Production Process and Technological Optimization of Vanadium-Titanium Ore Sintering

Vanadium-titanium magnetite is a strategic resource rich in iron, vanadium, titanium, and other valuable metals, with global reserves exceeding 40 billion tons. China’s major deposits are located in Panzhihua, Chengde, and Chaoyang. However, sintering vanadium-titanium ore faces challenges such as low sinter strength and severe low-temperature reduction pulverization (RDI). This article systematically outlines the production process and key optimization technologies for vanadium-titanium ore sintering.

I. Raw Material Characteristics and Pretreatment

Vanadium-titanium ore has complex chemical compositions, with TiO₂ content (2%~21%) directly affecting sintering behavior. High-titanium ore (TiO₂>7%) forms perovskite (CaO·TiO₂), weakening bonding phases and reducing strength. Pretreatment involves classifying ores (low-, medium-, and high-titanium) and optimizing blends with limonite (low melting point, high assimilation). For example, adding 30%~40% limonite enhances liquid phase formation and reduces perovskite content.

II. Core Production Process

1. Raw Material Blending and Mixing

• Composition: Vanadium-titanium concentrate (60%~80%), limonite (20%~40%), fluxes (limestone, dolomite), and fuels (coke breeze, coal powder).

• Granulation Enhancement: Adding 5%~8% quicklime as a binder generates slaked lime colloids, improving pelletization and thermal stability.

2. Sintering Process

• Temperature Control: Target temperature 1,300°C with fuel ratio 5.4%~5.8%. Excess temperature (>1,300°C) promotes perovskite formation, while insufficient heat reduces liquid phase.

• Basicity Adjustment: Optimal basicity (CaO/SiO₂) is 2.1–2.5. Higher basicity increases calcium ferrite (CaO·Fe₂O₃) bonding phases, reducing perovskite content (from 23% to 15%) and improving tumbler strength by 6%–8%.

• Composite Agglomeration: Combining acid pellets with high-basicity sinter forms a “pellet-sinter” structure. Adding 70% pellets increases tumbler strength by 8.4% and reduces fuel consumption by 7.9 kg/t.

3. Cooling and Post-Treatment

• Surface Spraying: Applying CaCl₂ or B₂O₃ solutions seals pores, inhibiting Fe₂O₃→Fe₃O₄ reduction. RDI improves from 57% to 97%.

• Tailings Management: Dry stacking reduces land use, while partial tailings are repurposed into building materials (e.g., glass-ceramics), achieving 80% utilization.

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III. Key Technological Optimization Measures

1. Fuel Ratio and Combustion Efficiency

• Fuel Selection: Blending coke breeze (60%~70%) with coal powder improves combustion efficiency by 15%.

• Thermal Balance: AI models dynamically adjust fuel ratios to ensure uniform sintering temperatures.

2. Boron-Containing Additives

Adding boron ore or B₂O₃ solution (0.2%~0.3%) lowers melting points, enhances liquid phase formation, increases calcium ferrite by 5%, and reduces perovskite by 2%.

3. Smart and Green Technologies

• IoT Monitoring: Real-time data on temperature and permeability optimize processes.

• Closed-Loop Water Systems: Reduce freshwater consumption by 50% through wastewater recycling.

IV. Future Directions

1. Superconducting Magnetic Separation: Enhances recovery of fine-grained ore.

2. Biohydrometallurgy: Utilizes microbes to leach vanadium and titanium, reducing energy consumption.

3. Zero-Emission Processes: Full resource utilization converts 100% tailings into high-value products.

Conclusion

By optimizing raw material blends, controlling basicity and fuel ratios, and adopting composite agglomeration, vanadium-titanium ore sintering achieves significant improvements in strength and metallurgical performance. Future integration of smart and green technologies will drive efficient and sustainable resource utilization, empowering the global steel industry.