Oxygen content of high ferrotitanium prepared by thermite method with different melt separation temperatures
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High ferrotitanium prepared directly by the thermite method has a disadvantageously high O content (≥ 10 wt%) because of the short slag-metal separation time. In this study, CaO and CaF2 are added to the melt to improve the basicity of the slag and melt separation under heat preservation is performed to strengthen slag-metal separation. The thermodynamics of the step-by-step reduction process of TiO2 in the Ti–Al–Fe–Si–O system whose composition is close to the alloy after melt separation were calculated. Samples of alloys and slags before and after melt separation were systematically analyzed. The result indicates that the reaction that TiO is reduced by Al to Ti is the limited step in the reduction process of TiO2. The O content of the alloys slightly decreases with temperature from 1873 to 2023 K, which agrees with the changes in the law of deoxidation limit. It is mainly attributed to the movement of chemical reactions in the alloy melt at different temperatures and slag-metal interfacial reaction. The addition of Al2O3–CaO–CaF2 slag and high temperature promote the removal of Al2O3 and titanium suboxides. The minimum contents of O and Al in the alloy reach 1.84 wt% and 3.26 wt%, respectively.
KeywordsHigh ferrotitanium Oxygen content Melt separation Slag-metal separation Thermite method
This study was financially supported by the National Natural Science Foundation of China (Nos. 51422403, 51774078 and U1508217) and the Fundamental Research Funds for the Central Universities (No. N162505002).
- Panigrahi M, Paramguru RK, Gupta RC, Shibata E, Nakamura T. An overview of production of titanium and an attempt to titanium production with ferro-titanium. High Temp Mater Processes. 2010;29(5–6):495.Google Scholar
- Tan S, Örs T, Aydnol MK, Öztürk T, Karakaya İ. Synthesis of FeTi from mixed oxide precursors. J Alloys Compd. 2009;475(1):1.Google Scholar
- Hu M, Bai C, Liu X, Qiu G, Du J. Preparation of FeTi alloy by electrochemical method in molten salt. Metal Int. 2011;16(8):20.Google Scholar
- Ta S, Hu ML, Bai CG, Lv XW, Du JH. The deoxidizing process of the preparation FeTi alloy by electrolysis ilmenite concentrate in molten salt. J Funct Mater. 2011;42(2):2042.Google Scholar
- Yi WU, Yin C, Zou Z, Wei H, Li XM. Combustion synthesis of fine TiFe series alloy powder by magnesiothermic reduction of ilmenite. Rare Met. 2006;25(z1):280.Google Scholar
- Zhadkevich ML, Biktagirov FK, Shapoval VA. Use of electroslag melting for the production of ferroalloys from mineral raw materials. Sovrem Electrometall. 2005;1(5):12.Google Scholar
- Song XJ, Wei L, Zhang TA, Tang GH. Analysis of forming mechanism of oxygen in high ferrotitanium and deoxidizing oxygen experiment. Chin J Process Eng. 2008;8(S1):176.Google Scholar
- Dou ZH, Zhang TA, Yao JM, He JC. Preparation of high ferroalloy with low oxygen through vacuum reduction refining. J Northeast Univ Nat Sci. 2011;31(11):400.Google Scholar
- Dou ZH, Zhang TA, Zhang HB, Zhang ZQ, Niu LP, Yao YL, He JC. Preparation of high titanium ferrous with low oxygen content by thermit reduction-SHS. J Cent South Univ Technol Nat Sci. 2012;41(5):899 (Chinese Edition).Google Scholar
- Dou ZH, Zhang TA, Zhang HB, Zhang ZQ, Niu LP, He JC. Basic research on preparation of high titanium ferroalloy with low oxygen content by thermit reduction. Chin J Process Eng. 2010;10(6):1119.Google Scholar
- Dou ZH, Wang C, Fan SG, Shi GY, Zhang TA. Al control in high titanium ferro with low oxygen prepared by thermite reaction. In: 6th International Symposium on High-Temperature Metallurgical Processing TMS. Orlando, 2015. 11.Google Scholar
- Zhang TA, Dou ZH, Yin ZS, Tang HG, Niu LP, Liu LY, Lv GZ, He JC. A method of preparing high titanium ferrotitanium by step-by-step metal thermal reduction. China Patent, 101967531 A. 2012. http://www2.soopat.com/Patent/201010514572?lx=FMSQ.
- Dou ZH, Zhang TA, Zhang ZM, Wang C, Liu Y, Lv GZ, He JC, Jiang XL. A method of preparing titanium ferroalloys based on the thermal self-propagating and spray deep reduction. China Patent, 104131128 B. 2014. http://www2.soopat.com/Patent/201410345901.
- Zhao K, Wang YW, Chen B, Li YL, Feng NX. Extraction of Ti by a combination of vacuum carbothermal reduction and electrolysis with soluble TiO. J Vaccum Sci Technol. 2015;35(6):678.Google Scholar
- Zhang J, Cheng GG, Wang LJ, Zhu R. Calculating Thermodynamics of Metallurgical Melts. In: Zhang J, editor. Beijing: Metallurgy Industry Press; 1998. 5.Google Scholar
- Zhang J. Thermodynamic properties and mixing thermodynamic parameters of two-phase metallic melts. Univ Sci Technol Beijing. 2005;12(3):213 (English Edition).Google Scholar
- Zhang J. Thermodynamic properties and mixing thermodynamic parameters of binary homogeneous metallic melts. Rare Met. 2003;22(1):25.Google Scholar
- Guo QW, Guo GC, Atlas of binary alloy phase commonly used in non-ferrous metallurgy. In: Guo QW, editor. Beijing: Chemical Industry Press; 2010. 48.Google Scholar
- Zhang J. Models for calculating mass action concentrations for Fe-V and Fe-Ti melts. Eng Chem Metall. 1991;12(3):173.Google Scholar
- Zhang J, Cheng GG. Calculating Models for mass action concentrations for the metallic melt Fe-Al. J Univ Sci Technol Beijing. 1991;13(6):514.Google Scholar
- Zhang J. Thermodynamic properties and mixing thermodynamic parameter of binary metallic melt involving compound formation. J Iron Steel Res Int. 2005;12(2):11.Google Scholar
- Zhu R, Zhang J, Qiu Y. Calculation model of mass action concentrations for Fe-C-O metallic melts. J Univ Sci Technol Beijing. 1996;10(5):25.Google Scholar
- Liang YJ, Che YC. Handbook of inorganic thermodynamic data. In: Liang YJ, Che YC, editors. Shengyang: Northeastern University Press; 1988. 8.Google Scholar
- Ence E, Margolin H. Re-examination of Ti-Fe and Ti-Fe-O phase relations. J Met. 1956;8(5):572.Google Scholar