Research on Mechanism and Influencing Factors of TiO2 Carbothermal Reduction

doi:10.12068/j.issn.1005-3026.2025.20240111

Abstract

Abstract:

Excessive reduction of TiO₂ in the process of smelting vanadium-bearing titanomagnetite in the blast furnace has a great effect on the smooth operation of the blast furnace. Based on the thermodynamic calculation of the carbothermal reduction of TiO₂， the effects of the temperature， atmosphere， and the type of reductant on the carbothermal reduction process of TiO₂ were explored by the loss-in-weight method. The results indicate that the starting reaction temperature of Ti（C _x，N _y ） solid solution increases with the increase in the mole fraction of TiC. The mole fraction of TiN in Ti（C _x，N _y ） increases with the increase in the partial pressure of N₂ at the same temperature. The reduction degree of TiO₂ increases with the increase in temperature within the same reaction time. TiO₂ can be reduced to produce TiC or TiN with graphite under the atmospheres of Ar or N₂， while in the air and CO₂ atmosphere， graphite will be oxidized with O₂ and CO₂. Of all the reductants， TiO₂ has the greatest difficulty in undergoing carbothermal reduction with graphite. Increasing the graphitization degree of the coke in the blast furnace is conducive to inhibiting the excessive reduction of TiO₂ in the blast furnace.

Key words: vanadium-bearing titanomagnetite, TiO₂, carbothermal reduction, Ti（C _x，N _y ）solid solution, reduction degree

CLC Number:

TF 111.13

Guo-peng ZHANG, Feng-man SHEN, Wei-ling ZHANG, Hai-yan ZHENG. Research on Mechanism and Influencing Factors of TiO₂ Carbothermal Reduction[J]. Journal of Northeastern University(Natural Science), 2025, 46(11): 66-72.

Figures/Tables 12

Fig.1 Standard Gibbs free energy variation for TiN and TiC generation

Fig.2 Standard Gibbs free energy of Ti(C x, N y ) solid solution generation for different molar fractions of TiC

Fig.3 Initial reaction temperatures for Ti(C x, N y ) solid solution generation with different molar fractions of TiC

Fig.4 Variation of TiC and TiN mole fractions in Ti(C x, N y ) solid solution with temperature at N2 partial pressure of 101.325 kPa

Fig.5 Variation of TiC and TiN mole fractions in Ti(C x, N y ) solid solution with temperature at different N2 partial pressures

Table 1 Composition ratios of test samples

样品编号	成分组成	配比
TSM1	TiO₂+石墨	1∶3.3
TJT2	TiO₂+焦炭	1∶3.3
TYM3	TiO₂+烟煤	1∶3.3
TWYM4	TiO₂+无烟煤	1∶3.3

Fig. 6 Schematic diagram of test equipment

Fig.7 Variation of weight loss rate and reduction degree of samples after carbothermal reduction of TiO2 at different temperatures

Fig.8 Variation of weight loss rate and reduction degree in carbothermal reduction reaction of TiO2 under different atmosphere conditions

Fig.9 Physical phase analysis of samples after carbothermal reduction of TiO2 under different atmosphere conditions

Fig.10 Variation of weight loss rate and reduction degree in carbothermal reduction reaction of TiO2 under different reductant conditions

Fig.11 Physical phase analysis of samples after carbothermal reduction reaction of TiO2 under different reductant conditions

References 37

[1]	Chen D S， Song B， Wang L N， et al. Solid state reduction of Panzhihua titanomagnetite concentrates with pulverized coal［J］. Minerals Engineering， 2011， 24（8）：864-869.
[2]	Zhang L， Zhang L N， Wang M Y， et al. Precipitation selectivity of perovskite phase from Ti-bearing blast furnace slag under dynamic oxidation conditions［J］. Journal of Non-Crystalline Solids， 2007， 353（22/23）：2214-2220.
[3]	Pang Z D， Jiang Y Y， Ling J W， et al. Blast furnace ironmaking process with super high TiO₂ in the slag： density and surface tension of the slag［J］. International Journal of Minerals， Metallurgy and Materials， 2022，29（6）：1170-1178.
[4]	Valighazvini F， Rashchi F， Khayyam Nekouei R. Recovery of titanium from blast furnace slag［J］. Industrial & Engineering Chemistry Research， 2013， 52（4）：1723-1730.
[5]	Yuan Z F， Wang X Q， Xu C， et al. A new process for comprehensive utilization of complex titania ore［J］. Minerals Engineering， 2006， 19（9）：975-978.
[6]	Saito N， Hori N， Nakashima K， et al. Viscosity of blast furnace type slags［J］. Metallurgical and Materials Transactions B， 2003， 34（5）：509-516.
[7]	Zheng H Y， Zhou S F， Zhang S， et al. Viscosity estimation of TiO₂-bearing blast furnace slag with high Al₂O₃ at 1 500 ^oC［J］. Metals， 2023， 13（3）：573.
[8]	Shankar A， Görnerup M， Seetharaman S， et al. Sulfide capacity of high alumina blast furnace slags［J］. Metallurgical and Materials Transactions B， 2006， 37（6）：941-947.
[9]	Sohn I， Wang W L， Matsuura H， et al. Influence of TiO₂ on the viscous behavior of calcium silicate melts containing 17 mass% Al₂O₃ and 10 mass% MgO［J］. ISIJ International， 2012， 52（1）：158-160.
[10]	Zheng H Y， Zhou X R， Hu X G， et al. Desulphurisation behaviour of blast furnace slag with high Al₂O₃ content at 1823 K［J］. Ironmaking & Steelmaking， 2022，49（6）：596-603.
[11]	Gao K， Jiao K X， Zhang J L， et al. Dissection investigation of forming process of titanium compounds layer in the blast furnace hearth［J］. ISIJ International， 2020， 60（11）： 2385-2391.
[12]	Qiu G B， Ma S W， Deng Q Y， et al. Study on the formation of Ti（C，N） between blast furnace hot metal and slag bearing high TiO₂ ［J］. Metalurgia International， 2012， 17（4）： 94-99.
[13]	Narita K， Maekawa M， Onoye T， et al. Formation of titanium compounds， so-called titanium bear， in the blast furnace hearth［J］. Transactions of the Iron and Steel Institute of Japan， 1977， 17（8）：459-468.
[14]	Zhen Y L， Zhang G H， Chou K C. Carbothermic reduction of titanium-bearing blast furnace slag［J］. High Temperature Materials and Processes， 2016， 35（3）： 309-319.
[15]	张建良，焦克新，刘征建，等.长寿高炉炉缸保护层综合调控技术［J］.钢铁，2017， 52（12）：1-7.
	Zhang Jian-liang， Jiao Ke-xin， Liu Zheng-jian， et al. Comprehensive regulation technology for hearth protective layer of blast furnace longevity［J］. Iron and Steel， 2017， 52（12）：1-7.
[16]	赵永彬，张建良，宁晓钧，等.低钛高炉渣中Ti（C，N）形成的研究［J］.钢铁钒钛，2014， 35（1）：79-84.
	Zhao Yong-bin， Zhang Jian-liang， Ning Xiao-jun， et al. Study on the formation of Ti（C，N） in low TiO₂ content blast furnace slag［J］. Iron Steel Vanadium Titanium， 2014， 35（1）：79-84.
[17]	高运明，李慈颖，李亚伟，等.TiO₂碳热还原与高炉钛渣提取碳氮化钛分析［J］.武汉科技大学学报（自然科学版），2007， 30（1）：5-9.
	Gao Yun-ming， Li Ci-ying， Li Ya-wei， et al. Analysis of carbothermal reduction of TiO₂ and extraction of titanium carbonitride from the blast furnace slag bearing titania［J］. Journal of Wuhan University of Science and Technology（Natural Science Edition），2007， 30（1）：5-9.
[18]	Wang Y Z， Zhang J L， Liu Z J， et al. Carbothermic reduction reactions at the metal-slag interface in Ti-bearing slag from a blast furnace［J］. JOM， 2017， 69（11）：2397-2403.
[19]	Jiao K X， Zhang J L， Hou Q F， et al. Analysis of the relationship between productivity and hearth wall temperature of a commercial blast furnace and model prediction［J］. Steel Research International， 2017，88（9）： 1600475.
[20]	Jiao K X， Zhang J L， Liu Z J， et al. Dissection investigation of Ti（C， N） behavior in blast furnace hearth during vanadium titano-magnetite smelting［J］. ISIJ International， 2017， 57（1）： 48-54.
[21]	詹星.小高炉冶炼钒钛磁铁矿解剖研究［J］.钢铁钒钛，1984， 5（2）：3-15.
	Zhan Xing. Anatomical study on smelting vanadium-titanium magnetite in small blast furnace［J］. Iron Steel Vanadium Titanium， 1984， 5（2）：3-15.
[22]	郑常乐，邵球军，张建良，等.富氧率对钒钛磁铁矿球团还原行为的影响［J］.东北大学学报（自然科学版），2016， 37（2）： 198-202， 212.
	Zheng Chang-le， Shao Qiu-jun， Zhang Jian-liang， et al. Influence of oxygen enrichment rate on reduction behavior of titanomagnetite pellets［J］. Journal of Northeastern University （Natural Science），2016， 37（2）： 198-202， 212.
[23]	焦克新，张建良，刘征建，等.高炉炉缸含钛保护层物相及TiC_0.3N_0.7形成机理［J］.工程科学学报，2019， 41（2）：190-198.
	Jiao Ke-xin， Zhang Jian-liang， Liu Zheng-jian， et al. Mineralogical phase and formation mechanism of titanium-bearing protective layers in a blast furnace hearth［J］. Chinese Journal of Engineering， 2019， 41（2）：190-198.
[24]	焦克新，张建良，左海滨，等.高炉炉缸黏滞层物相及形成机理［J］.东北大学学报（自然科学版），2014， 35（7）：987-991.
	Jiao Ke-xin， Zhang Jian-liang， Zuo Hai-bin， et al. Composition and formation mechanism of viscous layers in blast furnace hearth［J］. Journal of Northeastern University （Natural Science）， 2014， 35（7）：987-991.
[25]	Wada H， Pehlke R D. Nitrogen solubility and nitride formation in austenitic Fe-Ti alloys［J］. Metallurgical Transactions B， 1985， 16（4）： 815-822.
[26]	Ozturk B， Fruehan R J. Thermodynamics of inclusion formation in Fe-Ti-C-N alloys［J］. Metallurgical Transactions B， 1990， 21（5）： 879-884.
[27]	Li Y， Li Y Q， Fruehan R J. Formation of titanium carbonitride from hot metal［J］. ISIJ International， 2001，41（12）：1417-1422.
[28]	Xiang D W， Shen F M， Jiang X， et al. Pyrolysis characteristics of industrial lignin for use as a reductant and an energy source for future iron making［J］. ACS Omega， 2021，6（5）： 3578-3586.
[29]	Lyu T T， Hu T， Tian F. Hydrogen-enhanced carbothermal reduction for the synthesis of TiC from TiO₂ ［J］. Journal of Alloys and Compounds， 2025， 1039： 183002.
[30]	Tang S Y， Song G Q， Guo J J， et al. Oxidation behavior of TiC and TiCN and their potential photocatalytic activity in semi-oxidized state［J］. Nanoscale Advances， 2025，7（16）： 5031-5041.
[31]	Chen M， Chen B X， Jiang Y， et al. Study of Ti（C，N） formations in TiO₂-containing slags［J］. Metallurgical and Materials Transactions B， 2025， 56（1）： 1018-1028.
[32]	Sui J H， Yang S T， Wang Q， et al. Influence of blast furnace burden with different TiO₂ contents on the process of reduction and slag formation in cohesive zone［J］. ISIJ International， 2025，65（4）： 521-532.
[33]	Zhang S S， Zhang J L， Wang Z Y， et al. Advancements in oxygen blast furnace technology and its application in the smelting of vanadium-titanium magnetite： a comprehensive review［J］. Minerals Engineering， 2024， 212： 108732.
[34]	Huang Y， Zhang Z D， Tang J， et al. Mathematical simulation on smelting vanadium-bearing titanomagnetite by oxygen blast furnace［J］. ISIJ International， 2025，65（11）： 1690-1700.
[35]	Chen B X， Chen M， Zhang K X， et al. Metallurgical properties of vanadium titanomagnetite sinter in the cohesive zone of H₂-rich oxygen blast furnace［J］. Metallurgical and Materials Transactions B， 2025： 1-12.
[36]	Qu Y X， Xing L， Gao M L， et al. Progress and prospects for titanium extraction from titanium-bearing blast furnace slag［J］. Materials， 2024， 17（24）： 6291.
[37]	Zheng K， Wang W， Huang T， et al. Influence of temperature and slag composition on wetting behavior of titanium-containing blast furnace slag and tuyere coke［J］. Journal of Iron and Steel Research International， 2025，32（10）： 3298-3307.

Research on Mechanism and Influencing Factors of TiO₂ Carbothermal Reduction

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