Flotation Optimization and Sulfidation Strategies for Maximizing Copper Recovery from a Complex Mixed Oxide-Sulfide Ore

Abstract

This study systematically examines the flotation optimization and sulfidation strategies for enhancing copper recovery from a complex mixed oxide-sulfide ore containing approximately 62% copper oxide and 38% copper sulfide. Comprehensive mineralogical characterization using XRD, SEM-EDS, and EPMA identified a silicate-rich gangue and delineated copper-bearing mineral phases. Laboratory flotation experiments investigated the influence of particle size, reagent type and dosage, pulp pH, and reagent addition sequence on copper recovery. Optimal conditions resulted in a copper oxide recovery of 76% at a particle size of 53 μm and pH 10.5, with total copper recovery reaching 81% through staged reagent addition. Sodium sulfide and sodium hydrosulfide proved effective as sulfidizing agents, with potassium amyl xanthate (PAX)—especially in combination with a co-collector—significantly improving performance. Distributing the sulfidizing agent between the grinding mill and flotation cell balanced the activation of oxide and sulfide minerals, maximizing overall recovery. These results highlight the importance of integrated mineralogical analysis and process parameter optimization for efficient beneficiation of complex copper oxide-sulfide ores, providing practical insights for developing robust flotation flowsheets for similar mineral systems.