Hu Meilong

Effect of the Basicity on the Crystallization Behavior of Titanium Bearing Blast Furnace Slag

Abstract Basicity of titanium bearing blast furnace (BF) slag is critical for its crystallization behavior. Thermodynamics calculation indicates that rutile is the main phase after crystallization (or at room temperature). It precipitates during the cooling when the basicity of the slag is lower than 0.7. With increasing basicity, perovskite appears and becomes the main phase instead which contains titanium. Crystallization temperature of perovskite is higher than that of rutile and the other phases. Namely, perovskite crystallizes firstly from the molten slag during decreasing temperature. XRD analysis shows that CaTi21O38 is the main phase with a basicity of 0.6. CaMg0.39Al0.87Ti0.48Si1.26O6, CaTiSiO5 and CaMgSi2O6 are the main crystallization phases with a basicity of 0.8. The difference between experimental and thermodynamics calculation is due to the complicate crystallization behavior of the multiple slag under super cooling rate. When the slag basicity increases to 1.1, the main precipitatied phase is perovskite, which agrees well with theory calculation. In addition, the crystal structure of the synthesized titanium bearing slag is basically similar regardless of the basicity.

Effect of Electrical Conductivity and Porosity of Cathode on Electro-Deoxidation Process of Ilmenite Concentrate

Abstract The performance of the cathode is always closely related to the electro-deoxidation process and its current efficiency. In this work, the effect of sintering temperature on the electrical resistivity of an ilmenite concentrate cathode was measured. The results show that the sintering temperature has a significant effect on the electrical conductivity of the cathode. The electrical resistivity of the ilmenite concentrate cathode decreases with increasing of the sintering temperature and increasing of the contact area. Besides, the influence of the cathode porosity on electrochemical process during preparation of Ti-Fe alloy in molten salt was studied. The results also reveal that the porosity of ilmenite concentrate cathode directly affects the electro-deoxidation process. The increasing of porosity is beneficial to the formation of intermediate product (CaTiO3) and improvement of the current efficiency.

Crystallization Behavior of Molten Blast Furnace Slag Using Confocal Scanning Laser Microscope

Extracting perovskite from high titanium-bearing blast furnace (BF) slag is a green and potential method to recover the second titanium resource. The non-isothermal crystallization process of perovskite in synthesized high titanium-bearing slag was studied in situ by confocal scanning laser microscope (CSLM) with cooling rate of 20 K/min. The results showed that perovskite was the primary phase formed during cooling process in the titanium-bearing synthesized slag (TiO2=23%). Perovskite started to precipitate at 1719 K and finally presented an orthogonal straight lines morphology.