引入泡沫对含多孔基质的刚玉-尖晶石浇注料性能的影响

Effect of foaming on properties of corundum-spinel castables with porous matrix

为了改善刚玉-尖晶石浇注料的抗热震性,以板状刚玉、烧结镁铝尖晶石、活性α-Al2O3微粉为主要原料,以铝酸钙水泥为结合剂,添加十二烷基苯环酸钠和水性高分子泡沫为造孔剂,制备了含多孔基质的刚玉-尖晶石浇注料。研究了泡沫加入量(2 kg的原料中分别加入0、100、150、200、250、300 mL泡沫)对刚玉-尖晶石浇注料1 550℃烧后试样的常温物理性能、抗渣渗透性能、抗热震性及显微结构的影响。结果表明:1)引入一定量的泡沫,耐火浇注料基质中可形成分布均匀、圆球形的单分散气孔,但当泡沫加入量为300 mL时,其基质部分的圆球形的单分散气孔减少,并且基质部分结构疏松;2)当泡沫加入量为0、100、150、200 mL时,对试样的抗渣性和常温物理性能无显著影响,但加入量为250、300 mL,会明显降低试样的抗渣性和力学性能;3)多孔基质结构有效地阻止了裂纹的生长,改变了裂纹的扩展方向,提高了其抗热震性。综合考虑刚玉-尖晶石浇注料的各项性能,泡沫的合适加入量为2 kg的原料中加入200 mL。

Corundum-spinel castables with porous matrix were prepared using tabular alumina, sintered magnesium aluminate spinel and active α-Al2O3 micropowder as main starting materials,calcium aluminate cement as binder,extra-adding dodecylbenzenephenylic sodium and water-solubility macromolecule foaming as pore former in order to improve thermal shock resistance. Effects of foaming additions （adding 0, 100,150,200,250 and 300 mL foam in 2 kg of starting materials,respectively） on cold physical properties, slag penetration resistance, thermal shock resistance and microstructure of the specimens after firing at ! 550 ~C were investigated. The results show that. （ 1 ）with a certain amount of foaming,the isolated spheric pores form in the matrix of castable specimens with even distribution, however,when foaming addition is 300 mL,the distributions of these pores and the matrix are loose;（2）when foaming addition is 0,100,150 or 200 mL,it has no obvious influence on slag penetration resistance and cold physical properties of specimens,however,when foaming addition is 250 or 300 mL, slag resistance and mechanical properties decrease significantly; （3）porous structure in the matrix effectively prevents the growth of the crack and changes the crack propagation direction, therefore, the thermal shock resistance is improved. Considering the comprehensive properties of corundum-spinel castables,the best addition of foaming is 200 mL in 2 kg of starting materials.