SiO_2微粉和Al_2O_3微粉加入量对莫来石-刚玉浇注料性能的影响

Effects of additions of microsilica and alumina micropowder on properties of mullite-corundum castables

以莫来石M45(10～5mm,5～3mm)、电熔莫来石(3～1mm,≤1mm)作骨料,刚玉粉(≤0.074mm)、电熔莫来石粉(≤0.074mm)、纯铝酸钙水泥、Al2O3微粉(d50=2.11μm)和SiO2微粉(d50=1.07μm)作基质,制备了脱硫枪用莫来石-刚玉浇注料,并分别研究了SiO2微粉加入量(分别为2%、3%、4%、5%)和Al2O3微粉加入量(分别为2%、4%、6%)对浇注料体积密度、显气孔率、强度、烧后永久线变化率、抗热震性和抗渣性的影响。结果表明:仅加入SiO2微粉时,随着其加入量在2%～5%范围内增加,莫来石-刚玉浇注料的体积密度提高,显气孔率降低,强度增加,抗渣性变好,但抗热震性变差;在加入3%SiO2微粉的基础上再加入2%～6%的Al2O3微粉时,浇注料的各项性能随Al2O3微粉增加没有明显改善,但均比仅加入3%SiO2微粉时有明显改善。

Mullite -corundum castables for desulphurizing lance were prepared using mullite M45 （ 10 ～ 5 mm,5 ～ 3 mm） ,fused mullite（3～1 mm, ≤1 mm）as aggregates,and corundum powder（≤0. 074 mm）,fused mullite powder（ ≤0.074 mm）, pure calcium alumiante, α-Al2O3 micropowder （ d50 = 2.11 μm）, microsilica （ d50 = 1.07 μm）as matrix. The effects of microsilica additions（2% ,3% ,4% ,5% ）and α-Al2O3 micropowder additions（2%, 4%, 6% ） on bulk density, apparent porosity, strength, permanent linear change rate, thermal shock resistance and slag resistance were investigated. The results show that： （ 1 ） Only adding microsilica, bulk density, strength and slag resistance of mullite -corundum castables are improved, while apparent porosity and thermal shock resistance decrease with the increase of microsilica addition from 2% to 5%. （2）Adding 2% ～6% of Al2O3 micropowder into the specimens with 3% microsilica,the properties of the specimens are obviously improved, but they don＇t increase with the increase of Al2O3 micropowder addition.