Dry beneficiation of three high loss-on-ignition (LOI) fly ashes were conducted. The combination of two different types of dry separation techniques-ultrasonic sieving and triboelectrostatic separation-were used for this study. The results indicate that a simple separation of unburned carbon from fly ash is achievable at particle sizes of 149, 74 and 44 mum, and screening could be utilized as the rough separation mechanism for fly ash. Subsequently, triboelectrostatic separations were conducted on these different particle size fractions of the fly ash and indicated that the final carbon content in the products, as low as 2.5% or as high as 60%, can be further adjusted with the combination of dry sieving and triboelectrostatic separation. (C) 2002 Elsevier Science B.V. All rights reserved.