Recycling of Coal Fly Ash for the Fabrication of Porous Mullite/Alumina Composites
AbstractCoal fly ash with the addition of Al2O3 was recycled to produce mullite/alumina composites and the camphene-based freeze casting technique was processed to develop a controlled porous structure with improved mechanical strength. Many rod-shaped mullite crystals, formed by the mullitization of coal fly ash in the presence of enough silicate, melt. After sintering at 1300–1500 °C with the initial solid loadings of 30–50 wt.%, interconnected macro-sized pore channels with nearly circular-shaped cross-sections developed along the macroscopic solidification direction of camphene solvent used in freeze casting and a few micron-sized pores formed in the walls of the pore channels. The macro-pore size of the mullite/alumina composites was in the range 20–25 μm, 18–20 μm and 15–17 μm with reverse dependence on the sintering temperature at 30, 40 and 50 wt.% solid loading, respectively. By increasing initial solid loading and the sintering temperature, the sintered porosity was reduced from 79.8% to 31.2%, resulting in an increase in the compressive strength from 8.2 to 80.4 MPa. View Full-Text
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Kim, K.H.; Yoon, S.Y.; Park, H.C. Recycling of Coal Fly Ash for the Fabrication of Porous Mullite/Alumina Composites. Materials 2014, 7, 5982-5991.
Kim KH, Yoon SY, Park HC. Recycling of Coal Fly Ash for the Fabrication of Porous Mullite/Alumina Composites. Materials. 2014; 7(8):5982-5991.Chicago/Turabian Style
Kim, Kyu H.; Yoon, Seog Y.; Park, Hong C. 2014. "Recycling of Coal Fly Ash for the Fabrication of Porous Mullite/Alumina Composites." Materials 7, no. 8: 5982-5991.