Effects of slurry properties on simultaneous removal of SO2 and NO by ammonia-Fe(II)EDTA absorption in sintering plants

Abstract

Simultaneous removal of SO2 and NO by ammonia-Fe(II)EDTA absorption has become a research focus in recent years. In order to get useful data for further industrialization, in this work the practical operating conditions of the sintering plant were simulated in a pilot-scale reactor in order to explore the effects of slurry properties on simultaneous removal of SO2 and NO. It was not conducive to the absorption of NO when (NH4)2SO4 concentration and slurry temperature had been increased. The initial NO removal efficiency decreased from 90.63% to 44.12% as the (NH4)2SO4 concentration increased from zero to 3.5 mol/L. With the increasing of Fe(II)EDTA concentration, SO32− concentration and pH value of absorption liquid and the absorption capacity of NO by Fe(II)EDTA solution increased. Especially the existence of SO32− ions in slurry had significantly improved the service life of chelating agents. The NO removal efficiency only decreased by 16.46% with the SO32− concentration of 0.3 mol/L after 30-min of operation. The chloride ions had no effects on the absorption of SO2 and NO. The results indicated that changes of slurry properties had different effects on simultaneous removal of SO2 and NO by ammonia-Fe(II)EDTA solution. The basic data offered by the experiments could effectively contribute to further industrial applications.