莫来石纤维加入量对刚玉质耐火浇注料性能的影响

Effects of mullite fibre additions on properties of corundum based refractory castables

以w(Al_2O_3)=99.23%、w(Na_2O)=0.32%的板状刚玉颗粒,w(Al_2O_3)=99.4%、w(Na_2O)=0.25%的电熔白刚玉颗粒和细粉以及w(SiO_2)=96.5%、w(R_2O)=0.7%的二氧化硅微粉为主要原料,Alphabond300为结合剂,制备了刚玉质无水泥耐火浇注料。研究了莫来石纤维外加量(w)分别为0、0.3%、0.5%、0.8%、1.0%、1.5%和2.0%时对浇注料流动性的影响,以及对浇注料经110、800、1 100和1 400℃热处理后的常温抗折强度、耐压强度、显气孔率、体积密度和抗热震性能的影响,并进行了显微结构分析。结果表明:1)固定耐火浇注料的流动值不变,加水量随着莫来石纤维的增加而逐渐增加。2)莫来石纤维的加入会导致耐火浇注料显气孔率上升,体积密度下降;常温抗折强度随莫来石纤维的增加先增加后降低,但增加幅度不是很明显;莫来石纤维能显著提高耐火浇注料的抗热震性能。

The cement-free corundum based refractory castables were prepared using tabular corundum particles（ Al_2O_3 99. 23%,Na_2O 0. 32%,by mass,the same hereinafter）,white fused corundum（ Al_2O_3 99. 4%,Na_2O 0. 25%） and silica fume（ Si O296. 5%,R_2O 0. 7%） as main raw materials,Alphabond300 as binder.Effects of mullite fibre extra additions（ 0,0. 3%,0. 5%,0. 8%,1. 0%,1. 5%,and 2. 0%） on the flowability of the castables and cold modulus of rupture,cold crushing strength,apparent porosity,bulk density and thermal shock resistance of the castable specimens hot treated at 110,800,1 100,and 1 400 ℃ were studied,respectively. The SEM was used to analyze the microstructure. The results show that：（ 1） when the flow value is fixed,water demand of refractory castables gradually increases with mullite fibre addition increasing;（ 2） with mullite fibre,the apparent porosity increases and bulk density decreases; the cold modulus of rupture increases firstly and then decreases with the mullite fibre addition increasing,however,the increasing amplitude is not obvious; mullite fibre can obviously enhance the thermal shock resistance of the castables.