Environment-friendly fluoride-free KR desulfurization powder and use method thereof

Abstract

The invention provides environment-friendly fluoride-free KR desulfurization powder which comprises the following components in percentage by mass: 78-90% of CaO; 1%-4% of Al; 4%-8% of Al2O3; 0 to 3 percent of SiO2; 0 to 3 percent of MgO; 0 to 0.05 percent of S; the balance is impurities; traditional fluorite is not used as a fluxing agent, so that the environment is not polluted, a ladle is not eroded, and the steelmaking cost is reduced; high-efficiency desulfurization is realized, Al2O3 can be generated by combining with free oxygen in molten iron, the oxygen activity is reduced, and the desulfurization reaction speed can be further increased; and compensating temperature drop. The formula is simple, and the problems that fluorite is harmful to the environment and can erode ladles, and the steelmaking cost is increased are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to an environmentally friendly fluorine-free KR desulfurization powder and a use method thereof. Background Art

[0002] The KR (Kambara Reactor) method immerses a cross-shaped stirring head that has been cast with refractory materials and baked into the molten iron pool to a certain depth, and uses the vortex generated by the rotation of the stirring head to make the desulfurizer fully contact and react with the molten iron to achieve the purpose of desulfurization; it effectively improves the desulfurization efficiency. However, some steel mills still use a desulfurizer composed of lime and fluorite in the KR desulfurization process, and fluorite is not only harmful to the environment, but also corrodes the molten iron ladle and increases the cost of steelmaking. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides an environmentally friendly fluorine-free KR desulfurization powder, wherein the environmentally friendly fluorine-free KR desulfurization powder comprises, by mass percentage:

[0004] CaO: 78%~90%;

[0005] Al: 1% to 4%;

[0006] Al2O3: 4%~8%;

[0007] SiO2: 0-3%;

[0008] MgO: 0-3%;

[0009] S: 0~0.05%;

[0010] The rest are impurities.

[0011] Furthermore, in the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the raw materials of the environmentally friendly fluorine-free KR desulfurization powder are lime and AD powder, and the lime and the AD powder are ground by using a Raymond mill.

[0012] Furthermore, in the environmentally friendly fluorine-free KR desulfurization powder described in the present invention, the particle size of the environmentally friendly fluorine-free KR desulfurization powder is 0 to 1 mm.

[0013] The present invention also provides a method for using an environmentally friendly fluorine-free KR desulfurization powder; the environmentally friendly fluorine-free KR desulfurization powder is added to a molten iron ladle in a spraying manner through a spray gun.

[0014] Furthermore, in the method for using the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the spray gun uses an inert gas as a carrier.

[0015] Furthermore, in the method for using the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the amount of the environmentally friendly fluorine-free KR desulfurization powder added is 6 to 10 kg per ton of steel.

[0016] Furthermore, in the method for using the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the temperature of the molten iron is 1300° C. to 1400° C. when the environmentally friendly fluorine-free KR desulfurization powder is added.

[0017] Compared with the prior art, the present invention adopts an environmentally friendly fluorine-free KR desulfurization powder, which includes, by mass percentage: CaO: 78% to 90%; Al: 1% to 4%; Al2O3: 4% to 8%; SiO2: 0 to 3%; MgO: 0 to 3%; S: 0 to 0.05%; the rest are impurities. Since the present invention does not use traditional fluorite as a flux, it will not pollute the environment and corrode the iron ladle, thereby reducing the cost of steelmaking. High-efficiency desulfurization, and Al2O3 in the AD powder has a strong activity, which is very easy to combine with high-quality active lime to form low-melting-point calcium aluminate, has a high sulfur capacity, and can desulfurize efficiently. Deoxidation. The environmentally friendly fluorine-free KR desulfurization powder in the present invention contains metallic aluminum powder, which can combine with free oxygen in molten iron to generate Al2O3, reduce oxygen activity, and further increase the desulfurization reaction rate. Compensation for temperature drop. Aluminum powder combined with free oxygen will generate heat, which can compensate for the temperature drop of molten iron caused by part of the desulfurization process. The formula is simple, the production process is not complicated, the cost is low, and it can be widely promoted and applied. It solves the problem that fluorite is not only harmful to the environment, but also corrodes the ladle and increases the cost of steelmaking.

[0018] The invention has the following advantages: environmental friendliness. The environmentally friendly fluorine-free KR desulfurization powder in the present invention does not use traditional fluorite as a flux, will not pollute the environment and corrode the iron ladle, and reduces the cost of steelmaking. Highly efficient desulfurization. The Al2O3 in the AD powder has a strong activity and can easily combine with high-quality active lime to generate low-melting-point calcium aluminate, which has a high sulfur capacity and can efficiently desulfurize. Deoxidation. The environmentally friendly fluorine-free KR desulfurization powder in the present invention contains metallic aluminum powder, which can combine with free oxygen in molten iron to generate Al2O3, reduce oxygen activity, and further increase the desulfurization reaction rate. Compensation for temperature drop. Aluminum powder will generate heat when combined with free oxygen, which can compensate for the temperature drop of molten iron caused by part of the desulfurization process. The formula is simple, the production process is not complicated, the cost is low, and it can be promoted and applied on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] none DETAILED DESCRIPTION

[0020] In the first embodiment of the present invention, an environmentally friendly fluorine-free KR desulfurization powder is provided, which comprises, by mass percentage:

[0021] CaO: 78%~90%;

[0022] Al: 1% to 4%;

[0023] Al2O3: 4%~8%;

[0024] SiO2: 0-3%;

[0025] MgO: 0-3%;

[0026] S: 0~0.05%;

[0027] The rest are impurities.

[0028] Since the present invention does not use traditional fluorite as a flux, it will not pollute the environment or corrode the iron ladle, thereby reducing the cost of steelmaking. Highly efficient desulfurization, and the Al2O3 in the AD powder has a strong activity, which is very easy to combine with high-quality active lime to form low-melting-point calcium aluminate, has a high sulfur capacity, and can efficiently desulfurize. Deoxidation. The environmentally friendly fluorine-free KR desulfurization powder in the present invention contains metallic aluminum powder, which can combine with free oxygen in the molten iron to generate Al2O3, reduce oxygen activity, and further increase the desulfurization reaction rate. Compensation for temperature drop. Aluminum powder combined with free oxygen will generate heat, which can compensate for the temperature drop of the molten iron caused by part of the desulfurization process. The formula is simple, the production process is not complicated, the cost is low, and it can be promoted and applied on a large scale. It solves the problem that fluorite is not only harmful to the environment, but also corrodes the iron ladle and increases the cost of steelmaking.

[0029] The raw materials of the environmentally friendly fluorine-free KR desulfurization powder in this embodiment are lime and AD powder, and the lime and AD powder are ground by Raymond mill. The particle size of the environmentally friendly fluorine-free KR desulfurization powder is 0-1mm. The environmentally friendly fluorine-free KR desulfurization powder is added to the molten iron ladle by spraying through a spray gun.

[0030] In the method for using the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the spray gun uses an inert gas as a carrier. In the environmentally friendly fluorine-free KR desulfurization powder of the present invention, the amount of environmentally friendly fluorine-free KR desulfurization powder added is 6-10 kg / ton of steel. When the environmentally friendly fluorine-free KR desulfurization powder is added, the molten iron temperature is 1300°C-1400°C.

[0031] In order to better illustrate the above technical effects, three examples of using the environmentally friendly fluorine-free KR desulfurization powder of the present invention are listed:

[0032] A KR powder spray desulfurization test was carried out on a 270t KR ladle in a domestic steel plant.

[0033] In the comparative example, a conventional fluorite desulfurizer was used, and its composition was: CaO: 83.7%, CaF2: 8.92%.

[0034] The composition of Example 2 is: CaO: 85.2%, Al: 2.7%, Al2O3: 7.3%, SiO2: 2.1%, MgO: 1.4%, S: 0.016%. The temperature of the molten iron in the ladle is 1350°C, and the unit consumption of the desulfurizer is 7kg / t.

[0035] The composition of Example 3 is: CaO: 84.4%, Al: 2.3%, Al2O3: 6.5%, SiO2: 2.7%, MgO: 1.8%, S: 0.018%. The temperature of the molten iron in the ladle is 1380°C, and the unit consumption of the desulfurizer is 7kg / t.

[0036] The composition of Example 4 is: CaO: 85.8%, Al: 2.6%, Al2O3: 6.7%, SiO2: 1.5%, MgO: 1.7%, S: 0.016%. The temperature of the molten iron in the ladle is 1350°C, and the unit consumption of the desulfurizer is 8kg / t.

[0037] The results are as follows:

[0038]

[0039] Based on the above technical effects, in Example 2, Example 3, and Example 4, after adding the environmentally friendly fluorine-free KR desulfurization powder in this example, the desulfurization rate is increased from 82% in the comparative example to 91%, 94%, and 93%, respectively, which effectively improves the desulfurization rate, reduces the temperature drop of molten iron, and saves steelmaking costs.

Claims

1. An environmentally friendly fluorine-free KR desulfurization powder, characterized in that: The environmentally friendly fluorine-free KR desulfurization powder comprises, by mass percentage: CaO: 78%~90%; Al：1％～4％； Al2O3: 4%~8%; SiO2: 0-3%; MgO: 0-3%; S：0～0.05％； The rest are impurities.

2. The environmentally friendly fluorine-free KR desulfurization powder according to claim 1 is characterized in that: The raw materials of the environmentally friendly fluorine-free KR desulfurization powder are lime and AD powder, and the lime and the AD powder are ground by using a Raymond mill.

3. The environmentally friendly fluorine-free KR desulfurization powder according to claim 1 is characterized in that: The particle size of the environmentally friendly fluorine-free KR desulfurization powder is 0-1 mm.

4. A method for using an environmentally friendly fluorine-free KR desulfurization powder, characterized in that: The environmentally friendly fluorine-free KR desulfurization powder is added into the molten iron ladle in a spraying manner through a spray gun.

5. The method for using the environmentally friendly fluorine-free KR desulfurization powder according to claim 4, characterized in that: The spray gun uses inert gas as a carrier.

6. The method for using the environmentally friendly fluorine-free KR desulfurization powder according to claim 4, characterized in that: The amount of the environmentally friendly fluorine-free KR desulfurization powder added is 6-10kg / ton of steel.

7. The method for using the environmentally friendly fluorine-free KR desulfurization powder according to claim 4, characterized in that: When the environmentally friendly fluorine-free KR desulfurization powder is added, the molten iron temperature is 1300°C to 1400°C.

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