Composition optimization and performance enhancement of lightweight and high-strength mullite castables
To actively respond to the dual-carbon policy and reduce industrial energy consumption,it is urgent to develop lightweight and high-strength refractories.Lightweight mullite castables were prepared using microporous mullite,mullite fine powder,alumina micropowder,alumina bubbles and silica micropow-der as the raw materials and cement as the binder.The effects of the alumina bubbles addition(0,3％,6％and 9％,by mass,respectively)on the properties of the mullite castables were studied.The results show that alumina bubbles can increase the porosity of the samples and promote the formation of mullite from alumina micropowder and silica micropowder,which solves the problem that the mechanical properties of the samples decrease greatly due to the increase of the apparent porosity.With the increase of the alumina bubbles addition,the apparent porosity of the samples increases significantly,the bulk density decreases,the thermal conductivity decreases significantly,the thermal shock resistance improves,and the strength decreases slightly.When the alumina bubbles addition is 9％,the apparent porosity of the sample heat treated at 1 400 ℃ is high,the bulk density and thermal conductivity are low,but the cold strength is still high.
万方数据
维普
