Novel steel ladle covering agent

Abstract

The invention discloses a novel steel ladle covering agent, and belongs to the technical field of steel ladle covering agents. The steel ladle covering agent is composed of the following components in percentage by weight: 65-75% of red mud, and the calcium content of the red mud is 45% or above; 15%-25% of calcined aluminum ash; 5%-15% of clay, wherein the silicon content in the clay is more than 50%; 1%-4% of pulverized coal; and 1%-4% of an alkaline material. The novel steel ladle covering agent is good in heat retaining property, has good spreadability, can well adsorb inclusions in molten steel, is obvious in desulfurization effect, reduces the steelmaking cost, and improves the steelmaking quality and the steelmaking efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of ladle covering agents, and specifically to a new type of ladle covering agent. Background Art

[0002] A suitable molten steel temperature is a necessary condition to ensure the smooth casting of molten steel into qualified ingots. In order to prevent the molten steel in the ladle from being directly exposed to the air, resulting in too rapid a temperature drop of the molten steel during the casting process, it is necessary to add a certain amount of molten steel heat preservation agent to the surface of the molten steel after tapping from the converter for heat preservation. The quality of the heat preservation effect of the heat preservation agent has a great impact on the quality of the ingots.

[0003] The raw materials of traditional covering agents are made from materials such as high-calcium powder, bauxite, and pulverized coal through high temperature. Their cost is high and the heat preservation effect is poor, resulting in low steelmaking efficiency.

[0004] With the continuous improvement of the market's requirements for steel quality, traditional ladle covering agents can no longer meet the requirements of steelmaking production. Developing new types of ladle covering agents has become a new demand for steelmaking production. Summary of the Invention

[0005] The purpose of the present invention is to provide a new type of ladle covering agent to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions: A new type of ladle covering agent, calculated by weight percentage, consists of the following components: Red mud 65% - 75%, where the calcium content in the red mud is more than 45%; Calcined aluminum ash 15% - 25%; Clay 5% - 15%, where the silicon content in the clay is more than 50%; Pulverized coal 1% - 4%; Alkaline material 1% - 4%.

[0007] As a further preferred solution of the present invention: the alkaline material is magnesium oxide.

[0008] A preparation method of a new type of ladle covering agent includes the following steps: Step 1: Add calcined aluminum ash to the red mud, stir evenly, stack, and after sufficient reaction heat generation, add pulverized coal and the alkaline material; Step 2: Put the mixed material in Step 1 into a mixer for grinding and stirring evenly to make the moisture content of the material reach 13% - 15%; Step 3: Feed the material with a moisture content of 13% - 15% into a drum granulator at 200°C - 210°C to make semi-finished products with a spherical particle size of 0 - 0.3 mm; Step 4: Feed the semi-finished product into an open-flame roller drying kiln at 600°C - 610°C to obtain a finished covering agent with a spherical particle size of 0 - 0.3 mm and a moisture content of less than 0.5%. Step 5: Package the finished covering agent through an automatic packaging machine and store it in the warehouse.

[0009] Mechanism of action: Calcium in red mud can play a role in desulfurizing molten steel; calcined aluminum ash can play a role in deoxidizing molten steel, while silicon in magnesia and clay and carbon in pulverized coal can play a role in heat preservation and purifying molten steel, reducing the bulk density of the covering agent and improving the comprehensive performance of the covering agent. The scientific proportioning of various materials can achieve better overall effects, reduce costs, and improve the efficiency of steelmaking.

[0010] Compared with the prior art, the beneficial effects of the present invention are: The novel ladle covering agent has good heat preservation performance, good spreading performance, can well adsorb inclusions in molten steel, has obvious desulfurization effect, reduces the cost of steelmaking, and improves the quality and efficiency of steelmaking. Specific embodiments

[0011] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment 1

[0012] This embodiment provides a novel ladle covering agent, which is composed of the following components by weight percentage: Red mud 65% - 75%, where the calcium content in the red mud is more than 45%; Calcined aluminum ash 15% - 25%; Clay 5% - 15%, where the silicon content in the clay is more than 50%; Pulverized coal 1% - 4%; Alkaline material 1% - 4%, where the alkaline material is preferably magnesia.

[0013] Furthermore, the above components are prepared into a finished covering agent according to the following steps: Step 1: Add the calcined aluminum ash to the red mud, stir evenly, stack it, and then add the pulverized coal and alkaline material after the reaction generates heat sufficiently; Step 2: Put the mixed material in Step 1 into a mixer, grind and stir evenly to make the moisture content of the material reach 13% - 15%; Step 3: Feed the material with a moisture content of 13% - 15% into a roller granulator at 200°C - 210°C to make a semi-finished product with a spherical particle size of 0 - 0.3 mm; Step 4: Feed the semi-finished product into an open-flame rotary drying kiln at 600°C - 610°C to obtain a finished covering agent with a spherical particle size of 0 - 0.3 mm and a moisture content of less than 0.5%. Step 5: Package the finished covering agent into storage by an automatic packaging machine. Example 2

[0014] Take the following raw materials by weight percentage: 65% red mud, 15% calcined aluminum ash, 15% clay, 1% pulverized coal, 4% magnesium oxide, and prepare the above raw materials into a finished ladle covering agent according to the preparation steps in Example 1.

[0015] When tapping steel from the converter, the molten steel temperature is 1630°C. After tapping steel from the converter, add the ladle covering agent of this example to the ladle, and transfer it to the refining furnace after tapping steel from the converter. The measured temperature upon entering the furnace reaches 1605°C, and the temperature drop is 25°C. Example 3

[0016] Take the following raw materials by weight percentage: 75% red mud, 15% calcined aluminum ash, 5% clay, 4% pulverized coal, 1% magnesium oxide, and prepare the above raw materials into a finished ladle covering agent according to the preparation steps in Example 1.

[0017] When tapping steel from the converter, the molten steel temperature is 1635°C. After tapping steel from the converter, add the ladle covering agent of this example to the ladle, and transfer it to the refining furnace after tapping steel from the converter. The measured temperature upon entering the furnace reaches 1608°C, and the temperature drop is 27°C. Example 4

[0018] Take the following raw materials by weight percentage: 65% red mud, 25% calcined aluminum ash, 5% clay, 4% pulverized coal, 1% magnesium oxide, and prepare the above raw materials into a finished ladle covering agent according to the preparation steps in Example 1.

[0019] When tapping steel from the converter, the molten steel temperature is 1632°C. After tapping steel from the converter, add the ladle covering agent of this example to the ladle, and transfer it to the refining furnace after tapping steel from the converter. The measured temperature upon entering the furnace reaches 1605°C, and the temperature drop is 27°C. Example 5

[0020] Take the following raw materials by weight percentage: 68% red mud, 17% calcined aluminum ash, 10% clay, 3% pulverized coal, 2% magnesium oxide, and prepare the above raw materials into a finished ladle covering agent according to the preparation steps in Example 1.

[0021] When tapping molten steel from the converter, the temperature of the molten steel is 1635 °C. After tapping from the converter, the ladle covering agent of this embodiment is added to the ladle, and then it is transported to the refining furnace after tapping from the converter. The measured temperature upon entering the furnace reaches 1606 °C, and the temperature drop is 29 °C.

[0022] In summary, the present invention can effectively improve the heat preservation effect of the covering agent, control the temperature drop of the molten steel below 30 °C, reduce the time and materials required for secondary heating during refining, reduce the steelmaking cost, and improve the steelmaking efficiency.

[0023] In addition, the technical solution of this application is not limited to the above embodiments. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation manners understandable to those skilled in the art.

Claims

1. A new type of ladle covering agent, characterized in that, By weight percentage, it consists of the following components: Red mud 65% - 75%, in which the calcium content in the red mud is more than 45%; Calcined aluminum ash 15% - 25%; Clay 5% - 15%, in which the silicon content in the clay is more than 50%; Coal powder 1% - 4%; Alkaline material 1% - 4%.

2. The novel ladle covering agent according to claim 1, characterized in that, The alkaline material is magnesium oxide.

3. A preparation method of a novel ladle covering agent as described in claim 1, characterized in that, It includes the following steps: Step 1: Add the calcined aluminum ash to the red mud, stir evenly, stack it, and after the reaction generates heat sufficiently, add the coal powder and the alkaline material; Step 2: Put the mixed material in Step 1 into a mixer for grinding and stirring evenly to make the moisture content of the material reach 13% - 15%; Step 3: Feed the material with a moisture content of 13% - 15% into a drum granulator at 200°C - 210°C to make semi-finished products with a spherical particle size of 0 - 0.3 mm; Step 4: Feed the semi-finished products into an open-flame drum drying kiln at 600°C - 610°C to obtain finished covering agents with a spherical particle size of 0 - 0.3 mm and a moisture content of less than 0.5%; Step 5: Package the finished covering agents through an automatic packaging machine and store them in the warehouse.