Sulfur distribution in preparation of high titanium ferroalloy by thermite method with different CaO additions
- 8 Downloads
Ferrotitanium is used as a deoxidizer and alloying agent during steelmaking process, which has a high demand for sulfur control. Sulfur was introduced from raw materials in the process of producing ferrotitanium by thermite method, where CaO was used as fluxing agent. At the same time, CaO has a great desulfurization capability. Effects of CaO addition on the distribution of sulfur in high titanium ferroalloy prepared by thermite method were studied in this work. The equilibrium diagram of Ti–Al–Fe–S system was calculated by FactSage 6.4 software package with FactPS and FTmisc database. The alloy and slag samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectrometer (ICP-AES), X-ray fluorescence (XRF) and high-frequency infrared ray carbon sulfur analyzer. The result indicates that the sulfur in the alloy firstly exists in the form of liquid FeS, thereafter TiS (s) and eventually Ti2S (s) during cooling. The sulfur is mainly distributed in the alloy, and only a small amount of sulfur remains in the slag. Moreover, it is noted that the sulfur in the alloy does not distribute homogeneously, and it exists in the form of solid solution phase, (Ti, Al, Fe)S. S content in the slag, the sulfur capacity of the slag and the sulfur distribution ratio (LS) all increase with the increment of CaO addition, while S content in alloys decreases.
KeywordsDesulfurization Sulfur partition ratio Optical basicity High titanium ferroalloy Thermite method
This study was financially supported by the National Natural Science Foundation of China (Nos. 51422403 and 51504064), the Fundamental Research Funds for the Central Universities (No. N162505002) and the National Basic Research Program of China (No. 2013CB632606).
- Demos A, Kremin D. Titanium and its alloys for use in iron and steelmaking. J ASTM Int. 1981;10(5):144.Google Scholar
- Xu ZB, Gammal EL. Influence of inclusion content and morphology mechanical properties of steel. J Iron Steel Res. 1994;6(4):18.Google Scholar
- Zhadkevich ML, Biktagirov FK, Shapovalov VA, Ignatov AP, Gnatushenko AV. Application of electroslag melting for production of ferroalloys from mineral raw material. Sovrem Electrometall. 2005;1:12.Google Scholar
- Cheng XX, Qu SJ, Feng AH, Shen J. Recent advances in size effect of lamellar colony and lamellar spacing in intermetallic titanium aluminides. Chin J Rare Met. 2016;40(4):393.Google Scholar
- Deng GZ, Wang XF. Methods of preparing high grade titania feedstock from Panzhihua titanium concentrate. Iron Steel Vanadium Titan. 2002;23(4):14.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, 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 (Chin Ed). 2012;41(5):899.Google Scholar
- Wei YW, Li N, Chen FY. Effect of Fe2O3 addition in MgO–CaO refractory on desulfurization of liquid iron. J Iron Steel Res Int. 2003;10(4):4.Google Scholar
- Gao YH, Bian LT. Desulfurization characteristics of CaO–SiO2–BaO–CaF2–Al2O3–MgO refining slag. J Iron Steel Res Int. 2005;12(5):1.Google Scholar
- Yang YD, Mclean A, Sommerville ID, Poveromo JJ. The correlation of alkali capacity with optical basicity of blast furnace slags. I&SM. 2000;27(10):103.Google Scholar
- Zhao HM, Wang XH, Xie B. Effect of components on desulfurization of an Al2O3–CaO base premolten slag containing SrO. J Univ Sci Technol Beijing. 2005;12(3):225.Google Scholar