Characterization of the Oum El Khacheb phosphorites (South Tunisia) and enrichment of big rejections by grinding

In the last decade, the phosphate reserves have started to decrease. In this study, both phosphate of Oum El Khacheb's (O.E.K) region (South of Tunisia) and its big rejections were characterized mineralogically and chemically by several analysis methods such as the binocular magnifying glass, X-rays diffraction technique, Technicon auto-analyzer, atomic absorption spectroscopy, and carbon sulfur analyzer. Then, this work focuses on the coarse rejections of O.E.K's phosphorites which can be valorized by the wet grinding method. Therefore, we have used the methodology of experimental research to determine the optimal grinding conditions. Results found by Doelhert matrix are: a duration at about 4 min, a pulp on solid concentration of 45.00%, a number of cycles equals to 60 rpm and 3.87 as the jar's loading. The enhancement of the weight yields of phosphate recuperation increased significantly by 46.39% from big rejections with 24.60% of P2O5 concentration.