颗粒组成对刚玉质弥散型透气砖性能的影响

Effect of particle distribution on properties of corundum based dispersive purging plugs

为改善刚玉质弥散型透气砖的透气性能,以粒度为1~0.15、≤0.15 mm的板状刚玉颗粒为骨料,以≤0.044 mm的板状刚玉细粉、d_(50)=3μm的α-Al_(2)O_(3)微粉为基质,外加R1减水剂,以Secar 71水泥为结合剂,浇注成型后经1600℃保温4 h热处理,制备了弥散型透气砖。基于Andreasen分布方程,通过改变分布指数q值,研究了颗粒组成对材料性能和显微结构的影响。结果表明:1 q值从0.21增至0.33的过程中,烧后试样的显气孔率减小,体积密度、常温抗折强度、常温耐压强度和高温抗折强度增大,透气度均≤0.6 Nm^(3)·h^(-1);2当q值从0.33增至0.53时,烧后试样的显气孔率增大,体积密度、常温抗折强度、常温耐压强度和高温抗折强度减小,透气度增大;3当q值为0.49时,烧后试样的综合性能较优,其显气孔率、常温耐压强度、常温抗折强度、高温抗折强度、透气度分别为25.6%、67.1 MPa、20.9 MPa、9.4 MPa、2.8 Nm^(3)·h^(-1)。

To improve their air permeability,corundum based dispersive purging plugs were prepared with tabular corundum(1-0.15 and≤0.15 mm)as aggregates,tabular corundum fines(≤0.044 mm)and α-Al_(2)O_(3) micropowder(d_(50)=3μm)as the matrix,R1 as the water reducer,and cement Secar 71 as the binder,cast molding and heat-treating at 1600℃ for 4 h.Based on the Andreasen distribution equation,the effect of the particle distribution on the properties of the materials was studied by changing the distribution index q.The results show that:(1)with the q value increasing from 0.21 to 0.33,the apparent porosity of the fired samples decreases,the bulk density,the cold modulus of rupture,the cold compressive strength and the hot modulus of rupture increase,and the air permeability is≤0.6 Nm^(3)·h^(-1);(2)with the q value increasing from 0.33 to 0.53,the apparent porosity of the fired samples increases,the bulk density,the cold modulus of rupture,the cold compressive strength and the hot modulus of rupture decrease,while the air permeability increases;(3)when the q value is 0.49,the sample has good comprehensive performance:the apparent porosity of 25.6%,the cold compressive strength of 67.1 MPa,the cold modulus of rupture of 20.9 MPa,the hot modulus of rupture of 9.4 MPa,and the air permeability of 2.8 Nm^(3)·h^(-1).