Pyrite flotation in the presence of galena. Study on galvanic interaction

In this investigation, galvanic interaction between galena and pyrite in flotation and its effect on floatability of pyrite were studied. Rest and mixed potential studies in the presence and absence of a collector indicated that pyrite was nobler than galena under all investigated conditions. Therefore, pyrite served as a cathode in galvanic interactions with galena. Floatability of pyrite was performed alone and as a mixture with galena in the ratios of pyrite to galena equal to 1:4, 1:1 and 4:1. The experiments were conducted with air and nitrogen. In any galvanic contact between pyrite and galena, anodic oxidation occurred on the galena surface, and hydrolysed lead species adsorbed on the pyrite surface. The investigation of the various reactions occurring on the sample surface was investigated by ethylene diamine-tetra acetic acid disodium salt (EDTA) extraction and X-ray photoelectron spectroscopy (XPS) measurements. In the presence of nitrogen, floatability of pyrite increased. The recovery of pyrite in the presence of air was 22%, while in the mixture with galena (ratio 1:4) the recovery increased to 43%. The results indicated that the presence of galena improved floatability of pyrite.