Method for reducing converter steelmaking carbon emission

Abstract

The invention relates to the technical field of iron and steel smelting, and particularly discloses a method for reducing converter steelmaking carbon emission, which comprises the following steps: blast furnace ironmaking, and controlling the blast furnace tapping temperature to be greater than 1515 DEG C; the ratio of the mass of molten iron to the mass of molten steel in the converter ranges from 0.74 to 0.76, and waste steel is put into the converter in three times; before the steel scrap is added for the first time, the mass of the steel scrap added for the first time accounts for 20-40% of the total mass of the steel scrap; after the second time of addition of the waste steel is finished, the mass of the second time of addition of the waste steel accounts for 60-80% of the total mass of the waste steel; when the waste steel is added for the third time and the steel is discharged, the mass of the waste steel for the third time is 1000-3000 Kg. According to the method for reducing the converter steelmaking carbon emission, on the premise of reducing the mass of molten iron in the converter, increasing the proportion of scrap steel and ensuring stable steelmaking production, the carbon content of metal materials in the converter can be reduced without additionally increasing energy consumption, so that the oxidation reaction of carbon is reduced, the carbon emission is reduced, and energy conservation and emission reduction are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of steel smelting, and more specifically to a method for reducing carbon emissions from converter steelmaking. Background Art

[0002] Carbon emissions refer to the amount of greenhouse gas emissions generated when a product is produced, transported, used and recycled. The most important greenhouse gas is carbon dioxide, so "carbon" is usually used to represent greenhouse gas emissions. Carbon emissions have a significant impact on the environment and climate. Studies have shown that the main reason for the rise in global average temperatures over the past 50 years is related to the increase in greenhouse gases produced by human use of fuels such as oil.

[0003] Converter steelmaking is a steelmaking method that does not require external heat sources and mainly uses liquid iron as raw material. Carbon emissions from converter steelmaking are an important environmental issue that has a profound impact on global climate change and sustainable development.

[0004] The conventional steelmaking process, which is mainly based on the blast furnace-converter long process, has a high dependence on fossil fuels such as coal and coke, resulting in high carbon emissions in the steel industry. Therefore, how to effectively reduce carbon emissions in the converter smelting process and achieve energy conservation and emission reduction is a problem that technical personnel in this field need to solve. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a method for reducing carbon emissions from converter steelmaking, which can effectively solve the problem of high carbon emissions from steelmaking.

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

[0007] A method for reducing carbon emissions from converter steelmaking, comprising:

[0008] Blast furnace ironmaking, and control the blast furnace iron temperature to be greater than 1515℃;

[0009] In converter steelmaking, the mass ratio of molten iron to molten steel in the converter ranges from 0.74 to 0.76, and scrap steel is added to the converter in three batches;

[0010] Among them, the first addition of scrap steel is done before the blast furnace taps iron. The first addition of scrap steel accounts for 20-40% of the total scrap steel mass. The molten iron tank then receives the blast furnace iron.

[0011] After the slag splashing is completed, the second scrap steel is added to the converter, and the molten iron mixed with the first scrap steel is added. The mass of the second scrap steel added accounts for 60-80% of the total scrap steel mass, and then blowing is carried out;

[0012] When the third scrap steel is added and the steel is tapped, the converter tapping temperature is controlled at 1610~1640℃, and the third scrap steel is added to the molten steel with a mass of 1000~3000Kg, and then LF refining is used to adjust the steel liquid composition temperature.

[0013] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the scrap steel added for the first time is steel bar briquettes.

[0014] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the scrap steel added for the third time is steel bar pellets.

[0015] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the outer diameter of the steel bar cut particles is φ≤28 mm and the length is less than 16 mm.

[0016] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the binary basicity R at the converter steelmaking endpoint is ≤2.4, and the iron-containing material intake is ≤5Kg / t.

[0017] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the composition of blast furnace molten iron, by mass, includes: C: 4.5%, Si: 0.45%, Mn: 0.35%, P: 0.130%, S: 0.035%, and the remainder is Fe and impurities.

[0018] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the amount of scrap steel added for the third time corresponding to different steel-out temperatures is obtained by calculation, and compiled into a table for distribution.

[0019] Optionally, in the above method for reducing carbon emissions from converter steelmaking, when adding scrap steel for the third time, the mass of the scrap steel added for the third time and the tapping temperature satisfy the relationship:

[0020] M3=(T 出 -T LF -T 温降 )÷ΔT;

[0021] ΔT=Q 吸 *1000Kg÷C÷m÷1000kg;

[0022] Q 吸 =Q1+Q2+Q3;

[0023] Where, M3 is the mass of the third scrap steel;

[0024] T 出 is the tapping temperature of the converter;

[0025] T LF is the LF refining temperature;

[0026] T 温降 Normal temperature drop for steel tapping from converter;

[0027] m is the mass of molten steel, in t;

[0028] ΔT is the temperature drop of molten steel corresponding to the addition of 1000kg of third-time scrap steel into molten steel of mass m;

[0029] C is the specific heat capacity of liquid steel, which is 0.790KJ / (kg·℃);

[0030] Q1 is the heat that 1 kg of the third scrap steel needs to absorb when heated from the initial temperature to the melting point;

[0031] Q2 is the latent heat of fusion required for 1 kg of third scrap steel to transform from solid to liquid;

[0032] Q3 is the heat required to heat 1 kg of third scrap steel from its melting point to the LF refining temperature.

[0033] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the converter steel tapping temperature range is 1610~1640°C.

[0034] Optionally, in the above method for reducing carbon emissions from converter steelmaking, the converter blowing slag material is controlled by two batches of materials. After oxygen ignition is normal, the first batch of slag material is added, accounting for 70% of the total slag material. The second batch of slag material is added 3.5 to 5 minutes after oxygen blowing.

[0035] The method for reducing carbon emission in converter steelmaking provided by the present invention is applied. During blast furnace ironmaking, the blast furnace tapping temperature is controlled to be greater than 1515°C; during converter steelmaking, the mass ratio of molten iron to molten steel in the converter is controlled to be in the range of 0.74-0.76, and scrap steel is added into the converter in three times; wherein, before the blast furnace tapping, the first scrap steel is added into the molten iron tank in advance, and the mass of the first scrap steel added accounts for 20-40% of the total scrap steel mass, and then the molten iron tank receives the blast furnace molten iron; after the second scrap steel is added, the second scrap steel is added into the converter after slag splashing, and the molten iron mixed with the first scrap steel is added, and the mass of the second scrap steel added accounts for 60-80% of the total scrap steel mass, and then blowing is performed; when the third scrap steel is added, the converter tapping temperature is controlled to be 1610-1640°C, the third scrap steel is added into the molten steel, and the mass of the third scrap steel is 1000-3000 kg, and then LF refining is performed to adjust the temperature of the molten steel composition.

[0036] In summary, in this application, by reducing the quality of molten iron in the converter and increasing the ratio of scrap steel, the specific iron-steel ratio range is between 0.74 and 0.76, and the scrap steel is added in three times. By setting the timing and quality of each addition of scrap steel, the carbon content of the metal material in the converter can be reduced without increasing energy consumption while ensuring stable steelmaking production, thereby reducing carbon oxidation reactions, reducing carbon emissions, and achieving energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 The present invention is a flowchart of a method for reducing carbon emissions from converter steelmaking according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0039] The embodiment of the invention discloses a method for reducing carbon emission from converter steelmaking, so as to reduce carbon emission from steelmaking.

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Converter steelmaking uses molten iron and scrap steel as the main raw materials. It relies on the physical heat of the liquid iron in the converter and the chemical heat generated by the chemical reaction of the components in the molten iron (such as carbon, manganese, silicon, phosphorus, etc.) with the oxygen fed into the furnace to make the metal reach the composition and temperature required for steelmaking. This process will produce a large amount of CO and CO2 gases, which are positively correlated with the carbon content of the metal.

[0042] Based on this, the present application provides a method for reducing carbon emissions from converter steelmaking, by reducing the carbon content of metal materials in the converter, reducing carbon oxidation reactions, and thus reducing carbon emissions. The method for reducing carbon emissions from converter steelmaking is based on solving the problem of high carbon emissions in the converter smelting process, and can effectively reduce a certain amount of carbon emissions in the converter smelting process, thereby achieving the purpose of energy conservation and emission reduction. The method utilizes the most common steelmaking equipment, does not require additional equipment investment, has low cost, simple methods, is easy to implement, has quick results, is widely applicable, and can improve the competitiveness of enterprises.

[0043] In some embodiments, see Figure 1 The method for reducing carbon emissions from converter steelmaking provided in the present application comprises:

[0044] S1: blast furnace ironmaking, and control the blast furnace tapping temperature to be greater than 1515℃;

[0045] By setting the blast furnace tapping temperature at greater than 1515°C, compared to a molten iron temperature greater than 1250°C, this provides a basis for reducing the iron-to-steel ratio, thereby reducing molten iron consumption.

[0046] S2: Converter steelmaking, the mass ratio of molten iron to molten steel in the converter is in the range of 0.74-0.76, and scrap steel is added to the converter in three times;

[0047] Among them, the first addition of scrap steel is done before the blast furnace taps iron. The first addition of scrap steel accounts for 20-40% of the total scrap steel mass. The molten iron tank then receives the blast furnace iron.

[0048] After the slag splashing is completed, the second scrap steel is added to the converter, and the molten iron mixed with the first scrap steel is added. The mass of the second scrap steel added accounts for 60-80% of the total scrap steel mass, and then blowing is carried out;

[0049] When the third scrap steel is added and the steel is tapped, the converter tapping temperature is controlled at 1610~1640℃, and the third scrap steel is added to the molten steel with a mass of 1000~3000Kg, and then LF refining is used to adjust the steel liquid composition temperature.

[0050] Different from conventional scrap steel added to the converter together with molten iron, in this embodiment, scrap steel is added three times, and the timing of the three additions is before the blast furnace tapping, the end of slag splashing and the scrap steel tapping, and the weight of the scrap steel added three times is 20-40% of the total scrap steel mass, 60-80% of the scrap steel mass and 1000-3000Kg, respectively. Of course, the sum of the mass of the scrap steel added three times should be the corresponding total scrap steel mass. It is understandable that the form of the scrap steel added three times can be the same or different, such as steel blocks, steel grains, etc. By adding scrap steel three times, the mass ratio of the mass of molten iron in the converter to the mass of molten steel is reduced to between 0.74-0.76, ensuring that the steelmaking production is stable, without additional energy consumption, and at the same time, it can ensure that the tapping temperature meets the demand. It should be noted that the mass ratio of the mass of molten iron in the converter to the mass of molten steel in the present application refers to the ratio of the mass of molten iron consumed by the converter steelmaking to the mass of molten steel produced, that is, the iron-steel ratio. Exemplarily, the mass ratio of molten iron to molten steel in the converter is 0.74, 0.742, 0.744, 0.746, 0.748, 0.75, 0.752, 0.754, 0.756, 0.758, or 0.76.

[0051] In the method provided in the present application, by reducing the mass of molten iron in the converter and increasing the ratio of scrap steel, the specific iron-steel ratio is reduced to between 0.74 and 0.76, and the scrap steel is added in three times. By setting the timing and mass of adding scrap steel each time and ensuring the steelmaking temperature, the carbon content of the metal material in the converter can be reduced, thereby reducing the carbon oxidation reaction, reducing carbon emissions, and achieving energy conservation and emission reduction.

[0052] In some embodiments, the scrap steel added for the first time is a steel bar briquette. The scrap steel added for the first time is the first scrap steel, and the use of steel bar briquette can ensure the purity of the scrap steel quality. At the same time, the block structure is convenient for adding into the molten iron tank, and the block structure is also convenient for estimating the added weight. If the steel bar briquette is a standard block, that is, the steel bar briquette adopts the same specifications, then the mass of a single steel bar briquette is determined, and the total mass can be calculated by counting the steel bar briquettes, without the need to obtain the mass through weighing operations, thereby simplifying the operation.

[0053] In some embodiments, the scrap steel added for the third time is steel bar pellets. The scrap steel added for the third time is the third scrap steel, which is steel bar pellets. Since the third scrap steel is added when the scrap steel is tapped, the steel bar pellets can be obtained by preliminary processing of steel bars such as scrap threaded steel bars by a steel bar shearing machine. The material is clean, so the water yield is high. In addition, steel bar pellets are easy to process and easy to handle. And steel bar pellets can be melted faster due to their uniform size and shape, which helps to improve the efficiency of steelmaking.

[0054] In some embodiments, the outer diameter φ of the steel bar pellets is ≤ 28 mm, and the length is less than 16 mm. Exemplarily, the outer diameter φ of the steel bar pellets is 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, and the length of the steel bar pellets is 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm. The size of the steel bar pellets is set within the above range, which can melt faster and further improve the efficiency of steelmaking.

[0055] In some embodiments, the binary basicity R at the end of converter steelmaking is ≤2.4, and the iron-containing material intake is ≤5Kg / t. The basicity of converter slag at the end is usually controlled between 3.0 and 4.0. In this embodiment, since the iron-steel ratio is controlled above 0.74, the binary basicity R at the end of converter steelmaking is controlled to be no more than 2.4, that is, the binary basicity at the end of converter steelmaking is dynamically adjusted to achieve the best steelmaking effect.

[0056] In addition, the intake of iron-containing materials is controlled. Specifically, the iron-containing materials include ores and the like.

[0057] In some embodiments, the composition of blast furnace molten iron includes, by mass, 4.5% C, 0.45% Si, 0.35% Mn, 0.130% P, 0.035% S, and the balance is Fe and impurities. The composition of blast furnace molten iron is set as above to achieve the best steelmaking effect.

[0058] In some embodiments, the converter adopts a slag pouring and slag splashing mode, leaving 2-3 tons of red slag from the previous smelting, and the slag splashing time is less than 2 minutes. The slag splashing adopts the above settings to achieve the best steelmaking effect.

[0059] In some embodiments, the mass ratio of the molten iron in the converter to the mass ratio of the scrap steel is determined according to the heat balance, and the converter steelmaking process does not use an external heat source. In the present application, the iron-steel ratio is controlled to be between 0.74 and 0.76. According to the iron-steel ratio, the steel tapping temperature of the converter can be calculated according to the heat balance to obtain the amount of scrap steel added corresponding to the converter steelmaking process without using an external heat source.

[0060] In some embodiments, when adding scrap steel for the third time, the mass of the scrap steel added for the third time and the tapping temperature satisfy the relationship:

[0061] M3=(T 出 -T LF -T 温降 )÷ΔT;

[0062] ΔT=Q 吸 *1000Kg÷C÷m÷1000kg;

[0063] Q 吸 =Q1+Q2+Q3;

[0064] Where, M3 is the mass of the third scrap steel;

[0065] T 出 is the tapping temperature;

[0066] T LF is the LF (ladle refining furnace) refining temperature;

[0067] T 温降 Normal temperature drop for steel tapping from converter;

[0068] ΔT is the temperature drop of molten steel corresponding to the addition of 1000kg of third-time scrap steel into molten steel of mass m;

[0069] C is the specific heat capacity of liquid steel, which is 0.790KJ / (kg·℃);

[0070] m is the mass of molten steel, in t;

[0071] Q1 is the heat that 1 kg of the third scrap steel needs to absorb when heated from the initial temperature to the melting point;

[0072] Q2 is the latent heat of fusion required for 1 kg of third scrap steel to transform from solid to liquid;

[0073] Q3 is the heat required to heat 1 kg of third scrap steel from its melting point to the LF refining temperature.

[0074] The above formula can be used to calculate the amount of scrap steel added for the third time based on heat balance. That is, by accurately controlling the amount of scrap steel added for the third time, the tapping temperature can be guaranteed while improving the temperature control accuracy.

[0075] For example, in order to ensure the melting speed of the third batch of scrap steel, the third batch of scrap steel is made of ribbed steel bar pellets, whose melting point is generally between 1500 and 1530°C, and is calculated here as 1512°C. 温降 The process requires LF refining temperature T LF Not less than 1540℃, add 1Kg scrap steel (ribbed steel bar granules) into m=120t molten steel, and heat it from the initial temperature of 15℃ to the LF refining temperature of 1540℃. The specific heat capacity C of solid steel is 0.760KJ / (kg·℃), the specific heat capacity C of liquid steel is 0.790KJ / (kg·℃), and the latent heat of melting is 272kJ / kg. Based on heat balance, the theoretical calculation is as follows:

[0076] The heat from 15℃ to the melting point 1512℃:

[0077] Q1=1kg×0.760K J / (kg·℃)×(1512−15)℃=1137.72kJ;

[0078] The latent heat of fusion required for the ribbed steel bar to change from solid to liquid: Q2=1kg×272kJ / kg=272kJ;

[0079] (3) Heat required for the melting point to rise from 1512°C to 1540°C:

[0080] Q3=1kg×0.79 0KJ / (kg·℃)×(1540−1512) ℃=22.12kJ;

[0081] Adding the heat of the above three stages, we can get the total heat absorbed by melting 1kg of scrap steel (ribbed steel bar pellets): 吸 :

[0082] Q 吸 =Q1+Q2+Q3=1431.84 kJ;

[0083] Therefore, 1000kg of scrap steel (ribbed steel bar pellets) can reduce the temperature of 120t of molten steel by ΔT.

[0084] ΔT=1431.84 kJ*1000Kg÷0.790KJ / (kg·℃)÷120÷1000kg=15.1℃

[0085] That is, the effect of 1 ton of scrap steel on the temperature of 120t of molten steel is about 15℃, so the amount of scrap steel (ribbed steel bar pellets) added in the third time M3 and the tapping temperature T 出 The relationship is:

[0086] M3=(T 出 -1540℃-50℃)÷ΔT;

[0087] The tapping temperature T 出 Substituting the value of ΔT into the above formula, the amount of scrap steel added for the third time M3 can be obtained by calculation.

[0088] In some embodiments, the amount of scrap added for the third time corresponding to different tapping temperatures is obtained by calculation, and is compiled into a table for distribution, so that the amount of scrap added for the third time corresponding to the tapping temperature can be obtained by looking up the table during production. That is, the amount of scrap added for the third time corresponding to different tapping temperatures is calculated in advance, and during production, there is no need to perform calculations again, and the corresponding amount of scrap added for the third time can be read according to the tapping temperature of the current process, which further improves work efficiency.

[0089] For example, the mass m of the molten steel is 120t, and the tapping temperature T 出 The temperature is 1600℃, 1605℃, 1610℃... with a temperature interval of 5℃ until the tapping temperature Tout is 1650℃. The corresponding amounts of scrap steel added for the third time are shown in Table 1.

[0090] Table 1 Corresponding relationship between the amount of scrap steel added in the third time and the tapping temperature

[0091]

[0092] In some embodiments, the converter blowing slag material adopts two-batch material control. After the oxygen is turned on and the ignition is normal, the first batch of slag material is added, and it accounts for 70% of the total slag material. The second batch of slag material is added after blowing oxygen for 3.5 to 5 minutes. It can be understood that the second batch of slag material accounts for 30% of the total slag material. Slag making adopts two-batch material control. By adding slag material in batches, the properties of slag can be more effectively controlled, thereby improving steelmaking efficiency. And adding slag material in batches helps to form better quality slag, improve the fluidity and desulfurization and dephosphorization capabilities of slag. In addition, by accurately controlling the amount and timing of adding slag material, the consumption of slag material can be reduced and the cost of steelmaking can be reduced. Adding slag material in batches can reduce the splashing of slag, improve the operating conditions in front of the furnace, and improve the safety of operation. The two-batch material control provides more process adjustment space, and the strategy of adding slag material can be flexibly adjusted according to the composition of molten iron and steelmaking goals. In addition, reducing the consumption of slag material and optimizing the performance of slag helps to reduce dust and harmful gas emissions in the steelmaking process and reduce environmental pollution. In summary, the second batch material control can optimize the slag making effect, improve the metal recovery rate, reduce costs, reduce harmful gas emissions, and achieve more precise process control while ensuring the efficiency of converter steelmaking.

[0093] Furthermore, the oxygen inlet diameter φ: 38 mm, the outlet diameter φ: 49.8 mm, and the angle ɑ: 13.5° were used.

[0094] A specific embodiment is described below.

[0095] Example 1

[0096] The mass of molten iron in blast furnace required for converter smelting is 90 tons. As the main raw material for converter steelmaking, it provides physical heat and chemical heat for converter smelting. The tapping temperature of molten iron needs to be greater than or equal to 1515℃. The composition of molten iron by mass includes: C: 4.5%, Si: 0.45%, Mn: 0.35%, P: 0.130%, S: 0.035%, and the balance is Fe and impurities.

[0097] The molten iron transportation adopts a one-tank-to-the-end mode, using an online circulating molten iron tank to keep it red and clean. Before adding the molten iron, 9 tons of steel briquettes, i.e. 9t of the first scrap steel, are added to the red and clean molten iron tank. Then it is immediately taken to the iron outlet to receive the blast furnace molten iron. The molten iron temperature is measured to be about 1350℃.

[0098] The converter adopts the mode of pouring slag first and then splashing slag, leaving 2~3 tons of red slag from the previous smelting furnace, and the rapid slag splashing time is less than 2 minutes. By standardizing the amount of slag left and the slag splashing time, the temperature drop inside the furnace is uniform, reducing the difference between furnaces.

[0099] Immediately swing the converter mouth to the scrap steel adding position, add 27 tons of scrap steel into the converter with the scrap steel bucket, and then immediately add molten iron into the converter for blowing.

[0100] The converter blowing slag material adopts two batches of material control. After the oxygen is turned on and the ignition is normal, add a batch of slag material, accounting for 70% of the total slag material. Add the second batch of slag material after blowing oxygen for 3.5-5 minutes. The end point basicity R is less than 2.4, and the operation mode is controlled according to the table below. The diameter of the oxygen inlet is φ: 38mm, the outlet diameter is φ: 49.8mm, and the angle ɑ: 13.5°

[0101] Specifically, the parameters of the gun position, oxygen pressure and slag making materials during slag making can refer to Table 2. By controlling the slag making according to the parameters in Table 2, a good slag making effect can be obtained.

[0102] Table 2 Slag making parameters

[0103]

[0104] The tapping temperature is greater than or equal to 1610℃. Argon is blown from the bottom of the ladle during tapping. Immediately add 1500Kg of clean steel bar pellets to the argon blowing station. The steel bar pellets are φ≤28mm and less than 16mm in length. The amount of steel bar pellets added is 1000~3000Kg according to the tapping temperature, and then go to the LF refining furnace to adjust the composition temperature.

[0105] Through the above steps, the proportion of scrap steel is increased, and the final steel output is 121 tons, the weight of molten iron is 90 tons, the amount of scrap steel is 38.5 tons (a total of 9+28+1.5 scrap steel are input in three times), and the iron-steel ratio is 0.744, which reduces the consumption of molten iron and the carbon content of metal materials in the converter.

[0106] In summary, the above-mentioned method of reducing carbon emissions from converter steelmaking can reduce molten iron by more than 100 kg per ton of steel and carbon by more than 4.3 kg per ton of steel. According to the ratio of 80% CO and 20% CO2 generated in converter smelting, the ultimate carbon emission reduction is 11.21 kg.

[0107] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0108] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may 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 the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for reducing carbon emissions from converter steelmaking, characterized in that: include: Blast furnace ironmaking, and control the blast furnace iron temperature to be greater than 1515℃; In converter steelmaking, the mass ratio of molten iron to molten steel in the converter is in the range of 0.74 to 0.76, and scrap steel is added to the converter in three times; Among them, the first addition of scrap steel is done before the blast furnace taps iron. The first addition of scrap steel accounts for 20-40% of the total scrap steel mass. The molten iron tank then receives the blast furnace iron. After the slag splashing is completed, the second scrap steel is added to the converter, and the molten iron mixed with the first scrap steel is added. The mass of the second scrap steel added accounts for 60-80% of the total scrap steel mass, and then blowing is carried out; When the third scrap steel is added and the steel is tapped, the converter tapping temperature is controlled at 1610~1640℃, and the third scrap steel is added to the molten steel with a mass of 1000~3000Kg, and then LF refining is used to adjust the steel liquid composition temperature.

2. The method for reducing carbon emissions from converter steelmaking according to claim 1, characterized in that: The first scrap steel added is steel bar briquettes.

3. The method for reducing carbon emissions from converter steelmaking according to claim 1, characterized in that: The third added scrap steel is steel bar pellets.

4. The method for reducing carbon emissions from converter steelmaking according to claim 3, characterized in that: The outer diameter of the steel bar cuttings is φ≤28mm and the length is less than 16mm.

5. The method for reducing carbon emissions from converter steelmaking according to claim 1, characterized in that: The binary basicity R at the end point of converter steelmaking is ≤2.4, and the iron-containing material intake is ≤5Kg / t.

6. The method for reducing carbon emissions from converter steelmaking according to claim 1, characterized in that: The composition of blast furnace molten iron, by mass, includes: C: 4.5%, Si: 0.45%, Mn: 0.35%, P: 0.130%, S: 0.035%, and the balance is Fe and impurities.

7. The method for reducing carbon emissions from converter steelmaking according to any one of claims 1 to 6, characterized in that: When adding scrap steel for the third time, the quality of the scrap steel added for the third time and the tapping temperature satisfy the relationship: M3=(T 出 -T LF -T 温降 )÷ΔT; ΔT=Q 吸 *1000Kg÷C÷m÷1000kg; <h2 style=";text-align:left;direction:ltr">Q<h2 style=";text-align:left;direction:ltr"> 吸 <h2 style=";text-align:left;direction:ltr"> =Q1+Q2+Q3; Where, M3 is the mass of the third scrap steel; T 出 is the tapping temperature of the converter; T LF is the LF refining temperature; T 温降 Normal temperature drop for steel tapping from converter; ΔT is the temperature drop of molten steel corresponding to the addition of 1000kg of third-time scrap steel into molten steel of mass m; C is the specific heat capacity of liquid steel, which is 0.790KJ / (kg·℃); m is the mass of molten steel, in t; Q1 is the heat that 1 kg of the third scrap steel needs to absorb when heated from the initial temperature to the melting point; Q2 is the latent heat of fusion required for 1 kg of third scrap steel to transform from solid to liquid; Q3 is the heat required to heat 1 kg of third scrap steel from its melting point to the LF refining temperature.

8. The method for reducing carbon emissions from converter steelmaking according to claim 7, characterized in that: The amount of scrap steel added for the third time corresponding to different steel-out temperatures is obtained by calculation and compiled into a table for distribution.

9. The method for reducing carbon emissions from converter steelmaking according to claim 7, characterized in that: The steel tapping temperature range of the converter is 1610~1640℃.

10. The method for reducing carbon emissions from converter steelmaking according to claim 1, characterized in that: The slag-making material for converter blowing is controlled by two batches. After the oxygen is turned on and the ignition is normal, the first batch of slag-making material is added, which accounts for 70% of the total slag-making material. The second batch of slag-making material is added 3.5 to 5 minutes after the oxygen is blown.

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