A control method for top-blown oxygen supply process in a converter smelting process

Abstract

The present application relates to a kind of control method of top blowing oxygen supply process in converter smelting process, belong to steel metallurgy technical field, to solve the problem that the existing top blowing oxygen lance cannot be automatically regulated in the position and flow in the process of converter smelting.A kind of control method of top blowing oxygen supply process in converter smelting process, comprising: starting, complete initial condition data acquisition in the process of converter smelting;Drop oxygen lance, oxygen blowing starts, while monitoring the content of carbon, silicon and manganese in molten iron, calculate oxygen supply process conversion point, form oxygen supply process conversion point determination;According to oxygen supply process conversion point, according to adjustment rule, adjust top blowing oxygen lance position and oxygen flow.The present application can realize the automatic regulation of top blowing oxygen lance position and flow in the process of converter smelting.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and in particular to a method for controlling the top-blown oxygen supply process in converter smelting. Background Technology

[0002] Top-blown oxygen is a relatively advanced oxygen-blown converter steelmaking process. Top-blown oxygen supply significantly improves the production efficiency and steel quality of the converter smelting process, but the direct injection of oxygen poses a significant challenge to process control. Existing top-blown oxygen supply processes mainly fall into two categories: one involves manually adjusting the lance height without regulating the oxygen flow rate; the other involves adjusting the lance flow rate and lance position based on an oxygen supply model. However, this method only mechanically adjusts according to the model's set values, lacking feedback and failing to achieve automatic adjustment of the lance position and flow rate.

[0003] Currently, the converter smelting process has put forward new requirements for the progress of converter steel hydrolysis and the economy of converter smelting. In order to meet the multiple objectives of hydrolysis progress and economy, the oxygen supply process must be optimized and adjusted. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a control method for the top-blown oxygen supply process in converter smelting, so as to improve the automation level of the top-blown oxygen lance position and flow rate regulation in the converter smelting process.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] This invention provides a method for controlling the top-blown oxygen supply process in converter smelting, comprising:

[0007] Step 1: At the start of the furnace run, complete the initial condition data collection for the converter smelting process;

[0008] Step 2: Oxygen removal lance, oxygen blowing begins, while monitoring the carbon, silicon and manganese content in the molten iron, and calculating the oxygen supply process switching point;

[0009] Step 3: Based on the oxygen supply process switching point, adjust the position of the top-blown oxygen lance and the oxygen flow rate according to the adjustment rules.

[0010] Furthermore, in step 2, the oxygen supply process conversion point includes the carbon-oxygen reaction conversion point and the iron-oxygen reaction conversion point.

[0011] Furthermore, the carbon-oxygen reaction conversion point is: T Si-C =8×k×(2.1W[Si]+1.3W[Mn])(1+T / 273) / (60Q);

[0012] Among them, T Si-CThe carbon-oxygen reaction conversion point, min;

[0013] k is a coefficient, k = 9 to 9.9;

[0014] W[Si] represents the silicon content of molten iron, in %;

[0015] W[Mn] represents the manganese content in molten iron, in %;

[0016] T is the molten pool temperature, in °C;

[0017] Q represents the oxygen supply rate of the top-blown oxygen lance, in Nm³. 3 / t·min.

[0018] Furthermore, the iron-oxygen reaction conversion point is: T C-Fe =T Si-C +(f×W[C]-C C-Fe ) / Dc,

[0019] Among them, T C-Fe The ferro-oxygen reaction conversion point, min;

[0020] f is a coefficient, f = 0.74q -0 .03;

[0021] W[C] represents the carbon content of molten iron, in %;

[0022] C C-Fe Critical carbon content, %.

[0023] Dc represents the decarburization rate, % / min.

[0024] Furthermore, the critical carbon content C C-Fe =0.25e -5.875q Where q is the bottom blowing stirring intensity of the converter, in Nm 3 / t·min.

[0025] Further, the decarburization rate Dc = 0.35ln(Q) + 0.037, where Q is the oxygen supply rate of the top-blown oxygen lance, in Nm³. 3 / t·min.

[0026] Furthermore, in step S3, the adjustment principle includes: the carbon-oxygen reaction conversion point T. Si-C After keeping the oxygen flow rate constant, adjust the oxygen lance position H1, where H1 = (0.99 - 0.17ln(W[Si]))h;

[0027] Wherein, W[Si] represents the silicon content of molten iron, in %;

[0028] h is 0 to T Si-C Forward gun position, m.

[0029] Furthermore, the adjustment principle also includes: the ferro-oxygen reaction conversion point T. C-Fe Then adjust the oxygen flow rate Q C-Fe Q C-Fe =Q×0.9596e -0.314q ;

[0030] Where Q is the oxygen supply rate of the top-blown oxygen lance, in Nm³. 3 / t·min;

[0031] q represents the bottom blowing stirring intensity of the converter, in Nm. 3 / t·min.

[0032] Furthermore, the adjustment principle also includes: the ferro-oxygen reaction conversion point T. C-Fe The oxygen lance position was then adjusted to H2, where H2 = H1 × 0.9157q. 0.03 ;

[0033] Where H1 is the carbon-oxygen reaction conversion point T. Si-C The oxygen gun position after that, m.

[0034] Furthermore, the oxygen blowing end time is

[0035] Among them, Q 总 Total oxygen supply, Nm 3 .

[0036] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0037] 1. The control method of top-blown oxygen supply process in converter smelting of the present invention, in the converter smelting process, by monitoring the content of carbon, silicon and manganese in molten iron, calculates the oxygen supply process switching point and forms an oxygen supply process switching point determination; then, according to the oxygen supply process switching point, the position of the top-blown oxygen lance and the oxygen flow rate are automatically adjusted according to the adjustment rules, so as to realize the automatic adjustment of the position and flow rate of the top-blown oxygen lance in the converter smelting process.

[0038] 2. The control method of top-blown oxygen lance oxygen supply process in the converter smelting process of the present invention can free up manpower from the tense converter blowing process, and at the same time avoid mechanical adjustment according to the set value of the oxygen supply mode of the model instead of automatic adjustment, which can improve the automation and high efficiency of converter smelting production.

[0039] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0040] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0041] Figure 1 This is a schematic diagram of the control method for top-blown oxygen supply process in converter smelting. Detailed Implementation

[0042] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0043] This invention provides a method for controlling the top-blown oxygen supply process in converter smelting, comprising:

[0044] Step 1: At the start of the furnace run, complete the initial condition data collection for the converter smelting process;

[0045] Step 2: Oxygen removal lance, oxygen blowing begins, while monitoring the carbon, silicon and manganese content in the molten iron, and calculating the oxygen supply process switching point;

[0046] Step 3: Based on the oxygen supply process switching point, adjust the position of the top-blown oxygen lance and the oxygen flow rate according to the adjustment rules.

[0047] Top-blown oxygen is a relatively advanced oxygen-based top-blown converter steelmaking method. It offers numerous advantages, including rapid smelting speed, a wide variety of high-quality steels, quick plant construction, and low investment. Existing top-blown oxygen supply processes mainly fall into two categories: one involves manually adjusting the lance height without regulating the oxygen flow rate; the other adjusts the lance flow rate and position based on an oxygen supply model, but this is merely a mechanical adjustment according to the model's set values, lacking feedback and failing to achieve automatic adjustment of the lance position and flow rate. The present invention addresses this by using a top-blown oxygen supply process control method during converter smelting. This method monitors the carbon, silicon, and manganese content in the molten iron to calculate the oxygen supply process transition point, establishing transition point determination criteria. Then, based on this transition point and adjustment rules, it automatically adjusts the top-blown oxygen lance position and flow rate, achieving automatic adjustment of these parameters during the converter smelting process.

[0048] Specifically, in step 1, the initial condition data acquisition refers to collecting the composition of molten iron at the start of converter smelting;

[0049] Specifically, in step 2, the oxygen-reducing lance is activated, oxygen blowing begins, and the carbon, silicon, and manganese content in the molten iron is monitored simultaneously. The oxygen supply process switching point is calculated to provide a basis for determining the oxygen supply process switching point. The oxygen supply process switching point includes T. Si-C T C-Fe , among which, T Si-C T is the carbon-oxygen reaction conversion point. C-Fe This is the iron-oxygen reaction transition point;

[0050] The carbon-oxygen reaction conversion point is:

[0051] T Si-C =8×k×(2.1W[Si]+1.3W[Mn])(1+T / 273) / (60Q),

[0052] Where k is a coefficient, k = 9 to 9.9;

[0053] W[Si] represents the silicon content of molten iron, in %;

[0054] W[Mn] represents the manganese content in molten iron, in %;

[0055] T is the molten pool temperature, in °C;

[0056] Q represents the oxygen supply rate of the top-blown oxygen lance, in Nm³. 3 / t·min;

[0057] The iron-oxygen reaction conversion point is: T C-Fe =T Si-C +(f×W[C]-C C-Fe ) / Dc,

[0058] Where f is a coefficient, f = 0.74q -0 .03;

[0059] W[C] represents the carbon content of molten iron, in %;

[0060] C C-Fe Critical carbon content, %.

[0061] Among them, C C-Fe =0.25e -5.875q ;

[0062] Where Dc is the decarburization rate, % / min, Dc = 0.35ln(Q) + 0.037, and q is the converter bottom blowing stirring intensity, Nm. 3 / t·min;

[0063] Specifically, in step 3, based on the oxygen supply process switching point and according to the adjustment rules, the position of the top-blown oxygen lance and the oxygen flow rate are adjusted. The adjustment rules are as follows:

[0064] Carbon-oxygen reaction conversion point TSi-C After keeping the oxygen flow rate constant, adjust the oxygen lance position H1, where H1 = (0.99 - 0.17ln(W[Si]))h;

[0065] Wherein, W[Si] represents the silicon content of molten iron, in %;

[0066] h is 0 to T Si-C Forward gun position, m.

[0067] Ferro-oxygen reaction conversion point T C-Fe Then adjust the oxygen flow rate Q C-Fe And the oxygen lance position H2, H2 = H1 × 0.9157q 0.03 Q C-Fe =Q×0.9596e -0.314q ;

[0068] Where Q is the oxygen supply rate of the top-blown oxygen lance, in Nm³. 3 / t·min;

[0069] q represents the bottom blowing stirring intensity of the converter, in Nm. 3 / t·min.

[0070] The oxygen blowing end time is:

[0071] Among them, Q 总 Q represents the total oxygen supply. 总 =K(13.3W[C]+11.4W[Si]+2.9W[Mn]-f 矿 ), m 3 / t;

[0072] Wherein, W[Si] represents the silicon content of molten iron, in %;

[0073] W[Mn] represents the manganese content in molten iron, in %;

[0074] W[C] represents the carbon content of molten iron, in %;

[0075] K is the oxygen utilization coefficient, K = 0.5 to 0.9;

[0076] f 矿 f is the oxygen content coefficient of the ore. 矿 =0.1~0.4.

[0077] The control method for top-blown oxygen supply process in converter smelting of the present invention involves monitoring the carbon, silicon, and manganese content in the molten iron during converter smelting to calculate the oxygen supply process switching point and form an oxygen supply process switching point determination; then, based on the oxygen supply process switching point, the position of the top-blown oxygen lance and the oxygen flow rate are automatically adjusted according to the adjustment rules, which can realize the automatic adjustment of the position and flow rate of the top-blown oxygen lance in the converter smelting process, and improve the automation and high efficiency of converter smelting production.

[0078] Example

[0079] This embodiment provides a method for controlling the top-blown oxygen supply process in converter smelting, including the following steps:

[0080] Step 1: At the start of the furnace run, complete the initial condition data collection for the converter smelting process;

[0081] Step 2: Oxygen removal gun, oxygen blowing begins, while monitoring the carbon, silicon and manganese content in the molten iron, calculating the oxygen supply process switching point, and forming the oxygen supply process switching point determination.

[0082] Monitoring showed that at the start of oxygen blowing, the molten iron contained 4.5% C, 0.2% Si, and 0.2% Mn, with a molten pool temperature of T = 1400℃ and an oxygen supply rate of Q = 3.5 Nm. 3 / t·min, converter bottom blowing stirring intensity q=0.1Nm 3 / t·min, k=9.6, determined based on the C content, Si content, Mn content, molten pool temperature, oxygen supply rate of the top-blown oxygen lance, and bottom-blown stirring intensity of the converter at the start of oxygen blowing. The calculation yields the following:

[0083] The carbon-oxygen reaction conversion point T is determined based on the C content, Si content, Mn content, molten pool temperature, oxygen supply rate of the top-blown oxygen lance, and bottom-blown stirring intensity at the start of oxygen blowing. Si-C Coefficient f, Critical carbon content C C-Fe Calculation of decarburization rate Dc and iron-oxygen reaction conversion point T C-Fe ;

[0084] Specifically:

[0085] First, calculate the carbon-oxygen reaction conversion point T. Si-C Coefficient f, Critical carbon content C C-Fe Decarburization rate Dc:

[0086] The carbon-oxygen reaction conversion point is:

[0087] T Si-C =8×k×(2.1W[Si]+1.3W[Mn])(1+T / 273) / (60Q)=1.994268132min;

[0088] The coefficient f = 0.74q -0.03 =0.792924286;

[0089] Critical carbon content C C-Fe =0.25e -5.875q =0.138877;

[0090] Decarburization rate Dc = 0.35ln(Q) + 0.037 = 0.475467039;

[0091] Then, the coefficient f and the critical carbon content C are... C-Fe Decarbonization rate Dc, carbon-oxygen reaction conversion point T Si-C Substitute T C-Fe =T Si-C +(f×W[C]-C C-Fe ) / Dc, we can get:

[0092] Ferro-oxygen reaction conversion point T C-Fe = 9.206717915 min;

[0093] In step 3, based on the oxygen supply process switching point and according to the adjustment rules, adjust the position of the top-blown oxygen lance and the oxygen flow rate:

[0094] Carbon-oxygen reaction conversion point T Si-C The oxygen supply rate Q of the rear top-blown oxygen lance remains constant, 0~T Si-C With the front lance position h = 1.8m, adjust the oxygen lance position H1. The adjusted oxygen lance position H1 is as follows:

[0095] H1=(0.99-0.17ln(W[Si]))h=2.274488m;

[0096] Ferro-oxygen reaction conversion point T C-Fe Then adjust the oxygen flow rate Q C-Fe And oxygen lance position H2, where:

[0097] H2 = H1 × 0.9157q 0.03 =1.953734m;

[0098] Q C-Fe =Q×0.9596e -0.314q =3.254339Nm 3 / t·min;

[0099] Oxygen utilization coefficient K = 0.7, ore oxygen content coefficient f 矿 =0.2, the calculation yields:

[0100] Q 总 =K(13.3W[C]+11.4W[Si]+2.9W[Mn]-f 矿 )=44.00727m 3 / t;

[0101] Oxygen blowing end time T end for:

[0102]

[0103] Following the same steps, calculate the carbon-oxygen reaction conversion point T for the following four furnace cycles at the start of oxygen blowing: C content, Si content, Mn content, molten pool temperature T, oxygen supply rate Q of the top-blown oxygen lance, and bottom-blown stirring intensity q and k value. Si -C and the iron-oxygen reaction transition point T C-Fe , where 0~T Si-C The front gun position h = 1.8m. Based on the adjustment principle, the oxygen flow rate and oxygen gun position are adjusted. Specific data are shown in Table 1.

[0104] Table 1. Data on top-blown oxygen supply process in converter smelting at times T1-T5 in Example 1

[0105]

[0106]

[0107] After controlling the top-blown oxygen supply process in the converter smelting process according to the control method provided by the present invention, the average O content in the molten iron is about 0.0540% after the top-blown oxygen supply is completed, which is 0.0050-0.010% lower than that of the normal process. The average iron content in the slag is reduced by 1.1%, and the oxygen utilization rate is increased by 2%, resulting in high-quality molten steel. Compared with the two existing top-blown oxygen supply processes (one is not to adjust the oxygen supply flow rate of the top-blown oxygen lance, but only to manually adjust the lance height; the other is to adjust the flow rate and lance position of the top-blown oxygen lance according to the oxygen supply model, but only to make mechanical adjustments according to the model's set values), the time is shortened by more than 30 seconds.

[0108] It is evident that by employing the control method of top-blown oxygen supply process in the converter smelting process described above in this invention, the oxygen supply process switching point is calculated by monitoring the carbon, silicon, and manganese content in the molten iron during the converter smelting process, thus forming the conditions for determining the oxygen supply process switching point. Then, based on the oxygen supply process switching point, the position of the top-blown oxygen lance and the oxygen flow rate are automatically adjusted according to the adjustment rules. This enables automatic adjustment of the position and flow rate of the top-blown oxygen lance during the converter smelting process, freeing up manpower from the intense converter blowing process. At the same time, it avoids mechanical adjustment based on the set values ​​of the oxygen supply mode of the model instead of automatic adjustment, which can significantly improve the automation and high efficiency of converter smelting production.

[0109] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the top-blown oxygen supply process in a converter smelting process, characterized in that, include: Step 1: At the start of the furnace run, complete the initial condition data collection for the converter smelting process; Step 2: Oxygen removal lance, oxygen blowing begins, while monitoring the carbon, silicon and manganese content in the molten iron, and calculating the oxygen supply process switching point; Step 3: Based on the oxygen supply process switching point and in accordance with the adjustment principles, adjust the position of the top-blown oxygen lance and the oxygen flow rate; In step 2, the oxygen supply process switching points include the carbon-oxygen reaction switching point and the iron-oxygen reaction switching point; The carbon-oxygen reaction conversion point is: T Si-C =8×k×(2.1W[Si]+1.3 W[Mn])(1+T / 273) / (60Q); Among them, T Si-C The carbon-oxygen reaction conversion point, min; k is a coefficient, k = 9~9.9; W[Si] represents the silicon content of molten iron, % . W[Mn] represents the manganese content in molten iron, % T is the molten pool temperature, in °C; Q is the oxygen supply rate of the top-blown oxygen lance, Nm³ / t·min; The ferro-oxygen reaction conversion point is: T C-Fe =T Si-C +(f×W[C]-C C-Fe ) / Dc, Among them, T C-Fe The iron-oxygen reaction conversion point, min; f is a coefficient, f = 0.74q -0.03 ; W[C] represents the carbon content of molten iron, % C C-Fe Critical carbon content, %. Dc represents the decarburization rate, % / min; The critical carbon content C C-Fe =0.25e -5.875q Where q is the bottom blowing stirring intensity of the converter, Nm³ / t·min; The decarburization rate Dc = 0.35ln(Q) + 0.037, where Q is the oxygen supply rate of the top-blown oxygen lance, Nm³ / t·min; In step S3, the adjustment principle includes: the carbon-oxygen reaction conversion point T. Si-C With the oxygen flow rate unchanged, adjust the oxygen lance position H1, where H1 = (0.99 - 0.17 ln(W[Si]))h; Wherein, W[Si] represents the silicon content of molten iron, % h is 0~T Si-C Forward gun position, m; The adjustment principles also include: the iron-oxygen reaction conversion point T. C-Fe Then adjust the oxygen flow rate Q C-Fe Q C-Fe =Q×0.9596e -0.314q ; Where Q is the oxygen supply rate of the top-blown oxygen lance, Nm³ / t·min; q represents the bottom blowing stirring intensity of the converter, in Nm³ / t·min; The adjustment principles also include: the iron-oxygen reaction conversion point T. C-Fe The oxygen lance position was then adjusted to H2, where H2 = H1 × 0.9157q. 0.03 ; Where H1 is the carbon-oxygen reaction conversion point T. Si-C The oxygen gun position after that, m; The adjustment principles also include: the oxygen blowing end time is T. end =T C-Fe +(Q 总 - ) / Q C-Fe ; Among them, Q 总 Total oxygen supply, Nm³.

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