Vanadium titano-magnetite (VTM) is one of the important iron ore resources in the world. High
viscosity and low fluidity are the basic characteristics of hot metal containing vanadium and titanium
during the ironmaking process. Clarifying the influencing mechanism of the melt viscosity would be
a significant issue for the high efficiency smelting of VTM. In this paper, a self-developed melt
viscometer based on the principle of torsional vibration theory was employed to measure the
viscosity of hot metal accurately. Simultaneously, the thermodynamic calculations and some modern
detection methods were also used to investigate the precipitation behaviour of high-melting-point
phases in hot metal containing vanadium and titanium. The measuring results show that the viscosity
of molten iron gradually increases with the increase of titanium content when the mass fraction of
titanium is between 0.09 wt per cent – 0.50 wt per cent. Meanwhile, the viscosity of the hot metal
was affected significantly by the vanadium content. When the vanadium mass fraction was higher
than 0.30 wt per cent, the viscosity of hot metal increased sharply, which will have a serious impact
on the fluidity of the hot metal. Furthermore, it was revealed by thermodynamic calculations that an
increase in titanium and vanadium content would result in the precipitation of high melting point
phases such as TiC, TiN, VC, and VN in the molten iron, ultimately resulting in a decrease in its
fluidity. Meanwhile, it was confirmed by Scanning Electron Microscope (SEM) observation that the
precipitates in the hot metal were compounds consisting of V, Ti, C, and N elements, which agrees
well with the thermodynamic analysis results.