标题:Alkali fusion using sodium carbonate for extraction of vanadium and tungsten for the preparation of synthetic sodium titanate from spent SCR catalyst
摘要:Alkali fusion method to extract vanadium and tungsten from spent SCR catalyst and to simultaneously prepare synthetic sodium titanate for the purpose of preparation of feedstock for TiO 2 manufacturing by hydrometallurgical processing was investigated. Based on the Na 2 O-TiO 2 phase diagram and experimentally obtained results, appropriate alkali-fusion temperature and molar ratio (MO x /Na 2 O + MO x ) were determined to prepare soluble vanadium, tungsten salts, and sodium titanate. As results, the extraction efficiency of vanadium and tungsten was >99% and sodium titanate as feedstock for making TiO 2 was obtained under the following alkali fusion conditions: Temperature, 950 °C; reaction time, 20 min; molar ratio, 0.5. When the molar ratio (MO x /Na 2 O + MO x ) was less than 0.5, complete liquidized product (eutectic melt of the feedstock and Na 2 CO 3 ) was obtained at the given conditions. This method, compared to conventional alkali roasting, is advantageous for rapid synthesis of water-soluble compounds for leaching of vanadium and tungsten, and for use as feedstock for the preparation of TiO 2 by hydrometallurgical route.