ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Selective depression of sphalerite by combined depressant K₃[Fe(CN)₆], ZnSO₄, and Na₂CO₃ in Pb–Zn sulfide flotation separation

Zhicong Wei, Hengsong Wang, Chen Xue, and Ming Zeng

Kunming University of Science and Technology, Kunming, People’s Republic of China

E-mail: 13577100486@126.com

Abstract: The depression performance and mechanism of the combined depressant containing potassium ferricyanide (K₃[Fe(CN)₆]), zinc sulfate (ZnSO₄), and sodium carbonate (Na₂CO₃) with potassium isobutyl xanthate (PPBX) as the collector in a mixed Pb–Zn sulfide flotation system were investigated using microflotation experiments, contact-angle experiments, adsorption capacity experiments, and scanning electron microscopy (SEM)–energy-dispersive spectroscopy (EDS) analysis. The microflotation results indicated that the combined depressant has a significant selective depression effect on sphalerite but a small effect on galena. When the dosages of K₃[Fe(CN)₆], ZnSO₄, and Na₂CO₃ were 1.8 × 10⁻⁵ mol/L, 8 × 10⁻⁵ mol/L, and 2.4 × 10⁻⁴ mol/L, respectively, the recovery of galena was 92.56%, whereas that of sphalerite (Pb²⁺ activation) was only 7.65%. The contact-angle experiment indicated that the order of the single depression effect was as follows: K₃[Fe(CN)₆] > ZnSO₄ > Na₂CO₃. The depression effect of the combined depressant was significantly better than the single depression effect. Adsorption capacity results demonstrated that after depressant addition, the decreasing order of xanthate adsorption capacity was as follows: ZnSO₄ + Na₂CO₃ > K₃[Fe(CN)₆] + Na₂CO₃ > K₃[Fe(CN)₆] + ZnSO₄ > K₃[Fe(CN)₆] + ZnSO₄ + Na₂CO₃. Scanning electron microscopy–energy-dispersive spectroscopy results showed that depression of sphalerite (Pb²⁺ activation) by the combined depressant generated numerous precipitates.

Keywords: Depressant ; Potassium ferricyanide ; Sphalerite ; Galena ; Pb–Zn separation 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-019-00884-w

Chemical Papers 74 (2) 421–429 (2020)