Dry triboelectrostatic separations of fly ash derived from both coal combustion and the combustion of coal mixed with 10 wt% biomass were conducted. Two different types of triboelectrostatic separators - parallel plate and louvered plate separators - were used for this study. It is found that the material of construction for the tribocharger in the louvered plate separator affects both the deposition pattern and the quantity of recovery of the separated products. The poor quality of separation for the biomass fly ash studied is probably due to the physical/chemical nature of the biomass fly ash which is signiftcantly different from that of coal Ay ash. Published by Elsevier Science Ltd.