Development of Red Mud Coated Catalytic Filter for NOx 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 NOx and dust in the high temperature range of 300–450 °C, which exhibits excellent deNOx activity/durability as well as low pressure drop with more than 80% NO conversion in the presence of H2O/SO2. 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 NH3 and thus excellent deNOx 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 deNOx activity. The excellent deNOx 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. The preparation of RM catalytic filter and the comparison of SCR performance between three kinds of catalytic filters.