为研究垃圾焚烧炉壁面结渣特性，现场采集了喉口区域前拱壁面、后拱壁面和侧墙壁面的3块渣样，结合灰熔点测试仪、扫描电镜、能谱分析和X射线衍射分析研究了渣样的熔融特性、微观形貌、元素分布和物相组成等物化性质。针对分层现象明显的渣样，沿渣样生长方向进行了元素分析和物相分析。分析测试结果表明,3块渣样的特征温度差值较小，且软化温度小于1 260 ℃，均属于易结渣灰；通过扫描电镜观察到3块渣样的微观形貌基本相似，主要为岩石状颗粒，说明垃圾焚烧形成的灰粒未经历熔融球化过程直接黏附在炉膛壁面或渣样表面；渣样中K、Na和Al三种元素的分布规律一致，其含量均沿渣样生长方向逐渐减少。K、Na、Al三种元素形成了熔点1 130 ℃的KAlSi3O8、熔点1 100 ℃的KAlSi2O6和熔点1 100 ℃的NaAlSi3O8，3种低熔点长石熔化后具有黏性，易凝结沉积在壁面或渣样表面；沿渣样生长方向，Ca元素含量逐渐增加，Si和Ca元素含量比值稳定在0.8～1.1；通过[JP2]物相分析发现Si和Ca两种元素形成了渣样中最主要的物质Ca2MgSi2O7，熔点为1 450 ℃；Ca2MgSi2O7的高熔点特性决定了渣样生长到一定厚度,渣样外层发生高温熔融，可阻止渣样继续生长。

In order to study the slagging characteristics of waste incinerator walls, three pieces of slag were collected on site from the front arch wall, rear arch wall and side wall in the throat area. The ash fusion point tester, scanning electron microscopy (SEM)/ energy dispersive X-ray(EDX), and X-ray diffractometer(XRD) analytical methods were used to determine the melting characteristics, microscopic morphology, element distribution, and phase composition and other physical and chemical properties of slag samples of slag. For the layered slag samples, elemental analysis and phase analysis were carried out along the growth direction of the slag. The results show that the difference in the characteristic temperatures of the three slag samples is small, and the softening temperature is less than 1 260 ℃, all of which are easy to slagging. The micromorphology of the three slag samples are similar through scanning electron microscope, mainly rock particles, indicating that the ash particles directly adhere to the furnace throat wall or slag surface without melting and spheroidization. The distribution of K, Na, and Al in the slag sample is similar, and the three elements gradually decrease along the slag growth direction。The K、Na and Al form three feldspar substances, such as KAlSi3O8 with a melting point of 1 130 ℃, KAlSi 2O6 with a melting point of 1 100 ℃, and NaAlSi3O8 with a melting point of 1 100 ℃. The three low-melting feldspars are viscous after melting and are easy to deposit on the wall or slag surface. Along the growth direction of the slag sample, the content of the Ca gradually increases, and the Si/Ca is 0.8-1.1. Through the XRD, it is found that Si and Ca form the Ca2MgSi2O7, which is the most important substance in the slag sample with a melting point of 1 450 ℃. The high melting point of Ca2MgSi2O7 determines that only when the slag grows to a certain thickness, the outer surface of the slag begins to melt, which can prevent the slag from continuing to grow.

0 引言

1 试验

   1.1 试验原料

   1.2 表征方法

2 结渣特性分析

   2.1 微观形貌分析

   2.2 元素组成分析

   2.3 物相分析

3 结论