Previous study has reported that adding elongated particles to cohesive granular matters can significantly improve their flowability. In this study, the mechanism of how the elongated particles work to this system was experimentally investigated. The experimental system included a quasi-two-dimensional visualization hopper and a high speed camera to record the flow behavior of the mixed granular systems consisting of glass beads and elongated particles during hopper discharge. Experiments revealed that the discharge rate first increased and then decreased as the mass fraction of elongated particles increased. It was observed that during the discharge flow, the elongated particles rotated and caused local secondary flow of the glass beads. This resulted in a significant increase in flowing layer thickness. Consequently, the effect of elongated particles rotation on discharge flow was discussed. Finally, the estimation of rotational torque of elongated particles was proposed to quantitatively describe the increase of discharge rate. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.