Chlorination Kinetics of Titanium Nitride for Production of Titanium Tetrachloride from Nitrided Ilmenite
- PDF / 2,451,630 Bytes
- 13 Pages / 593.972 x 792 pts Page_size
- 71 Downloads / 246 Views
ODUCTION
TITANIUM tetrachloride (TiCl4) is considered as intermediate raw material to produce metallic titanium and titanium dioxide (TiO2) pigment which are two main products of titanium industries. The demand for TiO2 pigment has widely increased in coatings, paper and paperboard, inks, plastics, water treatments, rubber industries, and photocatalytic applications due to its excellent UV protection, resistance to color changes, brilliant whiteness, and other physical properties.[1–4] TiCl4 has also been used as catalyst for polymerization in producing crystalline polystyrene, ethylene, propylene,[5] manufacturing nanostructured TiO2-based electron transport layers in perovskite and dye-
ELTEFAT AHMADI, SHEIKH ABDUL REZAN, NORLIA BAHARUN, SIVAKUMAR RAMAKRISHNAN, and AHMAD FAUZI are with the School of Materials & Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia. Contact e-mail: [email protected] GUANGQING ZHANG is with the School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia. Manuscript submitted November 24, 2016.
METALLURGICAL AND MATERIALS TRANSACTIONS B
sensitized solar cells,[6] and synthesizing photocatalytic nanoparticles.[7] Literature survey shows that the current practice in commercial TiCl4 production plants involves fluidized bed chlorination of titanium slag (>90 pct TiO2), natural rutile (~95 pct TiO2), and synthetic rutile (SR) (90 to 95 pct TiO2) by carbochlorination at high temperatures of about 1073 K to 1373 K (800 C to 1100 C).[8] In high-temperature chlorination, most of impurities such as iron and other metal oxides in feedstock are chlorinated to form metal chlorides which not only adversely affect the efficiency of chlorination but entail the removal by subsequent purification processes. The purified TiCl4 precursor is then converted to metallic Ti sponge through the mainstream Kroll process by magnesiothermic reduction.[9] or by recently developed CSIRO’s continuous titanium powder manufacture process (TiRO). The TiRO process comprises two main processing steps: (a) the reaction of TiCl4 and Mg in a fluidized bed reactor (FBR) to produce Ti metal powder and MgCl2 and (b) the separation step where the Ti metal powder is separated from the MgCl2.[10] Besides the abovementioned thermochemical methods, different electrochemical routes using high-grade TiO2 have also been developed for direct Ti metal production and lowering the processing
costs. Fray–Farthing–Chen (FFC) Cambridge process[11] and OS (Ono and Suzuki) process[12] are only some successful examples based on the electrochemical method that employs molten salt with titanium dioxide (TiO2) as the starting material.[1,13,14] Nevertheless, most of the direct metallothermic reduction processes require iron (Fe) free raw materials, high-grade TiO2, and SR as starting feedstock.[13,15–17] On the other hand, it has been reported that relatively pure TiCl4 could be produced by selective low-temperature chlorination o
Data Loading...
