燃烧温度对两淮烟煤中汞含量与赋存形态的影响

Influence of Combustion Temperature on Mercury Content and Occurrence Form of Bituminous Coal in Huainan and Huaibei Regions

为了调查两淮烟煤中汞元素在不同燃烧温度下的地球化学行为,在两淮地区4个典型煤矿床分别采集了4个烟煤样品。采用程序升温石英管式炉获得400、500、600、700、800℃和900℃下的煤灰样品。利用ICP-MS测定了原煤及煤灰样品中Hg元素的含量,结合X射线衍射(XRD)和傅里叶转换红外光谱(FTIR)分析,取得如下成果:烟煤中Hg的丰度值约为0.1μg/g;烟煤中Hg主要以残渣态形式为主,其次为可交换态和碳酸盐结合态;烟煤中Hg主要挥发温度位于400~500℃间,仅有少量的Hg会赋存在灰渣之中;XRD实验表明,烟煤中黏土矿物含量变化与汞的变化关系密切;此外,残渣中固定碳的存在影响着其Hg含量变化;FTIR实验表明,烟煤中Hg含量与C=O官能团含量呈较好的正相关关系,表明煤中C=O含量可以用作检测煤中Hg含量的指示剂。

In order to investigate the geochemical behavior of mercury in two bituminous coal at different combustion temperature,4 samples of bituminous coal were collected from 4 typical coal mines in Huainan and Huaibei regions. The samples of coal ash at400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃ and 900 ℃ were obtained by a quartz tube furnace. The content of Hg element in coal and coal ash samples were determined using ICP-MS, combined with X ray diffraction（XRD）and Fourier transform infrared spectroscopy（FTIR）analysis. The results obtained are as follows： the abundance of Hg in bituminous coal is about 0.1 μg/g; Hg in bituminous coal is mainly in the form of residue, followed by exchangeable and carbonate binding states; volatile temperature of Hg in bituminous coal is at 400 ℃ to 500 ℃, a small amount of Hg is deposited in the slag; XRD experiments show that the variation of clay mineral content in bituminous coal is closely related to the variation of mercury; the presence of fixed carbon in the residue affects its Hg content; FTIR experiment shows that Hg content in bituminous coal has a good positive correlation with C=O functional group content,it indicates that the content of C=O in coal can be used as an indicator to detect the Hg content in coal.