Investigation on microwave heating for direct leaching of chalcopyrite ores and concentrates

Abstract

The use of microwave energy in materials processing is a relatively new development presenting numerous advantages because of the rapid heating feature. Microwave technology has great potential to improve the extraction efficiency of metals in terms of both a reduction in required leaching time and an increase in the recovery of valuable metals. This method is especially pertinent in view of the increased demand for environment-friendly processes. In the present study, the influence of microwave heating on the direct leaching of chalcopyrite ores and concentrates were investigated. The results of microwave leaching experiments were compared with those obtained under conventional conditions. During these processes, parameters such as leaching media, temperature, and time have been worked to determine the optimum conditions for proper copper dissolution. Experimental results show that microwave leaching is more efficient than conventional leaching. The optimum leaching conditions for microwave leaching are the solid-to-liquid ratio of 1:100 g/mL, the temperature of 140°C, the solution of 0.5 M H₂SO₄ + 0.05 M Fe₂(SO₄)₃, and the time of 1 h.

Keywords

hydrometallurgy / chalcopyrite / leaching / microwave heating

References

[1] Akdag M. Hydrometallurgy: Basic Principles and Applications, 1992 88.

[2] Antonijevi MM, Bogdanovi GD. Investigation of the leaching of chalcopyritic ore in acidic solutions. Hydrometallurgy, 2004, 73, 245.

[3] Peng JH, Liu CP. The kinetics of ferric chloride leaching of sphalerite in the microwave field. Trans. Nonferrous Met. Soc. China, 1992, 2, 46.

[4] Saltiel C, Fathi Z, Sutton W. Materials processing with microwave energy. Mech. Eng., 1995, 117, 102.

[5] Haque KE. Microwave energy for mineral treatment processes: a brief review. Int. J. Miner. Process., 1999, 57, 1.

[6] Al-Harahsheh M, Kingman SW. Microwave-assisted leaching: a review. Hydrometallurgy, 2004, 73, 189.

[7] Córdoba EM, Muñoz JA, Blázquez ML, González F, Ballester A. Leaching of chalcopyrite with ferric ion: Part I. General aspects. Hyrdometallurgy, 2008, 93, 81.

[8] Hirato T, Majima H, Awakura Y. The leaching of chalcopyrite with ferric sulfate. Metall. Trans. B, 1987, 18, 489.

[9] Yilmaz T, Alp I, Deveci H, Duran C, Celep O. Ferric sulphate leaching of Kayabasi massive copper ore. J. Sci. Technol. Inst. Dumlupinar Univ., 2007, 20(2): 63.

[10] Hackl RP, Dreisinger DB, Peters E, King JA. Passivation of chalcopyrite during oxidative leaching in sulfate media. Hyrdometallurgy, 1995, 39, 25.

[11] Dutrizac JE, MacDonald RJC. Ferric ion as a leaching medium. Miner. Sci. Eng., 1974, 6, 59.

[12] Walkiewicz JW, Kazonich G, McGill SL. Microwave heating characteristics of selected minerals and compounds. Miner. Metall. Process., 1988, 5, 39.

[13] Vanetsev AS, Tretyakov YD. Microwave-assisted synthesis of individual and multicomponent oxides. Russ. Chem. Rev., 2007, 76, 397.

[14] Al-Harahsheh M, Kingman S, Hankins N, Somerfield C, Bradshaw S, Louw W. The influence of microwaves on the leaching kinetics of chalcopyrite. Miner. Eng., 2005, 18, 1259.

[15] Panias D, Krestou A. Use of microwave energy in metallurgy. 1st International Conference on Advances in Mineral Resources Management and Environmental Geotechnology, 2004 215.