宿州矿区煤矸石风化物中重金属元素的粒径分布特征研究

On particle size distribution characteristics of heavy metal in weathered coal gangue from Suzhou mine area

在宿州朱仙庄、祁南和桃园煤矿共采集煤矸石及其风化物样品各12个,利用原子吸收分光光度法测定了煤矸石、风化物及风化物4个粒径段颗粒物中重金属Cu、Pb、Zn、Cr、Cd、Ni的含量,重点探讨了矸石风化颗粒物在4个粒径段的质量组成、重金属元素含量分布以及元素总量赋存特征,并借助离散系数指标定量分析了风化物重金属元素的粒级效应。结果表明:(1)矸石风化物中以粗颗粒为主,其质量分布主要集中在0.15-0.25 mm和大于0.25 mm两个粒径段;(2)4个粒径段的风化颗粒物中重金属元素含量及元素总量呈现出相似的粒径分布特征,最大值均出现在小于0.075 mm粒径段,最小值则出现在0.15-0.25 mm和大于0.25 mm两个粒径段,说明元素更易赋存在细颗粒物中;(3)通过定量对比6种元素的粒级效应,其离散系数大小依次为Pb>Zn>Cd>Ni>Cr>Cu,其中Pb和Zn粒级效应显著,Cd、Ni和Cr粒级效应中等,而Cu的粒级效应较弱。

An investigation of 24 samples （12 coal gangue samples and 12 weathered coal gangue samples） which have been collected from different coal mines was conducted to study mass composition of particulate matter, content distribution and total a-mount characteristics of heavy metals （Cu, Pb, Zn, Cr, Cd, Ni） in 4 particle size segments, and to quantitative evaluate particle size effect of heavy metals in weathered coal gangue. The results show that： （1）The mass proportion of coarse grain size was higher in weathered coal gangue, and there were 29. 06% and 34. 27% particulate matter in the diameter of 〉 0. 25mm and 0. 15-0. 25mm respectively; （2）Element contents and total amounts of heavy metals in the 〈 0. 075mm particle size segment were highest, while in 0. 15-0. 25mm and 〉 0. 25mm were lowest, which indicated that the heavy metals were more enriched in fine grain size; （3）The or-der of variation coefficient in 6 heavy metal elements was： Pb 〉 Zn 〉 Cd 〉 Ni 〉 Cr 〉 Cu, and there were remarkable particle size effect with Pb and Zn, moderate effect with Cd, Ni and Cr, weak effect with Cu.