In this paper, three flotation approaches, bulk flotation followed by separation, selective Cu flotation followed by bulk flotation and then separation, and preferential Mo flotation followed by Cu flotation, were investigated to concentrate molybdenite from Dexing (Jiangxi Province, China) porphyry Cu-Mo ores. The bench-scale flotation results demonstrated that compared to other two flotation approaches, the preferential Mo flotation approach using a new non-thiol collector obtained a high recovery of molybdenite in a molybdenum circuit, while the tailing of molybdenum circuit was treated by a copper flotation circuit to obtain a high recovery of other co-present metal values. The industrial flotation tests indicated that compared to the bulk flotation approach, the preferential Mo flotation approach achieved an excellent cleaner concentrate containing 0.655% Mo with 88.49% Mo recovery, and increased Mo recovery and grade over 34.0% and 0.4% in the molybdenum circuit, respectively. For being uncontaminated with thiol collectors, this cleaner concentrate was readily treated to perform the Mo/Cu flotation separation which returned a superior Mo concentrate containing 48.83% Mo with 90.60% Mo operation recovery as well as saved about 1/2 Na2S consumption. (C) 2012 Elsevier Ltd. All rights reserved.