ZHANG Jiashuo 1, LIU Taoyong 1, HAN Lei 2, LUO Zhiwei 1, LU Anxian 1
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan, China; 2. Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China)
Abstract: High porosity, ultralight and high strength silica tailing foam ceramics were prepared by using direct foaming method. The effects of sodium dodecyl sulfate (SDS) concentration, solid content and sintering process on microstructure and mechanical properties of the samples were systematically. It was found that the slurry system with solid content of 40% had large foaming volume ratio and stable structure. A "pore-in-pore" structure produced at high temperature resulted in samples with contrast performances. After sintering at 1200 ℃, the sample had a high porosity and the compressive strength was 21.6 MPa, indicating that an increase in sintering temperature significantly improved compressive strength of the foam ceramics. According to the test results of heavy metal ion leaching and acid corrosion resistance, the foamed ceramics meet the requirements of industrial products and can be used as insulating and refractory materials.
Key words: direct foaming method; silica tailing; porosity; compressive strength