碳化硅陶瓷板上熔融煤灰侵蚀特性的实验研究

Experimental Investigation on Corrosion Characteristic of Melted Ash on SiC Based Refractory

分别将0.2 g云贵和金竹山煤灰以相同的面积与厚度疏松散布在硅酸锆结合含铬SiC陶瓷板上获得多组煤灰/陶瓷板试样对,依次置于高温马弗炉中分别升温至1 250℃,1 350℃和1 450℃并恒温40 h;试样自然冷却后,对灰渣与陶瓷板进行扫描电镜(SEM)分析,然后将灰渣进行X射线衍射(XRD)检测。结果表明,温度对煤灰在SiC陶瓷板上的侵蚀有重要影响,且在相同温度下,SiC陶瓷板上云贵煤灰的熔融烧结现象比金竹山煤灰严重得多。当用此种材料作锅炉卫燃带时,对于云贵煤与金竹山煤,其表面温度应分别控制在1 250℃与1 350℃以下。

Sample pairs of coal ash/refractory were prepared through spreading loosely 0.2 g ash of coal Yungui and Jinzhushan with identical area and thickness on SiC-based refractory board, which contains zirconium silicate and chromium oxide. Then the sample pairs were put into a high temperature muffle for 40 hours sintering at 1 250 ℃, 1 350 ℃ and 1 450 ℃ respectively. After being cooled down naturally, microscopic morphology analysis of these sample pairs was conducted with a scanning electron microscopy （SEM） and then, the sintered coal ash was analyzed by a X-ray diffraction （XRD） apparatus. The results show that temperature in the muffle has great effect on corrosion of the melted ash on the SiC-based refractory and the corrosion by ash of coal Yungui is more severe than that of coal Jinzhushan and imply that, if the SiC-based refractory is used as the heat-insulating layer on waterwalls of furnaces firing coal Yungui and Jinzhnshan, the surface temperature of the refractory should be controlled below 1 250 ℃ and 1 350 ℃ respectively.