Simulation of solute transportation within porous particles during the bioleaching process

Abstract

A mathematical model, accounting for the sulfuric acid and ferric ions diffusion and the copper sulfide mineral leaching process, was developed for an ore particle by considering its porous structure. It was simulated with the simulation tool COMSOL Multiphysics. The simulation results show that the highest acid and ferric concentrations near the particle surface are apparent, while the concentrations in the central particle increase slightly as the less-porous ore core with low permeability prevents the oxidation from penetrating. The extraction of the mineral near the particle surface is the maximum, mainly because of ample sulfuric acid, ferric ions, bacteria, and oxygen available for the leaching process. Because of low oxidation concentration in the central part of the particle, the reaction rate and copper sulphide conversion are small. The simulation shows good agreement with the experimental results.

Keywords

simulation / solute transportation / bioleaching / copper sulphide / porous particle

References

[1] Swamy K.M., Narayana K.L., Misra V.N. Bioleaching with ultrasound. Ultrason. Sonochem., 2005, 12, 301.

[2] Clark M.E., Batty J.D., Buuren C.B., Dew D.W., Eamon M.A. Biotechnology in minerals processing: Technological breakthroughs creating value. Hydrometallurgy, 2006, 83, 3.

[3] Watling H.R. The bioleaching of sulphide minerals with emphasis on copper sulphides—A review. Hydrometallurgy, 2006, 84, 81.

[4] Breed A.W., Hansford G.S. Studies on the mechanism and kinetics of bioleaching. Miner. Eng., 1999, 12, 383.

[5] D.G. Dixon, Heap leach modeling—the current state of the art, [in] Proceedings of the TMS Fall Extraction and Processing Conference, Warrendale, 2003, p.289.

[6] Rawlings D.E., Johnson D.B. Biomining, 2006 Berlin, Springer-Verlag, 153.

[7] D.G. Dixon and J. Petersen, Comprehensive modeling study of chalcocite column and heap bioleaching, [in] Proceedings of Copper 2003, Montreal, 2003, p.493.

[8] Leahy M.J., Davidson M.R., Schwarz M.P. A model for heap bioleaching of chalcocite with heat balance: Bacterial temperature dependence. Miner. Eng., 2005, 18, 1239.

[9] Crundwell F.K. Modeling, simulation, and optimization of bacterial leaching reactors. Biotechnol. Bioeng., 2001, 4, 255.

[10] Rawlings D.E. Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms used for the recovery of metals from minerals and their concentrates. Microb. Cell Factories, 2005, 4, 4.

[11] Balaz P., Kupka D., Bastl Z., Achimovicova M. Combined chemical and bacterial leaching of ultrafine ground chalcopyrite. Hydrometallurgy, 1996, 42, 237.

[12] Sheikhzadeh G.A., Mehrabian M.A., Mansouri S.H., Sarrafi A. Computational modelling of unsaturated flow of liquid in heap leaching—Using the results of column tests to calibrate the model. Int. J. Heat Mass Transfer, 2005, 48, 279.

[13] Braun R.L., Lewis A.E., Wadsworth M.E. In-place leaching of primary sulfide ores: Laboratory leaching data and kinetics model. Metall. Trans. B, 1974, 5(8): 1717.

[14] Munoz J.F., Rengifo P., Vauclin M. Acid leaching of copper in a saturated porous material: Parameter identification and experimental validation of a two-dimensional transport model. J. Contam. Hydrol., 1997, 27, 1.

[15] Wu A.X., Yin S.H., Qin W.Q., Liu J.S., Qiu G.Z. The effect of preferential flow on extraction and surface morphology of copper sulphides during heap leaching. Hydrometallurgy, 2009, 95(1–2): 76.

[16] Blight K., Ralph D.E., Thurgate S. Pyrite surfaces after bio-leaching: A mechanism for bio-oxidation. Hydrometallurgy, 2000, 58, 227.

[17] Abed N. The Sonochemical Leaching of Chalcopyrite, 2001 British Columbia, University of British Columbia, 90.