Alireza Javadi - Department of Engineering, University of Kashan, ۸۷۳۱۷۵۳۱۵۳ Kashan, Iran

Our recent studies revealed that the ground sulphide minerals in contact with water generate H۲O۲ but its effect on the oxidation of pulp components and hence in deteriorating the concentrate grade and recovery in flotation has not been explored yet. The use of Na۲S reductant at the grinding stage is thought to control the deleterious effects of H۲O۲ in the pulp liquid. Therefore, the effect of Na۲S addition during grinding stage on the formation of H۲O۲ and its influence on sulphide complex ore flotation was investigated. The results showed that the presence of Na۲S increases the formation of H۲O۲ but decreases the dissolved oxygen. An increase in Na۲S dosage in grinding, the Pb grade and recovery in Cu-Pb concentrate is decreased while pyrite is depressed marginally better. These changes in flotation response of sulphides have been discussed and explained with the formation of H۲O۲ quantitatively.

sulphide complex ore, Na۲S, depressant, Flotation