材料期刊网

为了提高烧结镁钙材料的抗水化性，在轻烧白云石粉中分别单一添加α-Al2 O3粉（质量分数分别为10％、20％、30％、40％、50％）或 Fe2 O3粉（质量分数分别为2％、4％、6％、8％）以及复合添加 Fe2 O3粉＋α-Al2 O3粉（质量分数分别为10％＋8％、10％＋2％）或 Fe2 O3粉＋α-Al2 O3粉＋ZrO2粉（质量分数分别为1．2％＋12％＋5％、1．2％＋12％＋10％），研究了单一和复合添加α-Al2 O3、Fe2 O3和ZrO2对不同温度（1350～1600℃）保温2 h烧后试样抗水化性能的影响。结果表明：单一添加Fe2 O3时，随着Fe2 O3含量的增加，水化质量增加率显著减小，温度的影响并不明显。单一添加α-Al2 O3时，随着α-Al2 O3含量的增加，水化质量增加率呈下降的趋势，升高温度，水化质量增加率逐渐下降。复合添加Fe2 O3＋α-Al2 O3以及Fe2 O3＋α-Al2 O3＋ZrO2时，生成的化合物和固溶体一方面减少了游离CaO的数量，另一方面加速了烧结致密化过程，阻碍了水蒸气向颗粒内部的扩散，能更有效地提高镁钙材料的抗水化性能，因此对白云石的抗水化性能优于单一添加物的。

In order to improve the hydration resistance of sintered magnesia calcia materials,α-Al2O3 pow-ders (10%,20%,30%,40%,and 50%,by mass,the same hereinafter),Fe2 O3 powders (2%,4%,6%,and 8%),Fe2 O3 +α-Al2 O3 composite powders (10%+8%,and 10%+2%),or the Fe2 O3 +α-Al2 O3 +ZrO2 com-posite powders (1 .2%+12%+5%,and 1 .2%+12%+10%)were added into light-calcined dolomite pow-der.Effects of above additives on the hydration resistance of light-calcined dolomite fired at different tem-peratures (1 350-1 600 ℃)for 2 h were researched.The results show that:(1)only adding Fe2O3,with its addition increasing,the hydration mass gain rate decreases significantly,and the effect of temperature is not obvious.(2)only adding α-Al2O3,with the addition increasing,hydration mass gain rate tends to de-crease;with temperature rising,the hydration mass gain rate decreases gradually.(3)When adding Fe2O3+α-Al2O3 or Fe2O3 +α-Al2O3 +ZrO2,the generation of compound and solid solution inside the material not only reduces the free CaO,but also accelerates the densification during firing and hinders the diffusion of vapor to particles inside,which can effectively improve the hydration resistance of magnesia calcia materi-als.Hence hydration resistance of dolomite with composite additives is superior to the single additives.