Discrete element method (DEM) has been used to investigate the effects of particle contact parameters, sliding friction coefficient (SFC), rolling friction coefficient (RFC) and restitution coefficient (RC), in a rotating drum. Their effects were examined in terms of mean power draw, mean collision energy and collision frequency employing response surface method (RSM) in conjunction with analysis of variance (ANOVA) to perform significance analysis for the effects of single factors and factor combinations. Various rotational speed was also considered in the present work. The results revealed that sliding friction coefficient was a determining factor for mean power draw and mean collision energy, and restitution coefficient had the greatest impact on collision frequency. Additionally, sliding friction coefficient and restitution coefficient showed interaction effects on both mean collision energy and collision frequency over the range of rotational speed. Moreover, the sensitivity of particle contact parameters varies with the rotational speed of the drum. (C) 2019 Elsevier B.V. All rights reserved.