Yuan Hudie, Yin Hongfeng, Tang Yun, Shuai Hang, Xin Yalou, Pu Xilou
College of Materials Science & Engineering, Xi'an University of Architecture & Technology, Xi'an 710055, China.
Materials (Basel). 2020 Mar 16;13(6):1346. doi: 10.3390/ma13061346.
In this paper, the products using three kinds of coal gasification slags as starting materials were obtained via carbothermal reduction-nitridation at 1450 °C. The effects of high-temperature liquid on the phase composition and morphology of the samples were investigated by XRD and SEM, while the content of high-temperature liquid was calculated by the computer software package FactSage. The results show that: (1) the existence of high-temperature liquid phase is beneficial to the formation and growth of Ca-α-SiAlON phase; (2) The formation of long-columnar Ca-α-SiAlON were greatly affected by the content and viscosity of liquid phase, which is in non-linear relationship with aspect ratios of Ca-α-SiAlON. Among the three kinds of slags, the HT slag with relatively high liquid phase content and the lowest viscosity is the most favorable to the growth of elongated Ca-α-SiAlON grain; the aspect ratio of the formed Ca-α-SiAlON is the largest; Compared to the SH slag with the highest liquid phase content and viscosity, Ca-α-SiAlON prepared from TE slag possesses the smallest aspect ratio, which exhibits equiaxed grain morphology.
本文以三种煤气化炉渣为原料，在1450℃下通过碳热还原氮化法制备了产物。利用X射线衍射仪（XRD）和扫描电子显微镜（SEM）研究了高温液相对样品相组成和形貌的影响，同时通过计算机软件包FactSage计算了高温液相的含量。结果表明：（1）高温液相的存在有利于Ca-α-SiAlON相的形成与生长；（2）长柱状Ca-α-SiAlON的形成受液相含量和粘度的显著影响，与Ca-α-SiAlON的长径比呈非线性关系。在三种炉渣中，液相含量相对较高且粘度最低的HT炉渣最有利于细长Ca-α-SiAlON晶粒的生长，所形成的Ca-α-SiAlON长径比最大；与液相含量和粘度最高的SH炉渣相比，由TE炉渣制备的Ca-α-SiAlON长径比最小，呈现等轴晶粒形貌。
