气化脱磷机理及对下炉次冶炼过程的影响研究
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摘要
为了解决转炉渣由于磷含量过高而不能返回到转炉内循环利用的问题,采用FactSage7.2并结合SEM+EDS对气化脱磷理论和影响因素、留渣操作和枪位控制对脱磷的影响以及气化脱磷渣形貌进行了分析。结果表明,在温度高于941 K时用C还原出炉渣中P_2O_5的P是可行的,同时降低反应分压有利于气化脱磷反应的进行;采用焦粉作为还原剂时,碳当量和底吹流量分别控制为2倍碳当量和300 m~3/h时气化脱磷效果最好;当底吹流量为300 m~3/h、2倍碳当量和w(FeO)≥18%时气化脱磷率最高,为42%。采用留渣操作溅渣护炉气化脱磷模式时终点钢液磷含量较低,前期采用稍高的吹炼枪位,后期逐渐降低枪位,气化脱磷渣形貌结构表明P元素主要富集在Ca、Si所在的深灰色区域。
In order to solve the problem that BOF slag can not be returned back into BOF due to its high P content,the dephosphorization mechanism of gasification and influencing factors,effect of slag remaining operation and lance controlling on dephosphorization,and morphology of gasification dephosphorization slag were analyzed by FactSage7.2 and SEM+EDS in this paper.The result shows that it is feasible to use C to reduce P of P_2O_5 for slag when temperature exceeding 941 K,and it is beneficial to the gasification dephosphorization reaction by reducing the reaction partial pressure.While taking coke powder as a reducing agent,the best results of gasification dephosphorization were obtained when the carbon equivalent and bottom blowing flow were controlled at 2 times the carbon equivalent and 300 m~3/h,respectively.Gasification dephosphorization rate can reach a maximum value of 42% when bottom blowing flow,carbon equivalent,FeO content are 300 m~3/h、2 times and≥18%.When using slag remaining operation for gasification dephosphorization mode of splashing furnace protection,where higher blowing lance operation at the early stage and gradually lower high and low blowing lance operation at later stage,the phosphorus content of molten steel at the end is relatively low.SEM observation on morphology structure of gasification dephosphorizationslag indicated that P mainly concentrated in enriched Ca and Si areas.
In order to solve the problem that BOF slag can not be returned back into BOF due to its high P content,the dephosphorization mechanism of gasification and influencing factors,effect of slag remaining operation and lance controlling on dephosphorization,and morphology of gasification dephosphorization slag were analyzed by FactSage7.2 and SEM+EDS in this paper.The result shows that it is feasible to use C to reduce P of P_2O_5 for slag when temperature exceeding 941 K,and it is beneficial to the gasification dephosphorization reaction by reducing the reaction partial pressure.While taking coke powder as a reducing agent,the best results of gasification dephosphorization were obtained when the carbon equivalent and bottom blowing flow were controlled at 2 times the carbon equivalent and 300 m~3/h,respectively.Gasification dephosphorization rate can reach a maximum value of 42% when bottom blowing flow,carbon equivalent,FeO content are 300 m~3/h、2 times and≥18%.When using slag remaining operation for gasification dephosphorization mode of splashing furnace protection,where higher blowing lance operation at the early stage and gradually lower high and low blowing lance operation at later stage,the phosphorus content of molten steel at the end is relatively low.SEM observation on morphology structure of gasification dephosphorizationslag indicated that P mainly concentrated in enriched Ca and Si areas.
引文
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[3] JungS,DoY,ChoiJ.Reduction behavior of BOF type slags by solid carbon[J].Steel Research International,2006,77(5): 305-311.
[4] Ai Liqun,Zhang Yanlong,Zhu Yiheng.Research on carbothermic reduction for dephosphorization from converter slag by microwave heating[J].Iron Steel Vanadium Titanium,2015,36(6): 63-67.(艾立群,张彦龙,朱祎姮.微波碳热还原转炉钢渣脱磷研究[J].钢铁钒钛,2015,36(6):63-67.)
[5] Yao Hongyong.Effect of slag splashing on gasification dephosphorization in converter[J].Iron Steel Vanadium Titanium,2017,38(6): 108-112.(么洪勇.转炉溅渣护炉冶炼因素对气化脱磷的影响[J].钢铁钒钛,2017,38(6):108-112.)
[6] Hao Huaqiang,Wang Shuhuan,Zhang Chaofa,et al.Dephosrization and recycle utilization practice of moltenslag in converter[J].China Metallurgy,2018,28(6): 56-58.(郝华强,王书桓,张朝发,等.转炉热态熔渣脱磷及循环利用生产实践[J].中国冶金,2018,28(6):56-58.)
[7] Xue Yuekai,Wang Shuhuan,Li Chenxiao,et al.Experimental study on recycle utilization of slag after gasification dephosphorization in 60 t converter[J].Steelmaking,2018,34(1): 20-24.(薛月凯,王书桓,李晨晓,等.60 t转炉炉渣气化脱磷后循环利用试验研究[J].炼钢,2018,34(1):20-24.)
[8] Wei Shoukun.Metallurgical process thermodynamics[J].Beijing: Beijing Science Press,2010.(魏寿坤.冶金过程热力学[M].北京:科学出版社,2010.)
[9] Huang Xihu.Principles of iron and steel metallurgy ( 3rd edition) [J].Beijing: Metallurgical Industry Press,2004.(黄希祜.钢铁冶金原理(第3版)[M].北京:冶金工业出版社,2004.)
[10] Zhou Chaogang,Wang Shuhuan,Wang Wenhui,et al.Study on dephosphorization technology in converter with high scrap ratio[J].Iron Steel Vanadium Titanium,2017,38(5): 123-128.(周朝刚,王书桓,王文辉,等.基于高废钢比的转炉脱磷工艺研究[J].钢铁钒钛,2017,38(5):123-128.)
[11] Han Xiao,Zhou Chaogang,Li Jing,et al.Effect of phase structure of converter dephosphorization slag on dephosphorization[J].Journal of Iron and Steel Research,2016,28(9): 40-49.(韩啸,周朝刚,李晶,等.转炉脱磷渣物相结构对脱磷的影响[J].钢铁研究学报,2016,28(9):40-49.)