Agglomeration characteristics of alumina sand-straw ash mixtures at elevated temperatures

• Autores: A.E. Ghaly, A. Ergudenler, E. Laufer
• Localización: Biomass and bioenergy, ISSN 0961-9534, Vol. 5, Nº 6, 1993, pág. 467
• Idioma: inglés
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• Resumen

  • The agglomeration characteristics of alumina sand-straw ash mixtures were investigated at various levels of ash content (0.0, 3.3, 27.8, and 43.5%) and temperature (620, 740, 850, and 1000°C) using scanning electron microscopy and energy dispersive X-ray analysis techniques. Agglomeration of alumina sand did not take place below the temperature of 850°C at all levels of ash content, but at the temperature of 850°C a weak bonding of particles was observed. However, at the temperature of 1000°C, the alumina particles agglomerated in the presence of straw ash at all levels of ash content as a layer of ash melt bonded the particles together. The temperature at which agglomeration occurred was within the range of the initial deformation (921°C) and softening (1054°C) temperatures of straw ash and the liquidus temperature of potash feldspar (990 ± 20°C). The softening of straw ash and the formation of low melting temperature eutectic (potash feldspar) are two possible mechanisms for the agglomeration of alumina sand.