New collectors in the flotation of sulphide minerals: a study of the electrokinetic, calorimetric and flotation properties of sphalerite, galena and chalcocite

Abstract

Three collector-mineral systems have been studied by means of electrophoresis, sedimentation, microcalorimetry and flotation. They are 2-mercaptobenzoxazole (MBO)-chalcocite, 2-mercaptobenzothiazole (MBT)-galena and 2-aminothiophenol (ATP)-sphalerite.The results have been compared with those for the common sulphide collectors potassium amyl-and hexyl-xanthate respectively (KAX and KHX).The flotation experiments have shown that the new collectors offer some important advantages over xanthate collectors in sulphide mineral benefication. They strongly improve the mineral recovery in the neutral pH range and in comparison to xanthates, a lower dosage of the new collectors was required to obtain high recoveries in flotation. The results of electrophoresis and sedimentation studies confirm the tonclusions drawn from flotation experiments.The study of the adsorption properties in combination with thermochemical measurements provided new information about the adsorption mechanism in each system. Especially on chalcocite, fundamental differences in the adsorption behaviour of MBO and KAX have been observed. The conclusion has been drawn that a higher affinity of a collector compound does not necessarily improve the flotation properties. The hydrophobic character of the collector has been shown to be the most decisive parameter in the flotation of the sulphides.