New Ways Of Recycling Titanium-bearing Blast Furnace Slag In Panzhihua

China is abundant in titanium, however, the recovery ratio of the titanium is too low in the current smelting process of the vanadium tianomagnetite resource.Although many works have been done, the recycling utilization of TiO2 bearing blast furnace slag still had some problems.All of these works were focused on the crystalline slags which were cooled in the air slowly aftersamples are reduced at different temperatures for different time, and thecrystalline phase containing spinel, akermanite-gehlenite and diopside and so on.Therefore, the aim of the present study is to obtain the glass slags and to avoid the precipitation of spineland other crystalline phase, and then find the new waysof recycling Titanium-bearing blast furnace slag in Panzhihua. At the same time, viscosity and structural characterizations were studied by the rotating cylinder methodand Raman spectroscopy, to explain the fluid dynamic of molten slags; Mechanism and kinetics of the carbothermic reduction og titanium-beaing blast were studied by different particle sizes of C and the gas analyzer; the effect of solid suspension on the viscosity of molten slags by the rotating cylinder method also was studied.The obtained conclusions are as follows:1.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 patterns results showed thatMgAl2O4 phase disappeared and the main phase of the reduced sample was TiC when the reduction temperature was more than 1773K. The SEM pictures show that the reduction rate of the titanium-bearing blast furnace slag could be increased by enhancing the temperature and the C content. Furthermore, it was also found that TiC had the tendency of concentrating around the iron.The kinetics of the leaching of carbothermic reduced titanium-bearing blast furnace slagin Panzhihua Iron and Steel Company with acid system and sodium hydroxide system under atmosphere pressure was studied. The results show that the temperature and concentration have significant influence on leaching of carbothermic reduced titanium-bearing blast furnace slag by acid andsodium hydroxide. The experimental data of leaching indicate that the shrinking core model with chemical reaction controlled process is most applicable. Furthermore, themain products are TiC and SiO2 after acid leaching and TiCafter sodium hydroxide leaching.2.The effects of reduction temperature, isothermal treatment time and carbon particle sizes on the formation of TiC were studied by X-ray diffraction(XRD) and scanning electron microscope(SEM). The SEM pictures show thatthe size of C has little influence on theparticle size of TiC in both cases with or without the addition of Si powder. The experimental results show that the shrinking core model is applicable and the carbothermic reduction is controlled by the chemical reaction. The apparent activation energy of reaction could be obtained to be 69.16kJ/mol.3. 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 3-17mol%. 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.4. The viscosities ofblast furnace melts containing different volume percentages of TiC particles are measured at different temperatures. In order to study the influences of particle size of TiC, two types of TiC particles (1.0 μm and 10μm) are utilized. It is found that for the same volume percentage of TiC addition, the smaller the size of TiC particle is, the higher the viscosity will be. Furthermore, the Arrhenius law was obeyed for both the melts with and without TiC particles. The viscosity for the TiC-containing melt increases with the addition of the particles, but decreases as increasing the rotation speed. It is also found that the temperature has little influence on the relative viscosity. By comparing with the model calculated viscosity, the influence of TiC appears to be much greater than that estimated by the Einstein-Roscoe equation. Better calculated resulted could be obtained by allowing the parameter of Einstein-Roscoe equation to vary with the rotation speed and particle size of TiC.