Decomposition Kinetics of Titania Slag in Eutectic NaOH-NaNO3 System
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The decomposition kinetics and mechanism of titania slag in eutectic NaOH-NaNO3 system were studied in the temperature range 623 K to 723 K (350 °C to 450 °C). Decomposed products were examined using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. It has been identified that the main product is Na2TiO3 and the decomposition kinetics of titania slag followed a shrinking unreacted core model. It is proposed that the chemical reaction process was the rate determining step with apparent activation energy of 62.4 kJ/mol. NaNO3 was mainly acted as oxygen carrier and mass transport agent to lower the viscosity of the system. The purity of TiO2 obtained in the product was up to 99.3 pct. A flow diagram to produce TiO2 and to recycle the media was proposed.
KeywordsNaNO3 Apparent Activation Energy Glassy Phase Particle Size Fraction Titanium Compound
The authors gratefully acknowledge supports from the project supported by the Major Program of the National Natural Science Foundation of China (Grant No. 51090380), the National Basic Research Program of China (973 Program, Grant Nos. 2013CB632604, 2013CB632601), National Science Foundation for Distinguished Young Scholars of China (Grant No. 51125018), and National Natural Science Foundation of China (Grant Nos. 51374191, 51104139).
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