关键词: 弥散型透气砖, 透气性能, Andreasen分布方程, q值

Abstract: 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-Al₂O₃ micropowder (d₅₀=3 μm) as the matrix,R1 as the water reducer,and cement Secar 71 as the binder,cast molding and heat-treating at 1 600 ℃ 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 Nm³·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 Nm³·h^-1.

Key words: dispersive purging plug, air permeability, Andreasen distribution equation, q value