Preparation and characterization of porous anorthite ceramics from red mud and fly ash
Preparation and characterization of porous anorthite ceramics from red mud and fly ash
复制标题
赤泥和粉煤灰多孔钙长石陶瓷的制备及表征
DOI：
10.1111/ijac.13148
复制
发表时间：
2020
影响因子：
2.1
通讯作者：
Zhang Gaozhan
中科院分区：
文献类型：
--
作者：
Xiang Weiheng;Ding Qingjun;Zhang Gaozhan
以赤泥和粉煤灰为原料，采用造孔法制备了孔隙率高、机械强度好、导热系数低的钙长石多孔陶瓷。研究了烧结温度和粉煤灰对陶瓷材料的相演变、致密化、抗压强度、导热系数和显微结构的影响。结果表明，随着粉煤灰掺量的增加，多孔陶瓷的抗压强度有明显提高，致密化程度和导热系数先降低后升高。特别是在1150°C下烧结的含有30wt%赤泥和40wt%粉煤灰的试样S2具有更好的性能。其吸水率为18.18%，开气孔率为38.52%，体积密度为1.29 g/cm 3，抗压强度为42.46 MPa，导热系数为1.24 W/m·K。X射线衍射分析表明，莫来石，钙长石，α-石英，透辉石铁是试样中的主要相。扫描电镜观察表明，试样中存在大量的条状开孔和轴晶状闭孔。此外，莫来石的存在可以阻止裂纹扩展，从而提高沿晶断裂的能量。它赋予钙长石多孔陶瓷高的孔隙率，良好的压缩强度，和低的热导率。
The porous anorthite ceramics with high porosity, good mechanical strength and low heat conductivity were prepared using red mud and fly ash as raw materials via the pore forming method. The effects of sintering temperature and fly ash on phase evolution, densification, compressive strength, thermal conductivity and microstructure of the ceramic materials were investigated. The results showed that the compressive strength of the porous ceramics had an obvious improvement with the increase in fly ash, and the densification and heat conductivity decreased firstly and then increased. In particular, specimen S2 containing 30 wt% red mud and 40 wt% fly ash sintered at 1150°C had the better performances. It had the water absorption of 18.18%, open porosity of 38.52%, bulk density of 1.29 g/cm3, compressive strength of 42.46 MPa, and heat conductivity of 1.24 W/m·K. X‐ray diffraction analysis indicated that mullite, anorthite, α‐quartz, and diopside ferrian were the dominant phases in the specimens. Scanning electron microscopy micrographs illustrated that plenty of open pores with strip shape and closed pores with axiolitic shape existed in the specimens. Furthermore, the existence of mullite could prevent crack propagation to enhance the energy of inter‐granular fracture. It endowed the porous anorthite ceramics with high porosity, good compressive strength, and low heat conductivity.