Accumulation of small particles is beneficial for dust removal. We have carried out experiments to investigate the influences of flue gas properties, especially temperature, humidity, sulfuric acid, and dust concentrations, on ash particle accumulation. The ash used was collected from an electric precipitator of a coal-fired power station. It is found that ash accumulation is strongly influenced by the flue gas temperature in comparison with the Engineering Acid Dew Temperature (EADT). With decreasing temperature below the EADT, both the sulfuric acid in flue gas and the ash humidity rise, and the collected particles weight and sizes increase. Therefore, the flue gas temperature can be controlled to enhance particle accumulation and improve ash collection efficiency. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.