The flotability of scheelite and calcite was studied with Dioctyl dimethyl ammonium bromide (BDDA). The experiments were conducted on individual and mixed minerals as a function of pH with a micro-flotation cell. And oleic acid was tested for comparison. The flotation results revealed that the performance of BDDA is better than that of oleic acid and the best separation could be achieved with BDDA over the pH range 8-10. Through preliminary analysis, it is concluded that BDDA reacts with scheelite through electrostatic interaction. (C) 2010 Elsevier Ltd. All rights reserved.