Device and method for realizing calcium treatment of molten steel by adopting calcium steam

Abstract

The invention relates to a device and method for achieving molten steel calcium treatment through calcium steam. The device comprises a molten steel tank, a water gap, an argon blowing nozzle, a calcium powder gasifier, an air brick, a carrier gas conveying pipeline, an argon blowing control valve and a calcium blowing control valve. A water gap, an argon blowing nozzle, an air brick and a calcium powder gasifier are arranged at the bottom of the molten steel tank, the top of the calcium powder gasifier is communicated with the interior of the molten steel tank through the air brick, and the calcium powder gasifier is used for containing metal calcium powder. Calcium powder preset in the calcium powder gasifier is gasified into calcium steam by using heat generated when molten steel is smelted by the molten steel tank, and the calcium steam enters the molten steel from the bottom by using bottom blowing argon as a power source for blowing the calcium steam, so that the calcium treatment efficiency is effectively improved, and the calcium treatment effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of molten steel refining, and in particular to a device and method for realizing calcium treatment of molten steel by using calcium vapor. Background Art

[0002] Calcium treatment of molten steel is a steel refining method, and its main purposes include: (1) deeply reducing the content of harmful elements such as [O] and [S] in steel; (2) changing the composition and morphology of inclusions and improving the mechanical properties of steel. Calcium treatment of molten steel is a key link that affects the smooth production and quality control of subsequent processes. When producing aluminum-killed steel, the risk of nozzle nodules increases during continuous casting because alumina inclusions in the molten steel are not easy to float up. By treating the molten steel with calcium, the alumina inclusions in the molten steel can be transformed into large-sized, low-melting-point calcium-aluminum composite oxides, which can quickly float up into the slag, thereby improving the cleanliness of the molten steel.

[0003] In the past, there have been methods of calcium treatment such as directly adding calcium alloy into the ladle and spraying calcium alloy into the molten steel, but due to unstable treatment effects or high costs, they have gradually been eliminated. Currently, the most widely used method is the ladle calcium wire feeding method, which is to wrap calcium alloy (Ca, Ca-Si, Ca-Fe, etc.) with steel skin to make a cored wire, and insert it into the molten steel at a very high speed through the guide tube of the wire feeder. The wire feeding process is accompanied by inert gas stirring to increase the residence time of Ca vapor bubbles in the molten steel and achieve good mixing.

[0004] However, when using the ladle calcium wire feeding method, due to the relatively low density of silicon calcium wire and iron calcium wire, and the limited feeding depth of the wire feeding machine, the silicon calcium wire recovery rate is low, which not only increases the smelting cost, but also seriously affects the calcium treatment effect of molten steel. Therefore, a new method that can improve the efficiency of calcium treatment is urgently needed to ensure that the calcium treatment effect is stable and controllable. Summary of the invention

[0005] The present invention provides a device and method for realizing calcium treatment of molten steel by using calcium vapor. A calcium powder gasifier is arranged at the bottom of a molten steel tank. The heat of the molten steel tank during smelting of molten steel is used to gasify the calcium powder pre-placed in the calcium powder gasifier into calcium vapor. Bottom-blown argon gas is used as a power source for calcium vapor injection to allow the calcium vapor to enter the molten steel from the bottom, thereby effectively improving the calcium treatment efficiency and the calcium treatment effect.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A device for treating molten steel with calcium by using calcium vapor comprises a molten steel tank, a water inlet, an argon blowing nozzle, a calcium powder gasifier, a gas permeable brick, a carrier gas delivery pipeline, an argon blowing control valve and a calcium blowing control valve; the bottom of the molten steel tank is provided with a water inlet and an argon blowing nozzle, the injection end of the argon blowing nozzle is communicated with the inside of the molten steel tank, the argon gas inlet end of the argon blowing nozzle is connected to the carrier gas delivery pipeline through a branch pipe 1, and the argon blowing control valve is arranged on the branch pipe 1; the bottom of the molten steel tank is also provided with a gas permeable brick and a calcium powder gasifier, the top of the calcium powder gasifier is communicated with the inside of the molten steel tank through the gas permeable brick, the bottom of the calcium powder gasifier is connected to the carrier gas delivery pipeline through a branch pipe 2, and the calcium blowing control valve is arranged on the branch pipe 2; the calcium powder gasifier is used to contain metallic calcium powder, and the top of the calcium powder gasifier is communicated with the gas permeable brick.

[0008] The air-permeable brick is a slit-type air-permeable brick, and the slit width is 0.1-0.3 mm.

[0009] The calcium powder gasifier consists of an inner cylinder and an outer cylinder. The inner cylinder is made of high-heat-conductivity, high-temperature-resistant metal, and the outer cylinder is made of refractory material. The top of the outer cylinder is connected to the air-permeable brick, and the top of the inner cylinder is provided with an air outlet.

[0010] The outer cylinder and the air-permeable brick are an integrated structure, or are connected via a snap-fit ​​structure.

[0011] A method for calcium treatment of molten steel using calcium vapor comprises the following steps:

[0012] (1) During the preparation of the steel ladle before refining, place metallic calcium powder in the calcium powder gasifier, and connect the air brick, calcium powder gasifier and carrier gas delivery pipeline;

[0013] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0014] (3) During the steel refining process, the heat from the steel tank smelting the steel is used to gasify the metallic calcium powder pre-placed in the calcium powder gasifier into calcium vapor; after the refining process is completed, calcium treatment is performed, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the steel through the air-permeable bricks;

[0015] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.4-0.8 Nm 3 / h·t, the calcium treatment time is 2 to 4 minutes, and after the treatment, the molten steel is poured on the machine;

[0016] (5) Remove the calcium powder gasifier during the preparation of the molten steel tank after pouring is completed.

[0017] The particle size of the metallic calcium powder is ≤0.5 mm.

[0018] The mass of calcium blown into the molten steel is calculated at 5 to 10 kg / min.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) A calcium powder gasifier is arranged at the bottom of the molten steel tank, and the heat of the molten steel tank during smelting is used to gasify the calcium powder pre-placed in the calcium powder gasifier into calcium vapor. Bottom-blown argon gas is used as the power source for calcium vapor injection, so that the calcium vapor enters the molten steel from the bottom, thereby effectively improving the calcium treatment efficiency and the calcium treatment effect;

[0021] 2) The calcium utilization rate of the calcium treatment method of the present invention reaches more than 50%, thus avoiding the loss of metal calcium caused by the wire feeding method.

[0022] 3) The effect of calcium treatment is stable. After calcium treatment, the calcium content of molten steel is stably controlled between 10 and 30 ppm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a device for realizing calcium treatment of molten steel by using calcium vapor according to the present invention.

[0024] Figure 2 It is a schematic diagram of the bottom of the steel tank.

[0025] In the figure: 1. Molten steel tank 2. Water inlet 3. Argon blowing nozzle 4. Carrier gas delivery pipeline 5. Carrier gas inlet 6. Argon blowing control valve 7. Calcium powder vaporizer 8. Air brick 9. Calcium blowing control valve DETAILED DESCRIPTION

[0026] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0027] like Figure 1 As shown, the device for treating molten steel with calcium vapor using calcium vapor of the present invention comprises a molten steel tank, a nozzle, an argon blowing nozzle, a calcium powder gasifier, a gas-permeable brick, a carrier gas delivery pipeline, an argon blowing control valve and a calcium blowing control valve; Figure 2 As shown, a water inlet and an argon blowing nozzle are provided at the bottom of the molten steel tank, the injection end of the argon blowing nozzle is connected to the inside of the molten steel tank, the argon gas inlet end of the argon blowing nozzle is connected to the carrier gas delivery pipeline through a branch pipe 1, and an argon blowing control valve is provided on the branch pipe 1; a breathable brick and a calcium powder gasifier are also provided at the bottom of the molten steel tank, the top of the calcium powder gasifier is connected to the inside of the molten steel tank through the breathable brick, the bottom of the calcium powder gasifier is connected to the carrier gas delivery pipeline through a branch pipe 2, and a calcium blowing control valve is provided on the branch pipe 2; the calcium powder gasifier is used to contain metallic calcium powder, and the top of the calcium powder gasifier is connected to the breathable brick.

[0028] The air-permeable brick is a slit-type air-permeable brick, and the slit width is 0.1-0.3 mm.

[0029] The calcium powder gasifier consists of an inner cylinder and an outer cylinder. The inner cylinder is made of high-heat-conductivity, high-temperature-resistant metal, and the outer cylinder is made of refractory material. The top of the outer cylinder is connected to the air-permeable brick, and the top of the inner cylinder is provided with an air outlet.

[0030] The outer cylinder and the air-permeable brick are an integrated structure, or are connected via a snap-fit ​​structure.

[0031] A method for calcium treatment of molten steel using calcium vapor comprises the following steps:

[0032] (1) During the preparation of the steel ladle before refining, place metallic calcium powder in the calcium powder gasifier, and connect the air brick, calcium powder gasifier and carrier gas delivery pipeline;

[0033] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0034] (3) During the steel refining process, the heat from the steel tank smelting the steel is used to gasify the metallic calcium powder pre-placed in the calcium powder gasifier into calcium vapor; after the refining process is completed, calcium treatment is performed, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the steel through the air-permeable bricks;

[0035] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.4-0.8 Nm 3 / h·t, the calcium treatment time is 2 to 4 minutes, and after the treatment, the molten steel is poured on the machine;

[0036] (5) Remove the calcium powder gasifier during the preparation of the molten steel tank after pouring is completed.

[0037] The particle size of the metallic calcium powder is ≤0.5 mm.

[0038] The mass of calcium blown into the molten steel is calculated at 5 to 10 kg / min.

[0039] The calcium powder gasification device of the present invention is filled with metal calcium powder in advance during the preparation of the molten steel tank and installed at the bottom of the molten steel tank. During the refining process, the metal calcium powder in the calcium powder gasification device is gasified under the heat of the molten steel tank to form calcium vapor. The calcium vapor is blown into the molten steel by the bottom-blown argon carrier gas, thereby achieving the purpose of calcium treatment of the molten steel.

[0040] During the refining process, for tanks that do not require calcium treatment, the calcium blowing control valve remains closed and only the argon bottom blowing function is used. For tanks that require calcium treatment, during calcium treatment, the argon blowing control valve is closed and the calcium blowing control valve is opened, and the same carrier gas source (argon) is used to blow the vaporized calcium vapor from the air-permeable bricks into the molten steel in the molten steel tank.

[0041] Preferably, during the calcium treatment process, the carrier gas flow rate during calcium blowing is adjusted according to the volume of the molten steel tank, and the carrier gas flow rate is controlled at 0.4-0.8 Nm 3 For steel ladle with height-to-diameter ratio greater than 1.35, the carrier gas flow rate during calcium treatment can be increased by 10% to 20% depending on the situation.

[0042] After refining, the amount of metallic calcium powder used in the calcium treatment process, the calcium content in molten steel, the calcium oxide content in the slag, and the calcium recovery rate are calculated based on the weight of the remaining metallic calcium powder.

[0043] The following embodiments are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0044] [Example 1]

[0045] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0046] (1) During the preparation of the steel ladle before refining, 50 kg of metallic calcium powder was placed in the calcium powder gasifier. The particle size of the metallic calcium powder was 0.45 mm. The air-permeable brick, the calcium powder gasifier and the carrier gas delivery pipeline were connected.

[0047] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0048] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0049] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.45 Nm 3 / (h·t), the calcium treatment time is 3min20s, and after the treatment, the molten steel is poured on the machine;

[0050] (5) During the preparation of the molten steel tank after pouring, the calcium powder gasifier was taken out, and the weight of the remaining metallic calcium powder was 22 kg.

[0051] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 28 kg, the calcium content in the molten steel is 19 ppm, the calcium oxide content in the slag is increased from 55% before calcium treatment to 56.1%, and the calcium recovery rate is 55.66%.

[0052] [Example 2]

[0053] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0054] (1) During the preparation of the steel ladle before refining, 50 kg of metallic calcium powder was placed in the calcium powder gasifier. The particle size of the metallic calcium powder was 0.45 mm. The air-permeable brick, the calcium powder gasifier and the carrier gas delivery pipeline were connected.

[0055] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0056] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0057] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.42Nm 3 / (h·t), the calcium treatment time is 3min, and after the treatment, the molten steel is poured on the machine;

[0058] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 29 kg.

[0059] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 21 kg, the calcium content in the molten steel is 16 ppm, the calcium oxide content in the slag is increased from 56% before calcium treatment to 56.9%, and the calcium recovery rate is 61.16%.

[0060] [Example 3]

[0061] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0062] (1) During the preparation of the steel ladle before refining, 48 kg of metallic calcium powder with a particle size of 0.42 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0063] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0064] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0065] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.5Nm 3 / (h·t), the calcium treatment time is 3min40s, and after the treatment, the molten steel is poured on the machine;

[0066] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 19 kg.

[0067] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 29 kg, the calcium content in the molten steel is 17 ppm, the calcium oxide content in the slag is increased from 53% before calcium treatment to 54.2%, and the calcium recovery rate is 56.06%.

[0068] [Example 4]

[0069] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0070] (1) During the preparation of the steel ladle before refining, 48 kg of metallic calcium powder with a particle size of 0.42 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0071] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0072] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0073] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.52Nm 3 / (h·t), the calcium treatment time is 2min50s, and after the treatment, the molten steel is poured on the machine;

[0074] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 28 kg.

[0075] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 20 kg, the calcium content in the molten steel is 23 ppm, the calcium oxide content in the slag is increased from 52% before calcium treatment to 52.6%, and the calcium recovery rate is 55.14%.

[0076] [Example 5]

[0077] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0078] (1) During the preparation of the steel ladle before refining, 48 kg of metallic calcium powder with a particle size of 0.39 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0079] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0080] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0081] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.5Nm 3 / (h·t), the calcium treatment time is 3min10s, and after the treatment, the molten steel is poured on the machine;

[0082] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 22 kg.

[0083] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 26 kg, the calcium content in the molten steel is 14 ppm, the calcium oxide content in the slag is increased from 55% before calcium treatment to 56%, and the calcium recovery rate is 51.98%.

[0084] [Example 6]

[0085] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0086] (1) During the preparation of the steel ladle before refining, 46 kg of metallic calcium powder with a particle size of 0.39 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0087] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0088] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0089] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.55 Nm 3 / (h·t), the calcium treatment time is 3min, and after the treatment, the molten steel is poured on the machine;

[0090] (5) After the pouring is completed, the calcium powder gasifier is taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder is 20 kg.

[0091] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 26 kg, the calcium content in the molten steel is 12 ppm, the calcium oxide content in the slag is increased from 56% before calcium treatment to 57.1%, and the calcium recovery rate is 59.17%.

[0092] [Example 7]

[0093] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0094] (1) During the preparation of the steel ladle before refining, 46 kg of metallic calcium powder with a particle size of 0.36 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0095] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0096] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0097] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.54Nm 3 / (h·t), the calcium treatment time is 3min20s, and after the treatment, the molten steel is poured on the machine;

[0098] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 19 kg.

[0099] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 27 kg, the calcium content in the molten steel is 12 ppm, the calcium oxide content in the slag is increased from 53% before calcium treatment to 54.2%, and the calcium recovery rate is 56.51%.

[0100] [Example 8]

[0101] The process of calcium treatment of molten steel using calcium vapor in this embodiment is as follows:

[0102] (1) During the preparation of the steel ladle before refining, 46 kg of metallic calcium powder with a particle size of 0.38 mm was placed in the calcium powder gasifier, and the air-permeable brick, calcium powder gasifier and carrier gas delivery pipeline were connected;

[0103] (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened;

[0104] (3) After the refining process is completed, calcium treatment is carried out, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the molten steel through the air-permeable bricks;

[0105] (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.49 Nm 3 / (h·t), the calcium treatment time is 4min5s, and after the treatment, the molten steel is poured on the machine;

[0106] (5) After the pouring was completed, the calcium powder gasifier was taken out during the preparation of the molten steel tank, and the weight of the remaining metallic calcium powder was 13 kg.

[0107] Calculations show that during the calcium treatment process of this embodiment, the amount of metallic calcium powder used is 33 kg, the calcium content in the molten steel is 15 ppm, the calcium oxide content in the slag is increased from 51.9% before calcium treatment to 53.4%, and the calcium recovery rate is 57.79%.

[0108] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for calcium treatment of molten steel using calcium vapor, characterized in that: It comprises a molten steel tank, a water inlet, an argon blowing nozzle, a calcium powder gasifier, a breathable brick, a carrier gas delivery pipeline, an argon blowing control valve and a calcium blowing control valve; the bottom of the molten steel tank is provided with a water inlet and an argon blowing nozzle, the injection end of the argon blowing nozzle is communicated with the inside of the molten steel tank, the argon gas inlet end of the argon blowing nozzle is connected to the carrier gas delivery pipeline through a branch pipe 1, and the argon blowing control valve is arranged on the branch pipe 1; the bottom of the molten steel tank is also provided with a breathable brick and a calcium powder gasifier, the top of the calcium powder gasifier is communicated with the inside of the molten steel tank through the breathable brick, the bottom of the calcium powder gasifier is connected to the carrier gas delivery pipeline through a branch pipe 2, and the calcium blowing control valve is arranged on the branch pipe 2; the calcium powder gasifier is used to contain metallic calcium powder, and the top of the calcium powder gasifier is communicated with the breathable brick.

2. The device for calcium treatment of molten steel using calcium vapor according to claim 1, characterized in that: The air-permeable brick is a slit-type air-permeable brick, and the slit width is 0.1-0.3 mm.

3. The device for calcium treatment of molten steel using calcium vapor according to claim 1, characterized in that: The calcium powder gasifier consists of an inner cylinder and an outer cylinder. The inner cylinder is made of high-heat-conductivity, high-temperature-resistant metal, and the outer cylinder is made of refractory material. The top of the outer cylinder is connected to the air-permeable brick, and the top of the inner cylinder is provided with an air outlet.

4. The device for calcium treatment of molten steel using calcium vapor according to claim 3, characterized in that: The outer cylinder and the air-permeable brick are an integrated structure, or are connected via a snap-fit ​​structure.

5. A method for calcium treatment of molten steel using calcium vapor, characterized in that: The device for calcium treatment of molten steel using calcium vapor according to any one of claims 1 to 4 is implemented, characterized in that it comprises the following steps: (1) During the preparation of the steel ladle before refining, place metallic calcium powder in the calcium powder gasifier, and connect the air brick, calcium powder gasifier and carrier gas delivery pipeline; (2) During the process from molten steel tapping to refining station entry, the calcium blowing control valve remains closed and the argon blowing control valve is opened; (3) During the steel refining process, the heat from the steel tank smelting the steel is used to gasify the metallic calcium powder pre-placed in the calcium powder gasifier into calcium vapor; after the refining process is completed, calcium treatment is performed, the argon blowing control valve is closed, and the calcium blowing control valve is opened, so that the calcium vapor gasified in the calcium powder gasifier enters the steel through the air-permeable bricks; (4) The carrier gas flow rate in the carrier gas delivery pipeline is controlled at 0.4-0.8 Nm 3 / h·t, the calcium treatment time is 2 to 4 minutes, and after the treatment, the molten steel is poured on the machine; (5) Remove the calcium powder gasifier during the preparation of the molten steel tank after pouring is completed.

6. A method for calcium treatment of molten steel using calcium vapor according to claim 5, characterized in that: The particle size of the metallic calcium powder is ≤0.5 mm.

7. A method for calcium treatment of molten steel using calcium vapor according to claim 5, characterized in that: The mass of calcium blown into the molten steel is calculated at 5 to 10 kg / min.

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