Paper Title
Phosphate Beneficiation Coarse Rejects: Mineralogical Characterization and Recovery Perspectives
Abstract
Phosphate beneficiation processes often produce coarse rejects, which are typically regarded as waste due to their lower phosphate content and significant gangue mineral concentrations. However, these rejects offer potential for resource recovery and valorization. This study focuses on the characterization and beneficiation of coarse rejects from a phosphate beneficiation plant. Through advanced analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), and chemical analysis (ICP-AES, ICP-MS), we investigated the mineralogical and chemical composition of three types of coarse rejects.
The results indicate that the samples contain significant amounts of carbonate-fluorapatite, calcite, quartz, and dolomite, with phosphorus pentoxide (P2O5) contents ranging between 15% and 16%. Cadmium, present in quartz, is a notable trace element that poses environmental challenges. A liberation study of the phosphate minerals shows varying degrees of mineral separation, with the highest liberation rate observed in Sample A (50% free phosphate).
Promising valorization strategies include advanced flotation techniques, gravity-based pre-concentration, and combined leaching-flotation processes to enhance phosphate recovery and reduce impurities such as calcite and cadmium. These findings highlight the potential for transforming coarse rejects from waste into valuable resources, contributing to more sustainable phosphate beneficiation practices.
Keywords - Phosphate Beneficiation, Coarse Rejects, Reverse Flotation, Mineral Characterization, Valorization.