Water Washing of Fungal-treated Carbonaceous Ores: Effect on Aurocyanide Adsorption by Activated Carbon in CIL Circuit
Keywords:
Carbonaceous Gold Ore, Carbon-In-Leach, Cell-free Extracts, Phanerochaete chrysosporiumAbstract
A typical challenge encountered on most gold processing plants during leaching of refractory ores is the reduction in recovery due to the presence of carbonaceous matter which preg-robs dissolved gold, thus reducing overall recovery. To reduce preg-robbing during cyanidation, carbonaceous matter has to undergo pretreatment to passivate the active surface. The fungus, Phanerochaete chrysosporium has been shown to possess the ability to biotransform carbonaceous matter, thus reducing its ability to preg-rob gold. However, the possible transfer of entrained fungal biomass into Carbon-In-Leach (CIL) circuits has been reported to decrease the activity of activated carbon, and a proposed solution to this was to wash the fungal-treated material thoroughly with sufficient water prior to CIL operation. This paper therefore set out to assess the effect of sufficient water washing on aurocyanide adsorption by activated carbon in CIL following fungal pretreatment of carbonaceous ores. To realise the objective, activated carbon was contacted with cell-free extract of P. chrysosporium under varying conditions of pH and time, after which it was washed with different volumes of water, and its gold-adsorption ability assessed. The results revealed a decrease in the activity of activated carbon as a function of increasing contact time with the cell-free extract. The percentage decrease was higher after treatment in the acidic medium (13%) than the basic medium (9%). After washing the carbon (treated in acidic medium) with various volumes of water, gold adsorption was found to increase directly with the volume of water used from 64% at 0 ml to 84% at 500 ml and 91% at 1000 ml. Correspondingly, the carbon treated in basic medium recorded 69% at 0 ml to 87% at 500 ml and 93% at 1000 ml. This paper thus concludes that, sufficient water washing should be employed after fungal-biotransformation of refractory ores before the material is transferred into the CIL circuit to decrease the effect of entrained biomass on the adsorption capacity of activated carbon.
References
Adam, A. S., Ofori-Sarpong, G. and Amankwah, R. K., (2017), “Assessing the Challenges in the Extraction of Gold from Bacterial-Treated Double-Refractory Concentrateâ€, SME Annual Meeting, Denver, USA, pp 1-7.
Adams, M. D., Burger, A. M., (1998), “Characterization and blinding of carbonaceous preg-robbers in gold oresâ€, Minerals Engineering 11 (10), pp. 919-927.
Adams, M. D., Swaney, S. J., Fried, J. and Wagner, F.E., (1996), “Preg-robbing Minerals in Gold ores and residuesâ€, Hidden Wealth. S. African. Inst. Min. and Metall., Johannesburg, pp. 163–172.
Amankwah, R. K. and Yen, W. T. (2006), “Effect of carbonaceous characteristics on biodegradation and preg-robbing behaviourâ€, In: Onal, G., Acarkan, N., Celik, M. S., Arslan, F., Atesok, G., Guney, A., Sirkecl, A. A., Yuce, A. E., Perek, K. T. (Eds.), Proceedings of the 23rd International Mineral Processing Congress, Promed Advertising Limited, Instanbul, pp. 1445-1451.
Amankwah, R.K., Yen, W.T. and Ramsay, J., (2005), “A Two-Stage Bacterial Pretreatment Process for Double Refractory Gold Oresâ€, Minerals Engineering, Vol. 18, pp. 103–108.
Andrawis, A., Johnson, K. A. Tien, M., (1988), “Studies on Compound I Formation of the Lignin Peroxidase from Phanerochaete chrysosporiumâ€, The Journal of Biological Chemistry, Vol. 3, pp. 1195-119.
Bhattacharyya, D., Depci, T., Elnathan, F. and Miller, J.D. (2014), “Effect of Activated Carbon Particle Size on The Adsorption/Desorption of Gold from Alkaline Cyanide Solutionâ€, SME Annual Meeting, SME, Salt Lake City, 3pp.
Bonnah, R. C., Ocran, B., Diko, C. S. and Ofori-Sarpong, G. (2016), “Effect of Fungal Treatment on Gold Adsorption by Activated Carbon –A Preliminary Studyâ€, 4th UMaT Biennial International Mining and Mineral Conference, Tarkwa, Ghana, pp. 189-194.
Brierley, C.L. (1997), “Mining biotechnology: research to commercial development and beyondâ€, In: Biomining: Theory, Microbes and Industrial Processes, Rawlings, D. E. (Ed.), Springer Verlag, Berlin, Germany, pp. 3-17.
Brierley, J. A., Kulpa, C. F., (1993), “Biometallurgical treatment of precious metal ores having refractory carbon contentâ€, US Patent, 5,244,493.
Cecen, F. (2014), “Activated Carbonâ€, www.researchgate.net/publication/263062486. Assessed: 17th February, 2017.
Helm, M., Vaughan, J., Staunton, W.P., and Avraamides, J. An investigation of the carbonaceous component of preg-robbing gold ores. World Gold Conference 2009, The Southern African Institute of Mining and Metallurgy, 2009.
Hutchins, S. E., Brierley, J. A., Brierley, C. L. (1988), “Microbial pretreatment of refractory sulfide and carbonaceous ores improves the economics of gold recoveryâ€, Mining Engineering, Vol. 40, pp. 249-254.
Ibrado, A. S., Fuerstenau, D.W. (1992), “Effect of the structure of carbon adsorbents on the adsorption of gold cyanideâ€, Hydrometallurgy, Vol. 30, pp. 243-256.
Madigan, M. T., Martinko, J. M., (2006), Brock’s biology of microorganisms, 11th ed., Pearson Prentice Hall, Upper Saddle River, NJ, pp 469-472, 691-692.
Marsden, J., House, I., (2006), The chemistry of gold extraction, 2nd ed., Society for Mining, Metallurgy and Exploration, Inc. Littleton, Colorado, pp 42-44, 111-126, 161-177, 191-193, 233-263, 297-333.
Ofori-Sarpong, G. and Osseo-Asare, K. (2013), “Preg-robbing of Gold from Cyanide and Non-Cyanide Complexes: Effect of Fungi Pretreatment of Carbonaceous Matterâ€, International Journal of Mineral Processing, Vol. 119, pp. 27-33.
Ofori-Sarpong, G., Amankwah, R.K., and Osseo-Asare, K. (2013a), “Reduction of Preg-Robbing by Biomodified Carbonaceous Matter–A Proposed Mechanismâ€, Minerals Engineering, Vol. 42, pp. 29-35.
Ofori-Sarpong, G., Osseo-Asare K., and Tien, M., (2011), “Fungal biotransformation of anthracite-grade carbonaceous matter: Effect on gold cyanide uptakeâ€, In: Biohydrometallurgy: Biotech key to unlock mineral resources value, Proceedings of the 19th International Biohydro-metallurgy Symposium, Qiu, G., Jiang, T., Qin, W., Liu, X., Yang, Y. and Wang, H. (Eds.), Vol. 1, Central South University Press, Changsha, China, pp. 445-451.
Ofori-Sarpong, G., Osseo-Asare K., and Tien, M., (2013b), “Mycohydrometallurgy: Biotransformation of Double Refractory Gold Ores by the Fungus, Phanerochaete chrysosporiumâ€, Hydrometallurgy, Vol. 137, pp. 38 – 44.
Ofori-Sarpong, G., Osseo-Asare K., and Tien, M., (2013c), “Pretreatment of Refractory Gold Ores using Cell-Free Extracts of Phanerochaete chrysosporium: a Preliminary Studyâ€, Advanced Materials Research, Vol. 825, pp. 427-430.
Ofori-Sarpong, G., Tien, M., and Osseo-Asare, K. (2010), “Myco-hydrometallurgy: Coal model for potential reduction of preg-robbing capacity of carbonaceous gold ores using the fungus, Phanerochaete chrysosporiumâ€, Hydrometallurgy 102, 66–72.
Portier, R. J. (1991), “Biohydrometallurgical Processing of Ores, and Microorganisms thereforeâ€, US Patent No. 5,021,088.
Qian LIU, Hong-ying YANG, Lin-lin TONG (2014), “Influence of Phanerochaete chrysosporium degradation and preg-robbing capacity of activated carbonâ€, Trans. Nonferrous Met. Soc. China, pp. 1905−1911.
Rawlings, D. E. (1998), “Industrial practice and the biology of leaching of metals from oresâ€, Journal of Industrial Microbiology and Biotechnology, Vol. 20, pp. 268-274.
Rees, K.L. and Van Deventer, J. S. J. (2000), “Preg-robbing Phenomena in the Cyanidation of Sulphide Gold Oresâ€, Hydrometallurgy, Vol. 58, pp. 61-80.
Schmitz, P.A., Duyvesteyn, S., Johnson, W.P., Enloe, L., McMullen, J., (2001), “Adsorption of aurocyanide complexes onto carbonaceous matter from preg-robbing Goldstrike oreâ€, Hydrometallurgy 61, 121–135.
Stenebraten, J. F., Johnson, W. P., McMullen, J., (2000), “Characterization of Goldstrike Oreâ€, Carbonaceous Material Part 2, Minerals and Metallurgical Processing 17, pp. 7-15.
Tan, H., Feng, D. and Van Deventer, J. S. J. (2003), “Effect of carbonaceous coatings on preg-robbing of chalcopyriteâ€, Proceedings Hydrometallurgy 2003 – Fifth International Conference, Young, C.A., Alfantazi, A.M., Anderson, C.G., Dreisinger, D.B., Harris, B. and James, A. (Eds), Pennsylvania, U.S.A, pp. 35-48.
Thompson, L.C., and MacCulloch, I.R. (2004), “Biological Processes for Gold Recoveryâ€, Proceedings of Bac-Min Conference, AUSIMM, Victoria, Australia.
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