SAPONIFIED PALM AND SOYBEAN OILS AS SUSTAINABLE COLLECTORS FOR IRON ORE FLOTATION: PERFORMANCE EVALUATION AND RESPONSE SURFACE OPTIMIZATION

The granulometric analysis and chemical composition highlight intrinsic challenges for flotation. The predominance of ultrafine particles generates slimes that reduce selectivity, while the high proportion of silica and alumina introduces gangue phases that compete with hematite for collector adsorption. These features justify the need for collectors capable of strong and selective adsorption under adverse particle-size conditions, providing the rationale for testing reagents with different molecular structures in microflotation assays. The results demonstrated that saponified palm (SPO) and saponified soybean oils (SSO) exhibit effective collecting ability under alkaline conditions, achieving iron recoveries comparable to sodium oleate. Collector dosage and pH were identified as the most influential parameters, with interaction effects defining operating windows for maximizing selectivity and metallurgical recovery. Surface chemistry analyses further indicated that the fatty acid composition and degree of saponification strongly affected adsorption efficiency at the hematite interface. These findings confirm that vegetable-oil-derived soaps can function as technically viable and environmentally benign collectors. The study highlights the potential of SPO and SSO to replace conventional surfactants and demonstrates the usefulness of response-surface methodology (RSM) as a tool for optimizing bio-based flotation reagents, contributing to greener mineral processing technologies.