Abstract
Technological challenges are encountered in the flotation recovery of zinc minerals from polymetallic ores. Typically, copper-lead-zinc ores are processed through a preliminary bulk flotation of all sulfide minerals, followed by separation of the bulk concentrate. From this bulk concentrate, a copper-lead concentrate is obtained, during which zinc and iron minerals are depressed. The subsequent task involves selectively recovering a zinc concentrate by maintaining the depression of iron minerals. That is, the zinc minerals remain in a depressed state and must be activated to become flotable. Copper sulfate is traditionally used as an activator for sphalerite; however, it is a significant source of sulfate ions in wastewater, posing environmental concerns. Therefore, the search for alternative sphalerite activators with reduced environmental impact is a relevant and pressing issue. Copper sulfide is considered as a potential alternative activator. The activating effect of copper sulfide was tested on a monomineralic sphalerite fraction with a particle size of 98.11% below 40 μm, depending on solution pH and activator dosage. The highest degree of sphalerite activation was observed at a pH range of 6–8. The optimal dosage of the conventional activator, copper sulfate, was determined to be 80 mg/dm³, whereas the optimal dosage of copper sulfide was 40 mg/dm³. Results from monomineralic flotation tests demonstrated that the recovery of sphalerite increased by 5–7% when copper sulfide was used, compared to copper sulfate. Adsorption capacity of CuS on the sphalerite surface. Effect of CuSO4 and CuS on the sphalerite activation. Flotation characteristics of sphalerite in the presence of CuSO4 and CuS at different pH levels.