轻量化钢包工作衬浇注料的制备及性能

Preparation and Properties of Lightweight Ladle Working Lining Castable

分别以板状刚玉、微孔刚玉和六铝酸钙(CA6)为骨料,板状刚玉细粉、活性α-Al2O3微粉、SiO2微粉、电熔镁砂粉为基质、纯铝酸钙水泥为结合剂,以及在基质中适当添加MgO超微粉(D50=5.4μm)和A(OH)3超微粉(D50=8.2μm),制备了轻量化钢包工作衬浇注料,研究了以上骨料和超微粉对浇注料物理性能、孔径分布、热导率、抗热震性能、以及抗渣性能的影响。结果表明:六铝酸钙(CA6)可降低浇注料体积密度,但会导致浇注料内部气孔孔径增大,强度和抗渣性降低;采用微孔刚玉不仅可降低浇注料的体积密度,而且增加浇注料中微气孔的比例,进而降低浇注料的热导率,提高抗热震性能和抗渣渗透性能;引入MgO超微粉和Al(OH)3超微粉,一是起到填充作用,可增强流动性,提高浇注料强度,二是利用Al(OH)3超微粉的原位分解成微孔,可提高浇注料中微气孔的比例,进而材料的断裂能、抗热震性能以及抗渣性能。

A series of lightweight ladle working lining castables were prepared with tabular alumina, microporous corundum, and calcium hexaaluminate(CA6) as aggregates, respectively, reactive α-Al2O3 ultrafine powder, SiO2 ultrafine powder, tabular alumina powder, and fused magnesia powder as matrices, calcium aluminate cement as a binder, and MgO ultrafine powder(D50=5.4 μm), Al(OH)3 ultrafine powder(D50=8.2 μm) as additives. The influence of aggregate and ultrafine powder on the physical properties, pore size distribution, thermal conductivity, thermal shock resistance, and slag resistance of lightweight refractory castables was investigated. The results show that calcium hexaaluminate(CA6) can make the castable lightweight, but increase the pore size and reduce the strength and slag resistance of castable. Using microporous corundum can reduce the bulk density of castble, and increase the proportion of micropores, which is beneficial to reducing the thermal conductivity, and improving the thermal shock resistance and slag resistance of castble. When MgO ultrafine powder and Al(OH)3 ultrafine powder are used as additives, the fluidity and strength of castable can be improved, the ratio of micropores in the castble can be increased, and the fracture energy, thermal shock resistance and slag resistance can be improved.