煤中可溶性有机质荧光光谱特征及其对微量元素赋存的影响

Fluorescence spectrum characteristics of dissolved organic matter and its effect on occurrence of trace elements in coal

煤中微量元素的赋存状态有多种形式,其中大部分微量元素都能与煤中有机质结合。煤中有机质的含量与煤的煤化程度有一定联系。实验选取了褐煤、烟煤、无烟煤3种共7个煤样进行分析,采用ICP-AES方法测定了煤中微量元素含量,采用三维荧光光谱仪分析了3种煤的可溶性有机质(DOM)的荧光光谱特征,并运用平行因子法对荧光数据进行了深入分析,探讨了煤中溶解性有机质与煤中微量元素赋存形态之间的关系。结果表明,煤中不同微量元素在褐煤、烟煤、无烟煤中的分布有差异,As,Mg,Cd,Mn在褐煤中含量最高,Li,Sr在无烟煤中含量最高,而Cu,Co在3种煤中含量差异不明显。褐煤中可溶性有机质以腐殖酸类为主,烟煤的荧光基团有腐殖类和类蛋白类,而无烟煤中未能检测出荧光峰。荧光强度亦随着煤化程度的递增呈现递减。煤中As和Mg的赋存与煤中可溶性有机质可能存在着一定联系,即煤中可溶性腐殖酸荧光强度越大,As和Mg越丰富,而Li和Sr则相反。

Trace elements in coal exist in many forms,most of which are combined with organic matter. Coal organic matter content also determines the degree of integration and the bound state of trace elements in coal. In terms of lignite,bituminous and anthracite coal,this paper analyzed the trace element content monitored by ICP-MS,studied the fluorescence spectroscopy characteristics of the dissolved organic matter（ DOM） existed in coal using 3D-EEM Absorbance and Fluorescence Scanning Spectrometer,and conducted a further investigation on the relationships of DOM with the degree of coalification,the levels and status of trace elements in coal with a utility of PARAFAC system.The conclusions indicated that there was significant difference in trace elements.The highest content was ranked by As,Mg,Cd and Mn in lignite,while Li and Sr in anthracite. There was no significant difference in the content of Cu and Co. The fluorescence spectrum characteristics of dissolved organic matter revealed that only humic-acid fluorescence peak was detected in lignite and both the peaks of humic acid and protein in bituminous,while no fluorescence peak in anthra-cite.Also the fluorescence intensity decreased with the increase of coal rank.It was found that the occurrence of certain trace elements related with the dissolved organic matter in coal,which the higher fluorescence intensity of humic acid,the richer the contents of trace elements for As and Mg,while the rarer for Li and Sr.