The existing methods for MoO3 production from high-grade molybdenite concentrates normally suffer from the inefficiency of oxidation and complexity of the overall process. In this work, a novel method for MoO3 production from alumina-silica-added molybdenite concentrate pellets by simultaneous oxidizing-volatilizing was proposed, validated and compared with other methods. Molybdenite concentrate mixed with additives was fabricated into spherical balls and roasted in air. Molybdenum disulfide was rapidly oxidized, volatilized and thus separated from pellets, wherein additives were sintered to be mullite as porous framework to keep the strength of single pellet, and in turn to support the stacked pellets. With mass ratio of additives to ore 1:2, ratios of S removal and Mo recovery from pellets reached over 99.9% and 97.2% respectively at 1050 degrees C within 20 min, and the condensed material was identified to be valuable MoO3 with purity over 99.9%. The excellent performance of MoO3 separation was attributed to the construction of firm pellet layers and favorable diffusion conditions inside pellets. (C) 2019 Elsevier B.V. All rights reserved.