CN114525164B

CN114525164B - Release agent and preparation method and application thereof

Info

Publication number: CN114525164B
Application number: CN202210086991.4A
Authority: CN
Inventors: 王少峰; 杨林; 姜乐; 苟浪
Original assignee: BEIJING RUIPU TONGCHUANG TECHNOLOGY DEVELOPMENT CO LTD
Current assignee: BEIJING RUIPU TONGCHUANG TECHNOLOGY DEVELOPMENT CO LTD
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2023-01-17
Anticipated expiration: 2042-01-25
Also published as: CN114525164A

Abstract

The invention relates to the technical field of release agents, and particularly relates to a release agent and a preparation method and application thereof. The release agent comprises the following components in parts by weight: 70-80 parts of talcum powder; 10-15 parts of magnesite powder; 5-10 parts of graphite; 3-5 parts of clay powder; 1-2 parts of latex powder; 0.2-0.3 part of HPM; 0.1-0.2 part of surfactant. The release agent is reasonable in component matching, the prepared slurry is uniform and stable, the prepared slurry can be well attached to the surface of a metal mold tire after being coated and dried to form a compact and smooth outer coating, the surface of the metal mold tire is easy to fall off after being heated, and no harmful substance is generated in the heating process. The release agent meets the construction requirement of the tundish dry material working lining, is more environment-friendly, and can be widely applied to the construction process of the tundish dry material working lining.

Description

Release agent and preparation method and application thereof

Technical Field

The invention relates to the technical field of release agents, and particularly relates to a release agent and a preparation method and application thereof.

Background

The tundish is key continuous casting equipment for steelmaking, and plays a role in temporarily storing molten steel and controlling the molten steel to flow into a molten steel crystallizer to form a continuous casting blank. The dry material working lining of the tundish is the most important refractory material in the tundish, and the construction quality of the dry material of the working lining of the tundish directly determines the continuous casting service life of the tundish.

When the tundish dry material working lining is constructed, paving the dry material at the bottom of the tundish according to the required construction thickness, putting the metal mold tyre into the tundish, adjusting the gap between the periphery of the metal mold tyre and the tundish permanent lining, then evenly pouring the dry material into the gap, after the gap is filled, vibrating the dry material tightly by using a vibrating motor fixed on the metal mold tyre, and supplementing the missing part in the vibrating process until the technical specification is met. And after the vibration is finished, heating the metal mold, heating and curing the dry material through heat conduction, and naturally cooling after the heating and curing step is finished. After the metal mold is cooled, a shrinkage joint is formed between the metal mold and the dry material working lining due to the effect of expansion with heat and contraction with cold. If the metal mold is not provided with the release agent, the solidified dry material is easy to adhere to the metal mold during demolding, and the dry material working lining is easy to drop or obvious demolding cracks occur when the mold is hung out of the tundish, so that huge potential safety hazards are brought to subsequent production. In order to overcome the defects and facilitate the separation of the metal mold tire from the dry material working lining after the construction is finished, a release agent is coated on the surface of the metal mold tire.

In the prior art, waste engine oil is added into flake graphite as a release agent or lime cream is used as the release agent during construction of a tundish dry material working lining. When the waste engine oil and the crystalline flake graphite are used as the release agent, the graphite is easily rolled into a dry material in the construction process because the graphite and the metal mold have almost no bonding strength, so that the construction quality of the working lining is influenced; in addition, the release agent can generate a large amount of harmful smoke in the construction heating and baking link, the field environment is influenced, and the damage to the human health is large. The lime cream release agent has low bonding strength and is not easy to be coated uniformly, lime powder on the surface of the mold is easy to be brought into a dry material during construction, impurities are introduced into the dry material, and the metal mold adhesion material often causes pits on the working lining during demolding, so that the construction quality of the working lining is influenced.

In conclusion, the release agent which meets the field construction requirement of the tundish dry material working lining and is more environment-friendly has important significance.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a release agent and a preparation method and application thereof.

In a first aspect, the invention provides a mold release agent, which adopts the following technical scheme:

the release agent comprises the following components in parts by weight:

70-80 parts of talcum powder;

10-15 parts of magnesite powder;

5-10 parts of graphite;

3-5 parts of clay powder;

1-2 parts of latex powder;

0.2-0.3 part of HPM;

0.1-0.2 part of surfactant.

The release agent provided by the scheme has the advantages that the components are reasonably matched, the prepared slurry is uniform and stable, the construction is easy, the coating and drying can be well attached to the surface of the metal mold, a smooth outer surface is formed, the release agent can easily fall off from the surface of the metal mold after heating, and no harmful substances are generated in the heating process.

Specifically, the talcum powder and the magnesite powder are used as main components, and the talcum powder and the magnesite powder have synergistic effect, so that the release agent is prepared into slurry and coated on the metal mold, the formed surface is smooth and is not easy to crack, and the talcum powder is fine and smooth, so that after the release agent is coated on the metal mold, the resistance is small during demolding, the demolding damage to a dry material is avoided, and the construction quality can be improved. The release agent is added with a proper amount of graphite, so that the lubricating effect can be increased, the resistance between the release agent and the dry material working lining when the tundish metal mold tire is released is reduced, the release agent is easy to fall off from the surface of the metal mold tire after being heated in the construction process, and the dry material working lining is not damaged when the tundish dry material working lining is released from the metal mold tire after the construction and baking are finished. The release agent contains clay powder, so that the adhesion of the release agent can be improved, and the release agent can be well adhered to the surface of a metal mold at low temperature after being coated and dried; in addition, the addition of the clay can ensure that the release agent has good suspension property after being prepared into slurry by adding water, is not easy to precipitate and delaminate, and can improve the coating property of the slurry. The latex powder contained in the release agent can further improve the adhesiveness of the release agent, can ensure that the release agent is firmly adhered to the surface of a metal mold, and avoids the introduction of impurities into a dry material caused by the fact that the release agent is brought into the dry material in the construction process. The release agent contains HPM, and the HPM is a high polymer material and has strong water absorption and water locking capacity, so that the viscosity of the release agent slurry can be greatly improved, the suspension property of the release agent slurry is further improved, the release agent slurry is not easy to precipitate, and the long construction time can be kept in the coating stage. The release agent also contains a certain amount of surfactant, so that the wettability of release agent powder can be increased, the water addition amount can be reduced, the release agent can be more easily and uniformly mixed in the process of adding water for preparing slurry, and the powder agglomeration can be avoided.

Preferably, the release agent further comprises 0.1-0.15 parts by weight of a defoaming agent.

In some embodiments, the defoamer can be 0.1 part, 0.3 part, 0.5 part, 0.8 part, 1.0 part, 1.2 parts, or 1.5 parts by weight.

The addition of the defoaming agent can ensure that large bubbles do not exist in the prepared slurry of the release agent when the release agent is used, so that the release agent coating coated on the surface of the metal mold is smoother and more compact, cracks are not easy to appear, and the construction quality is ensured.

Preferably, the talcum powder comprises 1000-1200 mesh talcum powder and 1400-1600 mesh talcum powder; according to the parts by weight, in the release agent, the parts by weight of the 1000-1200 mesh talcum powder are 50-60 parts, and the parts by weight of the 1400-1600 mesh talcum powder are 20-30 parts.

In some embodiments, the 1000-1200 mesh fineness of talc powder may be 50, 52, 55, 58, or 60 parts by weight, and the 1400-1600 mesh fineness of talc powder may be 20, 22, 25, 28, or 30 parts by weight.

Preferably, in the release agent, the talc powder with the fineness of 1000-1200 meshes accounts for more than 70 percent of the total weight of the talc powder in the release agent.

The two kinds of talcum powder with different fineness are adopted, so that the stacking density of the release agent is improved, the density of the slurry is improved, a coating formed on the surface of the metal mold is smoother and finer, and the influence of cracks on construction quality is avoided. When the talc powder with the fineness of 1000-1200 meshes accounts for more than 70% of the total amount of the talc powder in the release agent, the powder of the release agent is matched in thickness, the coarse material plays a role of a framework, the powder is filled between the frameworks, and the release agent is smoother and more compact in surface and better in wear resistance after being naturally dried. The quality of subsequent construction can be ensured.

Preferably, the fineness of the magnesite powder is 800-1000 meshes. The fineness is referred to as D50 value, and in some embodiments, magnesite powder D50 may be selected to be 800, 900 or 1000.

The magnesite powder with the fineness can better mutually cooperate with the talcum powder, plays a role of framework support for finer powder and reduces the occurrence of microcracks.

Preferably, the graphite is flake graphite. The scale graphite has excellent lubricity, can increase the lubricating effect, reduces the resistance between the tundish metal mould tire and the dry material working lining when the tundish metal mould tire is demoulded, ensures that the demoulding agent is easy to fall off from the surface of the metal mould tire after being heated in the construction process, and ensures that the hardened dry material working lining cannot be damaged when the tundish dry material working lining is removed from the metal mould tire after the construction and baking are finished.

Preferably, the graphite is a mixture of crystalline flake graphite and earthy graphite.

Preferably, the weight ratio of the crystalline flake graphite to the earthy graphite is 1-2. For example, in some embodiments, there may be 1.

Preferably, the fineness of the crystalline flake graphite and the fineness of the earthy graphite are 250-350 meshes. The fineness refers to a D50 value, and in some embodiments, the fineness D50 may be selected to be 250, 300, or 350.

The scale graphite has excellent lubricity and poor hydrophilicity, the soil graphite is also called microcrystalline graphite, the lubricity is slightly poor, but the hydrophilicity is good, the scale graphite and the microcrystalline graphite are mixed and used in the release agent according to a certain proportion, so that the effect of taking account of the lubricity and the adhesiveness can be achieved, the adhesiveness of the release agent and the shedding degree after heating can reach the best, the release agent can be kept firmly attached to the surface of a metal mold in the construction process, the release agent is prevented from being brought into a dry material in the construction process, impurities are prevented from being introduced into the dry material, and the release agent can be easily shed from the surface of the metal mold after heating.

On the other hand, the invention provides a preparation method of the release agent, which adopts the following technical scheme:

a preparation method of a release agent comprises the following steps: weighing the materials according to the proportion and uniformly mixing to obtain a mixture; and ball-milling the mixture for 30-40 minutes under the conditions that the ball-to-material ratio is 1-2.

The release agent prepared by the scheme is uniform and fine, all components are reasonably matched, the release agent is easier to be uniformly mixed in the process of adding water to prepare the slurry, agglomeration is avoided, the slurry has better suspension property and is difficult to precipitate, and the construction time can be kept longer in the coating stage. In addition, the release agent can be well attached to the surface of the metal mold after being coated and dried to form a compact and smooth outer surface, cracks are not easy to appear, the release agent is prevented from being brought into a dry material in the construction process, impurities are prevented from being introduced into the dry material, the construction quality is ensured, no harmful substances are generated in the heating process, the release agent is easy to fall off from the surface of the metal mold after being heated, the lubricating effect can be achieved when the dry material working lining of the tundish is separated from the metal mold after the construction and baking are completed, and the dry material working lining can not be damaged.

In a third aspect, the invention provides an application of a release agent in a construction process of a tundish working lining metal mold, wherein the metal mold is a steel mold, when the release agent is used, water is added to prepare uniform slurry, the uniform slurry is coated on the surface of the steel mold at the temperature of 20-80 ℃ at room temperature, the coating thickness is 0.2-0.4mm, and the steel mold is naturally dried.

The release agent provided by the scheme is mainly applied to the construction process of the tundish dry material working lining, and is convenient for separating the metal mold tire from the dry material working lining after construction is completed. Steel mold is often selected in consideration of the cost of metal mold, performance requirements and other factors. In the specific using process, firstly, adding water into the release agent to prepare uniform slurry, wherein the water-material ratio is generally 45-55.

In summary, the invention has the following beneficial technical effects:

1. the release agent provided by the scheme is uniform and fine, the components are reasonably matched, the prepared slurry has better suspension property, is not easy to precipitate, and can be kept for a longer construction time in the coating stage. In addition, the release agent can be well attached to the surface of the metal mold after being coated and dried to form a smooth outer surface, so that cracks are not easy to appear, the release agent is prevented from being brought into a dry material in the construction process, and the construction quality is ensured. And the hot-rolled metal mold is easy to fall off from the surface of the metal mold after being heated, and can play a role in lubricating when the tundish dry material working lining falls off from the metal mold after construction and baking are finished, so that the dry material working lining cannot be damaged.

2. The scheme selects proper materials, the prepared release agent does not generate harmful substances in the construction heating process, the construction requirement of the tundish dry material working lining can be met, and the environment is protected.

3. The release agent provided by the scheme is simple in preparation method and convenient to use, is uniformly coated on the surface of the metal mold base after being added with water and mixed with slurry, can be used after being naturally dried, can keep the release agent firmly attached to the surface of the metal mold base in the construction process, can easily fall off from the surface of the metal mold base after being heated, and can be widely applied to the construction process of tundish dry material working linings.

Detailed Description

The preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified. The materials used in the following examples are commercially available, unless otherwise specified.

Examples

Example 1

The release agent of the embodiment comprises the following components: 700g of 1000-1200 mesh talcum powder; 120g of 800-mesh magnesite powder; 80g of 300-mesh crystalline flake graphite; 40g of clay powder; 15g of latex powder; HPM 2.5g; 1.5g of surfactant.

The release agent of this example was prepared as follows:

weighing the materials according to the proportion, uniformly mixing to obtain a mixture, and performing ball milling on the mixture for 40 minutes at a ball-to-material ratio of 1.

Example 2

Example 2 differs from example 1 in that 1.2g of a coating defoamer was also included.

Examples 3 to 9

Examples 3-9 differ from example 2 in the fineness and amount of talc, as detailed in table 1 below.

TABLE 1 fineness of talc powder and dosage in examples 2-9

Examples 10 to 13

Examples 10 to 13 differ from example 7 in the fineness and amount of magnesite powder and are described in table 2 below.

TABLE 2 fineness and dosage table of magnesite powder in examples 10-13

Examples 14 to 17

Examples 14-17 differ from example 10 in the type, fineness or content of the graphite as detailed in table 3 below.

TABLE 3 graphite type, fineness and content in examples 14 to 17 are shown in Table

Example 18

Example 18 differs from example 10 in that the ball milling time during the preparation of the release agent was 30 minutes and the ball to material ratio was 2.

Comparative example

Comparative example 1

The release agent of comparative example 1 was a mixture of used oil and flake graphite.

Comparative example 2

The mold release agent of comparative example 2 was milk of lime.

Detection test

The release agents obtained in examples 1 to 18 and comparative examples 1 to 2 were examined.

The detection test is as follows:

510g of a release agent was taken, 490g of water was added to prepare a uniform slurry, and after the completion of the slurry preparation, the appearance was observed and evaluated at 30 minutes (the completion was within about 30 minutes in consideration of the actual working time), and then coating was started. The evaluation results are shown in Table 4.

In the specific coating process, a steel plate with the length of 10cm multiplied by the width of 10cm multiplied by the thickness of 1cm is taken, the slurry is uniformly coated on the surface of the steel plate, the coating thickness is 0.2-0.4mm, the temperature of the steel plate in the coating process is 25-35 ℃, and the steel plate is naturally dried after the coating is finished. The coating properties of the slurries and the associated phenomena after drying were evaluated in the above procedure and are detailed in table 4.

After drying, the coated steel plate is vertically placed in a steel tank of 50cm (length) x 30cm (width) x 40cm (height), fused magnesia with the grain diameter range of 5-1mm is poured in the steel tank, the steel tank filled with the magnesia is placed on a vibration table, vibrated for 10 minutes, taken out, observed for coating adhesiveness and abrasion, and evaluated, and detailed table 4 shows.

The steel plate after shaking was put in an oven and heated to 250 c, and after cooling, the adhesion of the steel plate was observed and evaluated, as detailed in table 4.

The evaluation criteria were as follows:

homogeneity 30 minutes after completion of the slurry formulation:

1-obvious precipitation, 2-little precipitation and 3-uniform no precipitation;

coating workability of the slurry:

1-poor, 2-qualified, 3-better;

and (3) the dried coating has no cracks:

1-obvious crack, 2-slight crack, 3-no crack, 4-compact no crack;

surface smoothness of the dried coating:

1-very coarse, 2-coarse, 3-smooth, 4-extremely smooth;

coating abrasion resistance in vibration test:

1-obvious scratch, 2-slight scratch, 3-no scratch and 4-smooth no scratch;

coating adhesion in vibration experiments:

1-large area shedding, 2-partial shedding, 3-no shedding and 4-smooth surface without shedding;

coating adhesion after heating and cooling:

1-hard to fall, 2-partial to fall, 3-integral to fall, 4-integral to fall the surface is smooth.

In addition, the mold release agent of comparative example 1 generated a large amount of smoke during heating, and the mold release agents of the remaining comparative examples and examples did not generate smoke during heating.

TABLE 4 evaluation results of mold release agents of examples 1 to 18 and comparative examples 1 to 2

Combining the results of the performance tests of the examples, comparative examples and table 4, it can be seen that: the release agents prepared in examples 1 to 18 are reasonable in component matching, have good suspension property after being prepared into slurry, are not easy to precipitate, and can keep a long construction time in a coating stage. The release agent can be well attached to the surface of the metal mold after being coated and dried to form a smooth outer surface, cracks are not easy to appear, the release agent can be prevented from being brought into a dry material in the construction process, and the construction quality is ensured. And the hot-melt adhesive is easy to fall off from the surface of the metal mold after being heated, can play a role in lubricating when the metal mold is removed after the construction and baking of the tundish dry material working lining are finished, and cannot damage the dry material working lining.

In addition, the scheme selects appropriate materials, and the prepared release agent does not generate harmful substances in the construction heating process, can meet the construction requirement of the tundish dry material working lining, and is more environment-friendly.

The data of the embodiment 1-2 show that when a certain amount of defoaming agent is added, bubbles are not easy to generate in the slurry, so that the release agent coating coated on the surface of the metal mold is more uniform and compact, cracks are not easy to generate, and the construction quality is ensured.

Examples 3-9 examined the effect of the fineness and the dosage of the talcum powder on the performance of the release agent, and the related data in tables 1 and 4 show that the release agent prepared by the talcum powder can meet the construction requirements in the fineness range and dosage claimed by the scheme. When the two talcum powders with different finenesses are matched for use, the stacking density of the release agent is favorably improved, so that the density of the sizing agent is improved, and a coating formed on the surface of the metal mold is smoother and finer. When the talc powder with the fineness of 1000-1200 meshes accounts for more than 70% of the total amount of the talc powder in the release agent, the powder of the release agent is matched in thickness, the coarse material plays a role of a framework, the powder is filled between the frameworks, and the release agent is smoother and more compact in surface and better in wear resistance after being naturally dried.

In examples 10 to 13, the influence of the fineness and the dosage of the magnesite powder on the performance of the release agent is considered, and the related data in tables 2 and 4 show that when the magnesite powder is selected in a proper fineness range and dosage, the prepared release agent meets the construction requirements. When the fineness of 900 meshes is selected, and the magnesite powder in the release agent accounts for 12 parts by weight, the magnesite powder can better interact with the talcum powder, plays a role of framework support for the talcum powder, reduces microcracks, and can keep the surface of a coating smooth and free of falling in the construction vibration process.

Examples 14 to 17 examined the influence of the type, fineness, amount and the like of graphite on the performance of the release agent, and the graphite increased the lubricating effect, reduced the resistance between the tundish metal mold blank and the dry material working lining when demolding, and made the release agent easily fall off from the surface of the metal mold blank after heating in the construction process. According to the relevant examples and the data in table 4, when the fineness and the use amount of the graphite are within the range claimed by the scheme, the prepared release agent can meet the construction requirements. When the scale graphite and the earthy graphite are mixed according to a certain proportion for use, the lubricating property and the adhesion can be considered, so that the adhesion of the release agent and the shedding degree after heating can reach the optimal.

Example 18 examines the performances of the release agents prepared under different process conditions, and in combination with relevant data, the release agents prepared by the method in the scheme of the application can meet the construction requirements.

The results of the table 4 show that the performance of the release agent provided by the scheme is superior to that of the release agent in the comparative example, and the release agent is more suitable for the construction process of the tundish dry material working lining. In addition, the release agent of the comparative example 1 generates a large amount of harmful smoke in the heating process, and the release agent provided by the scheme is more environment-friendly.

The release agent provided by the scheme is simple in preparation method and convenient to use, is uniformly coated on the surface of the metal mold base after being added with water and mixed with slurry, can be used after being naturally dried, can keep the release agent firmly attached to the surface of the metal mold base in the construction process, can easily fall off from the surface of the metal mold base after being heated, can be widely applied to the construction process of the tundish dry material working lining, and can improve the construction quality of the tundish dry material working lining.

The above-mentioned embodiments are merely illustrative and not restrictive, and those skilled in the art can modify the embodiments without inventive contribution as required after reading this description, but only fall within the scope of the claims of the present application.

Claims

1. The release agent is characterized by comprising the following components in parts by weight:

70-80 parts of talcum powder;

10-15 parts of magnesite powder;

5-10 parts of graphite;

3-5 parts of clay powder;

1-2 parts of latex powder;

0.2-0.3 part of HPM;

0.1-0.2 parts of surfactant;

the talcum powder comprises 1000-1200 meshes of talcum powder and 1400-1600 meshes of talcum powder; according to parts by weight, in the release agent, 50-60 parts of 1000-1200 mesh talcum powder and 20-30 parts of 1400-1600 mesh talcum powder are used.

2. The release agent of claim 1, further comprising 0.1 to 0.15 parts by weight of an antifoaming agent.

3. The mold release agent according to claim 2, wherein the talc having a fineness of 1000 to 1200 mesh accounts for 70% or more of the total weight of the talc in the mold release agent.

4. The mold release agent as claimed in claim 1, wherein the fineness of the magnesite powder is 800-1000 mesh.

5. The release agent claimed in claim 1 wherein said graphite is a mixture of flake graphite and earthy graphite.

6. The release agent according to claim 5, wherein the weight ratio of the crystalline flake graphite to the earthy graphite is 1-2.

7. The release agent according to any one of claims 5 or 6, wherein the fineness of the flake graphite and the earthy graphite is 250-350 mesh.

8. The process for preparing the release agent according to any one of claims 1 to 7, characterized in that it comprises the steps of:

weighing the materials according to the proportion and uniformly mixing to obtain a mixture;

and ball-milling the mixture for 30-40 minutes under the conditions that the ball-to-material ratio is 1-2.

9. The application of the release agent in the construction process of a metal mold of a tundish working lining, which is characterized in that the metal mold is a steel mold, the release agent is prepared into uniform slurry by adding water when in use, and the uniform slurry is coated on the surface of the steel mold at the temperature of 20-80 ℃ under the condition of room temperature, the coating thickness is 0.2-0.4mm, and the steel mold is naturally dried.