Preparation of free flowing fly ash granules containing multifunctional molecules

A new approach for the granulation of fly ash powder is studied. The fly as h dispersed in aqueous medium at pH > 10 in the presence of multifunctional molecules such as methylol urea, triethanol amine, glycerol, glucose and p entaerythritol, was centrifugally separated, dried to a moisture content < 0.5 wt. rb and then granulated by rotation granulation. Loosely packed powd er agglomerates are produced by particle bridging by the multifunctional mo lecules through hydrogen bonding. The flow property of the powder is remark ably improved by the granulation process. The granules redisperse in aqueou s medium, even after heating at 400 degreesC, without any appreciable incre ase in primary particle size. The heated fly ash granules disintegrate to t he primary particles and the particles disperse well in polyester resin by simple stirring. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights reserved.