Ejection lubricant for a once-formed alloy casting machine and a method for preparing the same

Abstract

The application discloses a one-time forming alloy casting machine release agent and a preparation method thereof. The release agent is composed of the following components: dust-removing ash of an electric furnace, coal slime, anthracite powder, pitch powder, suspending agent, rice husk powder, carbonized straw, yellow dextrin, water-quenched slag powder, white latex powder, sodium benzoate, sodium stearate and water. The prepared release agent can well utilize low-calorific-value coal slime and dry straw, the release agent coating can be firmly attached to the inner surface of a casting mold, and an effective isolation layer can be formed between alloy molten iron and the casting mold during casting. During the release process, a small gap is formed between the alloy iron block, the casting mold and the carbonized release agent coating, residual carbon in the release agent coating can well lubricate the surface of the alloy iron block, and the alloy iron block can be released from the mold under the action of gravity, the surface of the cast alloy iron block is smooth, and the application is especially suitable for producing small-size ferroalloy iron blocks.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical casting mold release technology, specifically relating to a mold release agent for one-time alloy casting machines and its preparation method. Background Technology

[0002] An alloy casting machine is a device for casting alloy iron blocks. Its shape resembles a continuously moving chain, with casting molds and chain plates arranged sequentially. During casting, molten alloy iron flows slowly into the casting mold along the molten iron flow channel. The casting mold, driven by the chain plates, moves slowly upwards. During operation, a cooling device above the casting mold sprays cooling water onto the surface of the cooled and crusted alloy iron block. When the casting mold reaches the drive sprocket position, it begins to tilt downwards. With the iron block facing down, it detaches under gravity. The demolded casting mold continues to move forward. When it reaches the spraying position, a release agent is re-sprayed onto the inner surface of the mold cavity. This release agent dries and solidifies rapidly under the residual heat of the casting mold. When the casting mold reaches the driven wheel position along the lower chain belt, it tilts upwards again and refills the molten alloy iron at the molten iron flow channel spout. This cycle repeats continuously.

[0003] Currently, the production process in ferroalloy plants involves directly pouring molten alloy iron into pits or ingot molds. After cooling, the resulting alloy ingots are relatively large and require manual or mechanical crushing into smaller sizes to meet the needs of different companies. This crushing process requires significant manpower and equipment investment. Manual crushing is labor-intensive, difficult to manage, inefficient, and costly. It also causes severe environmental pollution and is prone to splintering and injuries. Furthermore, the products obtained from manual and mechanical crushing are often uneven in size, especially when crushing low-strength, brittle alloys like silicon-manganese alloys. When these alloy ingots break, the cracks extend randomly, resulting in fragments of varying sizes. Larger alloy ingots, after multiple crushing operations, produce a large number of small fragments and a high powder content. Additionally, manually or mechanically crushed products have sharp edges, leading to secondary powdering during transportation.

[0004] Therefore, some manufacturers use casting molds to produce small-sized alloy ingots to avoid various problems caused by manual or mechanical breakage. The demolding issue is particularly important to consider when using casting molds to produce small-sized alloy ingots. Domestically, cast iron machine release agents are mainly composed of coal slime, lime, flake graphite, and water, or flake graphite and water glass. The former is suitable for producing large-sized alloy ingots, but the cast iron ingots have a small amount of coal slime or lime sintered layer on the surface, increasing the subsequent cleaning work, reducing the product's appearance, and also increasing the workload of decarburization in converter steelmaking. The latter release agent uses expensive flake graphite, which is used in large proportions. Flake graphite is a non-renewable resource, and its production requires high standards for environmentally friendly production equipment and qualifications; the price of flake graphite is also trending towards increasing exorbitant levels. Water glass, under high-temperature conditions, can corrode casting molds, reducing their service life. Large-scale use of this type of release agent would significantly increase production costs in the ferroalloy industry.

[0005] The mainstream release agents used in the domestic cast iron casting industry are ineffective in demolding small-sized ferroalloy blocks, resulting in low demolding rates and failing to meet the production needs of the ferroalloy industry. Factors affecting the demolding of alloy iron blocks include the coating formed between the alloy iron block and the release agent, the gap between the casting mold and the block, the size of the iron block itself, and the use of demolding machinery. The gaps created by the cooling shrinkage of small-sized ferroalloy casting are even narrower. Currently used release agents have strong sintering properties and a high coating residue ratio. When casting small-sized alloy iron blocks, the sintered coating can adhere simultaneously to both the surface of the alloy iron block and the inner surface of the casting mold, reducing the gap between the alloy iron block and the mold and hindering demolding. Furthermore, the small weight of the small-sized alloy iron blocks makes demolding by gravity alone impossible. The numerous mold cavities used in the production of small-sized alloy iron blocks also hinder their integration with demolding machinery. All these factors combined contribute to the difficulty in demolding small-sized alloy iron blocks. In addition, the steel industry is facing a difficult situation and low profits due to various factors. Therefore, developing a low-cost release agent with good release effect is conducive to the long-term development of the ferroalloy industry and is also an inevitable trend in the field of metallurgical casting release agents. Summary of the Invention

[0006] To address the aforementioned problems in the existing technology, this invention provides a low-cost, effective release agent suitable for producing small-sized ferroalloy blocks in a one-time molding alloy casting machine.

[0007] The object of this invention is achieved in the following manner: A release agent for a one-time alloy casting machine, comprising the following components by weight: 1-5 parts electric furnace dust, 30-70 parts coal slime, 3-10 parts anthracite powder, 3-15 parts asphalt powder, 4-12 parts suspending agent, 5-60 parts rice husk powder, carbonized straw (obtained from 60-200 parts of dry straw through carbonization), 1-10 parts yellow dextrin, 5-15 parts water-quenched slag powder, 0-3 parts white latex powder, 0-3 parts sodium benzoate, 0-3 parts sodium stearate, and 150-300 parts water.

[0008] The suspending agent is obtained by mixing calcium-based bentonite, attapulgite, and water in a mass ratio of 3:1:12, stirring evenly, and letting stand for at least 6 hours.

[0009] The carbonized straw is prepared by first cutting dry straw into small pieces of 10-12cm, drying it in a drying oven at 110-120℃ for 2-4 hours, then placing the dried straw in a carbonization furnace at 300-450℃ for 2-4 hours, removing it, and placing it in a closed silo to cool to room temperature to obtain carbonized straw.

[0010] The dry straw is composed of one or more of the following: corn stalks, wheat straw, rice straw, branches, and wood chips.

[0011] The electric furnace dust has a particle size of 200 mesh, the smokeless coal powder and asphalt powder have a particle size of 120 mesh, the rice husk powder has a particle size of 80 mesh, and the water-quenched slag powder has a particle size of 40 mesh.

[0012] A method for preparing a release agent for a one-time alloy casting machine includes the following steps: (1) Preparation of suspension Mix calcium-based bentonite, attapulgite, and water in a mass ratio of 3:1:12 to prepare a suspension. The suspension should be left to stand for 6 hours before use. (2) Preparation of carbonized straw Cut the dry straw into small pieces of 8-10cm, put them into a drying oven at 110-120℃ and dry them for 2-4 hours. Then put the dried straw into a carbonization furnace and calcine it at 300-450℃ for 2-4 hours. Take it out and put it into a closed silo to cool to room temperature to obtain carbonized straw. (3) Precast aggregate A Place 30-70 parts of coal slime into a drying oven at 110-120℃ and bake for 2-4 hours. Then, put the dried coal slime into a calcining furnace and calcine at 300-320℃ for 2-4 hours. Place it into a closed silo and cool it to obtain precast aggregate A. (4) Precast aggregate B The carbonized straw obtained by carbonizing 60-200 parts of dry straw in step (2) and the pre-aggregate A obtained in step (3) are put into a ball mill and ground for 40-50 minutes to obtain pre-aggregate B. (5) Precast aggregate C The prepared precast aggregate B is mixed with 1-5 parts of dust removal ash, 3-10 parts of anthracite powder, 3-15 parts of asphalt powder, 5-60 parts of rice husk powder, 5-15 parts of water-quenched slag powder, and 0-3 parts of sodium benzoate in a horizontal mixer. Then, 23-43 parts of water are added and the mixture is stirred to obtain precast aggregate C. (6) Preparation of release agent First, add 4-12 parts of the suspending agent prepared in step (1) to the powder mixer, add 50 parts of water, and stir evenly; then add 1-10 parts of yellow dextrin, 0-3 parts of white latex powder, and 0-3 parts of sodium stearate to the powder mixer, and stir evenly; after stirring evenly, add pre-made aggregate C, and continue to stir evenly; finally, add 77-207 parts of water, mix and stir, dilute evenly, and prepare the release agent.

[0013] In step (5), the stirring speed is 40-90 r / min and the stirring time is 20-50 min.

[0014] In step (6), the stirring speed when the suspending agent is mixed with water is 40-50 r / min and the stirring time is 20-40 min; after adding dextrin, the stirring speed is 60-100 r / min and the stirring time is 20-30 min; after adding pre-made aggregate C, the stirring speed is 50-70 r / min and the stirring time is 20-30 min.

[0015] All raw materials used in this invention are inexpensive and widely available, primarily utilizing renewable resources such as dry straw and rice husk powder, supplemented by coal slime as aggregate for the release agent. Because coal slime is easily sintered and tends to accumulate at the bottom of the inner surface of the casting mold, it makes demolding the alloy iron block difficult. The addition of easily combustible rice husk powder and easily oxidized carbonized straw creates numerous gas channels within the release agent coating at high temperatures, making the release agent structure porous. This significantly reduces the sintering strength of the release agent coating, making it prone to pulverization. It also reduces the sintering strength of the coal slime, increasing the gap between the alloy casting, the release agent coating, and the casting mold, thus facilitating the demolding of the alloy casting.

[0016] This invention incorporates easily carbonizable dextrin, white latex powder, and asphalt powder. After demolding, when the release agent is re-sprayed, the residual heat of the mold dries the release agent coating. The dextrin, white latex powder, and asphalt powder in the release agent coating gradually decompose upon heating, generating gas and forming numerous gas channels within the coating. This loosens the coating and promotes the pulverization of the sintered coating. The pyrolysis of dextrin and white latex powder forms a large amount of residual carbon in the release agent coating, lubricating the surface of the alloy ingot and improving the demolding rate of the alloy iron ingot. The thermal decomposition of asphalt powder forms a large amount of residual carbon chains, ensuring that the loose release agent coating has sufficient strength to resist the erosion of the molten alloy iron and preventing the release agent coating from being completely washed away by the molten alloy iron.

[0017] This invention incorporates water-quenched slag powder, utilizing waste materials from ferroalloy plants—materials that are difficult to comprehensively utilize—as release agent aggregates, enabling the recycling of these materials and reducing the production costs of iron plants.

[0018] This invention does not contain non-renewable resources such as flake graphite, which is conducive to the green and sustainable development of the foundry industry. Water glass can react with iron oxide on the surface of the casting mold at high temperatures, gradually corroding the mold and reducing its lifespan. This invention, however, does not contain corrosive materials like water glass and therefore does not corrode the casting mold, which is beneficial for the long-term operation of the equipment. This invention does not contain flake graphite or water glass. Using coal slime, rice husk powder, and dry straw as the main materials, along with anthracite powder, asphalt powder, yellow dextrin, water-quenched slag, white latex powder, and suspending agents, and with the defoaming effect of sodium stearate, the resulting release agent makes the alloy iron block have a smooth surface and is easy to demold. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the internal structure of the alloy casting; in which Figure 1 a is a schematic diagram of the internal structure of the alloy casting after demolding with the release agent prepared in Example 1. Figure 1 b is a schematic diagram of the internal structure of the alloy casting after demolding with the release agent prepared in Comparative Example 1.

[0020] Figure 2 This is a photograph showing the smooth surface of the alloy iron block after demolding with the release agent prepared in Example 1. Detailed Implementation

[0021] A release agent for a one-time alloy casting machine, comprising the following components in parts by weight: 1-5 parts electric furnace dust, 30-70 parts coal slime, 3-10 parts anthracite powder, 3-15 parts asphalt powder, 4-12 parts suspending agent, 5-60 parts rice husk powder, carbonized straw obtained by carbonization treatment of 60-200 parts dry straw, 1-10 parts yellow dextrin, 5-15 parts water-quenched slag powder, 0-3 parts white latex powder, 0-3 parts sodium benzoate, 0-3 parts sodium stearate, and 150-300 parts water.

[0022] The suspending agent is prepared by mixing calcium-based bentonite, attapulgite, and water in a mass ratio of 3:1:12 and stirring until homogeneous. The suspending agent must be left to stand for at least 6 hours before use.

[0023] The carbonized straw is prepared by first cutting dry straw into small pieces of 10-12cm, drying it in a drying oven at 110-120℃ for 2-4 hours, then placing the dried straw in a carbonization furnace and calcining it at 300-450℃ for 2-4 hours, removing it, and placing it in a closed silo to cool to room temperature to obtain carbonized straw.

[0024] The dry straw is composed of one or more of the following: corn stalks, wheat straw, rice straw, branches, and wood chips.

[0025] The electric furnace dust has a particle size of 200 mesh, the smokeless coal powder and asphalt powder have a particle size of 120 mesh, the rice husk powder has a particle size of 80 mesh, and the water-quenched slag powder has a particle size of 40 mesh.

[0026] A method for preparing a release agent for a one-time alloy casting machine includes the following steps: (1) Preparation of suspension Mix calcium-based bentonite, attapulgite, and water in a mass ratio of 3:1:12 to prepare a suspension. The suspension should be left to stand for 6 hours before use. It should be noted that the water used in mixing the suspension is part of the suspension and is not included in the above water usage. (2) Preparation of carbonized straw Cut the dry straw into small pieces of 8-10cm, put them into a drying oven at 110-120℃ and dry them for 2-4 hours. Then put the dried straw into a carbonization furnace and calcine it at 300-450℃ for 2-4 hours. Take it out and put it into a closed silo to cool to room temperature to obtain carbonized straw. (3) Precast aggregate A Place 30-70 parts of coal slime into a drying oven at 110-120℃ and bake for 2-4 hours. Then, put the dried coal slime into a calcining furnace and calcine at 300-320℃ for 2-4 hours. Place it into a closed silo and cool it to obtain precast aggregate A. (4) Precast aggregate B The carbonized straw obtained by carbonizing 60-200 parts of dry straw in step (2) and the pre-aggregate A obtained in step (3) are put into a ball mill and ground for 40-50 minutes to obtain pre-aggregate B. (5) Precast aggregate C The prepared precast aggregate B is placed in a horizontal mixer along with dust collector ash, anthracite powder, asphalt powder, rice husk powder, water-quenched slag powder, and sodium benzoate. Then, 23-43 parts of water are added. The preferred mixing speed is 40-90 r / min, and the mixing time is 20-50 min to obtain precast aggregate C. (6) Preparation of release agent First, add the suspending agent prepared in step (1) and 50 parts of water to the powder mixer, and stir evenly. The preferred stirring speed is 40-50 r / min and the stirring time is 20-40 min. Then, add yellow dextrin, white latex powder and sodium stearate to the powder mixer and stir evenly. The preferred stirring speed is 60-100 r / min and the stirring time is 20-30 min. After stirring evenly, add pre-made aggregate C. The preferred stirring speed is 50-70 r / min and the stirring time is 20-30 min. Finally, add 77-207 parts of water, mix and stir, and dilute evenly to prepare the release agent. Example

[0027] The release agent for a one-time alloy casting machine is composed of the following components in parts by weight: 2 parts electric furnace dust, 65 parts coal slime, 4 parts anthracite powder, 5 parts asphalt powder, 8 parts suspending agent, 10 parts rice husk powder, carbonized straw obtained by carbonization treatment of 60 parts dry straw, 10 parts yellow dextrin, 5 parts water-quenched slag powder, 3 parts white latex powder, 0.5 parts sodium benzoate, 1 part sodium stearate, and 205 parts water.

[0028] Release agent for one-time alloy casting machine: Prepare raw materials according to the above dosage and prepare according to the following steps: (1) Preparation of suspension: calcium-based bentonite: attapulgite: water are mixed and stirred evenly in a mass ratio of 3:1:12 to prepare a suspension. The suspension is used after being left to stand for 6 hours.

[0029] (2) Preparation of carbonized straw: The dry straw is cut into small pieces of about 10cm, put into a drying oven at 120℃ and dried for 3 hours. Then the dried straw is put into a carbonization furnace and calcined at 350℃ for 2.5 hours. After that, it is taken out and placed in a closed silo to cool to room temperature to obtain carbonized straw.

[0030] (3) Precast aggregate A: The coal slime is placed in a drying furnace at 120°C and baked for 3 hours. Then the dried coal slime is placed in a calcining furnace and calcined at 300°C for 3 hours. It is then placed in a closed silo and cooled to obtain precast aggregate A.

[0031] (4) Precast aggregate B: The carbonized straw obtained in step (2) and the precast aggregate A obtained in step (3) are put into a ball mill and ground for 45 minutes to obtain precast aggregate B.

[0032] (5) Precast aggregate C: The obtained aggregate B, dust, smokeless coal powder, asphalt powder, rice husk powder, water-quenched slag powder, sodium benzoate, and 25 parts of water are placed in a horizontal mixer. The mixing speed is 45 r / min and the mixing time is 50 min to obtain precast aggregate C.

[0033] (6) Preparation of release agent: First, add the suspending agent prepared in step (1) to the powder mixer, add 50 parts of water, stir at low speed, stirring speed is 40 r / min, stirring time is 30 min, and stir evenly; then add yellow dextrin, white latex powder, sodium stearate, stirring speed is 70 r / min, stirring time is 25 min, and stir and mix evenly; after stirring evenly, add all the precast aggregate C, stirring speed is 60 r / min, stirring time is 20 min; finally add 130 parts of water, mix and stir, dilute evenly, and prepare the release agent. Example

[0034] The release agent for a one-time alloy casting machine is composed of the following components in parts by weight: 5 parts electric furnace dust, 70 parts coal slime, 10 parts anthracite powder, 15 parts asphalt powder, 6 parts suspending agent, 25 parts rice husk powder, carbonized straw obtained by carbonization treatment of 110 parts dry straw, 7 parts yellow dextrin, 7 parts water-quenched slag powder, 1 part white latex powder, 1 part sodium benzoate, 2 parts sodium stearate, and 253 parts water.

[0035] Release agent for one-time alloy casting machine: Prepare raw materials according to the above dosage and prepare according to the following steps: (1) Preparation of suspension: calcium-based bentonite: attapulgite: water are mixed and stirred evenly in a mass ratio of 3:1:12 to prepare a suspension. The suspension is used after being left to stand for 6 hours.

[0036] (2) Preparation of carbonized straw: The dry straw is cut into 12cm pieces, placed in a drying oven at 110℃ and dried for 4 hours. Then the dried straw is placed in a carbonization oven and calcined at 300℃ for 2 hours. After being taken out, it is placed in a closed silo and cooled to room temperature to obtain carbonized straw.

[0037] (3) Precast aggregate A: The coal slime is placed in a drying furnace at 110℃ and baked for 4 hours. Then the dried coal slime is placed in a calcining furnace and calcined at 320℃ for 2 hours. It is then placed in a closed silo and cooled to obtain precast aggregate A.

[0038] (4) Precast aggregate B: The carbonized straw obtained in step (2) and the precast aggregate A obtained in step (3) are put into a ball mill and ground for 40 minutes to obtain precast aggregate B.

[0039] (5) Precast aggregate C: The obtained aggregate B, dust, smokeless coal powder, asphalt powder, rice husk powder, water-quenched slag powder, sodium benzoate, and 28 parts of water are placed in a horizontal mixer. The mixing speed is 50 r / min and the mixing time is 35 min to obtain precast aggregate C.

[0040] (6) Preparation of release agent: First, add the suspending agent prepared in step (1) to the powder mixer, add 50 parts of water, stir at low speed, stirring speed is 50 r / min, stirring time is 40 min, and stir evenly; then add yellow dextrin, white latex powder, sodium stearate, stirring speed is 90 r / min, stirring time is 20 min, and stir and mix evenly; after stirring evenly, add all the precast aggregate C, stirring speed is 52 r / min, stirring time is 28 min; finally add 175 parts of water, mix and stir, dilute evenly, and prepare the release agent. Example

[0041] The release agent for a one-time alloy casting machine is composed of the following components in parts by weight: 4 parts electric furnace dust, 40 parts coal slime, 3 parts anthracite powder, 12 parts asphalt powder, 12 parts suspending agent, 60 parts rice husk powder, carbonized straw obtained by carbonization treatment of 180 parts dry straw, 9 parts yellow dextrin, 8 parts water-quenched slag powder, 3 parts white latex powder, 2 parts sodium benzoate, 1.3 parts sodium stearate, and 300 parts water.

[0042] Release agent for one-time alloy casting machine: Prepare raw materials according to the above dosage and prepare according to the following steps: (1) Preparation of suspension: calcium-based bentonite: attapulgite: water are mixed and stirred evenly in a mass ratio of 3:1:12 to prepare a suspension. The suspension is used after being left to stand for 6 hours.

[0043] (2) Preparation of carbonized straw: The dry straw is cut into small pieces of about 10cm, put into a drying oven at 115℃ and dried for 2 hours. Then the dried straw is put into a carbonization furnace and calcined at 400℃ for 4 hours. After taking it out, it is put into a closed silo and cooled to room temperature to obtain carbonized straw.

[0044] (3) Precast aggregate A: The coal slime is placed in a drying furnace at 115℃ and baked for 2 hours. Then the dried coal slime is placed in a calcining furnace and calcined at 310℃ for 4 hours. It is then placed in a closed silo and cooled to obtain precast aggregate A.

[0045] (4) Precast aggregate B: The carbonized straw obtained in step (2) and the precast aggregate A obtained in step (3) are put into a ball mill and ground for 50 minutes to obtain precast aggregate B.

[0046] (5) Precast aggregate C: The obtained aggregate B, dust, smokeless coal powder, asphalt powder, rice husk powder, water-quenched slag powder, sodium benzoate, and 43 parts of water are placed in a horizontal mixer. The mixing speed is 60 r / min and the mixing time is 20 min to obtain precast aggregate C.

[0047] (6) Preparation of release agent: First, add the suspending agent prepared in step (1) to the powder mixer, add 50 parts of water, stir at low speed, stirring speed is 48 r / min, stirring time is 38 min, and stir evenly; then add yellow dextrin, white latex powder, sodium stearate, stirring speed is 60 r / min, stirring time is 30 min, and stir and mix evenly; after stirring evenly, add all the precast aggregate C, stirring speed is 55 r / min, stirring time is 23 min; finally add 207 parts of water, mix and stir, dilute evenly, and prepare the release agent. Example

[0048] The difference from Example 1 is that the amounts of each component are different: 1 part electric furnace dust, 58 parts coal slime, 3 parts anthracite powder, 15 parts asphalt powder, 11 parts suspending agent, 24 parts rice husk powder, carbonized straw obtained by carbonization treatment of 200 parts dry straw, 8 parts yellow dextrin, 15 parts water-quenched slag powder, 0.5 parts white latex powder, 1 part sodium benzoate, 0.3 parts sodium stearate, and 267 parts water.

[0049] Step (2) The carbonization temperature of the dry straw is 450℃. Step (5) Add 27 parts of water to the pre-made aggregate C, and stir at a speed of 50 r / min for 50 min. Step (6) When adding the suspending agent, add 50 parts of water, and stir at a speed of 47 r / min for 29 min; after adding dextrin, white latex powder and sodium stearate, stir at a speed of 68 r / min for 22 min; after adding pre-made aggregate C, stir at a speed of 62 r / min for 24 min, and finally dilute with 190 parts of water.

[0050] The dosages for Examples 5-8 are shown in Table 1 below, and the corresponding process parameters are shown in Table 2 below. The other preparation methods are the same as in Example 1.

[0051] Table 1

[0052] Table 2

[0053] The only difference from Example 1 is that the dry straw is not carbonized. The dry straw is cut into small pieces of about 2cm, put into an 80℃ drying oven to dry for 3 hours, and then the dried straw is ground in a roller mill for 2.5 hours. After that, it is taken out and put into a 60-mesh vibrating screen for sieving. The undersize material is straw powder.

[0054] The release agent prepared in Comparative Example 1 and the release agent prepared in Example 1 were used together with the same casting and cooling processes to cast small-sized alloy blocks, resulting in small-sized alloy blocks as shown in the figure. Figure 1As shown, when using the release agent prepared in Comparative Example 1 for demolding, a honeycomb structure easily appears inside the cast small-sized alloy ingot. Figure 1 b. This reduces the strength and density of the alloy ingot, while increasing the powder content. Demolding with the release agent prepared in Example 1 resulted in a relatively dense internal structure in the small-sized alloy ingot. (See...) Figure 1 a) The ingots have high strength, high density, and low powder content, resulting in small-sized alloy ingots with smooth surfaces that are easy to demold. Figure 2 As shown.

[0055] This is because the straw powder in Comparative Example 1 was not carbonized and contained a lot of organic matter. During casting, it rapidly vaporized upon contact with the molten iron, and the released gas could not completely escape from the surface of the molten iron. The cooling water sprayed by the cooling spray device fell onto the surface of the molten iron. After the cooling water carried away the heat, the surface of the molten iron gradually condensed into a shell, which would hinder the escape of gas below the molten iron. As a result, a small amount of gas remained inside the molten iron, which easily formed a honeycomb structure inside the casting during cooling.

[0056]

[0057] All raw materials used in this invention are inexpensive and widely available, primarily utilizing renewable resources such as dry straw and rice husk powder, supplemented by coal slime as aggregate for the release agent. Because coal slime is easily sintered and tends to accumulate at the bottom of the inner surface of the casting mold, it makes demolding the alloy iron block difficult. The addition of easily combustible rice husk powder and easily oxidized carbonized straw creates numerous gas channels within the release agent coating at high temperatures, making the release agent structure porous. This significantly reduces the sintering strength of the release agent coating, making it prone to pulverization. It also reduces the sintering strength of the coal slime, increasing the gap between the alloy casting, the release agent coating, and the casting mold, thus facilitating the demolding of the alloy casting.

[0058] This invention incorporates easily carbonizable dextrin, white latex powder, and asphalt powder. After demolding, when the release agent is re-sprayed, the residual heat of the mold dries the release agent coating. The dextrin, white latex powder, and asphalt powder in the release agent coating gradually decompose upon heating, generating gas and forming numerous gas channels within the coating. This loosens the coating and promotes the pulverization of the sintered coating. The pyrolysis of dextrin and white latex powder forms a large amount of residual carbon in the release agent coating, lubricating the surface of the alloy ingot and improving the demolding rate of the alloy iron ingot. The thermal decomposition of asphalt powder forms a large amount of residual carbon chains, ensuring that the loose release agent coating has sufficient strength to resist the erosion of the molten alloy iron and preventing the release agent coating from being completely washed away by the molten alloy iron.

[0059] This invention incorporates water-quenched slag powder, utilizing waste materials from ferroalloy plants—materials that are difficult to comprehensively utilize—as release agent aggregates, enabling the recycling of these materials and reducing the production costs of iron plants.

[0060] This invention does not contain non-renewable resources such as flake graphite, which is conducive to the green and sustainable development of the foundry industry. Water glass can react with iron oxide on the surface of the casting mold at high temperatures, gradually corroding the mold and reducing its lifespan. This invention, however, does not contain corrosive materials like water glass and therefore does not corrode the casting mold, which is beneficial for the long-term operation of the equipment. This invention uses coal slime, rice husk powder, and dry straw as the main materials, combined with anthracite powder, asphalt powder, yellow dextrin, water-quenched slag, white latex powder, and suspending agents. With the defoaming effect of sodium stearate, the resulting release agent makes the alloy iron block have a smooth surface and is easy to demold.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A release agent for a one-time alloy casting machine, characterized in that... The release agent is composed of the following components in parts by weight: 1-5 parts electric furnace dust, 30-70 parts coal slime, 3-10 parts anthracite powder, 3-15 parts asphalt powder, 4-12 parts suspending agent, 5-60 parts rice husk powder, carbonized straw obtained by carbonization treatment of 60-200 parts dry straw, 1-10 parts yellow dextrin, 5-15 parts water-quenched slag powder, 0-3 parts white latex powder, 0-3 parts sodium benzoate, 0-3 parts sodium stearate, and 150-300 parts water. Preparation method of release agent for one-time alloy casting machine Includes the following steps: (1) Preparation of suspension Mix calcium-based bentonite, attapulgite, and water in a mass ratio of 3:1:12 to prepare a suspension. Let it stand for at least 6 hours before use. (2) Preparation of carbonized straw Cut the dry straw into small pieces of 8-10cm, put them into a drying oven at 110-120℃ and dry them for 2-4 hours. Then put the dried straw into a carbonization furnace and calcine it at 300-450℃ for 2-4 hours. Take it out and put it into a closed silo to cool to room temperature to obtain carbonized straw. (3) Precast aggregate A Place 30-70 parts of coal slime into a drying oven at 110-120℃ and bake for 2-4 hours. Then, put the dried coal slime into a calcining furnace and calcine at 300-320℃ for 2-4 hours. Place it into a closed silo and cool it to obtain precast aggregate A. (4) Precast aggregate B The carbonized straw obtained by carbonizing 60-200 parts of dry straw in step (2) and the pre-aggregate A obtained in step (3) are put into a ball mill and ground for 40-50 minutes to obtain pre-aggregate B. (5) Precast aggregate C The prepared precast aggregate B is mixed with 1-5 parts of dust removal ash, 3-10 parts of anthracite powder, 3-15 parts of asphalt powder, 5-60 parts of rice husk powder, 5-15 parts of water-quenched slag powder, and 0-3 parts of sodium benzoate in a horizontal mixer. Then, 23-43 parts of water are added and the mixture is stirred to obtain precast aggregate C. (6) Preparation of release agent First, add 4-12 parts of the suspending agent prepared in step (1) to the powder mixer, add 50 parts of water, and stir evenly; then add 1-10 parts of yellow dextrin, 0-3 parts of white latex powder, and 0-3 parts of sodium stearate to the powder mixer, and stir evenly; after stirring evenly, add pre-made aggregate C, and continue to stir evenly; finally, add 77-207 parts of water, mix and stir, dilute evenly, and prepare the release agent.

2. The release agent for one-time alloy casting machines according to claim 1, characterized in that: The dry straw is composed of one or more of the following: corn stalks, wheat straw, rice straw, branches, and wood chips.

3. The release agent for one-time alloy casting machines according to claim 1, characterized in that: The electric furnace dust has a particle size of 200 mesh, the smokeless coal powder and asphalt powder have a particle size of 120 mesh, the rice husk powder has a particle size of 80 mesh, and the water-quenched slag powder has a particle size of 40 mesh.

4. The release agent for a one-time alloy casting machine according to claim 1, characterized in that: In step (5), the stirring speed is 40-90 r / min and the stirring time is 20-50 min.

5. The release agent for a one-time alloy casting machine according to claim 1, characterized in that: In step (6), the stirring speed when the suspending agent is mixed with water is 40-50 r / min and the stirring time is 20-40 min; the stirring speed after adding yellow dextrin is 60-100 r / min and the stirring time is 20-30 min; the stirring speed after adding pre-made aggregate C is 50-70 r / min and the stirring time is 20-30 min.

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