Development of Red Mud Coated Catalytic Filter for NO.sub.x Removal in the High Temperature Range of 300-450 °C

The red mud (RM) coated catalytic filter was developed as efficient multifunctional material to simultaneously remove NO.sub.x and dust in the high temperature range of 300-450 °C, which exhibits excellent deNO.sub.x activity/durability as well as low pressure drop with more than 80% NO conversion in the presence of H.sub.2O/SO.sub.2. The performance of the RM coated catalytic filter is obviously superior to that of the reference samples of V-W-Ti and Fe-Ti based filter. The multiple characterization data (including XRD, XRF, BET, SEM, TPX and LPSA) reveals the amorphous state of the RM catalyst with high dispersity of Fe active sites accounts for the high adsorption capacity of NH.sub.3 and thus excellent deNO.sub.x performance. Moreover, the prepared colloidal RM slurry is very uniform and stable with the smallest average particle size, which reduces the blocking up of the channel of filter and facilitates the decrease of pressure drop as well as the improvement of deNO.sub.x activity. The excellent deNO.sub.x performance, low pressure drop together with the low cost make the RM coated catalytic filter to be promising application prospect for purification of the high-temperature flue gas with high content of dust such as in cement and glass furnaces.