Characteristics of fine particulate matter released from burning coal with high content of alkali and alkaline earth metal

The amount of Zhundong coal is huge. The high content of alkali and alkaline earth metal (AAEM) in Zhundong coal results in more fine particulate matter during its combustion. In this paper, the emission of fine particulates from AAEM rich coal in Zhundong and AAEM poor coal in Zhunnan was investigated in a drop tube furnace. The size distribution, concentration and composition of the particulates were measured. The distribution of Na, K, Mg, Ca, Fe in fine particulates and their effects on the generation of fine particulates were obtained. The results show that the fine particulates from AAEM rich coal combustion mainly consist of sulfates and the oxides of AAEM. The amount of fine particulates from burning AAEM poor coal decreased significantly. Co-firing of AAEM rich coal with AAEM poor coal had an obviously synergistic effect of reducing the fine particulates emission. Ca and Fe played an important role in PM₁₀ reduction during blended coal combustion.