore, the tundish with a dry material working layer has also been widely used. The current dry materials mainly consist of basic magnesia materials, and a hard and flat working layer is formed through the vibration and baking of the engineering lining formwork. The smoother and flatter it is, the more effectively it can resist the erosion, scouring, and penetration of molten steel and slag.

[0004] However, after the dry material of the tundish is baked by the formwork, it often adheres to the working layer and is difficult to demould. In severe cases, it may even cause the situation of "pulling damage" to the working layer. Slight cracks can be repaired with fire clay and continue to be used. Even if repaired in severe cases, it will cause safety hazards such as caking after being put into operation, local accidental erosion, and steel penetration. In response to this situation, research has been carried out on how to reduce the possibility of dry material sticking to the mold, improve the demoulding isolation performance, and achieve the purpose of good demoulding. Summary of the Invention

[0005] The purpose of the present invention is to provide a demoulding agent for preventing adhesion between the formwork and the working layer of the tundish working layer to solve the problems existing in the prior art.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a demoulding agent for preventing adhesion between the formwork and the working layer of the tundish working layer, and the mass percentage of the composition components of the demoulding agent is: 50% talc powder, 44% graphite, 4% surfactant, and 2% dispersant;

[0007] The MgO content in the talc powder is ≥32%, the SiO2 content is ≥63.5%, and the talc powder is a mixture of talc powder particles with different particle sizes;

[0008] The C content in the graphite is ≥80.5%, and the graphite is a mixture of graphite particles with different particle sizes;

[0009] The surfactant is sodium hexametaphosphate, and the surfactant is a mixture of surfactant particles with different particle sizes;

[0010] The dispersant is MF water glass, the SiO2 content in the dispersant is ≥ 66.2%, and the dispersant is a mixture of dispersant particles with different particle sizes.

[0011] Furthermore, the talc powder particle mixture is composed of talc powder particles with a particle size of 0.5 mm - 1 mm, talc powder particles with a particle size of 0.25 mm - 0.5 mm, talc powder particles with a particle size of 0.075 mm - 0.25 mm, and talc powder particles with a particle size of less than 0.075 mm.

[0012] Furthermore, in the talc powder particle mixture, the talc powder particles with a particle size of 0.5 mm - 1 mm account for 35%, the talc powder particles with a particle size of 0.25 mm - 0.5 mm account for 45%, the talc powder particles with a particle size of 0.075 mm - 0.25 mm account for 10%, and the talc powder particles with a particle size of less than 0.075 mm account for 10%.

[0013] Furthermore, the graphite particle mixture is composed of graphite particles with a particle size of 0.075 mm - 0.25 mm and graphite particles with a particle size less than or equal to 0.075 mm.

[0014] Furthermore, the mixing ratio of the graphite particles with a particle size of 0.075 mm - 0.25 mm to the graphite particles with a particle size less than or equal to 0.075 mm is (5 - 30):(10 - 30).

[0015] Furthermore, the surfactant particle mixture is composed of surfactant particles with a particle size of 0.045 mm - 0.075 mm and surfactant particles with a particle size less than or equal to 0.045 mm, which are mixed in a mass ratio of 1:1.

[0016] Furthermore, the dispersant particle mixture is composed of dispersant particles with a particle size of 0.045 mm - 0.075 mm and dispersant particles with a particle size less than or equal to 0.045 mm, which are mixed in a mass ratio of 1:1.

[0017] The present invention has the following beneficial effects: The mold release agent provided by the present invention is particularly suitable for the construction of tundish dry mix, and can simultaneously meet the mold release treatment of both cold pressing and hot pressing processes, that is, the mold release agent of the present invention not only satisfies the surface coating of the cold tundish tire, but also can prevent the adhesion between the hot tundish tire and the dry mix, and can effectively carry out mold release, with a mold release rate reaching 100%. Furthermore, the production cost is reduced, and the labor and time costs consumed for mold cleaning and impurity removal on the surface of the tundish tire are reduced. By optimizing the content of each component, the heat resistance and stress performance of the mold release agent are greatly optimized. By controlling the particle size of each component, the mold release agent has excellent coatability, good molding, strong mold release property, is not easy to adhere during the on-line use process, and will not have safety hazards such as material collapse, local accidental erosion, and steel penetration. Specific Embodiments

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the following further elaborates on the present invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Embodiment 1

[0020] This embodiment provides a batching method and usage steps of a mold release agent for preventing adhesion between the mold membrane and the working layer of the tundish:

[0021] A batching method of a mold release agent for preventing adhesion between the mold membrane and the working layer of the tundish:

[0022] In 100 kg of the mold release agent, there are 50 kg of talcum powder, 44 kg of graphite, 4 kg of surfactant, and 2 kg of dispersant. The MgO content of the talcum powder is ≥32%, and the SiO2 content is ≥63.5%. The C content of the graphite is ≥80.5%. The surfactant is sodium hexametaphosphate, and the dispersant is MF water glass. The SiO2 content in the dispersant is ≥66.2%. The talcum powder is composed of 16 kg of talcum powder particles with a particle size of 0.5 mm - 1 mm, 22.5 kg of talcum powder particles with a particle size of 0.25 mm - 0.5 mm, 5 kg of talcum powder particles with a particle size of 0.075 mm - 0.25 mm, and 5 kg of talcum powder particles with a particle size of less than 0.075 mm. The graphite is composed of 6.3 kg of graphite particles with a particle size of 0.075 mm - 0.25 mm and 37.7 kg of graphite particles with a particle size less than or equal to 0.075 mm, and the mixing ratio is 5:30. The surfactant is composed of 2 kg of surfactant particles with a particle size of 0.045 mm - 0.075 mm and 2 kg of surfactant particles with a particle size less than or equal to 0.045 mm. The dispersant is composed of 1 kg of dispersant particles with a particle size of 0.045 mm - 0.075 mm and 1 kg of dispersant particles with a particle size less than or equal to 0.045 mm.

[0023] Usage steps of a mold release agent for preventing adhesion between the mold membrane and the working layer of the tundish:

[0024] (1) Bottom knotting of the ladle: Evenly spread the ladle bottom material on the bottom of the ladle and step on it firmly with feet. The required thickness is slightly higher than the nozzle mold and does not exceed 10 mm, and the thickness of the ladle bottom material is 120 mm.

[0025] (2) Suspension seat die: Evenly apply a layer of the mold release agent described in the present invention on the outer surface of the working layer die. Use a four-leg chain to lift the working layer die above the tundish; use a clamping tool to adjust the die, and jog the operation to align the die. It is required that the distance deviation of each symmetric point is <10 mm. According to the tundish life requirement, different thickness parameters are designed, and the overall thickness of the working lining of the tundish used in the continuous casting machine is controlled within 100 mm - 110 mm, and the thickness of the slag line at other positions is controlled at 100 mm.

[0026] (3) Lining the ladle wall: Evenly pour the dry material into the gap between the ladle die and the permanent layer until it reaches the ladle edge position. It is required to distribute the material at multiple points, and it is prohibited to pour the material at one position. After filling the material, start the vibration motor and vibrate for 5 - 10 min, then cut off the power supply and clean the dry material on the ladle edge.

[0027] (4) Baking the working layer: Start the blower to exhaust the excess gas in the ladle die, light the ignition rod, turn on the gas, and ignite each burner on the ladle die in sequence. Start the blower and adjust the flame, and at the same time record the ignition time. After baking for 3.5 - 4.5 h, observe whether the sintered part of the working layer turns yellow. Stop the fire when the depth of the yellowing part reaches 20 - 40 mm, and the total baking time is not more than 5 h.

[0028] (5) Lifting the working layer die: After the baking stops and cools for 10 h, use a four-leg chain and jog the operation to lift out the die.

[0029] Example 2

[0030] This example provides a mold release agent for preventing adhesion between the working layer die of the tundish and the working layer. The batching method and usage steps are basically the same as those in Example 1. The difference is that the graphite is composed of 33 kg of graphite particles with a particle size ranging from 0.075 mm to 0.25 mm and 11 kg of graphite particles with a particle size less than or equal to 0.075 mm, and the mixing ratio is 30:10.

[0031] Example 3

[0032] This example provides a mold release agent for preventing adhesion between the working layer die of the tundish and the working layer. The batching method and usage steps are basically the same as those in Example 1. The difference is that the graphite is composed of 20 kg of graphite particles with a particle size ranging from 0.075 mm to 0.25 mm and 24 kg of graphite particles with a particle size less than or equal to 0.075 mm, and the mixing ratio is 20:24.

[0033] The above-described examples are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various variations and improvements made by those of ordinary skill in the art to the technical solution of the present invention should fall within the protection scope of the present invention.

[0034] The technologies, shapes, and structures not described in detail in the present invention are all well-known technologies.

Claims

1. A mold release agent for preventing adhesion between the mold membrane of the tundish working layer and the working layer, characterized in that, The mass percentages of the components of the mold release agent are as follows: talcum powder 50%, graphite 44%, surfactant 4%, dispersant 2%; The MgO content in the talcum powder is ≥32%, and the SiO2 content is ≥63.5%. The talcum powder is a mixture of talcum powder particles with different particle sizes; The C content in the graphite is ≥80.5%. The graphite is a mixture of graphite particles with different particle sizes; The surfactant is sodium hexametaphosphate. The surfactant is a mixture of surfactant particles with different particle sizes; The dispersant is MF water glass. The SiO2 content in the dispersant is ≥66.2%. The dispersant is a mixture of dispersant particles with different particle sizes; By mass percentage, in the talcum powder particle mixture, the talcum powder particles with a particle size of 0.5 mm - 1 mm account for 35%, the talcum powder particles with a particle size of 0.25 mm - 0.5 mm account for 45%, the talcum powder particles with a particle size of 0.075 mm - 0.25 mm account for 10%, and the talcum powder particles with a particle size below 0.075 mm account for 10%; The graphite particle mixture is composed of graphite particles with a particle size of 0.075 mm - 0.25 mm and graphite particles with a particle size less than or equal to 0.075 mm, mixed in a mass ratio of (5 - 30):(10 - 30); The surfactant particle mixture is composed of surfactant particles with a particle size of 0.045 mm - 0.075 mm and surfactant particles with a particle size less than or equal to 0.045 mm, mixed in a mass ratio of 1:1; The dispersant particle mixture is composed of dispersant particles with a particle size of 0.045 mm - 0.075 mm and dispersant particles with a particle size less than or equal to 0.045 mm, mixed in a mass ratio of 1:1.