The innovative in-flight glass melting technology with induction thermal plasmas has been performed to investigate the influence of feed rate and particle size on the melting behavior of granulated powders for glass production. Results show that the properties of quenched glass powders are strongly dependent on the feed rate and particle size, especially for the alkali-free glass powders. Higher feed rate and larger particle size lead to lower vitrification degree and decomposition rate of raw material. The average diameter of quenched powders increases with an increase in feed rate and particle size of raw material. The high vitrification degree and decomposition rate obtained in short time shorten the melting and fining time of glass considerably. (C) 2007 Elsevier B.V. All rights reserved.