A control method for reducing the consumption of composite injection magnesium powder

Abstract

The application discloses a control method for reducing consumption of composite injection magnesium powder, comprising the following steps: S1: collecting initial process parameters in the hot metal pretreatment process, including hot metal weight W, hot metal temperature T, initial sulfur content S0 and target sulfur content S t ; S2: determining actual magnesium powder mass required for desulfurization; S3: calculating mass percentage R of magnesium powder in the composite desulfurizer by using a formula Mg ; S4: adjusting feeding speed of magnesium powder and other components of the composite desulfurizer in real time according to the calculated R Mg , and performing composite injection desulfurization. The method can dynamically adjust the proportion of magnesium powder in the composite desulfurizer according to the real-time state of the hot metal, overcome the problems of magnesium powder waste or insufficient desulfurization caused by the fixed proportion in the traditional process, significantly reduce the unit consumption cost of magnesium powder under the premise of ensuring the hit rate of the desulfurization endpoint, and improve the desulfurization efficiency.

Description

Technical Field

[0001] This invention relates to the field of molten iron pretreatment technology in iron and steel metallurgy, and in particular to a control method for reducing the consumption of composite injected magnesium powder. Background Technology

[0002] In steelmaking, pre-desulfurization of molten iron is a crucial step in reducing sulfur content and improving the quality of high-quality steel. The composite injection desulfurization process typically uses a mixture of magnesium powder and lime injected into the molten iron. Magnesium powder has extremely strong desulfurization activity but is expensive; lime and other auxiliary materials are inexpensive but have lower desulfurization efficiency.

[0003] Existing technologies typically employ a fixed ratio (e.g., magnesium / lime = 1:3 or 1:4) for injection. However, in actual production, the temperature and initial sulfur content of molten iron fluctuate significantly. When the molten iron temperature is too high, the magnesium vapor pressure increases, easily leading to violent reactions and overflow, resulting in a decrease in magnesium utilization. Maintaining a fixed low ratio results in inadequate desulfurization, while maintaining a fixed high ratio causes significant waste. Therefore, dynamically adjusting the magnesium powder consumption ratio according to real-time operating conditions to achieve "on-demand mixing" is key to reducing costs.

[0004] Application CN202311224658.6 provides a highly efficient composite injection desulfurization method for molten hot metal. The core concept is to achieve efficient and low-cost desulfurization by collecting molten hot metal parameters during ladle pouring, determining pre-injection parameters before injecting lime powder, and determining composite injection parameters before injecting lime powder and magnesium powder. However, this method only improves the efficiency by optimizing the proportion of injected materials and fails to control the consumption of injected materials more deeply and accurately. Application CN202010581061.7 provides a process control method to improve the desulfurization efficiency of calcium-magnesium composite injection hot metal. The core concept includes passivation magnesium powder injection process control, lance injection process control, and molten hot metal slag removal process control. This method only optimizes the injection process parameters and fails to achieve accurate prediction and control of magnesium powder consumption. In summary, neither of the above two methods is the optimal choice. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a control method for reducing the consumption of composite blown magnesium powder by dynamically optimizing the magnesium powder ratio.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention includes the following steps:

[0007] S1: Collect initial process parameters during the molten iron pretreatment process, including molten iron weight W, molten iron temperature T, initial sulfur content S0, and target sulfur content S. t ;

[0008] S2: Determine the actual mass of magnesium powder M required for desulfurization. Mg_actual ;

[0009] S3: Calculate the mass percentage R of magnesium powder in the composite desulfurizer using the following formula (1). Mg ;

[0010] R Mg =R base ·[1+α·(S0-S avg ) / S avg ]·exp[β·(TT ref ) / T ref ]·η Mg (1)

[0011] Among them, R Mg The percentage of magnesium powder in the composite desulfurizer is %; R base The standard magnesium powder ratio is %; α is the sulfur content sensitivity coefficient, ranging from 0.3 to 0.8; S0 is the initial sulfur content of the molten iron, %; S avg The historical average sulfur content of molten iron is %; β is the temperature correction factor, ranging from -0.3 to +0.3; T is the measured temperature of the molten iron, in °C. ref The reference temperature for molten iron is set at 1300–1400℃; η Mg A correction factor for the effective utilization rate of magnesium powder;

[0012] S4: Based on the calculated R Mg The feeding rate of magnesium powder and other components of the composite desulfurizing agent is adjusted in real time during the injection process to achieve composite injection desulfurization.

[0013] Furthermore, in step S3, the effective utilization rate correction factor η of magnesium powder Mg Determined by the following formula (2):

[0014] η Mg =1-k·(H / H0-1) 2 (2)

[0015] In the formula, k is the spray gun insertion depth influence factor, which is taken as 1.0 to 5.0; H is the actual spray gun insertion depth, m; H0 is the standard spray gun insertion depth, m.

[0016] Furthermore, in step S2, the required mass M of magnesium powder for theoretical desulfurization is first calculated. Mg_theory Then, calculate the actual required mass of magnesium powder M based on the magnesium powder yield. Mg_actual .

[0017] The beneficial effects of adopting the above technical solution are as follows:

[0018] 1) Significantly reduce desulfurizing agent costs and achieve refined cost reduction: Traditional processes typically use a fixed ratio of magnesium powder to auxiliary materials, which cannot adapt to fluctuations in molten iron conditions, often leading to "overtreatment of low-sulfur" or "undertreatment of high-sulfur." ​​This invention introduces a core formula that includes sulfur content deviation and temperature correction, enabling dynamic adjustment of the magnesium powder ratio based on real-time operating conditions, thus significantly reducing the desulfurization cost per ton of iron.

[0019] 2) Improve the accuracy of desulfurization endpoint and ensure steel quality. For high-quality steel products such as rails, the control requirements for sulfur content are extremely strict. This invention effectively avoids the problem of excessive sulfur content at the desulfurization endpoint due to insufficient magnesium powder ratio, requiring secondary blowing, and significantly improves the accuracy of desulfurization endpoint.

[0020] 3) Improve process safety and reduce molten iron splashing. Magnesium powder is highly reactive and vaporizes instantly upon contact with water or high-temperature molten iron. Maintaining a high proportion of magnesium powder injection can easily trigger a violent vaporization reaction, leading to molten iron splashing and posing a safety hazard. The formula of this invention introduces a temperature correction coefficient β, which can appropriately adjust the proportion under high-temperature conditions, and is combined with a kinetic correction factor η. Mg When the lance insertion depth is not ideal, the magnesium powder supply rate is proactively reduced. This "preventative" control strategy effectively suppresses the intensity of the reaction, reduces molten iron splashing accidents, and improves the safety of on-site operations.

[0021] 4) The formula can be written into the equipment's control system, thereby achieving intelligent control with multi-variable coupling. This invention overcomes the shortcomings of traditional experience-based operations, which rely on manual judgment, have strong lag, and low accuracy; it couples multiple key process parameters such as molten iron temperature, initial sulfur content, and nozzle insertion depth into the same mathematical model; the model has a fast response speed and high calculation accuracy, and can issue proportional adjustment commands at the second level, enabling the composite injection process to transform from "experience-driven" to "data model-driven," providing strong technical support for intelligent production in steel plants.

[0022] 5) This invention dynamically optimizes the magnesium powder ratio by establishing a mathematical model, thereby reducing the magnesium powder consumption ratio. By introducing a core formula that includes variables such as temperature and sulfur content, the optimal magnesium powder ratio is accurately calculated. This invention can dynamically adjust the proportion of magnesium powder in the composite desulfurizing agent according to the real-time state of the molten iron, overcoming the problems of magnesium powder waste or insufficient desulfurization caused by a fixed ratio in traditional processes. While ensuring the hit rate of the desulfurization endpoint, it significantly reduces the unit cost of magnesium powder consumption and improves desulfurization efficiency. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments.

[0024] This method for reducing the consumption of composite blown magnesium powder includes the following steps:

[0025] S1: Collect initial process parameters during the molten iron pretreatment process, including molten iron weight W, molten iron temperature T, initial sulfur content S0, and target sulfur content S. t ;

[0026] S2: Determine the actual mass of magnesium powder M required for desulfurization. Mg_actual It is best to first determine the reaction formula Mg (g) +[S]=MgS (s) Calculate the theoretical mass of magnesium powder M required for desulfurization Mg_theory Theoretically, removing 1 kg of sulfur requires 0.758 kg of magnesium powder, which can be calculated using the following formula: M Mg-theory =(S0-S t )×W×0.758, where S0 is the initial sulfur content of molten iron before pretreatment, wt%; S t The initial sulfur content (wt%) after molten iron pretreatment.

[0027] Then, based on the magnesium powder yield η yield Calculate the actual required mass of magnesium powder M. Mg_actual =M Mg-theory / η yield The magnesium powder yield η yield Based on production experience data, the value generally ranges from 40% to 60%.

[0028] S3: Desulfurization is carried out by injecting a composite mixture of lime powder and a composite desulfurizing agent. The composite desulfurizing agent contains magnesium powder, lime (CaO), and calcium carbide (CaC2). The total amount of magnesium powder injected into the composite desulfurizing agent is the actual magnesium powder mass M calculated above. Mg_actual The mass percentage R of magnesium powder in the composite desulfurizer is calculated using the following formula (1). Mg ;

[0029] R Mg =R base ·[1+α·(S0-S avg ) / S avg ]·exp[β·(TT ref ) / T ref ]·η Mg (1)

[0030] Among them, R Mg The percentage of magnesium powder in the composite desulfurizer is wt%; R baseThe baseline magnesium powder ratio is calculated based on the magnesium powder injection ratio in composite injection, i.e., magnesium powder weight / (composite desulfurizer weight + lime powder weight), generally taken as 18% to 25 wt%; α is the sulfur content sensitivity coefficient, which reflects the adjustment intensity of the magnesium powder ratio when the initial sulfur content deviates from the average level, with a value range of 0.3 to 0.8; S0 is the initial sulfur content before hot metal pretreatment, in wt%; S avg β represents the historical average sulfur content of the molten iron before pretreatment, in wt%, obtained from historical data; β is the temperature correction coefficient, ranging from -0.3 to +0.3; T is the real-time monitored temperature of the molten iron, in °C; T ref The reference temperature for molten iron is generally taken as 1300–1400℃; η Mg The effective utilization rate correction factor for magnesium powder is determined by the following formula (2):

[0031] η Mg =1-k·(H / H0-1) 2 (2)

[0032] In the formula, k is the influence factor of the lance insertion depth, which is taken as 1.0 to 5.0; H is the actual depth of the lance inserted into the molten iron, in meters; H0 is the standard lance insertion depth, which is determined according to the type of molten iron container and the depth of the molten pool, and is generally taken as 0.5 to 2.5 meters below the surface of the molten iron.

[0033] In the formula (1):

[0034] 1) Influence of sulfur content [1+α·((S0-S avg ) / S avg When the initial sulfur content S0 is higher than the average value, the proportion of magnesium powder should be appropriately increased to shorten the processing time by utilizing the rapid desulfurization characteristics of magnesium powder; when the sulfur content is low, the proportion of magnesium powder should be reduced to rely on inexpensive auxiliary materials for maintenance desulfurization.

[0035] 2) Temperature effect term exp[β·(TT) ref ) / T ref Temperature significantly affects the dissolution and vaporization of magnesium; as temperature increases, the vapor pressure of magnesium rises, the reaction becomes more vigorous, and the loss rate increases. The formula uses an exponential function for adjustment: if the temperature is too high, the proportion of magnesium powder needs to be adjusted or the coating effect of the auxiliary materials needs to be increased (adjusted according to the value of β; typically, at high temperatures, the proportion needs to be optimized to balance the loss).

[0036] 3) Utilization rate correction term η Mg The actual reaction efficiency of magnesium powder is corrected based on the spraying dynamics (such as the spray gun depth).

[0037] S4: Based on the calculated R Mg The feeding rate of magnesium powder and other components of the composite desulfurizing agent is adjusted in real time during the injection process to achieve composite injection desulfurization.

[0038] The control method of the present invention will be described in detail below with reference to specific embodiments.

[0039] Example 1:

[0040] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1350℃, initial sulfur content S0 = 0.035%, target sulfur content S t =0.005%, spray gun insertion depth H=1.5m.

[0041] Reference parameter: R base =20%, α=0.5, β=-0.15, T ref =1350℃, k=3.0, H0=1.5m, η yield =50%.

[0042] 2) Calculation process:

[0043] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.035%-0.005%)×100×1000×0.758=22.74kg.

[0044] Actual magnesium powder consumption calculation: M Mg-actual =22.74 / 50%=45.48kg.

[0045] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.5×((0.035-0.035) / 0.035)=1.0;

[0046] Temperature term: exp[β·(TT) ref ) / T ref ] = exp[-0.15×0] = 1.0;

[0047] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 3.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0048] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =20%×1.0×1.0×1.0=20%.

[0049] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.004%. The total amount of magnesium powder injected was 45.48 kg, accounting for 20%, which verified the correctness of the model under standard working conditions.

[0050] Example 2:

[0051] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1300℃, initial sulfur content S0 = 0.025%, target sulfur content S t =0.005%, spray gun insertion depth H=1.5m.

[0052] Reference parameter: R base =18%, α=0.3, β=-0.3, T ref =1350℃, S avg =0.035%, k=1.0, H0=1.5m, η yield =40%.

[0053] 2) Calculation process:

[0054] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.025%-0.005%)×100×1000×0.758=15.16kg.

[0055] Actual magnesium powder consumption calculation: M Mg-actual =15.16 / 40%=37.9kg.

[0056] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.3×((0.025-0.035) / 0.035)=0.914;

[0057] Temperature term: exp[β·(TT) ref ) / T ref ]=exp[-0.3×(1300-1350) / 1350]≈1.011;

[0058] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 1.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0059] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =18%×0.914×1.011×1.0=16.6%.

[0060] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.005%. Under low temperature and low sulfur conditions and with parameters at the lower limit, the proportion of magnesium powder was reduced to 16.6%, effectively reducing magnesium powder consumption.

[0061] Example 3:

[0062] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1420℃, initial sulfur content S0 = 0.055%, target sulfur content S t =0.005%, spray gun insertion depth H=1.5m.

[0063] Reference parameter: R base =25%, α=0.8, β=0.3, T ref =1350℃, S avg =0.035%, k=5.0, H0=1.5m, η yield =60%.

[0064] 2) Calculation process:

[0065] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.055%-0.005%)×100×1000×0.758=37.9kg.

[0066] Actual magnesium powder consumption calculation: M Mg-actual =37.9 / 60%=63.17kg.

[0067] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.8×((0.055-0.035) / 0.035)=1.457;

[0068] Temperature term: exp[β·(TT) ref ) / T ref ]= exp[0.3×(1420-1350) / 1350]≈1.016;

[0069] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 5.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0070] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =25%×1.457×1.016×1.0=37.0%.

[0071] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.005%. Under extreme conditions of high temperature and high sulfur, the proportion of magnesium powder is significantly increased to 37.0% to ensure the desulfurization effect.

[0072] Example 4:

[0073] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1380℃, initial sulfur content S0 = 0.040%, target sulfur content S t =0.005%, spray gun insertion depth H=1.5m.

[0074] Reference parameter: R base =18%, α=0.5, β=-0.20, T ref =1400℃, S avg =0.035%, k=3.0, H0=1.5m, η yield =50%.

[0075] 2) Calculation process:

[0076] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.040%-0.005%)×100×1000×0.758=26.53kg.

[0077] Actual magnesium powder consumption calculation: M Mg-actual =26.53 / 50%=53.06kg.

[0078] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.5×((0.045-0.035) / 0.035)=1.071;

[0079] Temperature term: exp[β·(TT) ref ) / T ref ]= exp[-0.2×(1380-1400) / 1400]≈1.003;

[0080] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 3.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0081] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =18%×1.071×1.003×1.0=19.3%.

[0082] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.005%. With a slightly higher sulfur content, changes in the baseline parameters lead to adjustments in the final calculated ratio.

[0083] Example 5:

[0084] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1350℃, initial sulfur content S0 = 0.035%, target sulfur content S t =0.005%, spray gun insertion depth H=2.0m.

[0085] Reference parameter: R base =20%, α=0.5, β=-0.15, T ref =1350℃, S avg =0.035%, k=5.0, H0=2.5m, η yield =50%.

[0086] 2) Calculation process:

[0087] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.035%-0.005%)×100×1000×0.758=22.74kg.

[0088] Actual magnesium powder consumption calculation: M Mg-actual =22.74 / 50%=45.48kg.

[0089] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.5×((0.035-0.035) / 0.035)=1.0;

[0090] Temperature term: exp[β·(TT) ref ) / T ref ] = exp[-0.15×0] = 1.0;

[0091] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 5.0 × (2.0 / 2.5 - 1) 2 =0.8;

[0092] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =20%×1.0×1.0×0.8=16%.

[0093] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.003%. The spray gun was inserted too shallowly, and the model automatically adjusted the scale to 16% to prevent violent splashing from affecting the final desulfurization effect.

[0094] Example 6:

[0095] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1350℃, initial sulfur content S0 = 0.035%, target sulfur content S t =0.005%, spray gun insertion depth H=0.7m.

[0096] Reference parameter: R base =20%, α=0.5, β=-0.15, T ref =1350℃, S avg =0.035%, k=2.0, H0=0.5m, η yield =50%.

[0097] 2) Calculation process:

[0098] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.035%-0.005%)×100×1000×0.758=22.74kg.

[0099] Actual magnesium powder consumption calculation: M Mg-actual =22.74 / 50%=45.48kg.

[0100] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.5×((0.035-0.035) / 0.035)=1.0;

[0101] Temperature term: exp[β·(TT) ref ) / T ref ] = exp[-0.15×0] = 1.0;

[0102] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 2.0 × (0.7 / 0.5 - 1) 2 =0.68;

[0103] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =20%×1.0×1.0×0.68=13.6%.

[0104] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.004%. Excessive insertion also leads to deterioration of dynamic conditions, requiring significant model correction.

[0105] Example 7:

[0106] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1450℃, initial sulfur content S0 = 0.040%, target sulfur content St =0.005%, spray gun insertion depth H=1.5m.

[0107] Reference parameter: R base =22%, α=0.6, β=-0.25, T ref =1300℃, S avg =0.035%, k=3.0, H0=1.5m, η yield =55%.

[0108] 2) Calculation process:

[0109] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.040%-0.005%)×100×1000×0.758=26.53kg.

[0110] Actual magnesium powder consumption calculation: M Mg-actual =26.53 / 55%=48.24kg.

[0111] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.6×((0.040-0.035) / 0.035)=1.086;

[0112] Temperature term: exp[β·(TT) ref ) / T ref ]=exp[-0.25×(1450-1350) / 1350]≈0.972;

[0113] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 3.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0114] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =22%×1.0×0.972×1.0≈23.2%.

[0115] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.006%. Even with a high sulfur content, the proportion of magnesium powder did not increase significantly due to the suppressive effect of the temperature correction term, reflecting the strategy of reducing energy consumption at high temperatures.

[0116] Example 8:

[0117] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1280℃, initial sulfur content S0 = 0.050%, target sulfur content S t=0.005%, spray gun insertion depth H=1.5m.

[0118] Reference parameter: R base =24%, α=0.7, β=-0.10, T ref =1400℃, S avg =0.035%, k=3.0, H0=1.5m, η yield =45%.

[0119] 2) Calculation process:

[0120] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.050%-0.005%)×100×1000×0.758=34.11kg.

[0121] Actual magnesium powder consumption calculation: M Mg-actual =34.11 / 45%=75.8kg.

[0122] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.7×((0.050-0.035) / 0.035)=1.30;

[0123] Temperature term: exp[β·(TT) ref ) / T ref ]=exp[-0.1×(1280-1400) / 1400]≈1.009;

[0124] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 3.0 × (1.5 / 1.5 - 1) 2 =1.0;

[0125] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =24%×1.30×1.009×1.0≈31.5%.

[0126] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.005%. Low temperature and high sulfur content, with a relatively high reference temperature setting, require a higher proportion of magnesium powder to overcome the kinetic disadvantages.

[0127] Example 9:

[0128] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1320℃, initial sulfur content S0 = 0.045%, target sulfur content S t =0.005%, spray gun insertion depth H=1.3m.

[0129] Reference parameter: R base =22%, α=0.4, β=-0.20, T ref =1350℃, S avg =0.035%, k=4.0, H0=1.5m, η yield =55%.

[0130] 2) Calculation process:

[0131] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.045%-0.005%)×100×1000×0.758=30.32kg.

[0132] Actual magnesium powder consumption calculation: M Mg-actual =30.32 / 55%=55.31kg.

[0133] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.4×((0.045-0.035) / 0.035)=1.114;

[0134] Temperature term: exp[β·(TT) ref ) / T ref ]=exp[-0.2×(1320-1350) / 1350]≈1.004;

[0135] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 4.0 × (1.3 / 1.5 - 1) 2 =0.929;

[0136] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =22%×1.114×1.004×0.929≈22.9%.

[0137] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.003%. Typical calculations under comprehensive working conditions verify the applicability of the model.

[0138] Example 10:

[0139] 1) Operating parameters: molten iron weight W = 100 tons, molten iron temperature T = 1360℃, initial sulfur content S0 = 0.020%, target sulfur content S t =0.005%, spray gun insertion depth H=1.5m.

[0140] Reference parameter: Rbase =20%, α=0.6, β=-0.2, T ref =1350℃, S avg =0.035%, k=2.0, H0=1.5m, η yield =40%.

[0141] 2) Calculation process:

[0142] Theoretical magnesium powder consumption calculation: M Mg-theory =(0.020%-0.005%)×100×1000×0.758=11.37kg.

[0143] Actual magnesium powder consumption calculation: M Mg-actual =11.37 / 40%=28.43kg.

[0144] Sulfur content term: [1+α·((S0-S avg ) / S avg )]=1+0.6×((0.020-0.035) / 0.035)=0.743;

[0145] Temperature term: exp[β·(TT) ref ) / T ref ]=exp[-0.2×(1360-1350) / 1350]≈0.999;

[0146] Utilization correction: η Mg =1-k·(H / H0-1) 2 =1 - 2.0 × (1.5 / 1.5 - 1.0) 2 =1.0;

[0147] Calculate the proportion of magnesium powder in the composite desulfurizer: R Mg =20%×0.743×0.999×1.0≈14.8%.

[0148] 3) Results Analysis: After pretreatment, the sulfur content (S) of the molten iron decreased. 实际 =0.002%. The extremely low sulfur content led to a significant reduction in the proportion of magnesium powder injected. Although the low magnesium powder yield resulted in an increase in the total amount, the optimization of the magnesium powder ratio effectively reduced costs.

[0149] As can be seen from the above 10 embodiments, this control method can flexibly respond to changes in molten iron temperature, sulfur content, and injection dynamics. Compared with the traditional fixed-ratio process, this method can effectively reduce magnesium powder consumption under low-sulfur conditions; ensure the desulfurization qualification rate through precise magnesium extraction under high-sulfur conditions; and achieve a balance between efficient magnesium powder desulfurization and stable process control under extreme conditions. This method achieves refined control of magnesium powder consumption and has significant economic benefits.

Claims

1. A method for controlling the consumption of composite blown magnesium powder, characterized in that, Includes the following steps: S1: Collect initial process parameters during the molten iron pretreatment process, including molten iron weight W, molten iron temperature T, initial sulfur content S0, and target sulfur content S. t ; S2: Determine the actual mass of magnesium powder M required for desulfurization. Mg_actual ; S3: Calculate the mass percentage R of magnesium powder in the composite desulfurizer using the following formula (1). Mg ; R Mg =R base ·[1+α·(S0-S avg ) / S avg ]·exp[β·(T-T ref ) / T ref ]·η Mg (1) Among them, R Mg The percentage of magnesium powder in the composite desulfurizer is %; R base The standard magnesium powder ratio is %; α is the sulfur content sensitivity coefficient, ranging from 0.3 to 0.8; S0 is the initial sulfur content of the molten iron, %; S avg The historical average sulfur content of molten iron is %; β is the temperature correction factor, ranging from -0.3 to +0.3; T is the measured temperature of the molten iron, in °C. ref The reference temperature for molten iron is set at 1300–1400℃; η Mg The effective utilization rate correction factor for magnesium powder; S4: Based on the calculated R Mg The feeding rate of magnesium powder and other components of the composite desulfurizing agent is adjusted in real time during the injection process to achieve composite injection desulfurization.

2. The control method for reducing the consumption of composite blown magnesium powder according to claim 1, characterized in that: In step S3, the effective utilization rate correction factor η of magnesium powder Mg Determined by the following formula (2): η Mg =1-k·(H / H0-1) 2 (2) In the formula, k is the spray gun insertion depth influence factor, which is taken as 1.0 to 5.0; H is the actual spray gun insertion depth, m; H0 is the standard spray gun insertion depth, m.

3. A method for controlling the consumption of composite blown magnesium powder according to claim 1 or 2, characterized in that: In step S2, the mass M of magnesium powder required for theoretical desulfurization is first calculated. Mg_theory Then, calculate the actual required mass of magnesium powder M based on the magnesium powder yield. Mg_actual .