Effect of TiO2 on the Crushing Strength and Smelting Mechanism of High-Chromium Vanadium-Titanium Magnetite Pellets

The effect of TiO2 on the crushing strength for high-Cr V-Ti magnetite pellets was studied in this paper. On one hand, the crushing strength obviously decreased with the increasing TiO2 contents. On the other hand, the crushing strength had an obvious increase after grinding treatment for the high-Cr V-Ti magnetite and titanium concentrate. It is found that the crushing strength has great relations with the mineral phase and microstructure. The effect of TiO2 on the smelting mechanism for high-Cr V-Ti magnetite pellets was also studied in this paper. With the increasing TiO2 contents in the range of 2.47 to 12.14 pct, the softening start temperature and softening temperature gradually increased, and the softening zone gradually narrowed down; the melting start temperature and the dripping temperature increased, and the melting-dripping temperature zone also increased. The permeability index increased with the increasing TiO2 contents as a whole. In the process of slag-iron's dripping and separating, it is proposed that amounts of Cr and V moving to the melted iron are obviously more than those moving to the slag, while amount of Ti moving to slag is much greater than that moving to the melted iron. It is demonstrated that Ti(C,N) generates increasingly with the increasing TiO2 contents and accumulates as especial regular rigid granules on the surface of coke. The size of melted iron decreased with the increasing TiO2 contents, and this is in accordance with the present investigations that the dripping difficulty increased with the increasing TiO2 contents. (C) The Minerals, Metals & Materials Society and ASM International 2016