Résumé: urpose. The objective of this work in the first stage is to characterize the poor iron ore from the El Ouenza mine. Then, in the second stage, it is a question of valorizing it by high intensity magnetic separation. Methodology. The characterization of representative samples taken from the study area was carried out using several techniques, including X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), and Fourier transform infrared spectroscopy (FTIR). Processes involving a combination of calcination and high-intensity dry magnetic separation were used to upgrade the poor iron ore to meet the requirements of the steel industry. Findings. The results obtained show that the El Ouenza iron ore consists mainly of ferrous minerals, notably hematite and goethite, as well as a siliceous and calcareous gangue. The treatment results enabled us to achieve a grade of 51.94% for the sample calcined at 900 C using a magnetic field of 2.3 T on the size fraction (-0.5+ 0.125) mm. Originality. The originality of the work lies in the possibility of using combined methods, calcination and magnetic separation, to valorize poor iron ore from the Ouenza mine. Practical value. This study shows that the results obtained by calcination and magnetic separation are very significant. These techniques enable us to obtain a concentrate with an iron content of 51.94%, bringing value to the steel industry, eliminating the reserves of poor iron ore stored near the mine site and preserving the environment.

Résumé: Iron mining waste is produced from the iron ore mining operations of El Ouenza Mine (north-east Algeria), and it is not currently recycled to preserve the environment. The current study aims at developing sustainable clay bricks by mixing clay with different proportions of iron mining waste (ranging from 10 to 50 wt.%) and fired at 850°C and 950°C. Addition of 30 wt.% Iron mining waste had a positive effect on the physical and mechanical properties of the fired clay bricks. Linear shrinkage, water absorption and porosity were reduced, while compressive and flexural strengths were increased. Furthermore, up to 30 wt.% of iron mining waste addition to the mixtures improved compressive and flexural strengths to 59.17 and 10.06 MPa, respectively, when the bricks were fired at 950°C. According to their thermal conductivity, the bricks with 10–50 wt.% iron mining waste are considered as thermal insulators, with thermal conductivity values ranging from 0.45 to 0.56 W m–1 K–1. Adding 30 wt.% of iron mining waste can lead to the production of eco-friendly bricks with high mechanical and thermal properties, generating economic and environmental benefits.

Résumé: Purpose. Choice of a method for treating the iron ore of the Khanguet mine depending on its characterization. Methodology. This work is focused on the study on physicochemical and mineralogical characterization of the poor iron ore of Khanguet mine, using multiple analysis techniques (X-ray diff raction, X-ray fl uorescence, scanning electron microscope and optical microscope), to identify the chemical composition and mineral phases of the ore. The study also focused on the possibility of enrichment, using the electrostatic separation process. For this purpose, two main parameters are studied, such as, the voltage between the electrodes and the rotation speed of the roll. Findings. The results of the characterization show the possibility of using the process of electrostatic separation for the enrichment of the Khanguet ore, which allows increasing the content of Fe2O3 up to 58.46 %. Originality. The originality of this work is the possibility to use the electrostatic treatment process for the poor iron ore of the Khanguet iron mine. Practical value. This study shows that the results obtained by the process of electrostatic treatment of ore are very signifi cant; this technique makes it possible to obtain a concentrate with an iron content of 58.46 % and to bring an added value to the company and the steelmaking industry, on the one hand, and, on the other hand, to eliminate reserves of these poor iron ores stored near the mining site, which is harmful for the environment.

Résumé: The recent developments of steel and iron industries generated a huge consumption of iron ores which has attracted much attention for utilizing low-grade iron resources to satisfy this increasing demand. The present study focuses on the characterization and enrichment of the low-grade iron ores from Rouina deposit -Ain Defla-. Currently, the ore is used in the cement industry because it is considered a low-grade iron ore. After the sampling process, a physico-chemical and mineralogical characterization was carried out and the results revealed that the sample consists of hematite, limonite and goethite as major opaque oxide minerals whereas silicates as well as clays form the gangue minerals in the sample. The average grade of FeTotal, SiO2 and Al2O3 contents in the raw material collected from the mine of the case study are 30.85%, 23.12% and 7.77% respectively. Processes involving combination of classification, washing and dry high-intensity magnetic separation were carried out to upgrade the low-grade iron ore sample to make it suitable as a marketable product. The sample was first ground and each closed size sieve fractions were subjected to washing followed by drying than dry high intensity magnetic separation and it was observed that limited upgradation is possible. As a result, it was possible to obtain a magnetic concentrate of 54.09% with a recovery degree of 89.30% and yield of 62.82% using a magnetic field intensity equal to 2.4 Tesla at the size fraction [-0.125 +0.063 mm].

Résumé: a complexité des paramètres minéralogiques, chimiques et exogènes entraîne une faible efficacité de la séparation électrique du minerai de fer oxydé. À cette fin, une étude a été menée afin de proposer une méthode de séparation électrostatique et de sélectionner les réactifs chimiques appropriés. Ceci afin d'augmenter le contraste des minéraux de séparation diélectrique dans le champ de décharge couronne. Le réactif-collecteur utilisé est l'auramine avec une consommation spécifique de 0,3 kg/t. Le réactif dépresseur est un mélange de carboxyméthylcellulose avec une consommation spécifique de 0,25 kg/t. Les résultats des essais obtenus confirment que le traitement électrique du minerai de fer oxydé est satisfaisant pour le procédé proposé.

Résumé: a complexité des paramètres minéralogiques, chimiques et exogènes entraîne une faible efficacité de la séparation électrique du minerai de fer oxydé. À cette fin, une étude a été menée afin de proposer une méthode de séparation électrostatique et de sélectionner les réactifs chimiques appropriés. Ceci afin d'augmenter le contraste des minéraux de séparation diélectrique dans le champ de décharge couronne. Le réactif-collecteur utilisé est l'auramine avec une consommation spécifique de 0,3 kg/t. Le réactif dépresseur est un mélange de carboxyméthylcellulose avec une consommation spécifique de 0,25 kg/t. Les résultats des essais obtenus confirment que le traitement électrique du minerai de fer oxydé est satisfaisant pour le procédé proposé.