Partitioning of trace elements in coal combustion products: A comparative study of different applications in China

The partitioning of twelve trace elements (Be, V, Cr, Mn, Ni, Cu, Zn, As, Se, Cd, Hg and Pb) in combustion products were carried out in this work. Samples of raw coal (RC), bottom ash (BA), fly ash (FA) were collected from China power plants and heating stations. The relative enrichment factors (RE) were calculated, and the influences of temperature, boiler types, coal type and characteristics of trace elements were discussed. The results indicate that only As, Se, Cd, Pb are strongly depended on temperature between 700 degrees C and 830 degrees C. As, Se, Hg have low REs in both BA and FA in three kinds of boiler, whereas Cr, Zn, Pb have low REs only in BA. Mass balance suggests that trace elements can be classified into four groups based on their volatility. The results of this study were based on China's actual power plants and heating stations, and the data could be used as a reference to the selection of coal, boiler type and operate temperature.