Xin Yalou, Jian Yunling, Yin Hongfeng, Tang Yun, Yuan Hudie, Liu Yuchi
College of Materials Science & Engineering, Xi'an University of Architecture & Technology, Xi'an 710055, China.
Materials (Basel). 2023 Aug 29;16(17):5908. doi: 10.3390/ma16175908.
The use of a lightweight corundum-spinel refractory in working lining could reduce the thermal conductivity of industrial furnaces. In this study, bubble alumina was introduced to realize a lightweight AlO-MgAlO refractory assisted by the reactive sintering of AlO and MgO. The effects of alumina bubble content and sintering temperature on the phase compositions, microstructure and properties of the lightweight refractory were investigated. The results indicated that the overall performance of the lightweight AlO-MgAlO refractory was mainly dominated by the content of alumina bubbles. The bulk density, compressive strength and thermal conductivity all decreased when the alumina bubble content increased from 10 to 30 wt%. Meanwhile, the sintering temperature also significantly affected the properties of the obtained refractory. It is worth noting that specimens fired at 1650 °C achieved a high refractoriness under load (RUL) of more than 1700 °C when alumina bubble content was less than 30 wt%, which was comparable to that of the dense AlO-MgAlO refractory. The thermal conductivity of the obtained samples was remarkably decreased to no more than 2.13 W/(m·K). In order to overcome the trade-off between the light weight of the refractory and overall performance, it is feasible to adjust the content of alumina bubbles and raise the sintering temperature appropriately.
在工作衬里中使用轻质刚玉 - 尖晶石耐火材料可以降低工业炉的热导率。在本研究中，引入泡沫氧化铝以通过AlO和MgO的反应烧结实现轻质AlO - MgAlO耐火材料。研究了氧化铝泡沫含量和烧结温度对轻质耐火材料的相组成、微观结构和性能的影响。结果表明，轻质AlO - MgAlO耐火材料的整体性能主要由氧化铝泡沫的含量决定。当氧化铝泡沫含量从10 wt%增加到30 wt%时，体积密度、抗压强度和热导率均降低。同时，烧结温度也显著影响所得耐火材料的性能。值得注意的是，当氧化铝泡沫含量小于30 wt%时，在1650℃下烧制的试样实现了超过1700℃的高荷重软化温度（RUL），这与致密的AlO - MgAlO耐火材料相当。所得样品的热导率显著降低至不超过(2.13W/(m·K))。为了克服耐火材料重量轻与整体性能之间的权衡，调整氧化铝泡沫含量并适当提高烧结温度是可行的。
