Title: Production of a Copper-Rich Concentrate from Low-Grade Sulfide Copper Ores Through Sulfidation Flotation of Oxidized Copper Compounds
Authors: Khojiev Sh.T., Karshiboyev Sh.B., Risqulova S.Y., G'ofurova S.Q.
Volume: 9
Issue: 12
Pages: 111-119
Publication Date: 2025/12/28
Abstract:
The growing contribution of low-grade and partially oxidized copper ores to the global raw material base requires improved flotation strategies capable of enhancing concentrate quality at the beneficiation stage. In this study, the sulfidization flotation of oxidized copper minerals from the "Yoshlik-1" copper deposit was systematically investigated and optimized using Response Surface Methodology (RSM) based on a Box-Behnken experimental design. The combined effects of sodium hydrosulfide (NaHS) dosage, pulp pH, and redox potential (Eh) on copper recovery, concentrate grade, and iron entrainment were evaluated. The results demonstrate that flotation performance is governed by the strong interaction between chemical (NaHS dosage, pH) and electrochemical (Eh) parameters. Contour and three-dimensional response surface analyses revealed the existence of a well-defined operational window in which sulfidization promotes the formation of a stable copper sulfide surface, thereby enhancing collector adsorption and flotation selectivity. Optimal conditions were identified at moderately alkaline pH (?9.7-10.0), NaHS dosage of approximately 450-500 g/t, and mildly reducing Eh values (?90 to ?110 mV), under which copper recovery exceeded 80% while iron reporting to the concentrate was minimized. The findings confirm that controlled sulfidization combined with electrochemical regulation represents an effective and economically feasible approach for upgrading low-grade, partially oxidized copper ores. The proposed methodology provides a practical basis for industrial implementation at concentrators processing similar ore types.