scholarly journals Geochemical Assessment and Mobility of Undesired Elements in the Sludge of the Phosphate Industry of Gafsa-Metlaoui Basin, (Southern Tunisia)

2021 ◽  
Vol 11 (3) ◽  
pp. 1075
Author(s):  
Olfa Smida ◽  
Radhia Souissi ◽  
Marzougui Salem ◽  
Fouad Souissi
Keyword(s):  
Rare Earth ◽  
Water Resources ◽  
Chemical Analysis ◽  
Leaching Tests ◽  
Mineralogical Analysis ◽  
P2o5 Content ◽  
Phosphate Industry ◽  
Carbonate Fluorapatite ◽  
Enrichment Process ◽  
Geochemical Assessment

The raw phosphates in the Gafsa-Metlaoui phosphate basin are valorized by wet processes that are performed in the laundries of the Gafsa Phosphates Company (CPG, Gafsa, Tunisia) to reach market grades (>28% P2O5). This enrichment process allows the increase of P2O5 content by the elimination of the coarse (>2 mm) and fine (<71 µm) fractions. Mineralogical analysis has shown that all the investigated materials (raw phosphate, marketable phosphate, coarse waste, and fine waste) from the laundries of M’Dhilla-Zone L and Redeyef are both composed of carbonate fluorapatite, carbonates, quartz, gypsum, clays, and clinoptilolite. Chemical analysis shows that Cr, Cd, Zn, Pb, and U are concentrated in the fine wastes and associated with the clay–phosphate fraction. The rare earth elements are more concentrated in both raw and marketable phosphates. Drilling and sludge-water analysis, along with leaching tests conducted on the fine wastes, showed that, due to phosphate industry, cadmium, fluorine, and sulfate contributing to the pollution of water resources in the region, pollution is more conspicuous at M’Dhilla.

Internal oxidation in solid solutions Bi2.1-xPbxSr2-yCa1-zRy+zCu2O8+d (R = Y, Nd or La).

2004 ◽  
Vol 848 ◽  
Author(s):  
A.V. Garshev ◽  
A.V. Knotko ◽  
M.N. Pulkin ◽  
D.I. Kirdyankin ◽  
A.V. Geyer ◽  
...  
Keyword(s):  
Rare Earth ◽  
Chemical Analysis ◽  
Rare Earth Element ◽  
Internal Oxidation ◽  
Solid Solutions ◽  
Oxidation Kinetics ◽  
Earth Element ◽  
Isothermal Condition ◽  
Element Content ◽  
Rare Earth Element Content

ABSTRACTBi2-xPbxSr2CaCu2O8+d solid solutions with substitution of Sr or Ca by Y, Nd or La were fabricated at 760 - 79°C in N2-flow. The as-synthesized solutions were oxidized in air under isothermal condition and tested with XRD, TGA chemical analysis, TEM, XANES. Effect of rare-earth element content on oxidation kinetics and microstructure of the product is discussed.

scholarly journals Separation of Monazite from Placer Deposit by Magnetic Separation

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 149 ◽  
Author(s):  
Kwanho Kim ◽  
Soobok Jeong
Keyword(s):  
Rare Earth ◽  
Magnetic Separation ◽  
Industrial Revolution ◽  
Supply And Demand ◽  
Modern Technology ◽  
Placer Deposit ◽  
Limited Information ◽  
Mineralogical Analysis ◽  
Separation Result ◽  
Magnetic Product

In this study, mineralogical analysis and beneficiation experiments were conducted using a placer deposit of North Korea, on which limited information was available, to confirm the feasibility of development. Rare earth elements (REEs) have vital applications in modern technology and are growing in importance in the fourth industrial revolution. However, the price of REEs is unstable due to the imbalance between supply and demand, and tremendous efforts are being made to produce REEs sustainably. One of them is the evaluation of new rare earth mines and the verification of their feasibility. As a result of a mineralogical analysis, in this placer deposit, monazite and some amount of xenotime were the main REE-bearing minerals. Besides these minerals, ilmenite and zircon were the target minerals to be concentrated. Using a magnetic separation method at various magnetic intensities, paramagnetic minerals, ilmenite (0.8 T magnetic product), and monazite/xenotime (1.0–1.4 T magnetic product) were recovered selectively. Using a magnetic separation result, the beneficiation process was conducted with additional gravity separation for zircon to produce a valuable mineral concentrate. The process resulted in three kinds of mineral concentrates (ilmenite, REE-bearing mineral, and zircon). The content of ilmenite increased from 32.5% to 90.9%, and the total rare earth oxide (TREO) (%) of the REE-bearing mineral concentrates reached 45.0%. The zircon concentrate, a by-product of this process, had a Zr grade of 42.8%. Consequently, it was possible to produce concentrates by combining relatively simple separation processes compared to the conventional process for rare earth placer deposit and confirmed the possibility of mine development.

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

Minerals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Haïfa Boujlel ◽  
Ghassen Daldoul ◽  
Haïfa Tlil ◽  
Radhia Souissi ◽  
Noureddine Chebbi ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Microscopic Observation ◽  
Recovery Rate ◽  
Coarse Fraction ◽  
Low Grade ◽  
Reverse Flotation ◽  
Chemical Analyses ◽  
Phosphate Ore ◽  
Carbonate Fluorapatite

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%.

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