Industrial practice of deep dephosphorization technology with less slag in converter
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摘要: 在梅钢250 t转炉上进行了脱磷期少渣深脱磷工业实践，研究了冶炼温度、炉渣成分、吹炼制度等参数对脱磷的影响规律。实践表明，转炉冶炼脱磷期结束时适宜的熔池温度为1 370～1 420 ℃、炉渣碱度为1.3～1.8、渣中FeO含量为18%～28%；合适的吹氧量为总氧气流量的24%～28%、废钢比为12%～16%、底吹孔数在8个以上；改进后，梅钢转炉冶炼脱磷期的平均脱磷率由不足50%提高至63.2%，实现了少渣工艺的稳定运行，2012年至2019年，少渣冶炼比例由0提高至83.7%，吨钢石灰消耗由53.3 kg降低至23.2 kg，降低了56.5%。Abstract: In this paper, the industrial practice of deep dephosphorization with less slag in dephosphorization period was carried out on 250 ton converter of Meigang. The effects of smelting temperature, slag composition and blowing system on phosphorus content in molten steel were studied. The practice shows that at the end of the dephosphorization period of converter smelting, the appropriate bath temperature is 1370～1420 ℃, the basicity of slag is 1.3～1.8, and the FeO content in slag is 18%～28%; The suitable oxygen blowing amount in the dephosphorization period of converter smelting is 24%～28% of the total oxygen flow, the scrap ratio is controlled at 12%～16%, and the number of bottom blowing holes is more than 8. Through above parameters optimization, average dephosphorization rate in converter smelting dephosphorization period of Meigang was increased from less than 50% to 63.2%, and finally achieved stable operation of the less slag process. During period from year 2012 to 2019, the less slag smelting proportion was increased from 0 to 83.7%, and the lime consumption per ton of steel was reduced from 53.3 kg to 23.2 kg, decrease by 56.5%.
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Key words:
- converter /
- less slag smelting /
- dephosphorization
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图 1 转炉脱磷期熔池温度对脱磷率的影响
Figure 1. Effect of bath temperature on dephosphorization rate during dephosphorization of converter
图 4 废钢比对矿石用量和脱磷率的影响
Figure 4. Effect of scrap ratio on ore dosage and dephosphorization rate
图 5 底吹孔数与脱磷率的关系
Figure 5. Relationship between the number of bottom blowing holes and dephosphorization rate
图 6 2012～2019年梅钢转炉少渣冶炼比例及吨钢石灰消耗变化
Figure 6. The relationship between ratio of less slag smelting and consumption of lime per ton steel in Meigang from year 2012～2019
表 1 梅钢250 t转炉冶炼参数
Table 1. Smelting parameters of 250 t converter in Meigang
氧枪马赫数 氧枪喷孔/个 氧枪供氧强度/(m3·t−1·min−1) 底吹孔数/个 底吹供气强度/(m3·t−1·min−1) 废钢比/% 2.05～2.10 5 3.4～3.6 12 0.03～0.10 0～25 
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表 2 铁水成分
Table 2. Hot metal compositions
w/% 温度/℃ C Si Mn P S 4.3～4.7 0.1～0.8 0.14～0.20 0.1～0.14 0.013～0.065 1200～1450
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表 3 转炉主要渣料成分
Table 3. Compositions of main slag material for converter
名称 w/% 烧损/% CaO SiO2 MgO TFe 石灰 88～95 2～5 3～8 轻烧白云石 55～60 2～5 34～40 4～10 矿石 3～5 62～65 2～9
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表 4 典型半钢钢水成分
Table 4. Typical molten steel composition of semi steel
% C Si Mn P S 2.8 0.012 0.052 0.055 0.009
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表 5 典型脱磷渣成分
Table 5. Typical dephosphorization slag composition
% CaO SiO2 Al2O3 Fe2O3 MnO MgO P2O5 36.28 21.27 2.17 18.75 5.76 6.54 4.46
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