Steelmaking method for smelting 40% scrap steel ratio by adopting single converter

Abstract

The invention belongs to the technical field of steelmaking, and relates to a steelmaking method adopting a single converter to smelt 40% scrap steel ratio, the method comprises the following steps: preparing steelmaking raw materials; loading the steelmaking raw materials into a single converter; blowing the steelmaking raw materials by using an oxygen lance; adding an auxiliary reaction material into the single converter; parameters of the oxygen lance and parameters of the single converter are adjusted; and steelmaking is carried out by adopting a single converter to smelt 40% scrap steel ratio according to parameters. According to the steelmaking method for smelting 40% scrap steel ratio through the single converter, the scrap steel ratio reaches 40%, the carbon dioxide emission per ton of steel in the steelmaking process can be reduced by 25%, and steel products stable and reliable in production quality are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of steelmaking, and particularly to a steelmaking method for smelting 40% scrap ratio with a single converter. Background Art

[0002] At present, the scrap ratio of converters in most steel mills is about 10-20%, and there are few with a scrap ratio of 40% or more. Steel mills are one of the main sources of carbon emissions. Using a high scrap ratio can significantly reduce carbon emissions, but there is currently a lack of corresponding technical solutions. Summary of the Invention

[0003] In view of this, the present invention provides a steelmaking method for smelting 40% scrap ratio with a single converter.

[0004] Specifically, the present invention is implemented through the following technical solutions:

[0005] According to the first aspect of the present invention, there is provided a steelmaking method for smelting 40% scrap ratio with a single converter, the method comprising the steps of:

[0006] Prepare steelmaking raw materials;

[0007] Load the steelmaking raw materials into a single converter;

[0008] Blow the steelmaking raw materials using an oxygen lance;

[0009] Add auxiliary reaction materials to the single converter;

[0010] Adjust the parameters of the oxygen lance and the parameters of the single converter;

[0011] Carry out steelmaking with a single converter smelting 40% scrap ratio according to the parameters.

[0012] Optionally, the preparation of the steelmaking raw materials includes the steps of:

[0013] Prepare non-desulfurized hot metal;

[0014] Prepare scrap steel;

[0015] Prepare ferrosilicon;

[0016] Prepare graphite balls.

[0017] Optionally, the mass of the non-desulfurized hot metal is 137t - 140t.

[0018] Optionally, the total mass of the scrap steel is 95t - 97t.

[0019] Optionally, the scrap steel is in 3 buckets, and the mass of each bucket is 20t - 45t.

[0020] Optionally, the mass of each batch of the graphite balls is 5t - 8t.

[0021] Optionally, adding auxiliary reaction materials to the single converter includes the steps of:

[0022] Adding quicklime to the single converter;

[0023] Adding lightly burned lime to the single converter.

[0024] Optionally, the mass of the quicklime is 12t - 15t.

[0025] Optionally, adjusting the parameters of the oxygen lance and the parameters of the single converter includes the steps of:

[0026] Adjusting the bottom blowing flow rate of the oxygen lance;

[0027] Adjusting the oxygen blowing volume of the oxygen lance;

[0028] Adjusting the end point temperature of the single converter.

[0029] Optionally, the bottom blowing flow rate of the oxygen lance is 600 - 1000 Nm3 / h.

[0030] The technical solution provided by the present invention at least brings the following beneficial effects:

[0031] A steelmaking method using a single converter to smelt 40% scrap ratio provided by the present application has a scrap ratio of 40%. The carbon dioxide emissions per ton of steel in the steelmaking process will be reduced by 25%, and high-quality and reliable steel products can be produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a schematic flow chart of a steelmaking method using a single converter to smelt 40% scrap ratio provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0036] Figure 1 Schematically shows a process flow diagram of a steelmaking method using a single converter to smelt 40% scrap ratio applicable to the embodiments of the present invention.

[0037] See Figure 1 , the embodiments of the present invention provide a steelmaking method using a single converter to smelt 40% scrap ratio, and the method may include the following steps:

[0038] S1: Prepare steelmaking raw materials;

[0039] Exemplarily, the preparation of steelmaking raw materials includes the steps of:

[0040] Prepare hot metal without desulfurization;

[0041] Prepare scrap steel;

[0042] Prepare ferrosilicon;

[0043] Prepare graphite balls.

[0044] Exemplarily, the preparation of steelmaking raw materials mainly includes: hot metal without desulfurization, scrap steel, ferrosilicon, and graphite balls, and the quantity of each raw material is selectively prepared according to needs.

[0045] In the embodiments of the present application, the hot metal is not desulfurized, which can save the temperature of the hot metal

[0046] Exemplarily, the mass of the hot metal without desulfurization is 137t - 140t.

[0047] In the embodiments of the present application, the mass of the hot metal without desulfurization is 137t - 140t, which can meet the reaction requirements.

[0048] Exemplarily, the total mass of the scrap steel is 95t - 97t, and the scrap steel is in 3 buckets, with the mass of each bucket being 20t - 45t.

[0049] In the embodiments of the present application, the scrap steel is divided into 3 buckets and is added separately with other raw materials for reaction.

[0050] In the embodiment of the present application, 2 buckets of scrap steel are added before smelting, with a total of about 53 - 60t. 0.5 - 1t of ferrosilicon is pre - charged into the furnace, and then hot metal is charged. After charging the hot metal, the furnace is rocked twice at a large angle. Subsequently, ferrosilicon for temperature increase is added according to the production situation, and the feeding amount each time is 300kg - 500kg.

[0051] Exemplarily, the mass of each batch of the graphite balls is 5t - 8t.

[0052] In the embodiment of the present application, multiple batches of graphite balls are prepared, and the mass of each batch of graphite balls is 5t - 8t for subsequent reactions.

[0053] S2: Charge the steel - making raw materials into a single - converter;

[0054] S3: Blow - refine the steel - making raw materials using an oxygen lance;

[0055] In the embodiment of the present application, after charging each steel - making raw material into the single - converter, the lance is lowered for blowing. The initial lance position is appropriately increased by about 100mm - 500mm according to the situation to prevent the oxygen lance from hitting the scrap steel. At the same time, pay attention to the water flow of the oxygen lance, and raise the lance in time for inspection if any abnormality is found.

[0056] S4: Add auxiliary reaction materials into the single - converter;

[0057] Exemplarily, adding the auxiliary reaction materials into the single - converter includes the steps of:

[0058] Add quicklime into the single - converter;

[0059] Add lightly - burned material into the single - converter.

[0060] In the embodiment of the present application, after normal ignition, pay attention to the change of flue - gas composition during over - mixing. After over - mixing, add 3t of quicklime and 2t of lightly - burned material for one batch of materials. Rock the furnace to pour out a small amount of slag, check the melting state of the scrap steel in the furnace, and add the third bucket of scrap steel. Rock the furnace back and forth once after adding the scrap steel. After ignition, pay attention to the change of flue - gas composition during over - mixing. After over - mixing, add the second - batch of materials, and add 5 - 8t of graphite balls in batches for temperature increase. The total amount of quicklime is added according to the actual Si addition amount, and the reference addition amount is 12t - 15t. The reference addition amount of the lightly - burned material is 5t. When slag overflow occurs during the process, a small amount of quicklime or lightly - burned material can be used to press the slag, and the addition amount per batch is about 300kg.

[0061] S5: Adjust the parameters of the oxygen lance and the parameters of the single - converter;

[0062] Exemplarily, adjusting the parameters of the oxygen lance and the parameters of the single - converter includes the steps of:

[0063] Adjust the bottom - blowing flow rate of the oxygen lance;

[0064] Adjust the oxygen - blowing volume of the oxygen lance;

[0065] Adjust the end-point temperature of the single converter.

[0066] In the embodiment of the present application, the bottom-blowing flow rate is set at 600 - 1000 Nm3 / h, which can ensure the stirring of each raw material; the total oxygen volume of the oxygen lance during the entire smelting process is expected to be about 13000 - 15000 Nm3, and the end-point temperature of the single converter is controlled at 1620 - 1640 °C.

[0067] S6: Use a single converter to smelt steel with a scrap ratio of 40% according to the parameters.

[0068] In the embodiment of the present application, steelmaking operations are carried out according to the set parameters and each raw material.

[0069] In summary, in view of the demand of steel mills to reduce carbon emissions, the above technical solution proposes a steelmaking method using a single converter to smelt steel with a scrap ratio of 40%. Through a series of specific steps and parameter adjustments, this method realizes the steelmaking process under the condition of a high scrap ratio, thus effectively solving the technical problem of reducing carbon emissions in steel mills. The following is an analysis of how this technical solution solves the problem and its patent creativity:

[0070] Reducing carbon emissions with a high scrap ratio: As a renewable resource, the use of scrap steel can significantly reduce the dependence on primary ore, thereby reducing energy consumption and carbon emissions during the steelmaking process. By setting a scrap ratio of 40%, this technical solution greatly increases the use of scrap steel compared with traditional steelmaking methods, thus effectively reducing carbon emissions.

[0071] Precisely controlling the steelmaking process: The technical solution details the steps of preparing, charging, blowing, adding auxiliary reaction materials, and parameter adjustment of steelmaking raw materials, ensuring the precise control of the steelmaking process. This precise control helps to ensure the stability and efficiency of steelmaking under the condition of a high scrap ratio, thereby further improving the effect of reducing carbon emissions. Optimizing auxiliary materials and oxygen lance parameters: By adding appropriate amounts of auxiliary reaction materials such as lime and light burning, and adjusting parameters such as the bottom-blowing flow rate, oxygen-blowing volume of the oxygen lance, and the end-point temperature of the single converter, the technical solution optimizes the chemical reactions and heat transfer during the steelmaking process, further improving the steelmaking

[0072] Innovation of the steelmaking method with a high scrap ratio: This technical solution proposes a specific and feasible steelmaking method using a single converter to smelt steel with a scrap ratio of 40%, which is an innovation in the steelmaking field. Traditional steelmaking methods usually have a low scrap ratio, while this technical solution realizes the steelmaking process under the condition of a high scrap ratio through precise control and parameter optimization. Innovation of detailed steps and parameter adjustment: The technical solution not only proposes a steelmaking method with a high scrap ratio but also details each step and parameter adjustment method in the steelmaking process. This detail makes the technical solution more operable and practical, and also reflects the creativity of the patent.

[0073] Significant energy conservation and emission reduction effects: This technical solution achieves significant energy conservation and emission reduction effects by increasing the scrap ratio and optimizing the steelmaking process. Such effects not only conform to the current global environmental protection and sustainable development trends but also provide an effective way for the steelmaking industry to reduce carbon emissions.

[0074] Example 1:

[0075] Heat No. 242G0650X

[0076] (1) Do not desulfurize the hot metal, which can save the hot metal temperature.

[0077] (2) The amount of hot metal is 138t, and there are 3 buckets of scrap steel with weights of 20t, 35t, and 42t respectively for each bucket. The total amount of scrap steel is about 97t.

[0078] (3) Add about 55t of scrap steel in 2 buckets before smelting, pre-charge 0.7t of ferrosilicon in the furnace, then charge the hot metal, and shake the furnace twice at a large angle after charging. Subsequently, add ferrosilicon for temperature increase according to the production situation, with each feeding amount being 350kg.

[0079] (4) Set the bottom blowing flow rate at 800 Nm3 / h to ensure stirring.

[0080] (5) Lower the lance for blowing. Appropriately raise the lance position by 250mm according to the situation at the start of blowing to prevent the oxygen lance from hitting the scrap steel. At the same time, pay attention to the water flow rate of the oxygen lance and raise the lance for inspection in a timely manner if any abnormality is found.

[0081] (6) After normal ignition, pay attention to the change in flue gas composition during over-mixing. After over-mixing, add 3t of quicklime and 2t of light-burned dolomite for one batch of materials.

[0082] (7) Shake the furnace to pour out a small amount of slag, check the melting state of the scrap steel in the furnace, and add the third bucket of scrap steel, which is 42t. Shake the furnace back and forth once after adding the scrap steel.

[0083] (8) After ignition, pay attention to the change in flue gas composition during over-mixing. After over-mixing, add the second batch of materials and add 7.5t of graphite balls in batches for temperature increase.

[0084] (9) Add quicklime in total according to the actual Si addition amount, with the reference addition amount being 13.5t, and the reference addition amount of light-burned dolomite being 5t. When slag overflow occurs during the process, a small amount of quicklime or light-burned dolomite can be used to press the slag, and the addition amount for each batch is about 300kg.

[0085] (10) The total oxygen volume of the oxygen lance is expected to be about 14,800 Nm3, and the end-point temperature of a single converter is controlled at 1627°C.

[0086] Example 2:

[0087] Heat No. 242F05X07

[0088] (1) Without desulfurizing hot metal, the hot metal temperature can be saved.

[0089] (2) The hot metal amount is 139 t, and there are 3 buckets of scrap steel with weights of 21 t, 36 t, and 40 t respectively for each bucket. The total amount of scrap steel is approximately 97 t.

[0090] (3) Before smelting, about 57 t of scrap steel is added in 2 buckets, 0.9 t of ferrosilicon is pre-charged into the furnace, and then the hot metal is charged. After charging the hot metal, the furnace is rocked twice at a large angle. Subsequently, ferrosilicon for temperature increase is added according to the production situation, and the feeding amount each time is 410 kg.

[0091] (4) The bottom blowing flow rate is set at 750 Nm3 / h to ensure stirring.

[0092] (5) The lance is lowered for blowing. At the start of blowing, the lance position is appropriately raised by 300 mm according to the situation to prevent the oxygen lance from hitting the scrap steel. At the same time, pay attention to the water flow rate of the oxygen lance, and raise the lance in time for inspection when abnormalities are found.

[0093] (6) After normal ignition, pay attention to the change of flue gas composition for over-mixing. After over-mixing, 3 t of quicklime and 2 t of light burned dolomite are added in one batch.

[0094] (7) The furnace is rocked to pour out a small amount of slag, check the melting state of the scrap steel in the furnace, and add 40 t of the third bucket of scrap steel. After adding the scrap steel, the furnace is rocked back and forth once.

[0095] (8) After ignition, pay attention to the change of flue gas composition for over-mixing. After over-mixing, the second batch of materials is added, and 7.5 t of graphite balls are added in batches to increase the temperature.

[0096] (9) The total amount of quicklime is added according to the actual Si content, and the reference addition amount is 13.5 t. The reference addition amount of light burned dolomite is 5 t. When slag overflow occurs during the process, a small amount of quicklime or light burned dolomite can be used to press the slag, and the addition amount per batch is about 300 kg.

[0097] (10) The total oxygen amount of the oxygen lance is expected to be about 14500 Nm3, and the end point temperature of a single converter is controlled at 1630 °C.

[0098] Example 3:

[0099] Heat number 242H0520X

[0100] (1) Without desulfurizing hot metal, the hot metal temperature can be saved.

[0101] (2) The hot metal amount is 140 t, and there are 3 buckets of scrap steel with weights of 22 t, 34 t, and 41 t respectively for each bucket. The total amount of scrap steel is approximately 97 t.

[0102] (3) Before smelting, about 56 t of scrap steel is added in 2 buckets, 0.85 t of ferrosilicon is pre-charged into the furnace, and then the hot metal is charged. After charging the hot metal, the furnace is rocked twice at a large angle. Subsequently, ferrosilicon for temperature increase is added according to the production situation, and the feeding amount each time is 400 kg.

[0103] (4) Set the bottom blowing flow rate at 780 Nm3 / h to ensure stirring.

[0104] (5) For bottom lance blowing, appropriately raise the lance position by 210 mm at the start of blowing to prevent the oxygen lance from hitting the scrap steel. At the same time, pay attention to the water flow rate of the oxygen lance and raise the lance for inspection in a timely manner if any abnormality is found.

[0105] (6) After normal ignition, pay attention to the change in flue gas composition during over-mixing. After over-mixing, add 3 t of quicklime and 2 t of calcined dolomite for one batch of materials.

[0106] (7) Tilt the furnace to pour out a small amount of slag, check the melting state of the scrap steel in the furnace, and add 41 t of the third hopper of scrap steel. After adding the scrap steel, rock the furnace back and forth once.

[0107] (8) After ignition, pay attention to the change in flue gas composition during over-mixing. After over-mixing, add the second batch of materials and add 6.7 t of graphite balls in batches to raise the temperature.

[0108] (9) Add the total amount of quicklime according to the actual Si addition amount. The reference addition amount is 13.1 t, and the reference addition amount of calcined dolomite is 5 t. When slag overflow occurs during the process, a small amount of quicklime or calcined dolomite can be used to press the slag, and the addition amount per batch is about 300 kg.

[0109] (10) The total oxygen amount of the oxygen lance is expected to be about 14200 Nm3, and the end-point temperature of a single converter is controlled at 1637 °C.

[0110] In summary of the above embodiments, when the scrap ratio reaches 40%, the carbon dioxide emissions per ton of steel in the steelmaking process will be reduced by 25%.

[0111] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modification examples falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0112] A steelmaking method using a single converter to smelt 40% scrap ratio provided by this application has a scrap ratio reaching 40%, the carbon dioxide emissions per ton of steel in the steelmaking process will be reduced by 25%, and high-quality and reliable steel products can be produced.

[0113] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0114] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A steelmaking method using a single converter to smelt 40% scrap steel, characterized in that: The method comprises the steps of: Prepare raw materials for steelmaking; The steel-making raw materials are charged into a single converter; Using an oxygen lance to blow the steelmaking raw material; adding auxiliary reaction materials into the single converter; Adjusting the parameters of the oxygen lance and the parameters of the single converter; According to the parameters, steelmaking is carried out by using a single converter with a 40% scrap steel ratio.

2. The steelmaking method using a single converter to smelt 40% scrap steel according to claim 1, characterized in that: The preparation of steelmaking raw materials comprises the steps of: Prepare undesulfurized hot metal; Prepare scrap steel; Prepare ferrosilicon; Prepare graphite spheres.

3. The steelmaking method of claim 2 using a single converter to smelt 40% scrap steel, characterized in that: The mass of the non-desulfurized molten iron is 137t-140t.

4. The steelmaking method using a single converter to smelt 40% scrap steel according to claim 2, characterized in that: The total mass of the scrap steel is 95t-97t.

5. The steelmaking method using a single converter to smelt 40% scrap steel according to claim 2, characterized in that: The scrap steel is 3 buckets, and the mass of each bucket is 20t-45t.

6. The steelmaking method of claim 2 using a single converter to smelt 40% scrap steel, characterized in that: The mass of each batch of graphite balls is 5t-8t.

7. The steelmaking method of claim 1 using a single converter to smelt 40% scrap steel, characterized in that: The adding of auxiliary reaction materials into the single converter comprises the steps of: Adding lime into the single converter; Light burn is added to the single converter.

8. The steelmaking method of claim 7 using a single converter to smelt 40% scrap steel, characterized in that: The mass of the lime is 12t-15t.

9. The steelmaking method of claim 1 using a single converter to smelt 40% scrap steel, characterized in that: The step of adjusting the parameters of the oxygen lance and the single converter comprises the following steps: Adjusting the bottom blowing flow rate of the oxygen lance; Adjusting the oxygen blowing volume of the oxygen lance; The end temperature of the single converter is adjusted.

10. The steelmaking method of claim 9 using a single converter to smelt 40% scrap steel, characterized in that: The bottom blowing flow rate of the oxygen lance is 600-1000Nm 3 / h.

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