1. Oxygen supply intensity
Oxygen consumption per ton of steel per unit time, generally 3.2m ³/ (t·min)~4.5m ³/ (t · min), take the middle and lower limit for converter below 100t and the upper limit for converter above 100t. The oxygen supply intensity represents the unit of converter smelting efficiency. At present, Wuxi xinsanzhou and Yangchun new iron and Steel Co., Ltd. have the best smelting speed in small converter in China, and the pure oxygen supply time is about 10min. The professional group with the best performance in large converter in China has a pure oxygen supply time of 12min ~ 13min. Representative formula: I = q (oxygen flow) / [t (tapping quantity) · t (pure oxygen supply time)].
2. Converter loading
Molten iron + scrap steel (pig iron), furnace capacity ratio 0.65t/m ³~ 0.90t/m ³, The volume ratio of converter below 100t takes the middle and lower limit, and the volume ratio of converter above 100t takes the middle and upper limit. It is a noun of converter tapping load.
3. Impact area
The area of the oxygen stream in contact with the calm metal surface. The impact area is related to the oxygen lance position of the converter and the process parameters of the oxygen lance (oxygen lance roar diameter and expansion angle). Generally, the impact area accounts for 60% - 80% of the whole upper surface area. If it erodes the furnace lining too much, the lower limit is taken for the converter below 100t and the upper limit is taken for the converter above 100t. The impact area also affects the smelting speed of the converter, but the safety of the furnace lining must be considered in the design.
4. Lime addition
The amount of lime consumed per ton of steel is also a key term affecting the smelting cost of converter. The calculation formula (as follows) is that on the premise of ensuring the safety of furnace lining and the quality of molten steel, domestic steel mills are pursuing the best low slag smelting mode. Some steel mills establish the smelting model with auxiliary gun or low slag, control the addition of lime and slag with model design, and the auxiliary gun is well done by Danieli and Wuhan chuangte, The best data models are Anhui University of technology and Beijing University of science and technology. The silicon content of converter molten iron is 0.20% ~ 0.40%. Through the calculation of less slag model data, lime is 20kg / t-40kg / T, which solves a lot of costs for the steel plant.
two point one four × [Si%] × R
Q＝———————— × W molten iron
(Cao%) effective
Where Q: lime addition (ton / furnace); R: Alkalinity; [Si%]: silicon composition of molten iron; (Cao%): effective CaO content of lime; (Cao%) effective = lime Cao% － R × Lime SiO2% remarks: the effective content of metallurgical lime (Cao%) is calculated as 75%, and the effective content of active lime (Cao%) is calculated as 90%.
