煤及其燃烧产物中有害痕量元素的淋滤特性研究

通过对我国西北部上湾与石嘴山电厂原煤、底灰和飞灰中As、Pb、Cd、Mop、Mo、Co和U等有害痕量元素在不同条件下的淋滤实验,采用原子荧光光谱（AFS）和电感耦合等离子体质谱法（ICP-MS）测定了痕量元素在2套（6个）样品、3种淋滤介质、4个不同时间段获取的淋滤液中的浓度,对比不同元素间淋出率、60h的最大淋出率和淋滤强度的差异性,分析痕量元素在不同条件下的淋滤特性;通过对比元素在原煤和燃煤产物中的含量、60h的最大淋出率以及淋滤液中元素的浓度,参考相关地下水的环境质量标准对痕量元素的环境效应进行了综合评价：As与Se的淋滤性较差,淋滤液中的最大浓度较低,对环境造成危害的可能性很小;Pb与Cd在淋滤液中的最大浓度较高,可能对环境造成危害.Mo与Co的淋出性好,淋出率高,同时淋滤液中的最大浓度是三类地下水环境质量标准的5～10倍,对环境造成危害的可能性最大.

Leaching characteristics of hazardous trace elements in coal and ash

Samples of coal, bottom ash and fly ash have been collected from Shizuishan and Shangwan power plants, Northwest of China. Comparative leaching experiments were carried out by different solution and leaching time. Leaching characteristics of environmentally-sensitive trace elements, such as As, Pb, Cd, Se, Mo, Co and U in coal, bottom ash and fly ash during different time was conducted. Based on the contents of trace element in different solutions measured by atomic fluorescence spectroscopy (AFS) and inductively coupled plasma mass spectrometry (ICP-MS), the leaching proportion, maximum relative leaching amount and leaching intensity of trace elements have been calculated. The result showed that the leaching behavior of different elements vary greatly, and pH value of solutions, leaching times and sample type have strong influence on leaching behavior. Reference to the environmental quality standard of underground water, the environmental impacts of trace elements were evaluated.