Characterization and Valorization of Tozeur-Nefta Phosphate Ore Deposit (Southwestern Tunisia)

Abstract

The Tozeur-Nafta phosphate deposit is located, in the southwest of Gafsa mining basin, about 12 kilometers west of Tozeur town. Geologically, this deposit is represented by an anticline with large radius of curvature and characterized by the absence of visible outcrops. Phosphate series show a clear analogy with the other deposits in the neighbor basin. The thickness of 6 exploitable layers is 10,61m with an average content of raw phosphate: P2O5: 22.67%. The collected samples were characterized from a mineralogical, chemical and grain size distribution point of view. Data analysis was firstly used to calculate various statistical parameters, correlations between the chemical elements and secondly to determinate mineral assemblages and useful fractions. The present study is complemented by a geostatistical analysis of geochemical data which consist of the establishment of spatial distribution maps by kriging techniques. The resulting thematic maps that can lead to the development of geochemical model assuming the spatial distribution of oxides and metals of the district.