A method for plotting an operating line for an oxygen-enriched hydrogen-low-carbon reduction melting furnace

Abstract

The application discloses a kind of drawing methods suitable for the operation line of full-oxygen hydrogen-rich low-carbon reduction melting furnace, it is related to hydrogen metallurgical low-carbon ironmaking production field.This method is committed to build the operation line model of adaptation full-oxygen hydrogen-rich reduction melting furnace, with the global material balance and heat balance data of full-oxygen hydrogen-rich low-carbon reduction melting furnace to draw operation line chart, to provide accurate guidance and optimization strategy for the production activities of reduction melting furnace.The method comprises: establishing the operation line model of upper indirect reduction zone of full-oxygen hydrogen-rich low-carbon reduction melting furnace by determining and point coordinates;The operation line model of lower direct reduction zone of full-oxygen hydrogen-rich low-carbon reduction melting furnace is established by determining and point coordinates;The connection of indirect reduction zone operation line model and direct reduction zone operation line model is realized at point to obtain full-oxygen hydrogen-rich low-carbon reduction melting furnace operation line model;By connecting, and straight line, draw the complete operation line chart of full-oxygen hydrogen-rich low-carbon reduction melting furnace.

Description

Technical Field

[0001] This invention relates to the field of hydrogen metallurgy and low-carbon ironmaking production technology, specifically to a method for drawing the operation line of an all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace. Background Technology

[0002] like Figure 1 As shown, the all-oxygen hydrogen-rich reduction melting furnace is divided into three functional zones from top to bottom: the indirect reduction zone (I), the softening and dripping zone (II), and the coke combustion and slag-iron zone (III). Among them, zones II and III together constitute the direct reduction zone, which undertakes the core function of the molten reduction reaction. Based on its process characteristics of using hydrogen-rich gas as a reducing agent, all-oxygen combustion, and low carbon emissions, this furnace type is classified as a "reduction melting furnace". Unlike traditional blast furnaces, the all-oxygen hydrogen-rich low-carbon reduction melting furnace uses all-oxygen to replace air blown into the lower tuyeres and injects hydrogen-rich reducing gas from the furnace body. The gas supply ratio of the two parts can be flexibly adjusted according to the degree of indirect reduction, changing the existing blast furnace ironmaking method of about 30-40% direct carbon reduction and about 70-60% indirect CO reduction, thus reducing the carbon consumption per ton of iron smelting.

[0003] The Rist operating line, serving as a "visualized mathematical model" of the blast furnace smelting process, cleverly links raw material composition, gas utilization rate, direct reduction degree, and coke ratio with a single straight line, providing a precise quantitative analysis tool for optimizing fuel consumption and reducing carbon emissions. The AE line shown in Figure 2 represents the Rist operating line of a blast furnace under specific smelting conditions. The slope of the Rist operating line represents the amount of C (mol or kmol) required to smelt 1 mol of Fe in the blast furnace, implying the iron-coke ratio; the two can be interconverted.

[0004] With the continuous development of blast furnace smelting technology, the role of H2 in blast furnace smelting has become indispensable. Therefore, later researchers introduced H2 into the traditional Rist operating line to create the Fe-OCH four-element system operating line diagram. The vertical axis in the diagram represents... n (O+H2) / n (Fe), x-axis is n (O+H2) / n (C+H2), the slope then becomes the sum of the amount of gasified carbon consumed in smelting 1 mol of Fe and the total amount of H2 entering the furnace. However, the current operating line of the quaternary system has the following key limitations: 1) The reaction pathway of hydrogen is ambiguous: After introducing hydrogen into the vertical axis, it is impossible to quantify the actual reaction rate of H2, and after adding hydrogen into the horizontal axis, it is difficult to distinguish its role as an oxidant or a gasifying agent. 2) The physical meaning of the slope is weakened: the slope of the operating line degenerates from n(C) / n(Fe) to n(C+H2) / n(Fe), resulting in the loss of the intuitive correlation between the focal ratio (C / Fe); 3) Insufficient process adaptability: It cannot be compatible with non-blast furnace ironmaking processes such as direct reduction (e.g., MIDREX) and molten reduction (e.g., COREX).

[0005] Therefore, it is urgent to construct a new operating line model to achieve quantitative analysis and energy efficiency optimization of the process through a dedicated operating line diagram of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for drawing the operation line of an all-oxygen-rich hydrogen-low-carbon reduction melting furnace. This method focuses on constructing an operation line model adapted to the all-oxygen-rich hydrogen-low-carbon reduction melting furnace, and uses global material balance and heat balance data of the furnace to draw the operation line diagram, thereby providing precise guidance and optimization strategies for the production activities of the reduction melting furnace, and improving production efficiency and quality.

[0007] The technical solution of this invention is: A method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reducing melting furnace, comprising the following steps: By determining point, Point and Establish the operation line model of the upper indirect reduction zone of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace using point coordinates; By determining point, Point and A point coordinate model is used to establish the operation line model of the lower direct reduction zone of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. exist The connection between the indirect reduction zone operation line model and the direct reduction zone operation line model is achieved at the point to obtain a complete oxygen-rich hydrogen-low carbon reduction melting furnace operation line model. Through connection , , and Draw a complete operation line diagram of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace using straight lines; where... This is the actual operation line of the upper indirect reduction zone of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. This is the ideal operating line for the upper indirect reduction zone of an all-oxygen, hydrogen-rich, low-carbon reducing melting furnace. and Used to characterize the actual and ideal amount of reducing gas consumed when reducing iron oxides to a certain metallization rate; and All are operating lines in the direct reduction zone of the lower part of the all-oxygen, hydrogen-rich, low-carbon reduction melting furnace, and the slope of the operating line TB can characterize the coke ratio per ton of pig iron produced. and The intersection point is the thermal equilibrium limit point P of the direct reduction region.

[0008] Furthermore, according to the method for drawing the operating line applicable to an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, the... The point is the separation point between indirect and direct reduction; The coordinates of the point are calculated based on the composition of the reducing gas introduced into the furnace and the metallization rate of the reduction product, sponge iron. The formula for calculating the x-coordinate of a point is as follows: (1) In the above formula represent The x-coordinate of the point; and The volume percentage of CO2 and H2O in the reducing gases introduced into the reducing melting furnace, % The formula for calculating the ordinate of a point is: (2) In the above formula Representing the The ordinate of the point; For the The ordinate of the point, ; The metallization rate of sponge iron can be adjusted and determined according to the operating characteristics of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace.

[0009] Furthermore, according to the method for drawing the operating line applicable to an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, the... The coordinates of the point are calculated based on the composition of the gas at the top of the furnace and the Fe oxide content and Fe content of the minerals entering the furnace. The formula for calculating the x-coordinate of a point is: (3) In the above formula represent The x-coordinate of the point; and These represent the volume percentages of CO2 and H2O in the top gas of the furnace. The formula for calculating the ordinate of a point is: (4) In the above formula represent The ordinate of the point; , , , These represent the percentages of Fe2O3, Fe3O4, FeO, and Fe in the iron ore fed into the furnace, respectively, relative to the bulk mass.

[0010] Furthermore, according to the method for drawing the operating line applicable to an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, the... The coordinates of the point need to be determined first to find the equilibrium constraint point. After obtaining the coordinates, the linear fitting points Obtain a straight line ,because Dot at On the extension line and The ordinate of a point and The points have the same y-coordinate Right now It can be obtained The x-coordinate of the point; The The ordinate of a point The formula for calculating its x-coordinate is as follows: (5) (6) In the above formula , This represents the number of moles of CO2 and H2O in the top gas under ideal conditions. , The CO and H2 consumed in the direct reduction reaction under ideal conditions; and It refers to the total amount of C and H2 participating in the direct reduction reaction; To be at temperature T The equilibrium constant at which the direct reduction reaction of CO reaches equilibrium; To be at temperature T The equilibrium constant when the direct reduction reaction of H2 reaches equilibrium; The The formula for calculating the x-coordinate of a point is as follows: (9) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; and For the reason The intercept and slope of the linear equation obtained by point fitting.

[0011] Furthermore, according to the method for drawing the operating line applicable to an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, the... The formulas for calculating the x and y coordinates of a point are as follows: (10) (11) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Si in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Mn in pig iron; This indicates the amount of oxygen introduced by the direct reduction of phosphorus (P) in pig iron. This indicates the amount of oxygen introduced during slag desulfurization.

[0012] Furthermore, according to the method for drawing the operation line applicable to the all-oxygen-rich hydrogen-low-carbon reduction melting furnace, the formula for calculating the horizontal and vertical coordinates of point B is as follows: (16) (17) (18) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; The amount of oxygen provided for the combustion of carbon during the blower process; The amount of carbon burned per ton of pig iron before the tuyeres during smelting, in kg; The percentage of Fe in pig iron.

[0013] Furthermore, according to the method for drawing the operating line applicable to an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, the... The formulas for calculating the x and y coordinates of a point are as follows: (twenty four) (25) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; The other reduction heat consumption is in the direct reduction zone of the all-oxygen-rich hydrogen reduction melting furnace; The direct reduction of floatite consumes heat.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention differs from the traditional blast furnace Rist operating line. The slope of the actual operating line AT of the upper indirect reduction zone of the reduction melting furnace can be converted into the total amount of reducing gas actually consumed when the sponge iron is indirectly reduced to a certain metallization rate. The slope of the ideal operating line A'T of the upper indirect reduction zone of the reduction melting furnace can be converted into the total amount of reducing gas consumed under ideal conditions when the sponge iron is indirectly reduced to a certain metallization rate. (2) This invention differs from the traditional blast furnace Rist operating line. The slope of the straight line in the operating line diagram of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace is... k = n (C+H2) / n (Fe), because no H2 enters the direct reduction zone of the reduction melting furnace, the straight line in the direct reduction zone operation line of the all-oxygen-rich hydrogen-low carbon reduction melting furnace is... The slope can be regarded as k = n (C) / n (Fe), The slope can directly reflect the focal ratio; (3) This invention differs from the traditional blast furnace Rist operating line by establishing the indirect reduction zone operating line model and the direct reduction operating line model separately. The model is connected at point T, which is determined by the composition of the reducing gas introduced into the furnace body and the metallization rate of the reduced product sponge iron. This allows for the establishment of a complete oxygen-rich hydrogen-low carbon reduction melting furnace operating line model. Based on the oxygen-rich hydrogen-low carbon reduction melting furnace model, a complete operating line diagram can be drawn, thereby characterizing the smelting situation of the entire oxygen-rich hydrogen-low carbon reduction melting furnace. Attached Figure Description

[0015] Figure 1 Functional area diagram of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace; Figure 2 This is a schematic diagram of a traditional Rist operation line; Figure 3 This is a flowchart illustrating the method for drawing the operation line of an all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace applicable to this embodiment. Figure 4 This is an operation line diagram applicable to an all-oxygen, hydrogen-rich, low-carbon reduction melting furnace. Detailed Implementation

[0016] To facilitate understanding of this application, a more comprehensive description of this application will be provided below with reference to the accompanying drawings.

[0017] Figure 3This is a flowchart illustrating the method for drawing the operation line of an all-oxygen, hydrogen-rich, low-carbon reduction melting furnace according to this embodiment. Figure 3 As shown, the method for drawing the operation line of the all-oxygen-rich hydrogen-low carbon reduction melting furnace includes the following steps: Step 1: By determining point, Dot and Establish the operation line model of the upper indirect reduction zone of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace using point coordinates; The actual operating line of the upper indirect reduction zone of the reduction melting furnace is derived based on the metallization rate of sponge iron fed into the furnace, the composition of the top gas, and the Fe and O content of the iron ore fed into the furnace. Based on the equilibrium constant of the direct reduction reaction of CO, H2, and iron oxides and the content of CO2 and H2O in the top gas, the ideal operating line of the upper indirect reduction zone of the reduction melting furnace is obtained. Upper indirect reduction zone operation line and It can characterize the actual and ideal amount of reducing gas consumed when reducing iron oxides to a certain metallization rate; The The coordinates of the point can be calculated from the composition of the reducing gas introduced into the furnace body of the reduction melting furnace and the metallization rate of the reduction product, sponge iron. The formula for calculating the x-coordinate of a point is: (1) In the above formula represent The x-coordinate of the point; and The volume percentage of CO2 and H2O in the reducing gases introduced into the reducing melting furnace, % The formula for calculating the ordinate of a point is: (2) In the above formula Representing the The ordinate of the point; For the The ordinate of a point is determined by the oxygen content of flour at a given temperature. Flour is Fe... 2+ A missing crystal is denoted as , x =0.88~0.95, the boundary between indirect and indirect reduction of stearite is at 900℃~1000℃, at this temperature x ≈0.95, the ordinate is n (O+H2) / n (Fe), then ; The metallization rate of sponge iron can be adjusted and determined according to the operating characteristics of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace, and the metallization rate can reach more than 90%.

[0018] The The coordinates of the point can be determined based on the composition of the gas at the top of the furnace and the Fe oxide content and Fe content of the minerals entering the furnace. The formula for calculating the x-coordinate of a point is: (3) In the above formula represent The x-coordinate of the point; and These represent the volume percentages of CO2 and H2O in the top gas of the furnace. The formula for calculating the ordinate of a point is: (4) In the above formula represent The ordinate of the point; , , , These represent the percentages of Fe2O3, Fe3O4, FeO, and Fe in the iron ore fed into the furnace, respectively, relative to the bulk mass.

[0019] The The coordinates of the point need to be determined first to find the equilibrium constraint point. After obtaining the coordinates, the linear fitting points Obtain a straight line ,because Dot at On the extension line and The ordinate of a point and The points have the same y-coordinate Right now It can be obtained The x-coordinate of the point.

[0020] The The ordinate of a point The formula for calculating its x-coordinate is as follows: (5) (6) In the above formula , This represents the number of moles of CO2 and H2O in the top gas under ideal conditions. , The CO and H2 consumed in the direct reduction reaction under ideal conditions; and It refers to the total amount of C and H2 participating in the direct reduction reaction; To be at temperature T The equilibrium constant at which the direct reduction reaction of CO reaches equilibrium; For temperature T The equilibrium constant when the direct reduction reaction of H2 reaches equilibrium.

[0021] Based on the two chemical reactions of low-valent iron oxides in the indirect reduction zone of the melting furnace shown in equations (7) and (8), the temperature at which the reaction occurs can be determined. T When these two direct reduction reactions reach equilibrium, the equilibrium constant is... and .

[0022] (7) (8) The formula for the x-coordinate of a point is: (9) In the above formula and For the reason The intercept and slope of the linear equation obtained by point fitting.

[0023] Step 2: By determining point, Dot and A point coordinate model is used to establish the operation line model of the lower direct reduction zone of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. Based on the alloying elements in the pig iron smelted in the direct reduction zone of the reduction melting furnace, as well as the oxygen and heat balance introduced by the slag desulfurization and carbon combustion blast, the operating line of the direct reduction zone of the reduction melting furnace can be derived. , , and The intersection yields the thermal balance limit point of the direct reduction zone in the reduction melting furnace. Direct recovery area operation line The slope can characterize the coke ratio per ton of pig iron smelted. The x and y coordinates of point U are as follows: (10) (11) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Si in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Mn in pig iron; This indicates the amount of oxygen introduced by the direct reduction of phosphorus (P) in pig iron. The amount of oxygen introduced during slag desulfurization is represented by the following formula: (12) (13) (14) in Alternatively, the slag ratio can be used for calculation, as shown in the following formula: (15) in , , , The contents of iron (Fe), silicon (Si), manganese (Mn), and phosphorus (P) in the predetermined pig iron composition, respectively, are % . The sulfur content in the slag, % For scumbags, t / t HM.

[0024] The formulas for calculating the x and y coordinates of a point are as follows: (16) (17) (18) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; The amount of oxygen provided for the combustion of carbon during the blower process; The amount of carbon burned per ton of pig iron before the tuyeres during smelting, expressed in kg; The percentage of Fe in pig iron.

[0025] The specific coordinates of the point can be determined based on the principle of heat balance, by calculating the heat input and heat output of the high-temperature zone in the lower part of the all-oxygen-rich hydrogen reduction melting furnace. This includes calculating the effective heat per kilomolar of heat input in the high-temperature zone in the lower part of the reduction melting furnace, as shown in the following formula: (19) In the formula The heat of combustion of C is taken as 9800 kJ / kg; The air volume per kilogram of C burned in front of the air vent, m 3 / kg; To calculate the amount of high-temperature gas produced per kg of C, m 3 / kg; , These are the specific heat capacities for blast air and coal gas, respectively, in kJ / (m³). 3 (kg); , These are the hot air temperature and the gas temperature, respectively, in °C.

[0026] in, The calculation formula is as follows: (20) In the above formula The air volume in front of the vent, m 3 ; The amount of carbon burned in front of the air vent is expressed in kg.

[0027] For heat expenditure in high-temperature zones, it is necessary to further divide it into direct reduction heat consumption. Compared with other reduction heat consumption .

[0028] Based on the principle of heat balance in high-temperature regions, the heat balance equation is as follows: (twenty one) In the above formula The amount of oxygen introduced by the blower for carbon combustion; To reduce the effective heat input per kilomolar in the high-temperature zone at the bottom of the melting furnace; For point The ordinate; The direct reduction of floatite consumes heat.

[0029] The thermal equilibrium is transformed as follows: (twenty two) In the formula = ; This reduces the heat consumed in the high-temperature zone at the bottom of the melting furnace.

[0030] In thermal equilibrium deformation / The ratio of other heat consumption in the high-temperature region to the heat consumed by the direct reduction of iron is represented by a line segment. The ordinate of the point.

[0031] The formulas for calculating the x and y coordinates of a point are as follows: (twenty three) (twenty four) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; The reduction heat consumed in the direct reduction zone of the reduction melting furnace; The direct reduction of floatite consumes heat.

[0032] Step 3: In The connection between the indirect reduction zone operation line model and the direct reduction zone operation line model is achieved at the point to obtain a complete oxygen-rich hydrogen-low carbon reduction melting furnace operation line model. By connecting the indirect reduction zone operating line model and the direct reduction zone operating line model at the separation point, a complete operating line model of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace can be obtained to characterize the smelting process of the reduction melting furnace. The separation point is determined by the composition of the furnace top gas and the metallization rate of sponge iron in the indirect reduction zone. Definite point, The point is the endpoint of indirect reconstruction and the starting point of direct reconstruction, therefore The point can serve as an important basis for distinguishing between the operating lines of the direct reduction zone and the indirect reduction zone, and is key to establishing the operating line model of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace.

[0033] Step 4: Connect , , and Draw a complete operation line diagram of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace using straight lines.

[0034] Example Basic production data for the all-oxygen-rich hydrogen-low-carbon reduction melting furnace are shown in Tables 1 and 2. Table 1. Composition of gas from the top of the reducing melting furnace (volume fraction) (%)

[0035] Table 2. Composition (volume fraction) of gas in the furnace body (indirect reduction zone) of the reduction melting furnace (%)

[0036] The composition of raw materials and fuels fed into the furnace is shown in Tables 3 to 5; Table 3. Composition of coke on a dry basis (mass fraction) (%)

[0037] Table 4 Ore composition (mass fraction) (%)

[0038] Table 5 Flux composition (mass fraction) (%)

[0039] Other original calculation parameters: metallization rate The efficiency was 90%; global aggregate ore was used in smelting, with a consumption of 1434.15 kg / t HM; limestone was selected as the flux; and the reducing gas consumption was 923.25 Nm³. 3 / t HM; fuel structure is coke; iron composition is shown in Table 6; slag S content is 1.305%, slag ratio =0.118t / t HM; the mass of carbon burned before the tuyeres is 203.68 kg / t HM; the oxygen consumption is 190.10 Nm³. 3 / t HM; The amount of gas produced in the lower part of the reduction melting furnace is 427.72 Nm³. 3 / t HM; The reduction equilibrium temperature of floatite in the indirect reduction zone is 1093 K; Thermodynamic data =1460.272 kJ / m 3 , =1403.861kJ / m 3 Direct reduction of floatite consumes heat. kJ.

[0040] Table 6. Composition of molten iron (%)

[0041] From equations (1) to (2), we can obtain Point coordinates:

[0042]

[0043] The coordinates of the point are (1, 0.106). From equations (3) to (4), we can obtain Point coordinates:

[0044]

[0045] The coordinates of the point are (1.392, 1.497). From equations (5) to (8), we can obtain Point coordinates:

[0046]

[0047] The coordinates of the point are (1.429, 1.056). From equation (9), we can obtain Point coordinates:

[0048]

[0049] The coordinates of the point are (1.628, 1.497). From equation (10), we can obtain Point coordinates:

[0050]

[0051] The coordinates of the point are (0, -0.028). From equations (11) to (12), we can obtain Point coordinates:

[0052]

[0053]

[0054] The coordinates of the point are (0, -1.031). From equations (13) to (15), we can obtain Point coordinates:

[0055]

[0056]

[0057]

[0058] .

[0059] The coordinates of the point are (1, -0.545). Through connection , , and A straight line will provide a complete operational diagram of the all-oxygen, hydrogen-rich, low-carbon reducing melting furnace, such as... Figure 4 As shown.

[0060] It should be understood that, inspired by the technical concept of this invention, those skilled in the art can make various improvements or modifications based on the above content without departing from the scope of this invention, and these modifications still fall within the protection scope of this invention.

Claims

1. A method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace, characterized in that, The method includes the following steps: By determining point, Dot and Establish the operation line model of the upper indirect reduction zone of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace using point coordinates; By determining point, Dot and A point coordinate model is used to establish the operation line model of the lower direct reduction zone of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. exist The connection between the indirect reduction zone operation line model and the direct reduction zone operation line model is achieved at the point to obtain a complete oxygen-rich hydrogen-low carbon reduction melting furnace operation line model. Through connection , , and Draw a complete operation line diagram of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace using straight lines; where... This is the actual operation line of the upper indirect reduction zone of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace. This is the ideal operating line for the upper indirect reduction zone of an all-oxygen, hydrogen-rich, low-carbon reducing melting furnace. and Used to characterize the actual and ideal amount of reducing gas consumed when reducing iron oxides to a certain metallization rate; and All are operating lines in the direct reduction zone of the lower part of the all-oxygen-rich hydrogen-rich low-carbon reduction melting furnace, and the operating lines The slope of the curve can characterize the coke ratio per ton of pig iron produced. and The intersection point is the thermal equilibrium limit point of the direct reduction region. The The coordinates of the point need to be determined first to find the equilibrium constraint point. After obtaining the coordinates, the linear fitting points Obtain a straight line ,because Dot at On the extension line and The ordinate of a point and The ordinate of a point Same It can be obtained The x-coordinate of the point; The The ordinate of a point The formula for calculating its x-coordinate is as follows: (5) ； (6) In the above formula , This represents the number of moles of CO2 and H2O in the top gas under ideal conditions. , The CO and H2 consumed in the direct reduction reaction under ideal conditions; and It refers to the total amount of C and H2 participating in the direct reduction reaction; For temperature T The equilibrium constant at which the direct reduction reaction of CO reaches equilibrium; For temperature T The equilibrium constant when the direct reduction reaction of H2 reaches equilibrium; The The formula for calculating the x-coordinate of a point is as follows: (9) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; b and For the reason The intercept and slope of the linear equation obtained by point fitting; The The point is the separation point between indirect and direct reduction; The coordinates of the point are calculated based on the composition of the reducing gas introduced into the furnace and the metallization rate of the reduction product, sponge iron. The formula for calculating the x-coordinate of a point is as follows: (1) In the above formula represent The x-coordinate of the point; and The volume percentage of CO2 and H2O in the reducing gases introduced into the furnace body of the reducing melting furnace; The formula for calculating the ordinate of a point is: (2) In the above formula Representing the The ordinate of the point; For the The ordinate of the point, ; The metallization rate of sponge iron is determined by adjusting the furnace itself based on the operating characteristics of the all-oxygen-rich hydrogen-low-carbon reduction melting furnace.

2. The method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace according to claim 1, characterized in that, The The coordinates of the point are calculated based on the composition of the gas at the top of the furnace and the Fe oxide content and Fe content of the minerals entering the furnace. The formula for calculating the x-coordinate of a point is: (3) In the above formula represent The x-coordinate of the point; and These represent the volume percentages of CO2 and H2O in the top gas of the furnace. The formula for calculating the ordinate of a point is: (4) In the above formula represent The ordinate of the point; , , , These represent the percentages of Fe2O3, Fe3O4, FeO, and Fe in the iron ore fed into the furnace, respectively, relative to the bulk mass.

3. The method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace according to claim 1, characterized in that, The The formulas for calculating the x and y coordinates of a point are as follows: (10) (11) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Si in pig iron; This indicates the amount of oxygen introduced by the direct reduction of Mn in pig iron; This indicates the amount of oxygen introduced by the direct reduction of phosphorus (P) in pig iron. This indicates the amount of oxygen introduced during slag desulfurization.

4. The method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace according to claim 3, characterized in that, The The formulas for calculating the x and y coordinates of a point are as follows: (16) (17) (18) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; This indicates the amount of oxygen introduced during the reduction of non-metallic elements in pig iron; The amount of oxygen provided for the combustion of carbon during the blower process; The amount of carbon burned per ton of pig iron before the tuyeres during smelting, expressed in kg; The percentage of Fe in pig iron.

5. The method for drawing the operation line of an all-oxygen-rich, hydrogen-rich, low-carbon reduction melting furnace according to claim 3, characterized in that, The The formulas for calculating the x and y coordinates of a point are as follows: (24) (25) In the above formula represent The x-coordinate of the point; represent The ordinate of the point; The other reduction heat consumption is in the direct reduction zone of the all-oxygen-rich hydrogen reduction melting furnace; The direct reduction of floatite consumes heat.

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