Determination of physicochemical parameters of Djebel Onk phosphate flotation (Algeria)

Purpose. To define the optimal physical-chemical parameters for the flotation of Djebel Onk phosphate in Eastern Algeria, for obtaining a concentrate of high quality with minimal dispenses and environment protection and using micro-flotation tests to achieve maximum recovery of the latter. Methodology. In order to achieve our purposes we used: the thermodynamic analysis method to characterize mineral surfaces and to define equilibrium pH value necessary for a complete phosphate recovery; micro-flotation tests to determine optimal quantity of sodium oleate and alkyl hydroxamic acid collector (AERO 6493) concentrations for a maximum concentrate extraction; Zeta-meter system to measure the Zeta potential of the phosphate electrokinetically to choose the suitable values insuring the best hydrophobicity of the particle surface. Findings. PH equilibrium value for the "mineral-water" system makes 8.7 for Ca3(PO4)2. The maximal mineral recovery is obtained, it is about 88.6 %, at Oleate concentration till 30.44 mg/l. However, in the case of AERO6493, it reaches 86 % provided pH value equals 8.7; Zeta potential (surface charge) values-20.45 and-10.87 mV, corresponding to concentration of Sodium Oleate collector 30.44 and 75 mg/l of alkyl hydroxamic acid collector, respectively, answering the minimal necessary concentrations for a maximum apatite flotation at equilibrium pH value of 8.7. Originality. The originality of this research is in the application of flotation process for the first time on Algerian phosphate ore, performed in optimal conditions (pH, collector concentrations, Zeta potential). This leads to a complete recovery of phosphate concentrate with minimal reagents dispenses and environment protection. Practical value. Application of the obtained optimal physical-chemical parameters of phosphate flotation permits a using phosphate ores rationally, obtaining a high quality concentrate with poor tailings. All this contributes to the improvement of technical-economical parameters of Djebel Onk plant and environment protection.