Abstract: To improve their thermal shock resistance,low carbon spinel-carbon refractories were prepared with MgAl₂O₄ and graphite as the main raw materials,and environmentally friendly asphalt Carbores P (CP),sodium tripolyphosphate and boron glass powder as the additives,insulating at 900 ℃ for 3 h in a carbon embedded atmosphere.The influence of additive types on the properties of the refractories was studied.The results show that:(1) the additives have little effect on the apparent porosity and bulk density of the samples;(2) compared to sodium tripolyphosphate,the addition of CP or boron glass powder significantly improves the cold modulus of rupture of the samples;while the addition of CP increases the hot modulus of rupture of the samples;(3) the introduction of sodium tripolyphosphate significantly reduces the thermal expansion coefficient and effectively improves the thermal shock resistance of the samples;(4) low carbon spinel-carbon refractories with high strength and good thermal shock resistance can be prepared by adding sodium tripolyphosphate.

Key words: spinel-carbon refractories, stress release phases, thermal expansion coefficient, thermal shock resistance

摘要： 为了提高低碳尖晶石-碳耐火材料的抗热震性,以镁铝尖晶石和石墨为主要原料,引入环保沥青Carbores P(CP)、三聚磷酸钠和硼玻璃粉作为添加剂,在900 ℃埋碳气氛下保温3 h制备低碳尖晶石-碳材料。研究添加剂种类对材料性能的影响。结果表明:1)引入添加剂对试样的显气孔率以及体积密度影响较小。2)相比于三聚磷酸钠,添加CP和硼玻璃粉能够显著提高试样常温抗折强度;而添加CP能够较大提高试样的高温抗折强度。3)添加三聚磷酸钠能显著降低试样的热膨胀系数,并且能够有效改善试样的抗热震性。4)添加三聚磷酸钠能够制备出强度高、抗热震性好的低碳尖晶石-碳耐火材料。

关键词: 尖晶石-碳耐火材料, 应力缓释相, 线膨胀系数, 抗热震性