Investigation of reducing particulate matter (PM) and heavy metals pollutions by adding a novel additive from metallurgical dust (MD) during coal combustion

In this study, a novel additive from metallurgical dust(MD)was applied to reduce particulate matter (PM) emissions and heavy metals pollutions during coal combustion. PM samples were collected and divided into 13 stages from 0.03 mu m to 10 mu m. Results showed that the irregular morphology of fine particles with equal to/less than 2.5 mu m (PM2.5), fine particles with equal to/less than 4 mu m (PM4) and fine particles with equal to/less than10 mu m (PM10) gradually became dense with increasing of MD content. The PM10 concentration with 10% MD dosage was about 3 times higher than that of raw coal. Zn, Ti, Cu and Cr were the most abundant elements in all particulate matters (PMs), meanwhile, heavy metals accumulated into large particles with increasing MD content. The mechanism of reducing PM emissions indicated that MD reacted with nucleation elements (Pb, Cd, etc.) and trapped a large amount of alkali metal (Na/K), which aggregated into large particles. The study highlights the potential of adding MD into coal to prevent the attachment of heavy metals onto ultrafine particles, thereby reducing the heavy metals emissions.