摘要
火电厂排放的粉煤灰是重要的大气颗粒污染物之一,利用粉煤灰的磁性监测环境污染是新近发展的新手段.应用矿物磁测技术和X射线衍射对浙江省主要电厂排放的粉煤灰的矿物磁性特征和磁性矿物学,以及与重金属元素的关系进行了研究,结果表明粉煤灰具有较高的磁化率(χ)、软剩磁(IRM20mT)和饱和等温剩磁(SIRM)值,粉煤灰频率磁化率(χfd)的平均值为2.5%,磁性矿物以多畴(MD)颗粒存在,粉煤灰的剩磁矫顽力(BCR)在42～53 mT之间.矿物测试结合X射线衍射分析表明粉煤灰中的氧化铁矿物以Fe3O4和Fe2O3-α为主,粉煤灰的磁化率与Fe、Mn、Pb、Zn、Cu、Cd含量呈显著线性正相关,相关系数(r)分别是0.924,0.866,0.725,0.756,0.945和0.867,磁化率可作为粉煤灰中重金属元素含量的代用指标.
The fly ash emitted from power plant was one of the important atmospheric particle pollutants. Magnetic measurements of fly ash have been used to differentiate atmospheric particulate pollution and outline the areas with increasing loading of heavy metals due to industrial activities. Magnetic susceptibility （X）, frequency-dependent susceptibility （Xfd）, acquisition of isothermal remanent magnetization （IRM）, alternating-field demagnetization of saturation remanence for fly ash were measured. X-ray diffraction analysis of magnetic extracts of fly ash was used to identify ferringanetic minerals. Mineral magnetism of fly ash was characterized by higher X, Soft IRM and SIRM values.The Xfd values of fly ash vary from 0.1% to 5.4% with a average of 2.5%, suggesting the dominance of multidomain（MD） grains in ferrimagnetic components. The IRM acquisition curves, and demagnetization curves and S.100mr ratio of flyash showed that magnetite （Fe3O4） and hematite （Fe2O3-α） were the main oxide iron minerals in fly ash. This finding wasalso evidenced by X-ray diffraction analysis. The best correlations have been found between magnetic susceptibility and the metals Fe, Mn, Pb, Zn, Cu and Cd in fly ash. Correlation coefficients between those parameters are 0.924 for Fe, 0.866for Mn, 0. 725 for Pb, 0. 756 for Zn,0. 945 for Cu and 0. 867 for Cd, respectively. The present study showed that magnetic susceptibility is a potential indicator of heavy metal contents in fly ash.
出处
《矿物学报》
CAS
CSCD
北大核心
2005年第2期141-146,共6页
Acta Mineralogica Sinica
基金
国家自然科学基金资助项目(批准号:40371056)
全国优秀博士学位论文作者专项资金资助项目(编号:200149)
关键词
粉煤灰
磁化率
磁性矿物
环境污染
fly ash
magnetic susceptibility
ferrimagnetic mineral
environmental pollution
