粉煤灰是我国堆放量最大的固体废弃物之一,本文采集淮北低硫燃煤电厂粉煤灰样品,测试分析了样品矿物组成和微量元素含量,探讨了低硫煤燃煤电厂粉煤灰理化特征.结果表明:(1)燃煤电厂粉煤灰中飞灰粒径主要集中在1—100μm,底渣粒径主要集中在250μm以上,除Mn元素之外,Co、Cr、Cu、Hg、Ni、Pb、V、Zn易吸附于飞灰等细颗粒物中;(2)飞灰和底渣的矿物组成含量不同,风化过程中晶格能较低的矿物易分解;(3)Co、Cr、Cu、Hg、Ni、Pb、V、Zn含量高于中国土壤背景值,具有潜在污染能力;(4)Co、Cr、Cu、Hg、Ni、Pb、V、Zn与S正相关,随着粉煤灰的自然风化,赋存在硫化物矿物中的这些微量元素将会分解进入环境,Hg由于其易挥发以及粉煤灰的吸附作用等会在粉煤灰中进一步累积.
Coal ash is one of the largest volume solid wastes in China.In this study,fly ash and bottom ash were collected from a low sulfur coal-fired power plant in Huaibei City,and their physicochemical characteristics including mineral compositions and concentrations of trace elements were measured.The results showed that:(1) The particle size of fly ash mainly distribute in the range of 1—100 μm,where as the particle size of bottom ash was mostly larger than 250 μm.Except Mn,heavy metals were easily adsorbed on the surface of fly ash.(2) The mineral compositions of fly ash and bottom ash were different,and the minerals of low lattice energy were readily decomposed.(3) The contents of Co,Cr,Cu,Hg,Ni,Pb,V,Zn in coal ash were higher than the soilbackground values of China,being the potential contaminants.(4) Co,Cr,Cu,Hg,Ni,Pb,V,Zn in coal ash had positive correlations with S; these elements would be released into the environment upon natural weathering,while Hg might be further concentrated into the fly ash due to its properties and adsorption capacity of fly ash and other factors.