Feeding method for improving converter carbon powder yield

Abstract

The invention discloses a feeding method for improving the yield of converter carbon powder, which comprises the following steps: feeding carbon powder in the tapping process of converter smelting, and adding the carbon powder 30 seconds before or more than 30 seconds after tapping according to the end point carbon content and whether peroxidation occurs or not. According to the method, on the basis of different end point carbon contents and different carbon powder yields at different steel tapping time, the carbon powder feeding time and the steel tapping carbon content during steel tapping are obtained, so that the burn-out rate of the carbon powder is reduced, the carbon powder yield is improved, and the purpose of reducing the smelting cost is achieved. The method has important practical guiding significance on converter smelting cost control, and the purposes of reducing the cost and improving the carbon powder yield are achieved.

Description

Technical Field

[0001] The invention relates to a feeding method for improving the recovery rate of converter carbon powder. Background Art

[0002] As market competition becomes increasingly fierce, steel prices are also falling, so cost reduction and efficiency improvement have become the most important research direction for production. However, due to the different steel-making times and the different carbon contents at the end of steel-making, the carbon powder recovery rate is not stable, which leads to increased costs and is not conducive to cost reduction and efficiency improvement. In addition, since the timing of adding carbon powder during the steel-making process is manually determined by experience, the carbon powder recovery rate is even more unstable. Therefore, stabilizing the timing of adding carbon powder during steel-making has become a problem that needs to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to provide a feeding method for improving the carbon powder recovery rate of a converter. Based on the differences in carbon content at different endpoints and carbon powder recovery rates at different steel-tapping times, the inventors have summarized and classified the best time to feed carbon powder during steel-tapping and the best carbon content for steel-tapping, so as to reduce the burn-off rate of carbon powder, thereby improving the carbon powder recovery rate and achieving the purpose of reducing smelting costs. This method has important practical guiding significance for converter smelting cost control, effectively solves the above-mentioned problems existing in the background technology, and achieves the goal of reducing costs and improving carbon powder recovery rates.

[0004] The technical solution of the present invention is: a feeding method for improving the recovery rate of converter carbon powder, in which carbon powder is added during the steel-tapping process of converter smelting, and the addition is completed 30 seconds before or more than 30 seconds after steel-tapping according to the carbon content at the furnace end and whether overoxidation occurs.

[0005] The present invention studies the timing of the highest carbon powder yield when adding carbon powder to reduce the amount of carbon powder used based on the different carbon powder yields at different end-point carbon contents and different steel-tapping times. The present invention divides the carbon powder yields at different steel-tapping times and end-point carbon contents into nine situations:

[0006] When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s before steel tapping;

[0007] When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s to 90s after steel tapping;

[0008] When the final carbon content is less than 0.06% (overoxidation) and carbon powder is added 90s after steel tapping;

[0009] When the final carbon content is between 0.06% and 0.10% and 30 seconds before steel tapping, add all the carbon powder;

[0010] When the final carbon content is between 0.06% and 0.10% and 30s to 90s after steel tapping, add all the carbon powder;

[0011] When the final carbon content is between 0.06% and 0.10% and 90 seconds after steel tapping, start adding carbon powder;

[0012] When the final carbon content is greater than 0.10% and the carbon powder is added 30 seconds before steel tapping;

[0013] When the final carbon content is greater than 0.10% and the carbon powder is added 30s to 90s after steel tapping;

[0014] When the final carbon content is greater than 0.10% and 90 seconds after steel tapping, start adding carbon powder.

[0015] Advantages of the present invention:

[0016] 1. The present invention obtains the optimal terminal carbon and tapping timing by statistically analyzing the carbon content at different steel-tapping endpoints and the recovery rate of the carburizer at different steel-tapping timings, thereby greatly reducing the usage of the carburizer in the steel-tapping process, thereby achieving the ultimate goal of saving costs and reducing costs and increasing efficiency, and has important practical guiding significance for converter smelting.

[0017] The present invention reduces the amount of carbon powder used by studying the timing of the highest carbon powder recovery rate when adding carbon powder according to the different carbon powder recovery rates at different final carbon contents and different steel-tapping times, and belongs to the technical field of converter steelmaking control. The present invention divides the carbon powder recovery rates corresponding to different steel-tapping times and final carbon contents into nine situations: when the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s before steel-tapping; when the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s to 90s after steel-tapping; when the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added after 90s of steel-tapping; when the final carbon content is between 0.06% and 0.10% and the carbon powder is added 30s before steel-tapping; 0s to add all the carbon powder; when the final carbon content is between 0.06% and 0.10% and 30s to 90s into steel tapping, add all the carbon powder; when the final carbon content is between 0.06% and 0.10% and start adding carbon powder 90s after steel tapping; when the final carbon content is greater than 0.10% and 30s before steel tapping, add all the carbon powder; when the final carbon content is greater than 0.10% and 30s to 90s into steel tapping, add all the carbon powder; when the final carbon content is greater than 0.10% and start adding carbon powder 90s after steel tapping. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with specific embodiments.

[0019] Embodiment 1

[0020] The best timing for carbon powder addition is determined based on different steel-tapping timings and different carbon contents at the steel-tapping endpoints, which reduces the amount of carbon powder burned during the steel-tapping process, obtains a relatively high carbon powder recovery rate, and reduces costs. The required carbon content during the steel-tapping process is as follows:

[0021]

[0022] The carbon powder recovery rate is mainly determined by the final carbon content and the timing of adding carbon powder during the steelmaking process. Therefore, the carbon powder input from January to April 2024 is analyzed as follows:

[0023] (1) When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30 seconds before steel tapping:

[0024] Average end point carbon Average joining time C powder yield 0.053％ 27.4s 43.67％

[0025] (2) When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added within 30s to 90s of steel tapping:

[0026] Average end point carbon Average joining time C powder yield 0.055％ 61.6s 55.41％

[0027] (3) When the final carbon content is less than 0.06% (overoxidation) and carbon powder is added 90 seconds after steel tapping:

[0028] Average end point carbon Average joining time C powder yield 0.049％ 133.4s 55.63％

[0029] (4) When the final carbon content is between 0.06% and 0.10% and the carbon powder is added 30 seconds before steel tapping:

[0030] Average end point carbon Average joining time C powder yield 0.071％ 26.4s 50.15％

[0031] (5) When the final carbon content is between 0.06% and 0.10% and the carbon powder is added within 30s to 90s of steel tapping:

[0032] Average end point carbon Average joining time C powder yield 0.082％ 57.6s 66.34％

[0033] (6) When the final carbon content is between 0.06% and 0.10% and carbon powder is added 90 seconds after steelmaking:

[0034] Average end point carbon Average joining time C powder yield 0.086％ 126.5s 60.22％

[0035] (7) When the final carbon content is greater than 0.10% and the carbon powder is added within 30 seconds before steel tapping:

[0036] Average end point carbon Average joining time C powder yield 0.113％ 20.3s 58.44％

[0037] (8) When the final carbon content is greater than 0.10% and the carbon powder is added within 30s to 90s of steel tapping:

[0038] Average end point carbon Average joining time C powder yield 0.104％ 43.3s 60.32％

[0039] (9) When the final carbon content is greater than 0.10% and carbon powder is added 90 seconds after steelmaking:

[0040] Average end point carbon Average joining time C powder yield 0.112％ 110.9s 66.46％

[0041] As shown in the above results, the carbon powder recovery rate increases with the increase of the final carbon content, but too high a final carbon content will cause the slag to stick to the strip steel during the first pouring process, resulting in an increase in steel consumption. Therefore, the final carbon content should be controlled at 0.06% to 0.10%, so that the carbon powder recovery rate will not be too low due to overoxidation, nor will the steel consumption be too high due to too high a final carbon content. The timing of adding carbon powder should be selected between 30s and 90s. When the carbon powder is added too early, the steel output is too low, and the argon stirring is uneven during steel output, resulting in a low carbon recovery rate, and the carbon powder burning rate is high when the carbon powder is added too early; when the carbon powder is added too late, the argon flow rate during steel output is relatively small compared to the previous period, resulting in the inability to fully stir the carbon element, resulting in uneven composition. Therefore, when all the carbon powder is added during the 30s to 90s stage of steel output, the recovery rate can be ensured, thereby reducing the amount of carbon powder used and reducing costs. At the same time, the final carbon content is controlled at 0.06% to 0.10%, reducing the situation of slag strip steel in the first pouring and reducing steel consumption. Therefore, when the final carbon content is controlled at 0.06% to 0.10%, adding a carburizer 30s to 90s after steel tapping can ensure a relatively high carbon powder recovery rate.

[0042] The present invention divides the carbon powder recovery rates corresponding to different steel-tapping times and final carbon contents into nine cases:

[0043] When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s before steel tapping;

[0044] When the final carbon content is less than 0.06% (overoxidation) and the carbon powder is added 30s to 90s after steel tapping;

[0045] When the final carbon content is less than 0.06% (overoxidation) and carbon powder is added 90s after steel tapping;

[0046] When the final carbon content is between 0.06% and 0.10% and 30 seconds before steel tapping, add all the carbon powder;

[0047] When the final carbon content is between 0.06% and 0.10% and 30s to 90s after steel tapping, add all the carbon powder;

[0048] When the final carbon content is between 0.06% and 0.10% and 90 seconds after steel tapping, start adding carbon powder;

[0049] When the final carbon content is greater than 0.10% and the carbon powder is added 30 seconds before steel tapping;

[0050] When the final carbon content is greater than 0.10% and the carbon powder is added 30s to 90s after steel tapping;

[0051] When the final carbon content is greater than 0.10% and 90 seconds after steel tapping, start adding carbon powder.

[0052] Embodiment 2

[0053] The final carbon content of the furnace is 0.0572%, the final temperature is 1631℃, 80kg of carbon powder is added from refining before tapping, 120kg of carbon powder is added during the tapping process, and all the addition is completed 30s after tapping. The inlet composition of this furnace is 0.1956%, the tapping amount is 119.6t, and the recarburizer recovery rate is 65.8%.

[0054] The final carbon content of the furnace is 0.0367%, the final temperature is 1630℃, 80kg of carbon powder is added by refining before tapping, 160kg of carbon powder is added during the tapping process, and it is added 30s to 90s after tapping. The inlet composition of this furnace is 0.2006%, the tapping amount is 117.03t, and the recarburizer recovery rate is 67.7%.

[0055] The final carbon content of the furnace is 0.0382%, the final temperature is 1636℃, 80kg of carbon powder is added from refining before tapping, 140kg of carbon powder is added during the tapping process, and the carbon powder is added 90s after tapping. The inlet composition of this furnace is 0.2146%, the tapping amount is 114.57t, and the recarburizer recovery rate is 66.3%.

[0056] Embodiment 3

[0057] The final carbon content of the furnace is 0.0839%, the final temperature is 1623℃, 80kg of carbon powder is added by refining before steel tapping, and 80kg of carbon powder is added during the steel tapping process, and it is added 30s before steel tapping. The carbon content of this furnace entering the station is 0.2122%, the steel tapping amount is 120.63t, and the recarburizer recovery rate is 75.9%.

[0058] The final carbon content of the furnace is 0.0976%, and the final temperature is 1627℃. 80kg of carbon powder is added by refining before tapping, and 60kg of carbon powder is added during the tapping process. The addition is completed 30 to 90s after tapping. The carbon content of the furnace entering the station is 0.1934%, the tapping amount is 118.9t, and the recarburizer recovery rate is 76.6%.

[0059] The final carbon content of the furnace is 0.0854%, the final temperature is 1618℃, 80kg of carbon powder is added from refining before tapping, and 80kg of carbon powder is added during the tapping process, 90s after tapping. The carbon content of this furnace entering the station is 0.2366%, the tapping amount is 118.3t, and the recarburizer recovery rate is 74.7%.

[0060] Embodiment 4

[0061] The final carbon content of the furnace is 0.1411%, the final temperature is 1636℃, 80kg of carbon powder is added from refining before steel tapping, 40kg of carbon powder is added during the steel tapping process, and all the addition is completed within 30s before steel tapping. The inlet composition of this furnace is 0.2258%, the steel tapping amount is 121.3t, and the recarburizer recovery rate is 75.6%.

[0062] The final carbon content of the furnace is 0.1198%, the final temperature is 1610℃, 80kg of carbon powder is added by refining before tapping, 40kg of carbon powder is added during the tapping process, and it is added 30s to 90s after tapping. The inlet composition of this furnace is 0.2155%, the tapping amount is 121.3t, and the recarburizer recovery rate is 76.4%.

[0063] The final carbon content of the furnace is 0.1232%, the final temperature is 1619℃, 80kg of carbon powder is added from refining before tapping, 20kg of carbon powder is added during the tapping process, and it is added 90s after tapping. The inlet composition of this furnace is 0.2171%, the tapping amount is 121.2t, and the recarburizer recovery rate is 75.3%.

Claims

1. A feeding method for improving the recovery rate of converter carbon powder, characterized in that: Carbon powder is added during the steel-tapping process of converter smelting, and is added 30 seconds before or more than 30 seconds after steel-tapping, depending on the final carbon content and whether overoxidation occurs.

2. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is less than 0.06% and the steel is overoxidized, the carbon powder is added 30 seconds before steel tapping.

3. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is less than 0.06% and the steel is overoxidized, the carbon powder is added completely 30s to 90s after steel tapping.

4. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is less than 0.06% and the steel is overoxidized, carbon powder is added 90 seconds after steel tapping.

5. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is between 0.06% and 0.10%, the carbon powder is added 30 seconds before steel tapping.

6. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is between 0.06% and 0.10%, the carbon powder is added completely within 30s to 90s of steel tapping.

7. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is between 0.06% and 0.10%, carbon powder is added 90 seconds after steel tapping.

8. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is greater than 0.10%, the carbon powder is added 30 seconds before steel tapping.

9. The method for increasing the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is greater than 0.10%, the carbon powder is added completely 30s to 90s after steel is tapped.

10. The feeding method for improving the recovery rate of converter carbon powder according to claim 1, characterized in that: When the final carbon content is greater than 0.10%, carbon powder is added 90 seconds after steel tapping.

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