Abstract:

Porous ceramics were prepared using fly ash as the main raw material,adding different kinds and different amounts of pore-forming agents (carbon powder:5%-50%;wood fiber 5%-30%;and carbide slag:0-50%,by mass),pressing under 100 MPa,and sintering at 1 100 ℃ for 2 h.The results show that (1)the apparent porosity,the average pore size,the gas permeability,and the nitrogen flux of the porous ceramics increase while their density decreases with the rising carbon powder addition;(2)with the increasing carbide slag addition,the apparent porosity,the gas permeability,and the nitrogen flux of the porous ceramics increase,the density decreases,while the average pore size remains almost unchanged;(3)as the wood fiber addition increases from 5% to 15%,the apparent porosity and the average pore size of the porous ceramics increase while the density decreases;as the wood fiber addition reaches 30%,the apparent porosity and the density of the porous ceramics remain unchanged,while the average pore size decreases gradually;the change of the gas permeability and the nitrogen flux shows no obvious trend;(4)the main phases of the porous ceramics prepared with carbon powder are quartz,anorthite and calcium silicate;while those with carbide slag are quartz,anorthite,gehlenite,and calcium silicate.Using carbon powder and carbide slag as pore forming agents,the properties and pore parameters of porous ceramics could be adjusted linearly by changing the addition of pore forming agents.

Key words: fly ash, carbon powder, carbide slag, porous ceramics, permeability properties

摘要：

以粉煤灰为主要原料,分别添加不同种类(碳粉、木质纤维、电石渣)和不同数量(碳粉添加质量分数为5%~50%,木质纤维添加质量分数为5%~30%,电石渣添加质量分数为0~50%)的造孔剂,以100 MPa压力成型后,在1 100 ℃保温2 h烧结制成多孔陶瓷。结果表明:1)碳粉添加量增多,多孔陶瓷的显气孔率、平均孔径、气体渗透率和氮气通量增大,容重减小。2)电石渣添加量增多,多孔陶瓷的显气孔率、气体渗透率和氮气通量增大,容重减小,平均孔径变化很小。3)木质纤维添加量从5%(w)增加至15%(w)时,试样的显气孔率和平均孔径增大,容重减小;继续增加至30%(w)时,试样的显气孔率和容重基本上没有发生变化,平均孔径逐渐减小,气体渗透率和氮气通量的变化无明显规律。4)以碳粉为造孔剂的多孔陶瓷的物相为石英、钙长石和硅酸钙相。以电石渣为造孔剂的多孔陶瓷的物相包含石英、钙长石、钙铝黄长石和硅酸钙。以碳粉和电石渣为造孔剂,可通过改变造孔剂添加量线性地调控多孔陶瓷的性能参数和孔参数。

关键词: 粉煤灰, 碳粉, 电石渣, 多孔陶瓷, 渗透性能