There are different kinds of ores :
- BIF (Banded Iron Formation) ore, is at the origin of Australia's huge resources, Brazil, and de main African deposits (Gabon, Congo, Mauritania, Guinea). It represents 90% of the mining reserves and world iron production. Iron is mainly present in the form of magnetite in the massive part or in the goethite or hematite form in the superficial part of the deposit which has undergone the weathering (climate). The iron content of these deposits is higher than 50 %.
- Oolitic ore. This ore is at the origin of many important mines in the East of France such as La Lorraine (minette of Lorraine) or Luxembourg. The iron content of these deposits is between 30-35%.
Process description :
The ore is first grinded and then undergo through several gravity and magnetic separation steps. A flotation step is added sometimes. At the end of these steps a concentrate is produced with a content of +90%. The others elements, mainly siliceous as quartz, are the mine tailings.
Iron beneficiation is done by wet process and important quantities of water are used. In order to recycle the main part of this water, process waters are clarified in a thickener before being reintroduced in the plant.
In desert area, the iron concentrate as well as the tailing mines are filtered in order to recover as much water as possible.
Neyrtec Minéral has an important know-how in ore beneficiation by wet process particularly two major projects in Mauritania (workshop Guels 2 in Zouerate) and in Nigeria (Itakpe) for which we have manufactured and delivered the main equipments and engineering (in the partnership with SOVRAM and KOCH).
The main part of the equipments necessary for iron ore beneficiation is in our equipment's range. The others equipments are manufactured by our partners with whom we have exclusive relationships.
NEYRTEC MINERAL has an engineering department composed of specialists and has the appropriate resources to carry out the conceptual study for detailed and general drawings.
Our wide hydrocyclones' range is suitable for :
- Carrying out grain size separations.
- Elutriating before flotation.
- Thickening the concentrates before filtering.
The LAVODUNE is used to carry out a high cut (between 200 and 800µm) by an hydraulic process.
For waters process our range is composed of :
- Conventional thickeners (40m diameter in Mauritania).
- High capacity CLARIFLUX.
- TASSTERS M for muds compaction.
- Automatic flocculation stations of the effluent and muds processing units.
Spirals are often used for gravimetric classification.
Magnetic separators are used at the end of the process to remove the non magnetic impurities contained in the concentrates.