Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5439226 | Ceramics International | 2017 | 17 Pages |
Abstract
The mullite phase in porcelain is important to the porcelain strength; however, its formation from clay minerals usually requires high temperature. Here we found that the activation of kaolin by citric acid would lower the formation temperature of mullite phase to 935.1 °C, which is 67.5 °C lower than that for the raw kaolin. Needle-like mullite crystal, a desired crystal shape in kaolin, could be observed in activated kaolin at 1050 °C. The reduction of mullite formation temperature is due mainly to the surface change in kaolin. Upon citric acid activation, the pseudohexagonal platelets of kaolinite crystal are disintegrated to non-uniform flakes, and the specific surface area increases from 8.18 m2/g to 31.21 m2/g, both leading to improved activity of kaolin and increased sintering driving force. The results are of interest in producing high-strength porcelain at reduced sintering temperatures and consequent energy saving for sintering process.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Chenyang Zhang, Zhijie Zhang, Yue Tan, Mingfeng Zhong,