Elaboration d’un nouveau schéma de traitement du minerai de phosphate, Mine de Djebel Onk, Tébessa

The research work undertaken in this thesis deals with the chemical-size and mineralogical characterizations of phosphate ore and the elaboration of a new processing flowsheet based on flotation. Preliminary studies carried out on the final product of the plant pointed out that the enrichment quality results are still unsatisfactory. The separation of dolomite from apatite has been recognized as one of the major constraints and one of the most difficult subjects in minerals separation because of their similarity in physicochemical properties. For this purpose, different characterization methods were carried out to identify phosphate ore, namely: the size, mineralogical XRD analysis, the microscopic observation as well as the morphological SEM analysis. In terms of granulometry, the phosphate ore is characterized by a fine fraction, dolomite clay and rich in P2O5. The different major mineral phases are carbonate apatite, carbonate hydroxyapatite, fluorapatite, and carbonate fluorapatiteThe application of the flotation process, after having optimized the physicochemical parameters of phosphate, namely: the pH values; the minimum required concentration of the Na-oleate collector; the Zeta potential values, allowed to obtain a very good quality concentrate with a recovery of 87%. Finally, a new flowsheet of phosphate ore based on flotation is proposed, in which the use of the Jameson cell is recommended, allowing a considerable phosphate recovery even of the tailing, thus the capture of heavy metals such as Uranium, Cadmium, Zinc, Copper, and Arsenic etc. Key words: phosphate, Jebel Onk deposit; characterization; equilibrium pH value; zêta potential; flotation.

Revalorisation des rejets barytines et impact environnemental", Mine d'Ain Mimoun, Khenchla.

SUMMARY Bibliographic and experimental research, made it possible to show that the flotation is the best process for baryte extraction from Ain Mimoun mine wastes, wilaya of Khenchla, because certain process are not suitable and other was not effective. For studying the floatability of baryte, the baryte waste was put through various types of analysis like particlesize analysis and microscopic observation in order to define the noble class of particle-size and the liberation degree of the particles from gangue. Optimization of the flotation parameters was carried out by using mathematical computing to define the bubbles dimensions necessary to a stiff fixing with the mineral particles while ensuring a good transport of the latter. Using the thermodynamic method of analysis helps for evaluating the baryte surface state in solution in order to determine the optimal pH values, type and quantity of the collector necessary for a mineral complete flotation, the results of analysis coincide completely with experimental results. Finally, the study was finished by choosing a flow sheet for baryte flotation and calling upon for applying the environmental standards in the caused mine.