Selective flotation of pyrite and gold tellurides

The separation of tellurides from pyrite can be carried out by selective flotation. The selection and dosage of collectors and pulp pH are very important to produce one concentrate containing tellurides and free gold, and a further concentrate containing pyrite. A number of thiol collectors were tested to determine their effect on the rate and recovery of tellurides and sulphides. Mineralogical and chemical analysis were used to determine the time-recovery curves of the individual tellurides and sulphides. ural pH, the tellurides floated readily with the addition of a frother only. This recovery could be enhanced by the further addition of an activator and xanthates while some dithiophosphate collectors decreased the natural floatability of the tellurides. The floatation rates and recoveries of the telluride minerals and tetrahedrite were similar making selective separation difficult. However there is sufficient difference in the floatation rates between tellurides and pyrite to make selective separation possible.