The Study On Constitutions And Mechanism Of Composite Additives With Catalytic Combustion,Simultaneous Desulfurization And Denitrification In Cement Industry

In view of the current energy and environmental pressure of the cement industry,it is very effective to realize energy saving and environmental pollution control by researching coal burning additives for cement industry.Therefore,the catalytic combustion,simultaneous desulfurization and denitrification of coal burning additives for cement industry are researched in this work.Meanwhile,the dispersing agents for coal burning additives are studied.This work has important significance.In this paper,two different types of inferior coals were selected for investigation.Four kinds of chemical reagents?BaCO₃,MnO₂,NaCl,NaClO₄?and three kinds of industrial wastes?steel slag,desulfurization slag,cold-rolled iron oxide?were selected as additives in our work.Among them,the chemical reagents were a whole,and the three industrial wastes were used to replace the whole as composite additives.First of all,the catalytic combustion experiments of composite additives were carried out by a drop tube furnace system.Burnout rate,SO₂ and NO_X content were studied as the indicator to evaluate the catalytic combustion and the simultaneous removal of SO₂ and NO_X.The results showed that the burnout rate,SO₂ and NO_X content of different sample varied.The composite additives not only increased the burnout rate,but also removed the NO_X and SO₂ simultaneously.Overall,the substitute of chemical reagents by cold-rolled iron oxide worked better than others,and the optimum substitution amount was 0.2%.Secondly,the visible light spectrophotometer was used to researched four dispersing agent(C₆H₅O₇?NH₄?₃,CMN,PAM,Na₆O₁₈P₆).Light transmittance was studied as the indicator to evaluate the disperse effect for three indissolvable substances?BaCO₃,MnO₂,cold-rolled iron oxide?in the composite additives.The results showed that the four dispersing agents have different degree of disperse effect on the three indissolvable substances,and the Na₆P₆O₆ worked best.Furthermore,the disperse effect of Na₆P₆O₆ on the composite additives was studied.The results showed that Na₆P₆O₆ also had good disperse effect on the composite additives,and the optimum addition amount was 0.2%.Finally,scanning electron microscopy and X-ray diffraction analysis were selected to discuss catalytic combustion mechanism of the composite additives,and a thermal gravimetric analyzer was used to research combustion characteristics of pulverized coal.In addition,the most probable mechanism function was obtained by thermal analysis method.The results showed that the composite additives could change the crystal structure and surface morphology of the raw coal.At the same time,it could reduce the ignition temperature and burnout temperature,and improve the burnout indexes.The most probable mechanism function model was f???=?1-??2...