A method for calculating the temperature of iron searching in the interior of a high-titanium blast furnace hearth

Abstract

This invention discloses a method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace. The method includes the following steps: (1) Collecting some operating and production parameters of the target blast furnace and calculating the oxygen partial pressure p inside the hearth of the target blast furnace using a formula. o (2): The initial slag and iron temperature T0 inside the target blast furnace hearth is obtained by calculation using the formula; (3): The slag and iron temperature inside the target blast furnace hearth is corrected by formula (3) to obtain the corrected slag and iron temperature T inside the target blast furnace hearth. x The present invention provides a method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace. This method can calculate the slag and iron temperature inside the hearth using some process operation parameters of the blast furnace through simple calculations. A more optimized technical solution determines a suitable slag and iron temperature value for the hearth through calculation, which helps blast furnace operators judge the hearth condition and facilitates timely adjustment and optimization of process operation parameters. It is simple, efficient, and practical, and is mainly applicable to high-titanium blast furnaces.

Description

Technical Field

[0001] This invention relates to the field of blast furnace steelmaking technology, specifically to a method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace. Background Technology

[0002] Blast furnace smelting is the core process of steel production, essentially involving the reduction and refining of iron ore. Temperature directly determines the chemical reaction rate and product properties; therefore, the slag-iron temperature within the hearth directly affects smelting efficiency, hearth activity, and equipment lifespan. This is especially true for the smelting of high-titanium vanadium-titanium magnetite, where the slag contains a high content of titanium dioxide (TiO2) (typically 15%-25%). Titanium readily combines with carbon and nitrogen to form high-melting-point titanium carbide (TiC, melting point 2950℃) and titanium nitride (TiN, melting point 3150℃). These titanium compounds are difficult to dissolve within the hearth and tend to deposit on the furnace walls or at the slag-iron interface, leading to difficulties in slag-iron separation, hearth buildup, and even affecting the fluidity of the molten iron. Due to the harsh internal environment of blast furnaces (high temperature, high pressure, chemical corrosion), direct temperature measurement is difficult. Therefore, traditional hearth thermal condition assessment mainly relies on the experience of blast furnace operators. Existing technologies for monitoring blast furnace hearth temperature can be achieved through thermocouple measurements on the hearth sidewalls or infrared imaging measurements after slag and iron are discharged from the furnace. However, these are all indirect measurements, and due to the influence of hearth corrosion, dust, etc., the data often deviates significantly from the actual values. At the same time, there are also methods that indirectly reflect the hearth temperature by calculating the theoretical combustion temperature. However, the theoretical combustion temperature calculation only applies to the combustion temperature in the tuyeres area, which is much higher than the actual slag and iron temperature inside the hearth, resulting in a large discrepancy.

[0003] Chinese patent application CN116050085A discloses a method for controlling blast furnace smelting of vanadium-titanium ore based on heat balance calculation. This invention, based on blast furnace heat balance calculation and judgment of blast furnace thermal state, comprehensively considers the combined results of most parameter adjustments during blast furnace smelting, providing a more accurate quantitative description of the blast furnace thermal state. This is more conducive to blast furnace operators judging the trend of furnace conditions. Simultaneously, considering the time lag characteristics of blast furnace operation adjustments, it allows for advance adjustments of appropriate magnitude to ensure stable and smooth blast furnace operation. However, this invention does not calculate the molten iron temperature, and cannot solve the problem that during smelting, excessively high molten iron temperatures can easily lead to the deposition of titanium compounds on the furnace wall or slag-iron interface, resulting in difficulties in slag-iron separation, hearth accumulation, and even affecting the fluidity of molten iron; thus impacting smelting efficiency, hearth activity, and equipment lifespan.

[0004] Therefore, existing technologies cannot accurately calculate the slag temperature inside the blast furnace hearth, which is insufficient to meet the smelting needs of high-titanium blast furnaces. There is an urgent need to develop a slag temperature calculation method that integrates the characteristics of titanium slag, has strong anti-interference capabilities, and is applicable, in order to improve smelting efficiency and resource utilization and extend the service life of the hearth. Summary of the Invention

[0005] The purpose of this invention is to provide a method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace. This method can calculate the slag and iron temperature inside the hearth using some process operation parameters of the blast furnace through simple calculations. A better technical solution is to determine the appropriate slag and iron temperature value of the hearth through calculation, so as to assist the blast furnace operator in judging the hearth condition. At the same time, it is conducive to timely adjustment and optimization of process operation parameters. It is simple, efficient, practical, and mainly applicable to high-titanium blast furnaces.

[0006] To achieve the above-mentioned objectives, this invention provides a method for calculating the slag-iron temperature inside the hearth of a high-titanium blast furnace, comprising the following steps: Step (1): Calculate the oxygen partial pressure p in the target blast furnace hearth using the following formula (1). o ;

[0007] Where λ is the oxygen enrichment index coefficient, which is dimensionless; T v P0 is the theoretical combustion temperature in front of the tuyeres, in K; P0 is the blast furnace blast pressure, in kPa; a, b, c, and d are constants.

[0008] Step (2): Calculate the initial slag and iron temperature T0 in the target blast furnace hearth using formula (2); Where T0 is the initial slag and iron temperature inside the target blast furnace hearth, in K; and These are the activity coefficients of SiO2 in the slag and Si in the molten iron of the target blast furnace, respectively. and , representing the SiO2 content in the slag and the Si content in the molten iron of the target blast furnace, respectively, %; m and n are constants; Step (3): Correct the slag and iron temperature inside the target blast furnace hearth using formula (3) to obtain the corrected slag and iron temperature T inside the target blast furnace hearth. x ;

[0009] Among them, T x The corrected target slag and iron temperature inside the blast furnace hearth, in K; and These represent the activity coefficients of TiO2 in the slag and Ti in the molten iron in the target blast furnace, respectively. and , where represents the TiO2 content in the slag and the Ti content in the molten iron of the target blast furnace, respectively; %; and i and j are constants.

[0010] In the above formulas (1)-(3), the process parameters are all process parameters collected during production and calculated results, including blast furnace hot metal composition, slag composition, oxygen enrichment rate, blast pressure and other data parameters; among them, in the above formula (3), p o The target is the partial pressure of oxygen in the hearth of the blast furnace.

[0011] As can be seen from the above, by collecting process parameters and performing calculations, the present invention can obtain accurate iron temperature, easily determine the operating status of the hearth, and facilitate subsequent adjustments to smelting process parameters. Compared with the prior art, it can effectively improve smelting quality and efficiency and extend the service life of the hearth.

[0012] According to the method for calculating the slag-iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (1), a, b, c, and d are -26.590 × 10⁻⁶. 3 -21.21, 1.5088 and 9.867×10 -3 .

[0013] According to the method for calculating the slag-iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (2), m and n are 98.320 × 10⁻⁶ respectively. 3 And 26.29.

[0014] According to the method for calculating the slag-iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (3), i and j are 102.570 × 10⁻⁶. 3 And 23.45.

[0015] According to the method for calculating the slag-iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (1), λ is obtained by calculation using formula (4):

[0016] Where w0 is the target blast furnace oxygen enrichment rate, %.

[0017] According to the method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, it further includes step (4): calculating the control range of the slag and iron temperature inside the hearth of the target blast furnace using formula (5):

[0018] Among them, T opt-s For a suitable target slag-iron temperature inside the blast furnace hearth, K, where s is the min or max; e and f are 200.890 × 10⁻⁶. 3 And 49.74.

[0019] According to the method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (4), ≥0.1%, ≥0.1%.

[0020] According to the method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace as described in this invention, preferably, in step (4), + The range is 0.2%-0.4%.

[0021] According to the method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace as described in the present invention, preferably, it further includes step (5), which determines the state of the blast furnace hearth by the following method: When T x <T opt-min When T is low, it is judged that the furnace hearth temperature is low; when T opt-min ≤T x ≤T opt-max When T is reached, it is judged that the furnace hearth temperature is suitable; when T is reached... x >T opt-max At that time, it was determined that the furnace hearth temperature was high.

[0022] In this invention, the specific method for determining the state of the blast furnace hearth in step (5) is as follows: (1) When Tx < T opt-min If the furnace hearth temperature is too low, the slag fluidity is poor, the furnace hearth condition is deteriorating, and there is a risk of furnace hearth accumulation, the heating regime should be adjusted in time. (2) When T opt-min ≤Tx≤T opt-max At that time, it was determined that the hearth temperature was suitable, the hearth operation was stable, the slag fluidity was good, and the furnace condition was stable, which was conducive to the stable and smooth operation of the blast furnace. (3) When Tx > T opt-max If the temperature is too high, the edge erosion will be aggravated, and the formation of titanium carbonitride will not be effectively suppressed, affecting the separation of slag and iron. The heat regime should be adjusted in time.

[0023] According to the method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace as described in the present invention, preferably, it further includes step (6): collecting and calculating T0 and T x T opt-min and T opt-max It is stored in an electronic database.

[0024] The beneficial effects of this invention are: This invention discloses a method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace. This method can calculate the slag and iron temperature inside the hearth using some process operation parameters of the blast furnace through simple calculations. A better technical solution determines the appropriate slag and iron temperature value of the hearth through calculation, so as to assist the blast furnace operator in judging the hearth condition. At the same time, it is conducive to timely adjustment and optimization of process operation parameters. It is simple, efficient, practical, and mainly applicable to high-titanium blast furnaces.

[0025] The method for calculating the blast furnace hearth temperature of this invention is not only applicable to high-titanium blast furnace smelting, but can also be extended to other ordinary smelting blast furnaces and high-titanium smelting blast furnaces, with great application value; the internal temperature of the hearth can be determined through certain process technical parameters of the blast furnace, which is simple to operate, highly practical, and has very high economic value. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating the calculation method for the slag and iron temperature inside the hearth of a high-titanium blast furnace according to the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0029] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0030] Example Figure 1 This is a flowchart illustrating the calculation method for the slag and iron temperature inside the hearth of a high-titanium blast furnace according to the present invention.

[0031] The internal operating and production parameters of the target high-titanium blast furnace hearth were collected, including the composition of molten iron, slag composition, oxygen enrichment rate, blast pressure and other data parameters, as shown in Table 1.

[0032] Table 1. Process and testing parameters of blast furnace hearth in the embodiment.

[0033] In this embodiment, the slag and iron temperature inside the hearth of a high-titanium blast furnace is calculated using the following method, including the following steps: Step (1): Calculate the oxygen partial pressure p0 in the target blast furnace hearth: Read the oxygen enrichment rate and blast pressure data in Table (1) above, and calculate the furnace oxygen pressure p according to the following formula. o :

[0034] in:

[0035] Where, p o λ represents the partial pressure of oxygen in the hearth of the target blast furnace, in atm; λ is the oxygen enrichment index coefficient, dimensionless; w0 is the oxygen enrichment rate of the target blast furnace, %; T v P0 is the theoretical combustion temperature before the tuyeres, in K; P0 is the blast furnace blast pressure, in kPa; a, b, c, and d are constants, which in this embodiment are taken as -26.590 × 102. 3 -21.21, 1.5088 and 9.867×10 -3 In other cases, the specific selection can be made based on the actual operating conditions of the blast furnace hearth.

[0036] Substituting the data into Table (1), we calculate λ = 1.125, p o =6.73×10 -13 atm.

[0037] Step (2): Calculate the initial slag and iron temperature T0 in the target blast furnace hearth using the following formula:

[0038] Where: T0 is the initial slag and iron temperature inside the target blast furnace hearth, in K; and These represent the activity coefficients of SiO2 in the slag and Si in the molten iron in the target blast furnace, respectively, and are taken as 0.14 and 8.50. and , representing the SiO2 content in the slag and the Si content in the molten iron of the target blast furnace, respectively; %, m and n are constants, respectively taken as 98.320 × 10. 3 And 26.29.

[0039] Substituting the data in Table (1) and the result calculated in step (1), we can obtain T0 = 1778.01K.

[0040] Step (3): Calculate the corrected target slag-iron temperature T in the hearth using the following formula. x :

[0041] Among them, T x The corrected target slag and iron temperature inside the blast furnace hearth, in K; and These represent the activity coefficients of TiO2 in the slag and Ti in the molten iron in the target blast furnace, respectively, and are taken as 0.1 and 0.25. and , representing the TiO2 content in the slag and the Ti content in the molten iron of the target blast furnace, respectively; %, i and j are constants, respectively taken as 102.570 × 10. 3 And 23.45.

[0042] Substituting the data from Table (1) and the result calculated in step (2), we can obtain T. x =1812.48K.

[0043] Step (4): Calculate the suitable control range of slag and iron temperature in the target blast furnace hearth using the following formula: The blast furnace selects molten iron... + The control range is 0.2%-0.4%, and ≥0.1%, ≥0.1%, we can obtain If the temperature is controlled within 0.01%-0.04%, the minimum suitable slag-iron temperature T in the target blast furnace hearth can be calculated based on the following formula. opt-min and the highest value T opt-max ;

[0044] Among them, T opt-s The target slag-iron temperature inside the blast furnace hearth is given in K, where s can be min and max; e and f are constants, each taken as 200.890 × 10⁻⁶. 3 And 49.74.

[0045] Then, when =0.01%, substitute the data in Table (1) and the calculation results of the above steps into formula (4) to calculate the appropriate minimum slag-iron temperature T inside the hearth. opt-min =1799.17K; Similarly, when =0.04%, substituting the data, we can obtain the maximum suitable slag-iron temperature T inside the hearth of this blast furnace. opt-max =1821.79K.

[0046] Step (5): Determine the state of the target blast furnace hearth: Based on the calculations in steps (3) and (4), the slag and iron temperature data of the hearth are obtained and compared to determine the current state of the hearth. It can be seen that T... x =1812.48K, T opt-min =1799.17K, T opt-max =1821.79K, satisfying T opt-min ≤T x ≤T opt-max It can be determined that the current hearth temperature of the blast furnace is suitable, the hearth operation is stable, and the slag has good fluidity, so there is no need to adjust the operating procedures for the time being.

[0047] Step (6): Output to electronic database: The initial value T0 and the correction value T of the slag and iron temperature are used. x The maximum value of the slag and iron temperature control index T opt-min and minimum value T opt-max The data is then saved to an electronic database.

[0048] As can be seen from the above embodiments, the calculation method of the present invention is simple and easy to operate, can accurately calculate the temperature of iron, can accurately determine the operating status of high-titanium blast furnace, and facilitates operators to adjust the blast furnace operating parameters in a timely manner.

[0049] It should be noted that the components or steps in the above embodiments can be interleaved, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of the present invention, and the protection scope of the present invention should not be limited to the above embodiments.

[0050] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0051] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace, characterized in that, Includes the following steps: Step (1): Calculate the oxygen partial pressure p in the target blast furnace hearth using the following formula (1). o ; Where λ is the oxygen enrichment index coefficient, which is dimensionless; T v P0 is the theoretical combustion temperature in front of the tuyeres, in K; P0 is the blast furnace blast pressure, in kPa; a, b, c, and d are constants. Step (2): Calculate the initial slag and iron temperature T0 in the target blast furnace hearth using formula (2); in, and These are the activity coefficients of SiO2 in the slag and Si in the molten iron of the target blast furnace, respectively. and , representing the SiO2 content in the slag and the Si content in the molten iron of the target blast furnace, respectively, %; m and n are constants; Step (3): Correct the slag and iron temperature inside the target blast furnace hearth using formula (3) to obtain the corrected slag and iron temperature T inside the target blast furnace hearth. x ; in, and These represent the activity coefficients of TiO2 in the slag and Ti in the molten iron in the target blast furnace, respectively. and , where represents the TiO2 content in the slag and the Ti content in the molten iron of the target blast furnace, respectively; %; and i and j are constants.

2. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 1, characterized in that, In step (1), a, b, c, and d are respectively -26.590 × 10 3 -21.21, 1.5088 and 9.867×10 -3 .

3. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 1, characterized in that, In step (2), m and n are 98.320 × 10⁻⁶ respectively. 3 And 26.

29.

4. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 1, characterized in that, In step (3), i and j are 102.570 × 10 3 And 23.

45.

5. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 1, characterized in that, In step (1), λ is obtained by calculation using formula (4): Where w0 is the target blast furnace oxygen enrichment rate, %.

6. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 1, characterized in that, It also includes step (4): Calculating the control range of slag and iron temperature in the target blast furnace hearth using formula (5): Among them, T opt-s For a suitable target slag-iron temperature inside the blast furnace hearth, K, where s is the min or max; e and f are 200.890 × 10⁻⁶. 3 And 49.

74.

7. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 6, characterized in that, In step (4), ≥0.1%, ≥0.1%.

8. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 7, characterized in that, In step (4), + The range is 0.2%-0.4%.

9. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 8, characterized in that, It also includes step (5), which determines the state of the blast furnace hearth using the following method: When T x <T opt-min When T is low, it is judged that the furnace hearth temperature is low; when T opt-min ≤T x ≤T opt-max When T is reached, it is judged that the furnace hearth temperature is suitable; when T is reached... x >T opt-max At that time, it was determined that the furnace hearth temperature was high.

10. The method for calculating the slag and iron temperature inside the hearth of a high-titanium blast furnace according to claim 9, characterized in that, It also includes step (6): collecting and calculating T0 and T x T opt-min and T opt-max It is stored in an electronic database.

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