摘要
从热力学角度理论分析了硅、锰和碳的竞争氧化反应;并结合现场统计数据,研究了影响转炉终点钢水余锰含量的因素。结果显示:铁水中硅含量的增加会导致渣量明显增加,进而降低渣中MnO的浓度和活度,加速Mn的氧化,降低锰的收得率;铁水中锰含量升高将提高锰的活度,锰氧化量越大,使锰收得率越低;终点碳含量增加将提高碳活度,促使碳还原MnO反应进行,因此提高终点碳含量可以有效提高余锰含量;锰的直接氧化和间接氧化均为放热反应,因此随出钢温度的升高,终点锰的收得率会逐渐升高;随炉渣中FeO含量增加,钢水中被FeO间接氧化的Mn量增加,使终点锰回收率明显降低;随着炉渣碱度升高,炉渣中自由(MnO)增加,有利于锰的还原反应,即钢水中锰含量增加。但是渣中CaO过量使渣量增加,反而降低了渣中MnO浓度,同时造成熔渣黏度增加,影响还原反应动力学;控制铁水硅含量≤0.30%,锰含量0.50%~0.60%,终点碳0.10%~0.18%(中高碳钢),温度1635~1660℃,渣中全铁≤13%,碱度3.0~3.5,渣量≤50 kg/t,渣中MnO浓度为6%~9%,有利于提高转炉终点余锰含量。
The competitive oxidation reactions of silicon,manganese and carbon were theoretically analyzed from the thermodynamic perspective.Combined with the on-site statistical data,the factors influencing the residual manganese content of the molten steel at the end of the converter were studied.The results show that the increase of silicon content in molten iron will lead to a significant increase in the amount of slag,thereby reducing the concentration and activity of MnO in the slag,accelerating the oxidation of Mn,and reducing the yield of manganese.The increase of manganese content in molten iron will enhance the activity of manganese.The greater the amount of manganese oxidation,the lower the yield of manganese.An increase in the endpoint carbon content will enhance the carbon activity and promote the carbon reduction manganese oxide reaction.Therefore,increasing the endpoint carbon content can effectively increase the residual manganese content.Both the direct oxidation and indirect oxidation of manganese are exothermic reactions.Therefore,as the steel tapping temperature increases,the yield of manganese at the end point will gradually increase.With the increase of FeO content in the slag,the amount of Mn indirectly oxidized by FeO in the molten steel increases,significantly reducing the manganese recovery rate at the end point.As the alkalinity of the slag increases,the free(MnO)content in the slag also increases,which is conducive to the reduction reaction of manganese,that is,the manganese content in the molten steel increases.However,excessive CaO in the slag increases the amount of slag,which instead reduces the concentration of MnO in the slag.At the same time,it causes an increase in the viscosity of the slag,affecting the kinetics of the reduction reaction.Controlling the silicon content of the molten iron to be not more than 0.30%,the manganese content to be 0.50%to 0.60%,the final carbon content to be 0.10%to 0.18%(medium and high carbon steel),the temperature to be 1635 to 1660℃,the total iron content in the slag to be not more than 13%,the alkalinity to be 3.0 to 3.5,the slag volume to be not more than 50 kg/t,and the MnO concentration in the slag to be 6%to 9%is conducive to increasing the residual manganese content at the end of the converter.
作者
史柱
张龙
郑亚旭
王波
张迪
冯捷
Shi Zhu;Zhang Long;Zheng Yaxu;Wang Bo;Zhang Di;Feng Jie(Steelmaking Plant of Tongling Fuxin Steel Co.,Ltd.,Tongling 244000,Anhui;Technology Center of Shanxi Jinnan Iron and Steel Group Co.,Ltd.,Linfen 041000,Shanxi;School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,Hebei)
出处
《河北冶金》
2025年第5期32-36,96,共6页
Hebei Metallurgy
基金
国家自然科学基金(52204341,52174311)
中国博士后科学基金(2023M740415)
河北省面上基金(E2024208002)。
关键词
转炉
终点控制
硅含量
终点温度
炉渣碱度
收得率
余锰含量
converter
endpoint control
silicon content
endpoint temperature
slag alkalinity
yield rate
residual manganese content
