The distribution behavior of vanadium between a hot metal and a FeO‐SiO2‐MnO (‐TiO2) slag system was studied under laboratory conditions, together with the effects of influencing factors such as temperature, slag composition, the ratio of slag to hot metal, and the initial Si and/or Ti content in hot metal. The results suggested that in a ternary FeO‐SiO2‐MnO slag system, with an increase in temperature and an increase in the SiO2 content of slag, the extraction ratio ($\eta _{V} $), distribution ratio of V ($L_{V} $) and the vanadium capacity of the slag ($C_{VO_{3} {}^{3{-} } } $) decreased, while the effect of MnO content in slag showed a different tendency under different situations. For both high and low ratios of slag to hot metal, the extraction ratio of V reached its maximum value under slag compositions of 13%–25% MnO and 10%–24% SiO2, which correspond to the regions with lower melting point and lower viscosity of the slag. In a quaternary FeO‐SiO2‐MnO‐TiO2 slag system,$\eta _{V} $,$L_{V} $, and $C_{VO_{3} {}^{3{-} } } $ decreased, while the activity coefficient of V2O3 increased, as the TiO2 content increased. Further, the data suggested that under laboratory conditions the effects of influencing factors on the extraction ratio of V from hot metal decreased in the following order: final slag composition > temperature > initial Si and/or Ti content in hot metal.

The microstructures of magnetite containing vanadium and titanium, found in Sichuam province, China, have been studied by hi_gh-resolution electron microscopy (HREM). The [110] structural images showed a multiply intimate intergrowth of magnetite and coulsonite as a result of exsolution along the [ 110] direction instead of the [ 111 ] direction as reported previously. The detectable different contrast of the two phases was confirmed by image simulation. The antiphase domain and various stacking faults related to the nonstoichiometry of the transitionmetal oxide in the same direction were also observed in magnetite and coulsonite, respectively. The possible genetic aspect and formation of these defects on exsolution are also considered. Oclh = 0.03 rad/~-!; and the size limited by the objective aperture, (sin 0)/h = 0.350 A-1. From the simulated images it is known that at a thickness from 50 0108-7673/89/040264-05503.00 AbstractThe structure of hexagonal Frank-Kasper (FK) phases can be described by the projection of the seven-dimensional (7D) Cr3Si and Zr4A13 cubes in a suitable projection subspace onto a 3D hyperplane. The close relationship between hexagonal FK phases and the dodecagonal quasicrystal with 12-fold rotational symmetry is discussed.