活性氧化铝加入量对活性氧化镁结合刚玉-尖晶石浇注料性能的影响

Effect of reactive alumina addition on properties of activated magnesia bonded corundum-spinel castables

为改善活性氧化镁结合刚玉-尖晶石浇注料的性能,以板状刚玉、活性氧化铝微粉、活性氧化镁微粉和乳酸铝为原料,制备了活性氧化镁结合刚玉-尖晶石浇注料,研究了活性氧化铝微粉加入量(加入质量分数分别为0、8%、13%和18%)对浇注料显微结构、物相组成、物理性能及抗渣侵蚀和渗透性能的影响。结果表明:1)活性氧化铝微粉的加入促进了活性氧化镁结合刚玉-尖晶石浇注料的烧结,提高了骨料和基质的结合程度,使浇注料显微结构更加致密;2)随着活性氧化铝微粉加入量的增加,试样体积稳定性提高,显气孔率降低,体积密度增加,常温抗折强度和耐压强度及抗渣性提高;3)当活性氧化铝微粉加入量为18%(w)时,活性氧化镁结合刚玉-尖晶石浇注料的综合性能最好(考虑到颗粒级配和原料成本的问题,没有必要再进一步增加活性氧化铝微粉),其体积密度为3.05 g·cm^(-3),显气孔率为18.5%,加热永久线变化为0.31%,常温抗折强度和耐压强度分别为13.5和73.8 MPa,抗渣性最佳。

To enhance their performance,reactive MgO-bonded corundum-spinel castables were prepared using tabular corundum,reactive alumina,reactive MgO and aluminum lactate as raw materials.The influence of the reactive alumina addition(0,8%,13%and 18%,by mass)on the microstructure,phase composition,physical properties,as well as the resistance to slag corrosion and penetration of the castables was investigated.The results reveal that:(1)the reactive alumina promotes the sintering of the reactive MgO-bonded corundum-spinel castables,enhancing the bonding between aggregates and matrix,thus densifying the microstructure;(2)with the increase of the reactive alumina addition,the volume stability of the samples increases,the apparent porosity decreases,the bulk density increases,and the cold modulus of rupture and cold crushing strength as well as the slag resistance are improved;(3)the reactive MgO-bonded corundum-spinel castable with 18%reactive alumina shows optimal comprehensive performance,with the bulk density of 3.05 g·cm^(-3),apparent porosity of 18.5%,permanent linear change rate after heating of 0.31%,cold modulus of rupture of 13.5 MPa and cold compressive strength of 73.8 MPa,as well as the best slag resistance.However,considering particle size distribution and raw material costs,there is no need to further increase the reactive alumina addition.