| 内容提要: |
The partitioning of twelve environmental trace elements (Be, V, Cr, Mn, Ni, Cu, Zn, As, Se, Cd, Hg and Pb) in combustion products were carried out during 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℃~830℃. As, Se, Hg have low REs in both BA and FA in three kinds of boiler, whereas Cr, Zn, Pb are found to have low REs only in BA. Mass balance suggests that trace elements can be classified into four groups based on their volatility. Se and Hg are classified into group A for high volatility. Medium volatile elements are divided into two groups. Zn, As, Cd, Pb are classified into Group B for enriched in fly ash partly. Group C (Be, V, Cr, Ni, Cu) are absolutely condensed on fly ash with medium volatile. Group D is Mn, which is not volatile and mainly remain in combustion residues. |