Enhancing Reduction Separation and Efficient Recovery of Iron, Vanadium, and Titanium for Ultra-High-Titanium Magnetite

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 55; no. 1; pp. 287 - 300
• Main Authors: Cheng, Gong-Jin, Han, Tong, Song, Han-Lin, Gao, Ming-Lei, Yang, He, Xue, Xiang-Xin
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2024; Springer Nature B.V
• Subjects: Additives; Boron oxides; Calcium fluoride; Characterization and Evaluation of Materials; Chemistry and Materials Science; Direct reduction; Electron microscopes; Fluorides; Fluorine; Iron; Magnetic separation; Magnetite; Materials Science; Metallic Materials; Metallizing; Nanotechnology; Original Research Article; Phase transitions; Recovery; Structural Materials; Surfaces and Interfaces; Thin Films; Titanium; Titanium oxides; Vanadium
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-023-02958-3

In this work, diboron trioxide and calcium fluoride are applied as composite additives to explore a process suitable for processing low-grade, high-vanadium, ultra-high-titanium vanadium–titanium magnetite. The metallized coal-based direct reduction–electromagnetic separation experiment was conducted. Results show that a good metallization ratio, separation, and the recovery of valuable components can be achieved under the following conditions: 8 pct diboron trioxide additive content, 8 pct calcium fluoride additive content, reduction temperature of 1100 °C, and reduction time of 30 min. The metallization ratio is 94 pct, and the recovery ratio of Fe, V, and Ti are 96, 84, and 85 pct, respectively. The X-ray diffraction results show that the phase transition under this condition is relatively simple, mainly metallic iron and different titanium oxides, without much intermediate product formation. Scanning electron microscope–energy-dispersive spectroscopy analysis shows that different conditions make the reduction products present differently in size, number, shape, and element distribution under different conditions, and this difference leads to differences in the separation and recovery effects of valuable components. The larger the metallic iron particle size is, the better the effect of component separation is. Diboron trioxide plays a role by destroying [SiO 4 ] radicals to promote reduction. Fluorine is mainly diffused into silicate slag phase, and part of calcium fluoride still exists at relatively lower temperature of 1100–1150 °C. Overall, the metallization reduction–magnetic separation process with diboron trioxide and calcium fluoride as composite additives has achieved excellent metallization ratio, satisfied separation and recovery of valuable components, and large-scale lowered reaction temperature and time.