Characterization by FTIR of sphalerite obtained in the flotation without collector in the presence of ferric iron

Sphalerite is generally recovered by flotation; however, it has been established that the success of this stage is affected by surface contamination with ferric iron precipitates during grinding. In this work, the flotation of sphalerite was carried out in the presence of iron precipitates 5, 25, 50, and 75 mgL⁻¹ of Fe⁺³ as ferric sulfate. The results show that the cumulative flotation of sphalerite, without collector at pH 6.4, with 60 mgL⁻¹ of frother, improves, with the increase in ferric ion, and thus, with 75 mgL⁻¹ and 2 min of flotation, 94% cumulative recoveries are achieved. Infrared analysis shows absorption bands of the Zn–O vibration at 1737, 1378, 1244, and 1021 cm⁻¹, in addition, the presence of the main band of the tetragonal sulfate ion at 1115 cm⁻¹, and an absorption band corresponding to Fe–O vibration of goethite at 619 cm⁻¹.