Optimal selection method and system for charging grade of blast furnace

Abstract

The invention discloses an optimal selection method for the charging grade of a blast furnace. The optimal selection method comprises the following steps: (1) fitting a relational expression among the charging grade of the blast furnace, ore consumption and fuel consumption; fitting a relational expression of iron ore grade and price; (2) determining a furnace charge structure proportion, grades and prices of pellets and lump ores, a coal ratio and prices of pulverized coal and coke; (3) calculating the sinter grade and the corresponding blended ore grade based on the set blast furnace charging grade, calculating the price of the blended ore according to the relational expression of the iron ore grade and the price, and further calculating the sinter price; (4) calculating the ore consumption and the fuel consumption according to the relation between the blast furnace charging grade and the ore consumption and the fuel consumption, and calculating the molten iron cost corresponding to the current blast furnace charging grade; and (5) changing the charging grade of the blast furnace, and executing the steps (3)-(5) until the charging grade TFe of the blast furnace corresponding to the lowest molten iron cost T is found in the limited charging grade change range of the blast furnace, namely the preferable charging grade of the blast furnace.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace ironmaking, and more specifically, the present invention relates to a method and system for optimizing the grade of iron entering a blast furnace. Background Art

[0002] At present, the iron ore and fuel costs of the steel industry account for more than 93% of the molten iron cost, of which iron ore costs account for 59%-62% and fuel costs account for 31%-34%. Iron ore has an important impact on the molten iron cost, especially for enterprises that mainly purchase iron ore from outside. With the sharp fluctuations in the market prices of iron ore and coal resources in recent years, how to choose a reasonable raw material and fuel price band to adjust and optimize the ore distribution structure has an important impact on the molten iron cost and affects the production and operation of enterprises.

[0003] There are more than 100 kinds of iron ore resources on the market. Different iron ore powders have different performances and prices. How to scientifically purchase and reasonably match them for production to achieve maximum economic benefits and lowest ironmaking costs is a difficult problem that steel companies urgently need to solve. Shougang Corporation's "A Method for Adjusting the Grade of Ore Entering a Blast Furnace" (CN112251550A) provides a low-cost molten iron production method for blast furnace sintering linkage. First, the SiO2 content and sintered ore basicity of the sintered ore that are compatible with the blast furnace charge structure are calculated based on sintered ore of different grades. Then, a sintering cup test is performed according to the sintered ore composition. The sintered ore price is obtained from the test results. Finally, the sintered ore price is brought into the molten iron raw fuel cost calculation formula to obtain the molten iron raw fuel cost corresponding to each sintered ore grade, and the lowest value is selected from them, which is the production plan with the lowest molten iron raw fuel cost.

[0004] The above scheme calculates the corresponding molten iron cost through different ore blending structures, selects the ore blending structure with the lowest molten iron cost, and thus the blast furnace feeding grade is determined accordingly. It is a ore blending method that passively selects the blast furnace feeding grade, which responds slowly to changes in the raw material market and makes it difficult to quickly seize market opportunities amid large fluctuations in raw material prices. Summary of the invention

[0005] The present invention provides a method for optimizing the grade of blast furnace charging, aiming to improve the above-mentioned problem.

[0006] The present invention is achieved by a method for optimizing the grade of a blast furnace, the method comprising the following steps:

[0007] (1) Calculate the molten iron cost T at the current blast furnace charging grade;

[0008] (2) Changing the blast furnace charging grade, taking the changed blast furnace charging grade as the current blast furnace charging grade, and executing step (1) until the blast furnace charging grade TFe corresponding to the lowest molten iron cost T is found within the set blast furnace charging grade change range.

[0009] Furthermore, the production plan or the actual blast furnace charging grade in the early stage is used as the initial blast furnace charging grade, and the allowable variation range of the initial blast furnace charging grade is set as the preferred range of blast furnace charging grade, and the blast furnace charging grade corresponding to the lowest molten iron cost T is found within the set blast furnace charging grade range.

[0010] Furthermore, the method for obtaining the molten iron cost T at the current blast furnace charging grade is as follows:

[0011] (11) Determine the required charge consumption O and coke consumption C at the current blast furnace charging grade;

[0012] (12) Determine the blast furnace fuel cost Tr based on the coke consumption C and the set coal powder amount M;

[0013] (13) Based on the determined charge structure ratio and the current required charge consumption O, the pellet cost Tq and lump cost Tk are calculated respectively;

[0014] (14) Determine the sinter grade TFes under the current blast furnace charging grade TFe and the mixed ore grade TFey under the sinter grade TFes; determine the price corresponding to the mixed ore grade TFey according to the relationship between iron ore grade and price, and calculate the sinter cost Ts;

[0015] (15) The sum of sintered ore cost Ts, pelletized ore cost Tq, lump ore cost Tk, blast furnace fuel cost Tr and blast furnace process cost Tg is the molten iron cost T.

[0016] Furthermore, the process of obtaining the required charge consumption O and coke consumption C under the current blast furnace charging grade is as follows:

[0017] Actual production data of the blast furnace is collected, and linear equations are used to fit the relationship between the blast furnace feeding grade TFe and the burden consumption O, as well as the blast furnace feeding grade TFe and the coke consumption C. The current blast furnace feeding grade TFe is input into the relationship between the blast furnace feeding grade TFe and the burden consumption O, as well as the blast furnace feeding grade TFe and the coke consumption C, to obtain the burden consumption O and coke consumption C required under the current blast furnace feeding grade TFe.

[0018] Furthermore, the blast furnace fuel cost Tr is composed of the pulverized coal cost Tm and the coke cost Tc;

[0019] The coal powder consumption M per ton of molten iron is set, and the coal powder cost Tm is calculated based on the coal powder amount M and the current coal powder price Pm; the coke cost Tc is calculated based on the coke consumption C and the current coke Pc.

[0020] Furthermore, the method for determining the proportion of the charge structure is as follows:

[0021] According to the actual production capacity of sintering and pelletizing processes, the charge structure ratio is determined: sintered ore Bs, pelletized ore Bq, lump ore Bk, and Bs+Bq+Bk=100%.

[0022] Furthermore, the method for determining the pellet cost Tq and lump cost Tk is as follows:

[0023] Set the pellet grade TFeq and its price Pq, the lump grade TFek and its price Pk, calculate the required amount of pellets and lump according to the charge consumption O and the determined charge structure ratio, and then multiply them by the corresponding prices to determine the pellet cost and lump cost.

[0024] Furthermore, the determination process of sintered ore cost Ts is as follows:

[0025] According to the current blast furnace charging grade TFe, pellet grade TFeq, lump grade TFek and charge structure ratio, calculate the sintered ore grade TFes = (TFe-TFeq×Bq-TFek×Bk)÷Bs;

[0026] Calculate the blended ore grade TFey = TFes × Bys, where Bys is the ratio of the blended ore grade to the sintered ore grade, which is obtained from the actual production data statistics of the sintering process;

[0027] For all different grades of iron ore and their corresponding prices, a linear equation is used to fit the relationship between the iron ore grade TFex and the iron ore price Px: Px = Kk × TFex + Bb. To improve the fitting accuracy, a curve equation can also be used for fitting;

[0028] Mixed ore is composed of iron ores of various grades. According to the relationship between iron ore grade and price, the price Py corresponding to the mixed ore grade TFey is calculated; the mixed ore cost Ty = Y × Py is calculated according to the mixed ore usage Y in the sintered ore, where the mixed ore usage Y is also obtained from the actual production data statistics of the sintering process;

[0029] Calculate the sintered ore price Ps = Ty + sintering material cost Tz + sintering process cost Tx;

[0030] According to the charge consumption O, the sintered ore proportion Bs and the sintered ore price Ps, the sintered ore cost Ts = O × Bs × Ps is calculated.

[0031] The present invention is achieved by a system for optimizing the grade of blast furnace charging, the system comprising:

[0032] Input unit and processing unit;

[0033] The current prices of iron ore of different grades, the set grades and prices of pellet ore and lump ore, the set prices of coal powder and coke, the set charge structure ratio, coal powder usage, and mixed ore usage are input into the processing unit through the input unit; the processing unit selects the blast furnace feeding grade corresponding to the lowest molten iron cost as the preferred blast furnace feeding grade based on the above-mentioned optimization method for blast furnace feeding grade.

[0034] After the preferred blast furnace entry grade is determined, the corresponding sintered mixed ore grade is also determined. The subsequent mixed ore blending selects suitable iron ore to make the mixed ore grade as close as possible to the sintered mixed ore grade corresponding to the preferred blast furnace entry grade, and the corresponding molten iron cost is the most economical; the above-mentioned blast furnace entry grade optimization method is a blending method that actively selects the blast furnace entry grade, provides a decision-making basis for the blast furnace entry grade adjustment direction, and provides guidance for the specific blending of sintered mixed ore, so that the molten iron cost is the most economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a method for optimizing the blast furnace charging grade provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the structure of a system for optimizing the blast furnace charging grade provided by an embodiment of the present invention;

[0037] Figure 3 A curve showing the relationship between the grade and price of iron ore provided in an embodiment of the present invention;

[0038] Figure 4 The relationship between the blast furnace charging grade and the charge consumption O, and the blast furnace charging grade and the coke consumption C provided in the embodiment of the present invention;

[0039] Figure 5 A comparison chart of the initial value and the preferred value of the blast furnace charging grade provided in an embodiment of the present invention, wherein (a) is the time in June 2024, and (b) is the time in May 2024. DETAILED DESCRIPTION

[0040] The specific implementation modes of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0041] The raw materials and fuels for blast furnace ironmaking generally include sintered ore, pelletized ore, lump ore (or raw ore), coke, and pulverized coal, among which sintered ore, pelletized ore, and lump ore are called charge, and coke and pulverized coal are called fuel. Charge structure refers to the proportion of sintered ore, pelletized ore, and lump ore. The typical charge structure of domestic blast furnaces is 65%-80% sintered ore, 5%-25% pelletized ore, and 5%-20% lump ore. The sum of the product of each charge structure ratio and the corresponding charge grade is called the blast furnace charging grade, which is a key indicator of blast furnace ironmaking, related to charge consumption and fuel consumption, and has an important impact on the cost of molten iron. Since sintered ore is the main charge for blast furnace ironmaking, the focus of the optimization of blast furnace charging grade is sintering ore blending, that is, the blending of mixed ore.

[0042] Figure 1 A flow chart of a method for optimizing the blast furnace charging grade provided by an embodiment of the present invention, the method comprising the following steps:

[0043] (1) Calculate the molten iron cost T at the current blast furnace charging grade TFe;

[0044] (2) Changing the blast furnace charging grade TFe, taking the changed blast furnace charging grade as the current blast furnace charging grade, and executing step (1) until the lowest molten iron cost T within the set blast furnace charging grade change range is found.

[0045] In an embodiment of the present invention, the blast furnace charging grade TFe of the ironmaking plant's production plan or the actual blast furnace charging grade TFe in the early stage is used as the initial blast furnace charging grade, the allowable variation range of the initial blast furnace charging grade is set as the preferred range of the blast furnace charging grade, starting from the initial blast furnace charging grade, the blast furnace charging grade is changed based on the set change direction, the molten iron cost at the current blast furnace charging grade is calculated, and it is checked whether the molten iron cost at the current blast furnace charging grade is higher than the molten iron cost at the initial blast furnace charging grade; if the test result is no, the blast furnace charging grade continues to be changed along the currently set change direction until an inflection point of the lowest value of the molten iron cost appears or the boundary of the blast furnace charging grade variation range is reached, and the blast furnace charging grade corresponding to the lowest molten iron cost is output; if the test result is yes, the blast furnace charging grade is changed in the opposite direction of the current change direction, and the blast furnace charging grade corresponding to the lowest molten iron cost is calculated according to the above steps.

[0046] For example: if the initial blast furnace feed grade TFe is 58.0%, the blast furnace feed grade change range can be limited to 56.0% to 60.0%. Set the blast furnace feed grade change step size to 0.1 percentage point, and change upwards in increments, i.e. 58.0%, 58.1%, 58.2%, ..., 60.0%. If the molten iron cost T of the blast furnace feed grade (TFe is 58.1%) after the upward increment change is 58.1％ The cost of hot metal lower than the initial blast furnace grade T 58.0％, then the blast furnace charging grade will continue to increase upward until the molten iron cost reaches the inflection point of the lowest value, or reaches the boundary of the limited range (≤60.0%); if the molten iron cost T of the blast furnace charging grade (TFe is 58.1%) after the upward change is increased 58.1％ The cost of hot metal T is higher than the initial blast furnace grade (TFe is 58.0%) 58.0％ , then the blast furnace charging grade will be changed downward in a decreasing manner, such as 57.9%, 57.8%, ..., 56.0%, until the molten iron cost reaches the inflection point of the lowest value, or reaches the boundary of the limited range (≥56.0%).

[0047] In a typical charge structure with sintered ore as the main charge, the ratio of sintered ore, pelletized ore and lump ore is fixed, the grade and price of pelletized ore and lump ore are set, and the sintered ore grade is calculated by setting the blast furnace entry grade, and the grade of the mixed ore for sintering is further deduced. According to the relationship equation between different grades of iron ore and price fitting, the price corresponding to the corresponding mixed ore grade is calculated, thereby calculating the price of the sintered ore. In addition, after the blast furnace entry grade is set, the charge consumption (ore consumption) is calculated according to the relationship equation between the blast furnace entry grade and the charge consumption, and the amount of sintered ore, pelletized ore and lump ore is calculated by the charge structure ratio; the fuel consumption (fuel consumption) is calculated according to the relationship equation between the blast furnace entry grade and fuel consumption, and the coke consumption is calculated by fixing the coal ratio, and then the molten iron cost is calculated. In an embodiment of the present invention, the calculation method of the molten iron cost T under the current blast furnace entry grade TFe is as follows:

[0048] (11) Determine the required charge consumption O and coke consumption C at the current blast furnace charging grade TFe;

[0049] The actual production data of the blast furnace was collected, and the relationship between the blast furnace charging grade TFe and the charge consumption O, and the blast furnace charging grade TFe and the coke consumption C were fitted by linear equations. The relationship between the blast furnace charging grade TFe and the charge consumption O is: O = Ko × TFe + Bo, where Ko is the slope, indicating the change in charge consumption corresponding to a unit change in the blast furnace charging grade TFe, and Bo is a constant term.

[0050] The relationship between the blast furnace charging grade TFe and the coke consumption C is: C=Kc×TFe+Bc, where Kc is the slope, indicating the change in coke consumption corresponding to a 1-unit change in the blast furnace charging grade TFe, and Bc is a constant term.

[0051] By inputting the current blast furnace charging grade TFe into the relationship formula, the required charge consumption O and coke consumption C under the current blast furnace charging grade TFe can be determined.

[0052] (12) Determine the blast furnace fuel cost Tr based on the coke consumption C;

[0053] Blast furnace fuel includes pulverized coal and coke. The amount of pulverized coal is generally set to a fixed value M, such as 150kg / t 铁 , that is, 150kg of pulverized coal is injected per ton of molten iron. Therefore, the effect of blast furnace feed grade TFe on fuel consumption R can be regarded as the effect on coke consumption C.

[0054] Calculate the pulverized coal cost Tm=M×Pm based on the pulverized coal amount M and the current pulverized coal price Pm;

[0055] Calculate the coke cost Tc=C×Pc based on the coke consumption C and the current coke Pc;

[0056] The blast furnace fuel cost Tr is composed of the pulverized coal cost Tm and the coke cost Tc, that is, Tr = Tc + Tm.

[0057] (13) Based on the determined charge structure ratio and the current required charge consumption O, the pellet cost Tq and lump cost Tk are calculated respectively;

[0058] According to the sintering and pelletizing process capacity of the ironmaking plant, determine the charge structure ratio: sintering ore ratio Bs, pelletizing ore ratio Bq, lump ore ratio Bk, and Bs+Bq+Bk=100%;

[0059] Set the pellet grade TFeq and its price Pq, the lump grade TFek and its price Pk, calculate the required amount of pellets and lump according to the charge consumption O and the set charge structure ratio, and then multiply by the corresponding price to determine the pellet cost Tq = O × Bq × Pq, and the lump cost Tk = O × Bk × Pk.

[0060] (14) Determine the sinter grade TFes under the current blast furnace charging grade TFe, and the mixed ore grade TFey under the sinter grade TFes; determine the price corresponding to the mixed ore grade TFey according to the relationship between iron ore grade and price, and calculate the sinter cost Ts;

[0061] According to the set blast furnace charging grade TFe, pellet grade TFeq, lump grade TFek and charge structure ratio, calculate the sintered ore grade TFes = (TFe-TFeq×Bq-TFek×Bk)÷Bs;

[0062] Calculate the blended ore grade TFey = TFes × Bys, where Bys is the ratio of the blended ore grade to the sintered ore grade, obtained from the actual production data of the sintering process, generally 1.07-1.10;

[0063] Linear equations are used to fit all iron ores of different grades and their corresponding prices to obtain the relationship between iron ore grade TFex and iron ore price Px: Px = Kk × TFex + Bb, where Kk is the slope, indicating the change in iron ore price Px corresponding to a unit change in iron ore grade TFex, and Bb is a constant term; mixed ore is composed of iron ores of different grades. Based on the relationship between iron ore grade and price, the price Py corresponding to the mixed ore grade TFey is calculated; the mixed ore cost Ty = Y × Py is calculated based on the amount of mixed ore used Y in the sintered ore. The amount of mixed ore used Y is also obtained from the actual production data of the sintering process, which is generally 750-800 kg / t 烧 , that is, about 800kg of mixed ore is required for every ton of sintered ore.

[0064] Calculate the sintered ore price Ps = Ty + sintering miscellaneous material cost Tz + sintering process cost Tx. The sintering miscellaneous material cost includes flux, solid fuel, return powder and other miscellaneous materials; the sintering process cost is other costs excluding the mixed ore cost Ty and the sintering miscellaneous material cost Tz.

[0065] According to the charge consumption O, the sintered ore proportion Bs and the sintered ore price Ps, the sintered ore cost Ts = O × Bs × Ps is calculated.

[0066] (15) The sintered ore cost Ts, pelletized ore cost Tq, lump ore cost Tk, blast furnace fuel cost Tr and blast furnace process cost Tg constitute the molten iron cost, T = Ts + Tq + Tk + Tr + Tg; the blast furnace process cost Tg is the other costs excluding the charge cost (Ts + Tq + Tk) and the fuel cost Tr. If Tg is set to zero, the molten iron cost T is expressed as the original fuel cost of the molten iron.

[0067] Figure 2 The schematic diagram of the structure of the optimal system for the blast furnace charging grade provided by the embodiment of the present invention, for the convenience of explanation, only shows the part related to the embodiment of the present invention, the system comprises:

[0068] Input unit and processing unit;

[0069] The current prices of iron ore of different grades, the set grades and prices of pellet ore and lump ore, the set prices of coal powder and coke, the set charge structure ratio, coal powder usage, and mixed ore usage are input into the processing unit through the input unit. The processing unit selects the blast furnace feeding grade corresponding to the lowest molten iron cost as the preferred blast furnace feeding grade based on the above-mentioned blast furnace feeding grade optimization method.

[0070] Under the iron ore guidance price of a certain iron ore plant in June 2024, the relationship between iron ore grade and price is shown in Figure 3 According to the linear fitting equation, if the iron ore grade changes by ±1 percentage point, the iron ore price will increase or decrease by about RMB 21.536 / t.矿 . Figure 4 This is the relationship between the blast furnace feed grade and the charge and coke consumption (the fuel consumption in the figure mainly refers to coke consumption) of a certain ironmaking plant. That is, if the blast furnace feed grade changes by ±1 percentage point, the charge consumption will decrease or increase by 25.55 kg / t. 铁 , fuel consumption decreased by 4.85kg / t 铁 .

[0071] Through the analysis of the ironmaking production data of a certain ironmaking plant, the proportion of its charge structure in the southern area is 68% sintered ore, 24.5% pelletized ore, and 7.5% lump ore; in the northern area, it is 74% sintered ore, 9% pelletized ore, and 17% lump ore. The amount of mixed ore for sintering is 790kg / t 烧 , the ratio of mixed ore grade to sintered ore grade is 1.078. According to the above data, the preferred furnace grade of a certain ironmaking plant in June 2024 should be 0.2-0.3 percentage points higher than the planned value (initial value). Figure 5 (a) As shown; By the same method, the optimization result of the blast furnace charging grade of a certain ironmaking plant under the guidance price in May 2024 is basically similar to the planned value (initial value), as shown in Figure 5 (b) as shown.

[0072] The present invention has been described exemplarily. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for optimizing the grade of blast furnace input, characterized in that: The method comprises the following steps: (1) Calculate the molten iron cost T at the current blast furnace charging grade; (2) Changing the blast furnace charging grade, taking the changed blast furnace charging grade as the current blast furnace charging grade, and executing step (1) until the blast furnace charging grade TFe corresponding to the lowest molten iron cost T is found within the set blast furnace charging grade range.

2. The method for optimizing the blast furnace charging grade as claimed in claim 1, characterized in that: The production plan or the actual blast furnace charging grade in the early stage is used as the initial blast furnace charging grade, and the allowable variation range of the initial blast furnace charging grade is set as the preferred range of blast furnace charging grade, and the blast furnace charging grade TFe corresponding to the lowest molten iron cost T is found within the set preferred range of blast furnace charging grade.

3. The method for optimizing the grade of blast furnace charging as claimed in claim 1, characterized in that: The method for obtaining the molten iron cost T at the current blast furnace charging grade is as follows: (11) Determine the required charge consumption O and coke consumption C at the current blast furnace charging grade; (12) Determine the blast furnace fuel cost Tr based on the coke consumption C and the set coal powder amount M; (13) Based on the determined charge structure ratio and the current required charge consumption O, the pellet cost Tq and lump cost Tk are calculated respectively; (14) Determine the sinter grade TFes under the current blast furnace charging grade TFe and the mixed ore grade TFey under the sinter grade TFes; determine the price corresponding to the mixed ore grade TFey according to the relationship between iron ore grade and price, and calculate the sinter cost Ts; (15) The sum of sintered ore cost Ts, pelletized ore cost Tq, lump ore cost Tk, blast furnace fuel cost Tr and blast furnace process cost Tg is the molten iron cost T.

4. The method for optimizing the grade of blast furnace charging as claimed in claim 3, characterized in that: The process of obtaining the required charge consumption O and coke consumption C under the current blast furnace charging grade is as follows: Actual production data of the blast furnace is collected, and linear equations are used to fit the relationship between the blast furnace feeding grade TFe and the burden consumption O, as well as the blast furnace feeding grade TFe and the coke consumption C. The current blast furnace feeding grade TFe is input into the relationship between the blast furnace feeding grade TFe and the burden consumption O, as well as the blast furnace feeding grade TFe and the coke consumption C, to obtain the burden consumption O and coke consumption C required under the current blast furnace feeding grade TFe.

5. The method for optimizing the grade of blast furnace charging as claimed in claim 3, characterized in that: The blast furnace fuel cost Tr is composed of pulverized coal cost Tm and coke cost Tc; Determine the amount of pulverized coal M per ton of molten iron, and calculate the pulverized coal cost Tm based on the pulverized coal amount M and the current pulverized coal price Pm; calculate the coke cost Tc based on the coke consumption C and the current coke price Pc.

6. The method for optimizing the grade of blast furnace charging as claimed in claim 3, characterized in that: The method for determining the proportion of charge structure is as follows: According to the actual production capacity of sintering and pelletizing processes, the charge structure ratio is determined: sintered ore Bs, pelletized ore Bq, lump ore Bk, and Bs+Bq+Bk=100%.

7. The method for optimizing the grade of blast furnace charging as claimed in claim 3, characterized in that: The specific method for determining the pellet cost Tq and lump cost Tk is as follows: Set the pellet grade TFeq and its price Pq, the lump grade TFek and its price Pk, calculate the required amount of pellets and lump according to the charge consumption O and the determined charge structure ratio, and then multiply them by the corresponding prices to determine the pellet cost and lump cost.

8. The method for optimizing the grade of blast furnace charging as claimed in claim 3, characterized in that: The specific process of determining the sintering cost Ts is as follows: According to the current blast furnace charging grade TFe, pellet grade TFeq, lump grade TFek and charge structure ratio, calculate the sintered ore grade TFes = (TFe-TFeq×Bq-TFek×Bk)÷Bs; Calculate the blended ore grade TFey = TFes × Bys, where Bys is the ratio of the blended ore grade to the sintered ore grade, which is obtained from the actual production data statistics of the sintering process; For all iron ores of different grades and their corresponding prices, a linear equation is used to fit the relationship between iron ore grade TFex and iron ore price Px: Px = Kk × TFex + Bb; Mixed ore is composed of iron ores of various grades. According to the relationship between iron ore grade and price, the price Py corresponding to the mixed ore grade TFey is calculated; the mixed ore cost Ty = Y × Py is calculated according to the mixed ore usage Y in the sintered ore, where the mixed ore usage Y is also obtained from the actual production data statistics of the sintering process; Calculate the sintered ore price Ps = Ty + sintering material cost Tz + sintering process cost Tx; According to the charge consumption O, the sintered ore proportion Bs and the sintered ore price Ps, the sintered ore cost Ts = O × Bs × Ps is calculated.

9. A system for optimizing the grade of blast furnace input, characterized in that: The system comprises: Input unit and processing unit; The current prices of iron ore of different grades, the set grades and prices of pellet ore and lump ore, the set prices of coal powder and coke, the set charge structure ratio, coal powder usage, and mixed ore usage are input into the processing unit through the input unit; the processing unit selects the blast furnace feeding grade corresponding to the lowest molten iron cost as the preferred blast furnace feeding grade based on the optimization method for blast furnace feeding grade as described in any one of claims 1 to 8.

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