Analysis of combined processing method of phosphate minerals from the Kef Essenoun deposit

Abstract

Currently, the processing of beige and black phosphates only concerns the main sub-layers, while the other sub-layers (lower and upper for beige phosphate and the upper for black phosphate) are considered waste rock and stored near the complex. Therefore, the object of this research is the use of mixtures of three beige phosphate sub-layers and two black phosphate sub-layers as a feed fraction for the calcination and reverses flotation processes. This research work aims to characterise and treat two types of phosphate: one beige with the sub-layers (main, lower and upper) and the other black with the sub-layers (main and upper) in order to have better recovery of P2O5. The working methodology consists of a series of sample preparation operations and characterization of the two types of beige and black phosphate. This characterization includes a petrographic study, a granulochemical analysis, an X-ray diffraction (XRD), a scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), and an atomic adsorption spectrophotometry (SAA), an auto analyzer (AA), a Bernard calcimeter. These analyzes allow on the one hand to identify the mineral phases in quantitative and qualitative manner, and on the other hand to choose the process for treating phosphates from the Kef Essenoun–Tebessa deposit. The combined method of treatment by calcination followed by reverse flotation gave satisfactory results. The P2O5 content reaches 33.88 % for beige phosphate and 33.13 % for black phosphate. The stored waste rock represents a problem for the company; this waste rock contains fairly high levels of phosphate. The treatment of the mixture of the main sub-layers with these waste rocks makes it possible to obtain a better recovery of P2O5, a better economic profitability of the Djebel Onk mining complex and an environmental impact in the region.