Influence of raw material moisture and fuel on sintering flue gas volatile organic compounds emissions

Volatile organic compounds (VOCs) present significant risks to both human health and the environment. As a result, there has been increasing research on their formation processes, emission patterns, and emission reduction technologies. Sintered ore, a key raw material in ironmaking, requires substantial amounts of fossil fuels such as coal and coke in its production, leading to significant VOC emissions. However, research on VOC emission patterns during the sintering process remains limited. Thus, the influence of factors such as moisture content in the sintering mixture, fuel type, fuel ratio, and coal-to-coke ratio on VOC emissions was investigated through sintering cup experiments. Additionally, the reaction pathways of hydrocarbons within the sintering bed were analyzed using temperature distribution and thermodynamic calculations. In the sintering process using coke powder, the emissions of total volatile organic compounds and non-methane hydrocarbons per ton of sintered ore are 18.78 and 11.14 g, respectively, whereas emissions from coal are substantially higher at 378.27 and 32.55 g. VOC emissions exhibit a linear correlation with the total volatile matter input during sintering, with most VOCs originating from volatile matter. The improved heat transfer conditions reduce the preheating zone thickness, allowing more VOCs to remain in the high-temperature region.