The spatial-temporal pattern of sintered flue gas emissions in iron and steel enterprises of China

This study provides a comprehensive survey of emissions from the sintering process in China to give an indication of the actual emission situation. Survey data were taken from China's continuous emission monitoring system (CEMS) from 209 sintering plants from 2015 to 2016. The standard-reaching rate of national emissions and the oxygen content ratio of the sintering process were considered as two indicators to evaluate the emissions level. Moreover, the CEMS-based emission factor (EF) estimation method was applied to improve the accuracy of EF estimation compared with existing methods. The emission concentration of total suspended particles (PM_TPS), SO₂ and NO_x decreased, and the standard-reaching rate of these three pollutants increased from 92%, 94% and 98%, respectively, to almost 100% during the research period. The average emission concentration in eastern China was lower than that in western China. More samples exceeded the oxygen regulation of <16% in 2016 than in 2015. This indicates that most plants should control air leakage to decrease the oxygen content. The national monthly average EF of PM_TPS and SO₂ decreased from 0.013 to 0.009 kg/ton-sintering and from 0.036 to 0.026 kg/ton, respectively, during the research period. The EF of NO_x remained around 0.068 kg/ton. These results are much lower than the results of former studies.