发泡法制备孔结构可控的镁质轻质料

Preparation of magnesia lightweight materials with controllable pore structure by foaming method

利用发泡法在1 580℃保温3 h烧成制备镁质轻质料,并研究泡沫搅拌时间(5、10、15和20 min)、泡沫加入量(每千克料浆中分别加入300、500、700和900 m L)、镁砂粒度(平均粒度0. 3、3. 48、20. 16和40μm)对烧后试样体积密度、显气孔率和耐压强度的影响,并通过SEM分析了其显微结构。结果表明:当泡沫搅拌时间为15 min时,烧后试样的体积密度最小,常温耐压强度最大,显气孔率最大,气孔分布均匀,孔径为20～40μm;随着料浆中泡沫量的增加,烧后试样的体积密度和常温耐压强度减小,显气孔率增加,孔径增大且分布分散;随着镁砂粒度的减小,烧后试样的体积密度减小,常温耐压强度增大,显气孔率增加,孔径减小且分布均匀,气孔壁变薄。

Lightweight magnesia materials were prepared by foaming method firing at 1 580℃for 3 h.Effects of foam stirring time(5,10,15,and 20 min),foam addition(300,500,700 and 900 mL for per kilogram slurry),and particle size of the magnesia(average particlesize 0.3,3.48,20.16,and 40μm)on the bulk density,apparent porosity,cold crushing strength of the fired specimens were researched,and the microstructure was analyzed by SEM.The results show that the stirring time has an important influence on the apparent porosity and pore size of the materials.With a stirring time of 15 min,the bulk density of the specimen is the smallest,the apparent porosity and the cold crushing strength are the highest,the pore distribution is uniform,the pore diameter is in the range of 20-40μm.With the foam amount increasing in the slurry,the bulk density of the specimen decreases,the apparent porosity increases,the cold crushing strength decreases,the pore diameter of the specimen becomes larger,the distribution becomes more dispersed.With the particle size of magnesia decreasing,the bulk density of the fired specimens decreases,the apparent porosity increases,the cold crushing strength increases,the pore diameter becomes smaller,the distribution is uniform,and the pore wall becomes thinner.