Dephosphorization behavior of molten steel based on high FeO converter slag
ZHOU Chao-gang1,2, HU Jin-zhen1, CHEN Hu3, AI Li-qun1,2, ZHAO Chang-liang3, WANG Shu-huan1,2
1. College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, Hebei, China; 2. Tangshan Special Metallurgy and Material Preparation Laboratory, Tangshan 063210, Hebei, China; 3. Steelmaking Department, Shougang Jingtang United Iron and Steel Co., Ltd., Tangshan 063200, Hebei, China
Abstract：In order to study the dephosphorization behavior of molten steel under the condition of high FeO converter slag, the industrial test of dephosphorization with high oxidizing converter slag was carried out on a 300 t dephosphorization converter of a steel plant by the duplex method. The influence of dephosphorization temperature, phase structure of converter slag and final slag composition on the dephosphorization of molten steel under high FeO converter slag was studied by means of theoretical analysis and XRD and Raman spectrum analysis. Through thermodynamic formula calculation, it is found that the optimal theoretical dephosphorization temperature of the converter is about 1 675 K. The mineral phase structures of the converter slag with different dephosphorization effects were compared and analyzed. The results showed that the mineral phase structures of 2CaO·SiO2 and 3CaO·P2O5 were conducive to the dephosphorization reaction, while the influence of 3CaO·SiO2 on the dephosphorization effect was not obvious. The larger the characteristic peak area of Si—O—Si and [FeO4], the smaller the characteristic peak area of Q0 and Q2 units, the better the dephosphorization effect. Finally, the optimum process parameters for controlling the final slag composition when the dephosphorization rate of molten steel in dephosphorization furnace is ≥60% are as follows, basicity R=1.05-1.30, w([FeO])=33%-37%, w([MgO])≤3.0%, w([MnO]) =4.3%-5.4%. This study can provide a theoretical basis and technical guidance for iron and steel enterprises to develop ultra-low phosphorus steel by the double method.
周朝刚, 胡锦榛, 陈虎, 艾立群, 赵长亮, 王书桓. 基于高FeO转炉渣的钢液脱磷行为[J]. 钢铁, 2021, 56(7): 63-74.
ZHOU Chao-gang, HU Jin-zhen, CHEN Hu, AI Li-qun, ZHAO Chang-liang, WANG Shu-huan. Dephosphorization behavior of molten steel based on high FeO converter slag[J]. Iron and Steel, 2021, 56(7): 63-74.
[1] 曾加庆, 杨利彬, 王杰, 等. 底吹搅拌对复吹转炉脱磷工艺的作用分析[J]. 钢铁, 2017, 52(6): 40.(ZENG Jia-qing, YANG Li-bin, WANG Jie, et al. Effect of bottom blowing on dephosphorization technology in combined blowing converter[J]. Iron and Steel, 2017, 52(6): 40.) [2] WANG Zhou, XIE Fei-ming, WANG Bin, et al. The control and prediction of end-point phosphorus content during BOF steelmaking process[J]. Steel Research International, 2014, 85(4): 599. [3] YANG Xiao, SUN Feng-Mei, YANG Jin-li, et al. Optimization of low phosphorus steel production with double slag process in BOF[J]. Journal of Iron and Steel Research, International, 2013, 20(8): 41. [4] ZHU Li-juan, GU Zheng-wei, XU Hong, et al. Modeling of microstructure evolution in 22MnB5 steel during hot stamping[J]. Journal of Iron and Steel Research, International, 2014, 21(2): 197. [5] Ogasawara Y, Miki Y, Uchida Y, et al. Development of high efficiency dephosphorization system in decarburization converter utilizing FetO dynamic control[J]. ISIJ International, 2013, 53(10): 1786. [6] Iwsaki M, Matsuo M. Change and development of steel-making technology[J]. Nippon Steel Technical Report, 2011, 391: 88. [7] Kawamoto M. Recent development of steelmaking process in sumitomo metals[J]. Journal of Iron and Steel Research, International, 2011, 18(s2): 28. [8] 徐匡迪, 肖丽俊. 转炉铁水预处理脱磷的基础理论分析[J]. 上海大学学报(自然科学版),2011, 17(4): 331.(XU Kuang-di, XIAO Li-jun. Theoretical analysis of hot metal dephosphorization pretreatment in converter[J]. Journal of Shanghai University(Natural Science),2011, 17(4): 331.) [9] 康复, 陆志新, 蒋晓放, 等. 宝钢BRP技术的研究与开发[J]. 钢铁, 2005,40(3): 25.(KANG Fu, LU Zhi-xin, JIANG Xiao-fang, et al. Research and development of BRP technology at Baosteel[J]. Iron and Steel, 2005,40(3): 25.) [10] WU Wei, DAI Shi-fan, LIU Yue. Dephosphorization stability of hot metal by double slag operation in basic oxygen furnace[J]. Journal of Iron and Steel Research, International, 2017, 24(9): 908. [11] LÜ M, ZHU R,WANG H, et al. Simulation and application of swirl-type oxygen lance in vanadium extraction converter[J]. Steel Research International, 2013, 84(3): 304. [12] Kikuchi N, Matsui A, Uchida Y I. Effect of lime dissolution rate in slag on hot metal dephosphorization[J]. ISIJ International, 2020, 60(5): 922. [13] Kitamura S Y, Saito S, Utagawa K, et al. Mass transfer of P2O5 between liquid slag and solid solution of 2CaO center dot SiO2 and 3CaO center dot P2O5[J]. ISIJ International, 2009, 49(12): 1838. [14] Ogawa Y, Yano M, Kitamura S, et al. Development of the continuous dephosphorization and decarburization process using BOF[J]. Tetsu-to-Hagane, 2001, 87(1): 21. [15] WANG Ming-lin, YANG Wen-yuan. Dephosphorization in the early stage of converter steelmaking[J]. Ironmaking and Steelmaking, 2019(6): 1. [16] 白雪峰, 张一民, 孙彦辉, 等. 转炉双联炼钢工艺热态渣再利用脱磷的工业试验[J]. 炼钢, 2018, 34(5): 31.(BAI Xue-feng, ZHANG Yi-min, SUN Yan-hui, et al. Research on recycling of hot slag in dephosphorization furnace of duplex process[J]. Steelmaking, 2018, 34(5): 31.) [17] 赵雷, 王金辉, 徐国义, 等. 260 t转炉冶炼极低磷钢的生产实践[J]. 炼钢, 2017, 33(6): 1.(ZHAO Lei, WANG Jin-hui, XU Guo-yi, et al. Production practice for super low phosphorus steel in 260 t converter[J]. Steelmaking, 2017, 33(6): 1.) [18] 王林珠,包燕平,李翔.转炉留渣双渣工艺两阶段脱磷对比[J].钢铁,2019,54(8):37.(WANG Lin-zhu, BAO Yan-ping, LI Xiang. Comparison of two-stage dephosphorization during remaining slag-double slag process in converter[J]. Steelmaking, 2019,54(8):37.) [19] WANG Yang, YANG Shu-feng, LI Jing-she, et al. Dephosphorization by double-slag process in converter steelmaking[J]. High Temperature Materials and Processes, 2017, 37(7):625. [20] 孙立根,郝剑桥,朱立光, 等.转炉冶炼高磷高带渣量铁液脱磷工艺研究[J].铸造技术,2018,39(5):1018.(SUN Li-gen, HAO Jian-qiao, ZHU Li-guang, et al. Process of dephosphorization of molten iron with high phosphorus and slag in converter smelting[J].Foundry Technology, 2018,39(5):1018.) [21] Kitamura S, Shibata H, Shimauchi K, et al. The importance of dicalcium-silicate on hot metal dephosphorization reaction[J]. Metallurgical Research and Technology, 2008, 105(5): 263. [22] 董文亮,潘宏伟,罗磊, 等.磷在多相脱磷转炉渣中的分布[J].钢铁,2020,55(2):75.(DONG Wen-liang, PAN Hong-wei, LUO lei, et al. Phosphorous distribution in dephosphorization slag[J]. Steelmaking,2020,55(2):75.) [23] LI Ming-ming, LI Qiang, ZOU Zong-shu, et al. Characterization of cavity oscillation and splashing distribution under excitation by bottom gas blowing in a steelmaking converter[J]. JOM, 2019, 71(2): 729. [24] LIU Fu-hai, SUN Dong-bai, ZHU Rong, et al. Effect of Side-blowing arrangement on flow field and vanadium extraction rate in converter steelmaking process[J]. ISIJ International, 2018, 58(5): 852. [25] ZHONG Liang-cai, ZHOU Xiao-bin, ZHU Ying-xiong. et al. Industrial experiment of steelmaking in a top-bottom-side blown converter with slag splashing process[J]. Steel Research International, 2012, 83(1): 16. [26] Naito K, Kitamura S, Ogawa Y. Effects of BOF top blowing and bottom stirring conditions on suppressing excessive oxidation[J]. Ironmaking and Steelmaking, 2002, 29(3): 208. [27] Tsukasaki A, Suzumura M, Nishijima W. Fractionation of phosphorus in steelmaking slags and aquatic particulate materials using a sequential extraction technique[J]. ISIJ International, 2015, 55(1): 183. [28] 周朝刚, 李晶, 武贺, 等. 转炉双渣脱磷一次倒渣温度研究[J]. 钢铁, 2014, 49(3): 24.(ZHOU Chao-gang, LI Jing, WU He, et al. Study on the temperature of first deslagging of double slag dephosphorization in converter[J]. Iron and Steel, 2014, 49(3): 24.) [29] 王杰,曾加庆,杨利彬. 复吹转炉双渣法脱磷冶炼工艺一次倒炉温度最优化选择[J].炼钢,2015,31(4):34.(WANG Jie, ZENG Jia-qing, YANG Li-bin. Optimal choice of the first turndown temperature of BOF double slag dephosphorization process [J]. Steelmaking, 2015,31(4):34.) [30] 汪成义,杨利彬,林腾昌, 等. 顶底复吹转炉双渣冶炼“脱磷窗口”温度控制模型[J].特殊钢,2017,38(6):1.(WANG Cheng-yi,YANG Li-bin, LIN Teng-chang, et al. Temperature control model for "dephosphorization window" of double slag process of top and bottom combined converter [J]. Special Steel, 2017,38(6):1.) [31] 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.(HAN Xiao, ZHOU Chao-gang, 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.) [32] ZHOU C G, LI J, SHI C B, et al. Dependence of temperature and slag composition on dephosphorization at the first deslagging in BOF steelmaking process[J]. High Temperature Materials and Processes, 2016, 35(4):433. [33] 吕宁宁, 苏畅, 杨金星, 等. CaO-SiO2-FeO-P2O5-Al2O3脱磷渣系中组元活度的计算[J]. 材料与冶金学报, 2017, 16(3): 171.(LÜ Ning-ning, SU Chang, YANG Jin-xing, et al. Activity calculation of components in CaO-SiO2-FeO-P2O5-Al2O3 dephosphorization slag[J]. Journal of Materials and Metallurgy, 2017, 16(3): 171.) [34] 苏畅, 梁素英, 杨金星, 等. CaO-SiO2-FeO-MgO-P2O5脱磷渣系中组元活度的计算[J]. 现代冶金, 2019, 47(3): 16.(SU Chang, LIANG Su-ying, YANG Jin-xing, et al. Calculation of component activity in CaO-SiO2-FeO-MgO-P2O5 dephosphorization slag system[J]. Modern Metallurgy, 2019, 47(3): 16.) [35] 张蕊, 闵义, 王宇, 等. 冶炼前期转炉渣熔体结构的转变行为[J]. 钢铁, 2019, 54(7): 30.(ZHANG Rui, MIN Yi, WANG Yu, et al. tructural transformation of converter slags during early stage of smelting process[J]. Iron and Steel, 2019, 54(7): 30.) [36] Heikkinen E P, Fabritius T M J, Kokkonen T M T, et al. An experimental and computational study on the melting behaviour of AOD and chromium converter slags[J]. Steel Research International, 2004, 75(12):800. [37] Kozhukhov A A. Influence of the viscosity and melting point of converter slag on its foaming behavior[J]. Steel in Translation, 2014, 44(2): 136. [38] 周振宇, 唐萍, 侯自兵, 等. w(SiO2)/w(V2O3)对含钒炉渣熔化温度及黏度的影响[J]. 钢铁研究学报, 2019, 31(5): 446.(ZHOU Zhen-yu, TANG Ping, HOU Zi-ping, et al. Effect of w (SiO2)/w(V2O3) on melting and viscosity properties of vanadium slag[J]. Journal of Iron and Steel Research, 2019, 31(5): 446.) [39] 智建国, 吴伟, 高琦, 等. 大型转炉优化造渣工艺提高脱磷的效果[J]. 钢铁, 2020, 55(7): 72.(ZHI Jian-guo, WU Wei, GAO Qi, et al. Effect of improving dephosphorization of molten steel by optimizing slagging in large converters[J]. Iron and Steel, 2020, 55(7): 72.)
[40] 王雨墨, 陶林, 郭皓宇, 等. 转炉铁水预处理脱磷的影响因素[J]. 钢铁, 2020, 55(9): 29.(WANG Yu-mo, TAO Lin, GUO Hao-yu, et al. Dephosphorization influence factors in converter hot metal pretreatment[J]. Iron and Steel, 2020, 55(9): 29.) [41] 李帅. 120 t转炉高磷铁水冶炼高碳低磷钢生产实践[J]. 中国冶金, 2017, 27(8): 28.(LI Shuai. Production practice of high carbon and low phosphorus steel by high phosphorus hot metal in 120 t converter[J]. China Metallurgy, 2017, 27(8): 28.) [42] 周朝刚, 杨会泽, 艾立群, 等. 转炉含磷钢渣循环利用技术的研究现状及展望[J]. 钢铁, 2021, 56(2): 22. (ZHOU Chao-gang, YANG Hui-ze, AI Li-qun, et al. Research status and prospect of recycling technology of converter slag containing phosphorus[J]. Iron and Steel, 2021, 56(2): 22.) [43] 叶玉奎, 王向红, 秦福同, 等. 复吹转炉双渣脱磷工艺实践[J]. 中国冶金, 2018, 28(1): 40. (YE Yu-kui, WANG Xiang-hong, QIN Fu-tong, et al. Practice of double-slag dephosphorization technology for combined blown converter[J]. China Metallurgy, 2018, 28(1): 40.) [44] 杨利彬, 曾加庆, 邓勇, 等. 大型转炉高效率、长寿命顶底复合吹炼技术[J]. 钢铁, 2020, 55(4): 45.(YANG Li-bin, ZENG Jia-qing, DENG Yong, et al. Highly efficiency and long-life combined blowing technology of big converter[J]. Iron and Steel, 2020, 55(4): 45.) [45] 李晨晓, 王书桓, 薛月凯, 等. 焦粉还原转炉熔渣气化脱磷试验[J]. 钢铁, 2018, 53(9): 20. (LI Chen-xiao, WANG Shu-huan, XUE Yue-kai, et al. Experiment on gasification dephosphorization with coke powder reducing converter molten slag [J]. Iron and Steel, 2018, 53(9): 20.)
2021, Vol. 56 
