Heavy metals partitioning in fly ashes between various stages of electrostatic precipitator after combustion of different types of coal

Abstract

The paper presents experimental studies of heavy metals partitioning in fly ash particles after combustion of various types of coal (lignite, sub-bituminous, bituminous, and anthracite) between different fields of electrostatic precipitator. The concentration of the following heavy metals has been measured: Ba, Sr, Zn, Cu, Ni, Cr, As, Co, Pb. The results show that the concentration of heavy metals is higher in small particles (<1μm) than in larger ones that correlates with consecutive fields of electrostatic precipitator. This relation is independent of the type of combusted coal, although differences in the values of concentrations of individual elements exist. Better knowledge on heavy metal partitioning in the combustion-precipitation system is needed for the development of emission control devices of higher efficiency, such as electrostatic agglomerators or hybrid filters, particularly for PM1 particles. The results of these investigations can also be helpful in the designing of novel physical and chemical processes for recovery selected trace elements from fly ash, for their further utilization.