The ladle is a container of molten steel. The commonly used refractory materials are aluminum-magnesium spinel ladle castable, magnesia-alumina spinel brick, ladle lining brick, etc. The use of aluminum-magnesium spinel can provide flaking resistance of refractory materials.
The aluminum-magnesium spinel castable is also called corundum or high-alumina magnesia spinel refractory castable, also called composite aluminum-magnesium spinel refractory castable. It has excellent functions and is used in large and medium-sized ladle.
Magnesium-aluminum spinel has excellent corrosion resistance, strong corrosion resistance, good slag resistance, anti-abrasive ability, good thermal shock resistance and high temperature resistance. It is the ambition material for the high-temperature belt of cement rotary kiln with magnesium-aluminum spinel brick, ladle lining brick, ladle castable and other refractory products. Magnesium-aluminum spinel is widely used in refractory materials, steel exercise, cement rotary kiln and glass industrial furnaces.
1. Aluminium-magnesium spinel ladle castable is a kind of special grade bauxite, corundum and high-purity spinel as the main material, which is mixed with appropriate additives and dispersants. High density and durability;
2. Ladle castables should be stored in warehouses with rainproof equipment and monotonous ventilation according to the varieties and trademarks. Beware of moisture, prevent prolonged agglomeration, chemical bond failure, and affect the application effect.
3. In the case of better storage conditions, the shelf life is half a year. After half a year, the physical and chemical function indicators need to be checked. Once the requirements are met, they can be used as usual.
Construction preparation
1. Plan the construction plan site before the construction of high temperature resistant castables, and do a good job of technical delivery for the construction personnel of each position, so that the operators can grasp the construction key of each process and understand the construction and application functions of the ladle castable.
2. The materials used for construction should be stacked on the site or next to the mixer. Organized personnel can also be transported from the warehouse to the site. Stacking and transporting should not be damp and rain.
3. Before the construction, it is necessary to sample and inspect the castables entering the plant, which is suitable for the talents of the technical requirements of the castables.
Pouring
1. Select 30~50mm vibrating rod for vibration pouring.
2. Firstly, the bottom of the package is filled with the material, and the vibrating rod is used to smooth the vibration to ensure the thickness of the casting layer or slightly thickened.
3, after the bottom of the package, after 2 to 4 hours, place the core, the core should be placed in the middle of the ladle, not offset, and should be leveled, the surface of the core should be clean, handle the slip and oil, Eli demould.
4. When pouring vibration operation, pay attention to the following items:
(1) The vibrating bar must not touch the core and the heat insulating material, so it should be kept at a certain distance from the core and the heat insulating material, but it should not be larger than 50mm.
(2) The penetration depth of the vibrating bar shall not touch the underlying castable, but the distance from the bottom layer shall not exceed 50 mm.
(3) The distance between the piercing points of the vibrating bar shall not exceed 200mm, and the uniform and dense vibration shall be adhered to. When the vibrating bar is pulled out, it shall be lifted slowly, and shall not be pulled out to prevent the air from being left empty.
(4) A special person should be in possession of the vibrating rod. If it is found that there are unqualified quality requirements, it should be treated in time to continue construction.
(5) Pouring the wall of the package is generally one circle of material vibration, each feeding thickness is about 250mm, to achieve uniform cloth, and pay attention to uniform vibration, avoid leakage vibration, vibration should be dense, no dead angle. To prevent the appearance of pockmarks, empty and so on. Vibration personnel and quality inspectors should be strictly mastered.
Demoulding
1. After vibrating the wall, the ladle is hoisted to a slightly higher temperature area for easy water evaporation. The casting body is monotonous. The demoulding time should be more than 12 hours, generally 12~24 hours, depending on the hardening of the lining. set.
2. After the mold release, it is naturally monotonous for 24 hours. It is best to place it in the baking bag area to facilitate the quick sweep of moisture and prepare the baking bag together.
Baking
1. Due to the large amount of water in the whole castable ladle and the fine structure of the material, the water is not easy to be discharged. Therefore, in the baking process of the ladle, in the long time of the small fire, the temperature is gradually raised to prevent the rapid heating, and the principle of roasting the fire is stopped. Otherwise, The ladle collapsed and the work was abandoned. Bake with a baking machine and bake according to the principle of 72 hours. The specific distribution is as follows:
Small fire stage: no less than 3 shifts, 24 hours (only 1/2 gas is opened, no cover);
Medium fire stage: no less than 3 shifts, 24 hours (only 1/3 gas is added, a small amount of wind is added, covered); Fire stage: no less than 3 shifts, 24 hours (open gas, add foot wind, cover)
2. The baking curve is shown in the figure:
3. The standard for baking is that the vent hole along the wall or the wall no longer evaporates the water vapor intermittently. 4. Once the baking is initially carried out, it shall not be interrupted halfway or it may cause delamination to fall.
Use
1. Try to speed up the turnover after putting into operation, and achieve the utilization rate and turnover rate of the red envelope Yinggang.
2. After the corrosion of the ladle slag line is repaired with the castable of the same material, it may be poured and shaken with a vibrating rod. The trowel may be used to extend the age and save the amount of castable.
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