The Beneficiation Processes of Low-Grade Sedimentary Phosphates of Tozeur-Nefta Deposit (Gafsa-Metlaoui Basin: South of Tunisia)

Minerals

Ghassen Daldoul¹  Fouad Souissi¹  Haïfa Tlil¹  Haïfa Boujlel¹  Radhia Souissi²  Noureddine Chebbi³  Nabil Fattah⁴ 

[1] Department of Geology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia;National Institute of Research and Physico-Chemical Analysis (INRAP), Technopole of Sidi Thabet, Ariana 2020, Tunisia;National Office of Mines (ONM), Tunis 2035, Tunisia;Research Centre of the Phosphate Company of Gafsa (CPG), Metlaoui 2130, Tunisia;

关键词: Gafsa-Metlaoui Basin;    low-grade phosphate;    silicate-carbonate gangue;    froth flotation;    upgrading;   

DOI  :  10.3390/min9010002

来源: DOAJ

【 摘 要 】

The enrichment of the low-grade-phosphate ore of the Tozeur-Nefta deposit was investigated using scrubbing-attrition, ball grinding and anionic/cationic reverse flotation in order to separate phosphate-rich particles from their gangue. The choice of the beneficiation process was based on the petrographic, mineralogical and chemical analyses. The petrographic and mineralogical studies have revealed the abundance of phosphatic (carbonate-fluorapatite-CFA) particles) coupled with carbonates (calcite, dolomite,) and silicates (quartz, illite, kaolonite) that constitute the (endo/exo) gangue of these ores. Chemical analysis has demonstrated that the raw phosphate sample contains low amounts of P₂O₅ (12.0%) and MgO (4.9%) and high amounts of CaO (40.7%) and SiO₂ (20.5%). Microscopic observation/counting has shown that the release mesh occurs in the 71⁻315 μm size. Scrubbing-attrition, grinding and reverse flotation methods were applied to the +71μm fraction. Scrubbing-attrition tests of the 71⁻315 μm fraction have helped to improve the P₂O₅ grade to 15.5%. Ball-grinding tests were used to reduce the coarse fraction +315 μm. Grounded materials were sieved to 71⁻315 μm and combined with the scrubbed fraction in the flotation feed. Reverse-flotation tests of the phosphate-rich fraction (71⁻315 μm) have helped to improve the P₂O₅ grade to 27.1%, with a recovery rate of 92.4%.

【 授权许可】

Unknown