炉内灰渣沉积物中矿物元素分布的电子探针分析

THE ELECTRON PROBE ANALYSIS OF MINERAL ELEMENTARY DISTRIBUTIONAT ASH DEPOSITION FROM FURNACE

提出了一种研究煤灰沉积机理及形成过程的新方法。从炉内选取5个不同部位的灰渣样品，利用电子探针对各矿物元素沿样品厚度方向的分布进行了分析，结果表明，Si和Al具有几乎完全一致的分布。X-射线衍射分析表明形成的主要矿物质为铝硅酸盐(如霞石)；积灰沉积物中Na与S的分布规律相似，主要以无水芒硝形式存在，部分结渣沉积物中的Na与Fe具有相似的分布。在初始层内，4个结渣样品中主要致渣元素的分布相似，而与积灰样品中的相反，表明积灰和结渣在机理上是不同的，受炉内局部空气动力场、气氛条件和温度水平等的控制。研究结果可为模拟灰沉积数学模型的建立或改进，以及防结渣添加剂、清灰剂的研制开发提供重要的依据和指导。

A novel method is presented in this paper to study the coal ash deposition mechanism and formation process. The electron probe microanalyzer is employed to analyze the mineral elementary distribution along thickness direction in ash deposits, sampled from five various locations inside the test furnace. The results show Si and Al have the almost same distribution pattern, which indicates essential mineral matter in ash deposits is aluminosilicate, such as nepheline, according to XRD analysis. In fouling deposits Na and S distribution trends are the same, which exists in form of thenardite mainly. The distribution of Na and Fe are similar in some samples of slagging deposits. At the initial layer, the principal mineral elementary distributions are similar among four slagging deposits, which is contrary with that of fouling deposit It indicates that the formation mechanisms of fouling is different from slagging, controlled by local aerodynamic fields, atmosphere and temperature level inside furnace. The results can provide important references and instructions for the foundation or improvement of ash deposition mathematical model, as well as the exploitation of anti-slagging additives and deashing agents.