Preparation Of Blast Furnace Slag SCR Denitration Catalyst And Its Mechanism Of At Low Temperature

In order to control the NOx of low-temperature flue gas in the non-power industry,the preparation cost of the denitration catalyst is reduced.This subject takes the blast furnace slag of a steel plant as the research object,prepares a series of denitration catalysts,tests and characterizes its performance and structure,and analyzes its SCR low temperature denitration mechanism.Modification of oxides other than CaO,MgO,Al2O3 and SiO2 is used to adjust the alkalinity of blast furnace slag,and the effects of different oxide modified blast furnace slag and alkalinity on its denitrification performance are clarified.Using blast furnace slag powder as the main material,bentonite as the binder,adding a certain amount of water to prepare a shaped blast furnace slag,using different methods to prepare a denitration catalyst,comparative analysis of its denitration performance and screening the best preparation process parameters.Ultrasonic-assisted Mn salt modified blast furnace slag was used to prepare the denitration catalyst,and the effects of different ultrasonic power and ultrasonic time on the slag-based catalyst were investigated.Adding the active additive Ce under the best preparation conditions,combined with the catalyst's denitration performance and sulfur resistance performance,and XRF,XRD,FT-IR,BET,XPS and SEM characterization,to elucidate its SCR denitration mechanism at low temperature.The experimental results show that the modification of alkaline oxides(CaO and MgO)has significantly improved the denitration performance of slag.The denitration performance increases with the increase of oxide content,while the acidic oxide(Al2O3 and SiO2)has no effect on the denitration performance of blast furnace slag.The basic oxide modified blast furnace slag can increase the NO removal efficiency by increasing the number and distribution of basic functional groups on its surface.In order to prepare shaped catalyst,accordin g to the denitration performance of different content of bentonite to blast furnace slag of the shaped carrier,a 4:1 ratio was selected as the molding condition;citric acid impregnation method,hydrothermal decomposition method and mixing method were used to prepare Mn-based blast furnace slag catalyst The denitration performance of the catalyst prepared by the hybrid method is superior to other methods.On the basis of the mixing method,the ultrasonic effect is introduced to make the prepared catalyst more dispersed active components.The best ultrasonic conditions are:ultrasonic power 80W and ultrasonic time 20min.In order to further improve the activity and sulfur resistance of the Mn-based blast furnace slag catalyst,the active additive Ce was introduced to modify the blast furnace slag under the best ultrasonic action,and the denitration performance of the Mn-Ce blast furnace slag catalyst was further improved and had a good performance with anti-sulfur properties.