水泥加入量对刚玉-尖晶石质钢包透气砖座砖性能的影响

Effect of calcium aluminate cement addition on properties of alumina-spinel well blocks of ladle purging plugs

以粒度6～3、3～1、≤1mm的板状刚玉颗粒为骨料，粒度≤0．074mm的板状刚玉和烧结尖晶石细粉为基质，活性α-Al2O3微粉、纯铝酸钙水泥为结合剂，聚丙烯纤维、偶氮甲酰胺、碳酸氢钠及聚丙烯纤维＋碳酸氢钠为防爆剂，制备了刚玉一尖晶石质钢包透气砖座砖，研究了水泥加入量（质量分数分别为2％、4％、6％、8％和10％）对透气砖座砖常温性能、抗热震性和抗爆裂性能的影响。结果表明：随着水泥加入量的增加，110℃干燥后常温强度增加，1560℃烧后常温强度、显气孔率和线变化率先增加后降低；水泥加入量6％（加）时试样的强度最低，显气孔率和线变化率最大，其常温性能最差；随着水泥加入量的增加，1100℃水冷3次后试样的强度保持率增加，抗热震性能改善，水泥加入量为10％（w）时抗热震性最好；采用碳酸氢钠或碳酸氢钠＋聚丙烯有机纤维复合的防爆剂试样的抗爆裂效果最好。研制的透气砖座砖在150t转炉钢包上使用，寿命由原来的平均31次提高到平均36次。

Alumina-spinel well blocks of ladle purging plugs were prepared by using tabular alumina （6-3, 3-1 ,and ≤lmm） as aggregates,tabular alumina fines （ ≤0.074 mm） and sintered spinel fines （ ≤0. 074 mm） as matrix,active α-Al2O3 micropowder and pure calcium aluminate cement as binders, polypropylene fibre, azodicarbonamide, sodium bicarbonate and polypropylene fibre ＋ sodium bicarbonate as explosion-proof additives. Effects of calcium aluminate cement additions （2% ,4% ,6% ,8% ,and 10% ） on cold prop-erties,thermal shock resistance and explosion resistance of alumina-spinel well blocks were investigated. The results show that with the increase of cement addition,cold strength of specimens dried at 1 10 ℃ in- creases,and cold strength,apparent porosity,and change in dimensions of specimens fired at 1560 ℃ in-crease at first, and then decrease; the specimen with 6% cement has the lowest strength, the highest change in dimensions and apparent porosity, and the worst cold properties;with the cement addition in-creasing,the residual strength ratio of specimens after 3 thermal shock cycles （1 100 ℃,water quenching） increases, indicating that thermal shock resistance of specimens is improved ,and the thermal shock resist-ance is the best when the cement addition is 10% ;explosion resistance of the specimen is the best with the appropriate amounts of sodium bicarbonate or polypropylene fibre ＋ sodium bicarbonate;the developed well blocks have been successfully used in a 150 t converter ladle,and the average service life increases from 31 heats to 36 heats.