关键词: 多孔隔热材料, 镁铝尖晶石, 羧甲基纤维素钠

Abstract: This work aims at improving the energy utilization efficiency of kilns.Magnesium aluminate spinel porous insulation materials were prepared as follows.Medium-grade magnesia fine powder and calcined alumina powder were mixed in a mass ratio of 35∶65,dried,and crushed into powders of d₅₀=2.3 μm.Then different amounts of sodium carboxymethyl cellulose (CMC) as a foam stabilizer and 0.6 mass% potassium oleate as a foaming agent were added to obtain the foaming slurry.Finally the slurry was injected into molds of 40 mm×40 mm×40 mm,demolded,dried at 110 ℃ for 24 h,and fired at 1 500 ℃ for 3 h.The effects of the CMC addition (0,0.1%,0.2%,0.3%,0.4%,and 0.5%,by mass,extra adding) on the properties of the slurry and the fired samples were studied.The results show that:(1)when the CMC addition is higher than 0.1%,the slurry has decreased expansion ratio,increased viscosity,and less and smaller bubbles;(2)when the CMC addition is 0.2%,the slurry has the maximum Zeta potential absolute value of 18.3 mV,which is the most stable;the sample has the most pores,which are spherical and closed;the apparent porosity,bulk density,and cold compressive strength of the sample are 73.5%,0.95 g·cm^-3,and 13.1 MPa.

Key words: porous insulation materials, magnesium aluminate spinel, sodium carboxymethyl cellulose