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The present study investigated the influence of TiC particle addition on the viscosity of CaO-MgOAl2O3-SiO2 melts by using the rotating cylinder method. It was found viscosity increased as increasing the volume fraction of TiC, but decreased as enhancing the rotation speed. The temperature dependence of viscosity for the same composition can be described by the Arrhenius law. However, temperature has little influence on the relative viscosity of TiC bearing slag. There is also no obvious difference of activation energies for different compositions with or without the addition of TiC solid particle. Therefore, the activation energy of solid-liquid mixture may be mainly determined by the composition of liquid phase. Two kinds of TiC with the particle sizes of 1.0 μm and 10 μm were used to study the influences of solid size on viscosity, and it was found the TiC particle with a small size can increase the viscosity much more greatly. The Einstein-Roscoe equation cannot be used directly to the TiC containing two-phase mixtures. By modifying the parameter, it can well describe the viscosity variation behavior. According to the calculated results, the maximum volume fraction increases as increasing the rotation speed or decreasing the particle size of TiC. The apparent volume of TiC is about 2.2-3.3 times of its real volume.

The effect of Al2O3/TiO2 ratio on viscosities of CaO-MgO-Al2O3-SiO2-TiO2 melts was investigated by the rotating cylinder method in this study. In addition, structural characterizations of these quenched vitreous samples were also studied by Raman spectroscopy. It was indicated from the experimental results that viscosity increases as gradually increasing Al2O3/TiO2 ratio while keeping the contents of other components constant. The Raman spectra analyses indicated that TiO2 mainly exists in the form of [TiO4] as a network former in composition range of 3-17 mol%. With increasing the Al2O3/TiO2 ratio, the [TiO4] content decreases and the degree of polymerization of the melt increases resulted from the increase of Al2O3 which behaviors as an acidic oxide and incorporates into the SiO2 network with the charge balance of CaO. Consequently, there will be an increase of viscosity with increasing Al2O3/TiO2 ratio.

The present study investigated the influence of TiN particle addition on the viscosity of CaO-MgO-Al 2 O 3 -SiO 2 melts using the rotating cylinder method. In order to study the influences of particle size of TiN, two types of TiN particles (diameters 1?0 and 10 mm) were used. It was found that the viscosity of the TiN containing melt increases with the addition of the particles, but decreases with increasing cylinder rotation speed. The temperature dependence of viscosity for the same composition can be described by the Arrhenius law. It was also found that the temperature has little influence on the relative viscosity. There is also no obvious difference of activation energies for different compositions with or without the addition of TiN solid particle. Furthermore, it was found that for the same volume percentage of TiN addition, the smaller the size of TiN particle is, the higher the viscosity will be. The influence of TiN on viscosity appears to be much greater than that estimated by the Einstein-Roscoe equation. Better calculated results could be obtained by allowing the parameter of Einstein-Roscoe equation to vary with the rotation speed and particle size of TiN. The maximum volume fraction of TiN corresponding to an infinite viscosity increases with increasing rotation speed and decreasing the TiN particle size. Based on the Einstein-Roscoe equation, the apparent volume of TiN is about 1?98-3?20 times its real volume.Cette é tude examine l'influence de l'addition de particules de TiN sur la viscosité de bains de CaO-MgO-Al 2 O 3 -SiO 2 en utilisant la mé thode du cylindre tournant. Afin d'é tudier l'influence de la taille de particule du TiN, on a utilisé deux types de particules de TiN (diamè tre de 1?0 mm et de 10 mm). On a trouvé que la viscosité du bain contenant du TiN augmentait avec l'addition de particules, mais diminuait avec l'augmentation de la vitesse de rotation du cylindre. On peut dé crire la dé pendance de la viscosité sur la tempé rature pour une mê me composition au moyen de la loi d'Arrhé nius. On a é galement trouvé que la tempé rature avait peu d'influence sur la viscosité relative. É galement, il n'y avait pas de diffé rence é vidente des é nergies d'activation des diffé rentes compositions, avec ou sans addition de particules solides de TiN. De plus, on a trouvé que pour un pourcentage de volume donné d'addition de TiN, plus petite é tait la taille de particule du TiN, plus é levé e é tait la viscosité . L'influence du TiN sur la viscosité semble ê tre beaucoup plus importante que la valeur estimé e par l'é quation d'Einstein-Roscoe. On pourrait obtenir de meilleurs ré sultats calculé s en permettant au paramè tre de l'é quation d'Einstein-Roscoe de varier en fonction de la vitesse de rotation et de la taille de particule du TiN. La fraction volumique maximale du TiN correspondant à une viscosité infinie augmente avec l'augmentation de la vitesse de rotation et la diminution de la taille de particule de TiN. En se basant sur l'é quation d'Einstein-Roscoe, le volume apparent de TiN...

The carbothermic reduction experiments were carried out for titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company in argon atmosphere at high temperatures. The effects of reduction temperature, isothermal treatment time and carbon content on the formation of TiC were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD pattern results showed that MgAl 2 O 4 phase disappeared and the main phase of the reduced sample was TiC when the reduction temperature was higher than 1,773 K. The SEM pictures showed that the reduction rate of the titanium-bearing blast furnace slag could be increased by enhancing the temperature and the C content (carbon ratio 1.0). Furthermore, it was also found that TiC had the tendency of concentrating around the iron. The effects of additives such as Fe and CaCl 2 on the formation of TiC were also studied in the present study.