An innovative in-flight melting technology with 12-phase alternating current (AC) arc has been developed to investigate the melting behavior of granulated alkali-free glass raw material. Results show that the melted particles have spherical shape with smooth surface and compact structure. Lower vitrification and decomposition degrees of raw material as well as lower volatilization of B2O3 are attributed to less heat transferred per particle under larger flow rate of carrier gas and higher feed rate. The high vitrification and decomposition degrees indicate that the new in-flight glass melting with 12-phase AC arc will be a promising technology for glass production. (C) 2008 Elsevier B.V. All rights reserved.