Flotation separation of calcareous minerals using didodecyldimethylammonium chloride as a collector

The flotation separation of scheelite from fluorite and calcite using dodecyltrimethylammonium chloride (DTAC), dodecyldimethylbenzylammonium chloride (DDBAC), or didodecyldimethylammonium chloride (DDDAC) as the collector has been investigated. The results show that the selectivity of these collectors for these three calcareous minerals falls in the order: DDDAC > DDBAC > DTAC. A significantly different flotation response of scheelite compared to the other two calcareous minerals was observed over the pH range from 7 to 8 for DDDAC as the collector. A concentrate containing 41.40% WO3 could be produced from a feed mixture containing 23.22% WO3 at the DDDAC concentration of 4.0 × 10−4 mol/L. The WO3 recovery was 92.92% under these conditions. The results of zeta potential measurements suggest that electrostatic interactions are the main forces between DDDAC and the minerals. When the concentration of DDDAC is from 2 × 10−4 to 4 × 10−3 mol/L large differences in adsorption density, and adsorption kinetics, of DDDAC onto scheelite, calcite, and fluorite provide desirable conditions for achieving high selectivity.