Modelisation et simulation des operations d'extraction par solvant et d'electrolyse (SX-EW) du cuivre (French text)

Solvent extraction (SX) followed by electrowinning (EW) has become over the last two decades a key process for the recovery of copper from solution obtained by leaching low grade copper ore. Indeed, several operations have been put on stream in North and South Americas in the last decade. From 1996 to 1997 les Mines Gaspé operated a pilot plant to test the economical feasibility of leaching an oxidised copper ore, consisting mainly of malachite, followed by solvent extraction and electrowinning of copper.; The aim of this PhD thesis is to develop and calibrate a phenomenological model of a copper solvent extraction mixer-settler and electrowinning cell to analyze simultaneously the behaviour of several elements (Cu, Fe,…) during the extraction process.; Experimental data are required to calibrate and validate the models. However since suitable data are not available in the literature, they were obtained by carrying out a series of experiments in both laboratory and pilot plant. The model equations of the SX-EW simulator are solved using a numerical routine. The unknown model parameters were evaluated using an optimisation routine operating on the SX and EW simulator. The calibrated models are used to simulate the SX-EW circuit of Mines Gaspé. The models used for the SX and EW processes are based on mass transfer and reaction kinetics to and at the organic/aqueous interface and at the aqueous/electrode interface. The input variables for the simulation are the aqueous and organic feed rate and composition, the cell tension and the hardware resistance. The simulation results compare well with pilot plant data despite some assumptions made concerning the mass transfer and rate of chemical reaction and by the fact that the stripping process is simulated using the model calibrated for an absorption mixer-settler.