2025, 46(6): 1-19.
doi: 10.7513/j.issn.1004-7638.2025.06.001
Abstract:
Iron-vanadium-titanium resources are globally recognized as strategic mineral resources and of critical importance to national defense, economic development, and technological advancement. The Panxi region, hosting China’s largest and a world-significant iron-vanadium-titanium resource base, has established a complete industrial chain for these metals. However, it still faces challenges such as low comprehensive utilization rates of vanadium and titanium, an insufficient share of high-end products, high energy consumption in production, and significant solid waste generation. Focusing on the efficient and clean utilization of vanadium-titanium resources in the Panxi region, this paper systematically analyzes the current state of resource utilization and proposes key directions for transformation and upgrading. These directions encompass five major aspects: technological and process innovation, product iteration and upgrading, utilization of clean energy, strengthening of solid waste management, and reengineering of beneficiation and metallurgical process flows. The proposed strategies aim to promote the efficient, high-value, green, and intelligent development of China’s vanadium and titanium industry. Such progress will contribute to achieving the national “dual-carbon” goals and ensure the secure supply of iron-vanadium-titanium resources and related raw materials for the country.
Iron-vanadium-titanium resources are globally recognized as strategic mineral resources and of critical importance to national defense, economic development, and technological advancement. The Panxi region, hosting China’s largest and a world-significant iron-vanadium-titanium resource base, has established a complete industrial chain for these metals. However, it still faces challenges such as low comprehensive utilization rates of vanadium and titanium, an insufficient share of high-end products, high energy consumption in production, and significant solid waste generation. Focusing on the efficient and clean utilization of vanadium-titanium resources in the Panxi region, this paper systematically analyzes the current state of resource utilization and proposes key directions for transformation and upgrading. These directions encompass five major aspects: technological and process innovation, product iteration and upgrading, utilization of clean energy, strengthening of solid waste management, and reengineering of beneficiation and metallurgical process flows. The proposed strategies aim to promote the efficient, high-value, green, and intelligent development of China’s vanadium and titanium industry. Such progress will contribute to achieving the national “dual-carbon” goals and ensure the secure supply of iron-vanadium-titanium resources and related raw materials for the country.
2025, 46(6): 29-39, 65.
doi: 10.7513/j.issn.1004-7638.2025.06.003
Abstract:
Accurate and reliable thermodynamic databases are of significance for optimizing vanadium extraction and synthesizing vanadate materials. This study employed sealed platinum crucibles combined with X-ray diffraction (XRD) and differential thermal analysis (DTA) to confirm the presence of K3V5O14 in the K2O-V2O5 system, melting temperature of K2V8O21 and KVO3 were also determined as 532.4 ℃ and 516.5 ℃, respectively. Modified Quasichemical Model (MQM) was adopted, incorporating short-range ordering of second-neighboring cations in solution to describe changes in Gibbs free energy of solution phases. Thermodynamic model for the Na2O-K2O-V2O5 system was then developed in the framework of CALPHAD (Calculation of Phase Diagrams) methodology, reproducing experimental data across the entire composition range of the system. A self-consistent set of thermodynamic parameters for all phases in the system was obtained, ultimately establishing a reliable thermodynamic database. Furthermore, the developed database was applied to optimize sodium-roasting of vanadium slag at elevated temperatures, clarifying the phase evolution of vanadium-containing phases and identifying optimal operating temperature windows.
Accurate and reliable thermodynamic databases are of significance for optimizing vanadium extraction and synthesizing vanadate materials. This study employed sealed platinum crucibles combined with X-ray diffraction (XRD) and differential thermal analysis (DTA) to confirm the presence of K3V5O14 in the K2O-V2O5 system, melting temperature of K2V8O21 and KVO3 were also determined as 532.4 ℃ and 516.5 ℃, respectively. Modified Quasichemical Model (MQM) was adopted, incorporating short-range ordering of second-neighboring cations in solution to describe changes in Gibbs free energy of solution phases. Thermodynamic model for the Na2O-K2O-V2O5 system was then developed in the framework of CALPHAD (Calculation of Phase Diagrams) methodology, reproducing experimental data across the entire composition range of the system. A self-consistent set of thermodynamic parameters for all phases in the system was obtained, ultimately establishing a reliable thermodynamic database. Furthermore, the developed database was applied to optimize sodium-roasting of vanadium slag at elevated temperatures, clarifying the phase evolution of vanadium-containing phases and identifying optimal operating temperature windows.
2025, 46(6): 78-83.
doi: 10.7513/j.issn.1004-7638.2025.06.009
Abstract:
The conventional metallothermic reduction process for vanadium production suffers from high metal consumption, elevated costs, and high oxygen content in the resulting metallic vanadium. While magnesium reduction is thermodynamically capable of reducing oxygen content to 0.01%, the formation of an MgO/MgV2O4 oxide layer severely impedes the reaction kinetics during the actual process. This study innovatively proposes a novel two-step process: “synergetic magnesiothermic reduction by hydrogen reduction-molten salt.” Firstly, low-valent vanadium oxides (V2O3, VO) are prepared via hydrogen reduction to serve as the feedstock for the magnesiothermic reduction step. Subsequently, reactive ZrCl4-KCl molten salt is employed as a medium to disrupt the oxide layer encapsulation effect and overcome the kinetic limitations. This enables the simultaneous magnesium reduction of vanadium oxides and interfacial purification of the oxide layer at a lower temperature. Following optimization of process parameters (Mg addition: 35%, reaction time: 1 h, temperature: 800 ℃), high-purity metallic vanadium with an oxygen content of approximately 0.16% was successfully produced.
The conventional metallothermic reduction process for vanadium production suffers from high metal consumption, elevated costs, and high oxygen content in the resulting metallic vanadium. While magnesium reduction is thermodynamically capable of reducing oxygen content to 0.01%, the formation of an MgO/MgV2O4 oxide layer severely impedes the reaction kinetics during the actual process. This study innovatively proposes a novel two-step process: “synergetic magnesiothermic reduction by hydrogen reduction-molten salt.” Firstly, low-valent vanadium oxides (V2O3, VO) are prepared via hydrogen reduction to serve as the feedstock for the magnesiothermic reduction step. Subsequently, reactive ZrCl4-KCl molten salt is employed as a medium to disrupt the oxide layer encapsulation effect and overcome the kinetic limitations. This enables the simultaneous magnesium reduction of vanadium oxides and interfacial purification of the oxide layer at a lower temperature. Following optimization of process parameters (Mg addition: 35%, reaction time: 1 h, temperature: 800 ℃), high-purity metallic vanadium with an oxygen content of approximately 0.16% was successfully produced.
2025, 46(6): 117-123.
doi: 10.7513/j.issn.1004-7638.2025.06.014
Abstract:
To enhance the inclusion absorption rate of mold slags during continuous casting of high-titanium steel, five candidate high-Ti steel slags were designed. The absorption behaviors and absorption rate differences of TiO2 inclusions by each slag were investigated through a combination of in-situ observation tests and rotating cylinder method with quantitative analysis. SEM-EDS was employed to analyze the interface between TiO2 samples and slags, elucidating the dissolution mechanism of TiO2 in the slag. Results demonstrate that TiO2 dissolution rate was fastest in the CaO-SiO2-BaO slag, followed by the low-basicity CaO-SiO2 slag. Both achieved complete dissolution with shorter durations during the in-situ tests, exhibiting dissolution rates of 0.285 mm/min and 0.281 mm/min respectively in the rotating cylinder tests. Comparatively, TiO2 dissolution rates decreased significantly in the high-basicity CaO-SiO2, CaO-SiO2-Al2O3, and CaO-SiO2-Al2O3-BaO systems, with only the CSAB slag completely dissolving (0.151, 0.101 mm/min, and 0.191 mm/min respectively). The primary inhibition mechanism was identified as the formation of high-melting-point CaTiO3 through reaction between dissolved TiO2 and CaO in the slag, which elevated local viscosity and melting point of the slags.
To enhance the inclusion absorption rate of mold slags during continuous casting of high-titanium steel, five candidate high-Ti steel slags were designed. The absorption behaviors and absorption rate differences of TiO2 inclusions by each slag were investigated through a combination of in-situ observation tests and rotating cylinder method with quantitative analysis. SEM-EDS was employed to analyze the interface between TiO2 samples and slags, elucidating the dissolution mechanism of TiO2 in the slag. Results demonstrate that TiO2 dissolution rate was fastest in the CaO-SiO2-BaO slag, followed by the low-basicity CaO-SiO2 slag. Both achieved complete dissolution with shorter durations during the in-situ tests, exhibiting dissolution rates of 0.285 mm/min and 0.281 mm/min respectively in the rotating cylinder tests. Comparatively, TiO2 dissolution rates decreased significantly in the high-basicity CaO-SiO2, CaO-SiO2-Al2O3, and CaO-SiO2-Al2O3-BaO systems, with only the CSAB slag completely dissolving (0.151, 0.101 mm/min, and 0.191 mm/min respectively). The primary inhibition mechanism was identified as the formation of high-melting-point CaTiO3 through reaction between dissolved TiO2 and CaO in the slag, which elevated local viscosity and melting point of the slags.
2021, 42(5): 54-61.
doi: 10.7513/j.issn.1004-7638.2021.05.009
Abstract:
2023, 44(3): 1-8.
doi: 10.7513/j.issn.1004-7638.2023.03.001
Abstract:
