Preparation of Fly Ash-Based Porous Ceramic with Alumina as the Pore-Forming Agent

Abstract

Low-cost porous ceramic from fly ash with alumina as the pore-forming agent was produced. The effect of the alumina content on line shrink, bulk density, mechanical strength, porosity, and phase composition of porous ceramic were investigated in detail. The results showed that the addition of alumina can help to improve the porosity and then it can change the pore structure of porous ceramic. Meanwhile, the addition of alumina can react with SiO2 in fly ash which can form the mullite. With the increase of alumina content, the content of quartz decreased gradually, while the alumina and mullite increased. Furthermore, the pore size becomes uniform and the permeability increased gradually. After sintering at 1250 ℃ for 0.5 h, the porous ceramic has been obtained the bending strength of ≥ 35MPa and the porosity of ≥ 28% with the addition content of alumina (25 wt%).

Physicochemical processes in the zone of local laser heating of porous aluminosilicate ceramics

“…Some weak peaks in the halo can be attributed to mullite nuclei in the glass phase. As follows from, 5 at a low Al 2 O 3 content in a SiO 2 ‐Al 2 O 3 mixture, the mechanical strength of the ceramics increases as a result of the rearrangement of initially randomly oriented mullite nano‐grains into stable acicular nano‐grains in high‐temperature glass melt.…”

“…Coarse-pored aluminosilicate materials are used not only as bricks [1,2] possessing heatprotecting and sound-absorbing properties [3,4], but also as filters and the base of catalyst carriers and flame arresters [5][6][7][8][9].…”

“…Coarse-pored aluminosilicate materials are used not only as bricks 1,2 possessing heat-protecting and sound-absorbing properties, 3,4 but also as filters and the base of catalyst carriers and flame arresters. [5][6][7][8][9] Porous ceramic materials are obtained by different methods, namely, by introduction of burnable organic or inorganic additives decomposing during sintering of clay. 10,11 Depending on the type, content, and geometric shape of introduced additives, it is possible to obtain porous ceramics of different type, up to foamed ceramics.…”

Microstructure and properties of porous ceramics synthesized using Kubuqi desert sand

“…Porous ceramic is a kind of ceramic material with specific pore structure and porosity prepared by batching, molding and sintering processes [1], which has high temperature resistance, acid and alkali corrosion resistance, good biological inertia, good thermal shock resistance, adjustable pore structure and porosity, and good reuse performance. Porous ceramic is commonly used in refractory heat insulation materials, lightweight structural materials, sound-absorbing materials, filtration materials, catalyst carriers and ceramic sensors, which plays a critical role in industry, life, electronics, national defense and aerospace fields [2][3][4][5][6][7][8][9].…”

Facile and Controllable Preparation of Poly(St-co-MMA)/FA Microspheres Used as Ultra-Lightweight Proppants

“…That is, the effective utilization of fly ash not only solves the problem of environmental pollution, but also produces high value-added products. It can improve the physical and mechanical performance of the composites with its incorporation in the polymer matrix [ 26 ].…”