Flotation separation of galena from sphalerite using hyaluronic acid (HA) as an environmental-friendly sphalerite depressant

A disaccharide unit glycosaminoglycan named hyaluronic acid (HA) was exploited as a novel sphalerite depressant in the flotation separation of Pb-Zn sulfides in this study. The effect of HA on the flotation of galena and sphalerite were evaluated by micro-flotation tests. The depression mechanisms were investigated by adsorption capacity, Zeta potential and X-ray photoelectron spectroscopy (XPS) analysis. The results of microflotation tests proved that HA was an efficient and selective sphalerite depressant, which could depress sphalerite but hardly influence the flotation of galena to achieve desirable separation results using sodium isobutyl xanthate as collector. The results of adsorption capacity and Zeta potential tests suggested that HA was more inclined to adsorb on sphalerite surface than that of galena, which hindered the adsorption of SIBX on sphalerite surface but insignificantly affected the interaction of SIBX with galena surface. XPS results indicated that HA chemisorbed on sphalerite through the coordination of carboxyl and N-acetyl groups with Zn sites, whereas it physically adsorbed on galena surface by means of hydrophobic interaction.