MgO对含钛烧结矿矿相结构及软熔滴落性能的影响
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摘要
为了深入探究MgO对烧结矿矿物组成及冶金性能的影响,采用扫描电子显微镜和荷重软化熔滴设备研究了MgO对含钛烧结矿矿相结构与软熔滴落性能影响.实验结果表明,随着烧结料中MgO质量分数从2.04%增加到3.96%,烧结过程液相生成量逐渐减少,烧结矿中的赤铁矿和铁酸钙等含量都有不同程度的降低,赤铁矿质量分数从13.57%降低到9.99%,铁酸钙的质量分数由38.7%降低到30.17%,磁铁矿、硅酸盐和烧结矿中的孔洞逐步增加.因此,增加烧结矿中MgO会降低烧结矿中液相生成量,不利于烧结矿转鼓强度和还原性的提高.高碱度含钛烧结矿中的镁主要分布于烧结矿中复合铁酸钙相中,进一步提高烧结矿中镁的质量分数,烧结矿的磁铁矿相比例将增加,有一部分镁固溶于磁铁矿中;在高镁烧结矿中,也会形成一定量的橄榄石,其中固溶有少量镁、钛等元素.随着烧结矿中MgO质量分数的增加,开始软化温度逐渐升高,试样软化开始温度均在1120℃以上,软化温度区间ΔtA随着MgO含量的升高而逐渐变宽.
Certain requirements regarding the chemical composition of slag have to be satisfied to perform a stable blast furnace operation. Particularly,the ratio of MgO to Al2 O3 in the slag is observed to have a significant influence on the fluidity and desulfurization ability of the slag,along with the the stability of the blast furnace. However,the amount of MgO in the ore could not satisfy the smelting requirement of the blast furnace. Thus,Mg-containing flux has to be added into the ferrous burden. In the ferrous burden structure of the blast furnace that is observed in China,sinter generally accounts for more than 70%. Therefore,the effects of various concentrations of MgO on the quality of sinter are of great significance and must be investigated in further detail. In this study,the influence of MgO on the mineral structure and softening-melting property of Ti-containing sinter were investigated using scanning electronic microscopy(SEM)-energy dispersive spectrometer(EDS) and drop testing. The results depict that increasing the concentration of MgO from2. 04% to 3. 96% results in a decrease in the contents of hematite and complex calcium ferrite in the sinter,whereas there is an increase in the mass of liquid phase,magnetite,and silicate. Further,the pore size also gradually increases. Additionally,the hematite content reduces from 13. 57% to 9. 99%,and the complex calcium ferrite in sinter reduces from 38. 7% to 30. 17%. Therefore,the increase of MgO in sinter is unfavorable for the development of a liquid phase,which depicts a negative effect on the tumbler strength and reduction index of sinter. Mg in sinter is mainly distributed in complex calcium ferrite. Further,an increase in the concentration of MgO causes a gradual increase in the concentration of magnetite. Additionally,it also causes a part of Mg to be dissolved in magnetite.An olivine solid solution,which contains a minor amount of Mg and Ti,can be observed in high-Mg sinter. Finally,by increasing the concentration of MgO in the sinter,the softening temperature can increase,which is observed to be greater than 1120 ℃. Further,the softening interval(ΔtA) of the sinter is observed to increase gradually with an increasing MgO content.
Certain requirements regarding the chemical composition of slag have to be satisfied to perform a stable blast furnace operation. Particularly,the ratio of MgO to Al2 O3 in the slag is observed to have a significant influence on the fluidity and desulfurization ability of the slag,along with the the stability of the blast furnace. However,the amount of MgO in the ore could not satisfy the smelting requirement of the blast furnace. Thus,Mg-containing flux has to be added into the ferrous burden. In the ferrous burden structure of the blast furnace that is observed in China,sinter generally accounts for more than 70%. Therefore,the effects of various concentrations of MgO on the quality of sinter are of great significance and must be investigated in further detail. In this study,the influence of MgO on the mineral structure and softening-melting property of Ti-containing sinter were investigated using scanning electronic microscopy(SEM)-energy dispersive spectrometer(EDS) and drop testing. The results depict that increasing the concentration of MgO from2. 04% to 3. 96% results in a decrease in the contents of hematite and complex calcium ferrite in the sinter,whereas there is an increase in the mass of liquid phase,magnetite,and silicate. Further,the pore size also gradually increases. Additionally,the hematite content reduces from 13. 57% to 9. 99%,and the complex calcium ferrite in sinter reduces from 38. 7% to 30. 17%. Therefore,the increase of MgO in sinter is unfavorable for the development of a liquid phase,which depicts a negative effect on the tumbler strength and reduction index of sinter. Mg in sinter is mainly distributed in complex calcium ferrite. Further,an increase in the concentration of MgO causes a gradual increase in the concentration of magnetite. Additionally,it also causes a part of Mg to be dissolved in magnetite.An olivine solid solution,which contains a minor amount of Mg and Ti,can be observed in high-Mg sinter. Finally,by increasing the concentration of MgO in the sinter,the softening temperature can increase,which is observed to be greater than 1120 ℃. Further,the softening interval(ΔtA) of the sinter is observed to increase gradually with an increasing MgO content.
引文
[1]Jiang D J,Lin Q G,He M G,et al.Industrial experimentation on influence of Mg O on sinter and BF slag smelting properties and technical parameters.China Metall,2010,20(1):35(蒋大军,林千谷,何木光,等.Mg O对烧结矿与高炉渣冶炼性能及工艺参数影响的试验.中国冶金,2010,20(1):35)
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[5]Jiang X.Study on Effect of Mg O Addition on Sinter Process and Sinter's Metallurgical Property[Dissertation].Shengyang:Northeastern University,2005(姜鑫.Mg O对烧结工艺及烧结矿冶金性能影响的研究[学位论文].沈阳:东北大学,2005)
[6]Yadav U S,Pandey B D,Das B K,et al.Influence of magnesia on sintering characteristics of iron ore.Ironmaking Steelmaking,2002,29(2):91
[7]Panigrahy S C,Verstraeten P,Dilewijns J.Influence of Mg O addition on mineralogy of iron ore sinter.Metall Trans B,1984,15(1):23
[8]Gan Q,He Q,Wen Y C.Study on influence of Mg O on mineral composition and metallurgical properties of V-bearing titaniferous magnetite sinter.Iron Steel,2008,43(8):7(甘勤,何群,文永才.Mg O对钒钛烧结矿矿物组成及冶金性能影响的研究.钢铁,2008,43(8):7)
[9]Gan Q,He Q,Wen Y C.Influence of Mg O content on productivity and quality of V-bearing titaniferous magnetite sinter.Iron Steel Vanadium Titanium,2008,29(1):54(甘勤,何群,文永才.Mg O对钒钛烧结矿产质量的影响.钢铁钒钛,2008,29(1):54)
[10]Zhou M,Yang S T,Jiang T,et al.Transference and influences of Mg O in sintering of Cr-bearing vanadium and titanium magnetite.Chin J Nonferrous Met,2014,24(12):3108(周密,杨松陶,姜涛,等.Mg O在含铬型钒钛烧结矿制备中的迁移及作用.中国有色金属学报,2014,24(12):3108)
[11]Liu R,Li H W,Li H J,et al.Effect of Mg O content on the quality of low-titanium sinter.Iron Steel Vanadium Titanium,2015,36(3):73(刘然,李红玮,李豪杰,等.Mg O含量对低钛烧结矿质量的影响.钢铁钒钛,2015,36(3):73)
[12]Li Z M,Liu L N,Duan S,et al.Influence of Mg O on structure of vanadium-titanium sinter.Iron Steel Vanadium Titanium,2014,35(3):69(李志民,刘丽娜,段珊,等.Mg O对含钛烧结矿矿相结构的影响.钢铁钒钛,2014,35(3):69)
[13]LüQ,Wang F J,Chen S J.Influence of Mg O content in sinter on droplet performance of vanadium-titanium burden.J Iron Steel Res,2016,28(9):24(吕庆,王福佳,陈树军.烧结矿Mg O含量对含钒钛炉料熔滴性能影响.钢铁研究学报,2016,28(9):24)
[14]Chen L J.Optimization on Softening-Dripping Behaviors of Blast Furnace Comprehensive Burdens for Vanadium-Titanium Magnetite Smelting[Dissertation].Shenyang:Northeastern University,2014(陈立杰.高炉冶炼钒钛磁铁矿综合炉料熔滴性能优化研究[学位论文].沈阳:东北大学,2014)
[15]Jin M F,Li G S,Chu M S,et al.Diffusion between Mg O and hematite during sintering.Iron Steel,2008,43(3):10(金明芳,李光森,储满生,等.烧结过程中Mg O在赤铁矿中的扩散行为的研究.钢铁,2008,43(3):10)
[16]Ren Y F,Jiang L Y,Wang S T.The existing state of Mg O and its effect on the properties of iron ore agglomerates.J Beijing Univ Iron Steel Technol,1983(4):1(任允芙,蒋烈英,王树同.Mg O在人造富矿中的赋存状态及作用.北京钢铁学院学报,1983(4):1)
[17]Wang Z,Zhang J L,Zuo H B,et al.Influence of Al2O3content on softening-melting property of high basicity sinter.Iron Steel,2015,50(7):20(王喆,张建良,左海滨,等.Al2O3质量分数对高碱度烧结矿软熔滴落性能影响.钢铁,2015,50(7):20)
[2]Umadevi T,Nelson K,Mahapatra P C,et al.Influence of magnesia on iron ore sinter properties and productivity.Ironmaking Steelmaking,2009,36(7):515
[3]Shi J S,Zhao J J,Pei Y D,et al.Shougang Jingtang natural magnesium sintering research and application//Proceedings of China Iron Annual Meeting.Zhengzhou,2014:364(石江山,赵景军,裴元东,等.首钢京唐自然镁烧结研究及应用//2014年全国炼铁生产技术会暨炼铁学术年会.郑州,2014:364)
[4]Wu S L,Han H L,Jiang W Z,et al.Mg O interaction mechanism in sinter.J Univ Sci Technol Beijing,2009,31(4):428(吴胜利,韩宏亮,姜伟忠,等.烧结矿中Mg O作用机理.北京科技大学学报,2009,31(4):428)
[5]Jiang X.Study on Effect of Mg O Addition on Sinter Process and Sinter's Metallurgical Property[Dissertation].Shengyang:Northeastern University,2005(姜鑫.Mg O对烧结工艺及烧结矿冶金性能影响的研究[学位论文].沈阳:东北大学,2005)
[6]Yadav U S,Pandey B D,Das B K,et al.Influence of magnesia on sintering characteristics of iron ore.Ironmaking Steelmaking,2002,29(2):91
[7]Panigrahy S C,Verstraeten P,Dilewijns J.Influence of Mg O addition on mineralogy of iron ore sinter.Metall Trans B,1984,15(1):23
[8]Gan Q,He Q,Wen Y C.Study on influence of Mg O on mineral composition and metallurgical properties of V-bearing titaniferous magnetite sinter.Iron Steel,2008,43(8):7(甘勤,何群,文永才.Mg O对钒钛烧结矿矿物组成及冶金性能影响的研究.钢铁,2008,43(8):7)
[9]Gan Q,He Q,Wen Y C.Influence of Mg O content on productivity and quality of V-bearing titaniferous magnetite sinter.Iron Steel Vanadium Titanium,2008,29(1):54(甘勤,何群,文永才.Mg O对钒钛烧结矿产质量的影响.钢铁钒钛,2008,29(1):54)
[10]Zhou M,Yang S T,Jiang T,et al.Transference and influences of Mg O in sintering of Cr-bearing vanadium and titanium magnetite.Chin J Nonferrous Met,2014,24(12):3108(周密,杨松陶,姜涛,等.Mg O在含铬型钒钛烧结矿制备中的迁移及作用.中国有色金属学报,2014,24(12):3108)
[11]Liu R,Li H W,Li H J,et al.Effect of Mg O content on the quality of low-titanium sinter.Iron Steel Vanadium Titanium,2015,36(3):73(刘然,李红玮,李豪杰,等.Mg O含量对低钛烧结矿质量的影响.钢铁钒钛,2015,36(3):73)
[12]Li Z M,Liu L N,Duan S,et al.Influence of Mg O on structure of vanadium-titanium sinter.Iron Steel Vanadium Titanium,2014,35(3):69(李志民,刘丽娜,段珊,等.Mg O对含钛烧结矿矿相结构的影响.钢铁钒钛,2014,35(3):69)
[13]LüQ,Wang F J,Chen S J.Influence of Mg O content in sinter on droplet performance of vanadium-titanium burden.J Iron Steel Res,2016,28(9):24(吕庆,王福佳,陈树军.烧结矿Mg O含量对含钒钛炉料熔滴性能影响.钢铁研究学报,2016,28(9):24)
[14]Chen L J.Optimization on Softening-Dripping Behaviors of Blast Furnace Comprehensive Burdens for Vanadium-Titanium Magnetite Smelting[Dissertation].Shenyang:Northeastern University,2014(陈立杰.高炉冶炼钒钛磁铁矿综合炉料熔滴性能优化研究[学位论文].沈阳:东北大学,2014)
[15]Jin M F,Li G S,Chu M S,et al.Diffusion between Mg O and hematite during sintering.Iron Steel,2008,43(3):10(金明芳,李光森,储满生,等.烧结过程中Mg O在赤铁矿中的扩散行为的研究.钢铁,2008,43(3):10)
[16]Ren Y F,Jiang L Y,Wang S T.The existing state of Mg O and its effect on the properties of iron ore agglomerates.J Beijing Univ Iron Steel Technol,1983(4):1(任允芙,蒋烈英,王树同.Mg O在人造富矿中的赋存状态及作用.北京钢铁学院学报,1983(4):1)
[17]Wang Z,Zhang J L,Zuo H B,et al.Influence of Al2O3content on softening-melting property of high basicity sinter.Iron Steel,2015,50(7):20(王喆,张建良,左海滨,等.Al2O3质量分数对高碱度烧结矿软熔滴落性能影响.钢铁,2015,50(7):20)