Dependence of Reduction Behaviors on the Molar Ratio of Fe2TiO5 and MgTi2O5 in the Pseudobrookite-Karrooite

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Process metallurgy and materials processing science, 2017-02, Vol.48 (1), p.302-307
• Main Authors: Zhang, Gengyu, Lei, Chao, Zhu, Qingshan, Zhang, Jianbo, Du, Zhan, Yang, Yafeng, Fan, Chuanlin
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Metallic Materials; Nanotechnology; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-016-0822-7

The dependence of the reduction behaviors of the M 3 O 5 -type (Fe 2 TiO 5 ) a (MgTi 2 O 5 ) b on the ratio of Fe 2 TiO 5 and MgTi 2 O 5 was investigated in a CO-CO 2 gas mixture at 1123 K (850 °C), and the phase transformation mechanism was revealed. The reduction process of (Fe 2 TiO 5 ) a (MgTi 2 O 5 ) b underwent the formation of the intermediate (FeTi 2 O 5 ) e (MgTi 2 O 5 ) f in the same M 3 O 5 -type, and subsequently this intermediate further decomposed into the M 2 O 3 phase. The a / b ratio had a marginal effect on its reduction of Fe 3+ →Fe 2+ but largely influenced its phase transformation. To obtain a complete phase transformation into M 2 O 3 , a / b  ≥ 0.9 is required, below which a considerable amount of inadequately decomposed intermediate M 3 O 5 phase remains. A principle of suitable acid leaching condition for titanium slags with different a / b ratios was proposed accordingly, and an optimized plan for the upgrading process of low-grade titanium slags was recommended.