Role of Mixed Collector Systems in Selective Separation of Albite from Greek Stefania Feldspar Ore

The adsorption behaviour of mixed cationic alkyl diamine and anionic sulfonate/oleate collectors and a combined cationic-anionic collector, N-tallow 1, 3-propane diamine dioleate (Duomeen TDO) at acidic pH values on albite and quartz minerals was investigated through Hallimond flotation, electrokinetic and diffuse reflectance FTIR studies. The reagent schemes are tested in bench scale flotation for the separation of albite from Greek Stefania feldspar ore. The single mineral flotation tests showed the feasibility of selective albite flotation from quartz at pH 2 where the doubly positively charged collector species adsorb on albite but not on quartz. However, the adsorption behaviour of mixed collectors on albite and quartz at the same pH value, as evidenced from zeta-potential and FTIR studies, is almost similar. The IR spectra show the co-existence of neutral oleic acid together with charged amine species at low pH values. The bench scale flotation results indeed showed that selective albite flotation takes place only after desliming the feed material. An albite concentrate exceeding 10 Wt% Na2O content is produced from a material containing about 6.5 wt% Na2O, where an albite product more than 9 wt% Na2O is considered to be valuable.