Abstract
The decomposition kinetics of niobium ore in the NaOH system was studied experimentally. The results show that the reaction products are sodium metaniobate and sodium niobate formed by the reaction of pyrochlore with sodium hydroxide under roasting. The effects of temperature, particle size, and mass ratio of alkali-to-ore were studied. The conversion rate of niobium exceeded 99 pct after 20 minutes at 923 K (650 °C) with a mass ratio of alkali-to-ore 1.2:1 and with initial particle size 75 to 106 μm. The kinetic study indicates that the shrinking core model is applicable and the process is controlled by a chemical reaction. The activation energy was calculated to be 78.82 kJ mol–1.
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The financial support for this work from Plan 863 Project of China under Grant 2009AA06Z103 and the National Natural Science Foundation of China under Grant 51004094 is greatly appreciated.
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Manuscript submitted May 22, 2012.
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Yang, XL., Wang, XH., Wei, C. et al. Decomposition of Niobium Ore by Sodium Hydroxide Fusion Method. Metall Mater Trans B 44, 45–52 (2013). https://doi.org/10.1007/s11663-012-9766-8
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DOI: https://doi.org/10.1007/s11663-012-9766-8