Production of pulverised fuel ash tiles using conventional ceramic production processes

Abstract

The feasibility of manufacturing sintered ceramic tiles containing a high proportion of pulverised fuel ash (PFA) using conventional ceramic tile processing methods has been investigated at pilot plant scale. From earlier laboratory experiments, a composition containing 92?0 wt-%PFA, 5?0 wt-% sodium bentonite and 3?0 wt-% talc produced good quality small disc samples. The scale-up trials reported here used this same composition and involved deflocculant addition, wet milling, spray drying, pressing and firing, with the behaviour during each processing stage being characterised. Although there were no substantial technical problems associated with forming green tiles, the composition selected needed high levels of deflocculant and produced pressed samples with low green densities, resulting in high shrinkage during firing. The high dependence of shrinkage on temperature caused excessive tile distortion. In addition, sintered samples with less than 2% water absorption exhibited a bloating effect, resulting in poor surface quality. Possible solutions to the problems encountered during the pilot scale trials are considered and the potential commercial viability of high PFA content ceramic products is discussed.

Synthesis of CFB-Coal Fly Ash Clay Bricks and Their Characterisation

“…It should be mentioned that the technique reported within this paper is one of the first applied for the fabrication of bricks by utilizing CFB-derived coal FA (an ash-type that normally contains high percentages of sulphur trioxide) and thus a lower (pilot) FA participation rate was applied at this particular time. On the other hand, several recent studies [10][11][12][13][14] report successful incorporation of Pulverized Coal Combustion-derived FA (as well as Coal Gasification FA) in clay mixtures, in the field of conventional-sintered bricks and tiles manufacturing, leading to final products with a mechanical performance strongly dependent upon the type of ash-free body and the properties of the utilized FA.…”

Leachability of trace elements from two stabilized low lime Indian fly ashes

“…In India the annual production of fly ash is nearly 45 million tons and is likely to increase to 70 million tons by 2010. Many attempts have been made to utilize this fly ash in several civil engineering applications, such as use as a fill material (Digioa and Nuzzo 1972;Faber and Digioa 1974;Horiuchi et al 2000), as a lightweight aggregate (Kishan 1988;Bin-Shafique et al 2004), for manufacture of clay flooring and terracing tiles (Bhatnagar et al 1988;Bou et al 2009), as an absorbent material (Ayala et al 1998;Héquet et al 2001;Alinnor 2007), in concrete technology as a binding material (McCarthy and Dhir 1999), and as a volume replacement and a self-compacting material for increasing the workability of concrete (Ganesh and Siva 1993;Siddique 2003;Jaturapitakkul et al 2004;Tsimas and Tsima 2005;Yen et al 2007;Sahmaran et al 2009). With only a very small utilization of about 12% of fly ash produced in India compared to global utilization of 25%, the ash deposits at the thermal power plants are increasing rapidly, and the problem of disposal is expected to become alarming because of the limited space available for its disposal near most of the thermal power stations.…”

Glass‐Ceramic Tiles Prepared by Pressing and Sintering DC Plasma‐Vitrified Air Pollution Control Residues

“…Density, Shrinkage, and Water Absorption Data Figure 3 gives property data for samples prepared in this study and commercially produced tile bodies (monoporosa, floor tiles and porcelain tiles). 15 100APC samples have comparable density to porcelain tiles at B2.4 g/cm 3 . The bulk density of 50APC:50CG tiles were lower but increased from 1.85 to 2.15 g/cm 3 as the sintering temperature increased from 7001C to 9001C as shown in Fig.…”

“…Figure 3 gives property data for samples prepared in this study and commercially produced tile bodies (monoporosa, floor tiles and porcelain tiles) 15 . 100APC samples have comparable density to porcelain tiles at ∼2.4 g/cm 3 .…”