APPLICATION OF THE HEAP BIOOXIDATION TECHNOLOGY FOR REFRACTORY GOLD CONCENTRATES

Abstract

Rapid depletion of free-milling and oxide gold ores worldwide has forced the mining industry to turn to refractory gold deposits. Hence, research companies have examined novel methods for gold recovery, and advances have been made toward the extraction of gold from many different types of refractory ores. GEOCOAT® technology (heap biooxidation), a proprietary process developed by GeoBiotics, Inc., incorporates elements of two successful and commercially proven processes: heap leaching and biooxidation. The process involves coating of ground gold bearing sulfide minerals concentrate onto relatively coarse inert rock and then bio-heap oxidation of this coated material. In this study, initially the use of biotechnologies in the mining industry was introduced. Detailed information about heap biooxidation process was presented; experiments carried out at laboratory scale and at pilot plant scale by using this technology were summarized; and then commercial plant for heap biooxidation of refractory gold bearing pyrite concentrate was introduced.

Keywords

• Heap Biooxidation,biomining processes,biohydrometallurgy

YIĞIN BİYOOKSİDASYON TEKNOLOJİSİNİN REFRAKTER ALTIN KONSANTRELERİNE UYGULANMASI

Abstract

Dünya çapında öğütmeyle serbestleşebilen ve oksitli altın cevherlerinin hızla tükenmesi, madencilik endüstrisini refrakter altın yataklarına yöneltmiştir. Bunun sonucu olarak araştırma şirketleri altın üretimi için yeni yöntemleri incelemeye başlamışlar ve altının refrakter cevherlerin çok farklı türlerinden kazanımı yönünde atılımlar yapmışlardır. GeoBiotics Şirketince geliştirilen tescilli bir proses olan GEOCOAT® teknolojisi (yığın biyooksidasyonu); işletme ölçekte kendini kanıtlamış ve başarılı iki proses olan yığın liçi ve biyooksidasyon yöntemlerini birleştirmektedir. Yöntem; altın içeren öğütülmüş sülfürlü mineral konsantrelerinin göreceli olarak daha iri inert cevher tanelerinin üzerine kaplanmasını ve daha sonra bu kaplanmış malzemenin biyo-yığın oksidasyonunu içermektedir. Bu çalışmada ilk olarak madencilik endüstrisinde biyoteknolojinin kullanımı tanıtılmıştır. Yığın biyooksidasyonu prosesi hakkında detaylı bilgiler verilmiş, bu teknolojinin kullanımıyla laboratuar ve pilot tesis çapta yürütülen deneyler özetlenmiş ve daha sonra refrakter altın içeren pirit konsantresinin yığın biyooksidasyonunun gerçekleştirildiği ticari tesis tanıtılmıştır.

 

Keywords

• Yığın biyooksidasyonu,biyomadencilik prosesleri,biyohidrometallurji

References

1. [1] Rawlings, D.E., “Biomining:Theory, Microbes and Industrial Processes”, Springer-Verlag, Berlin, (1997).
2. [2]Sand, W., Gehrke, T., Hallmann, R. and Schippers, A., “Appl. Microbial. Biotechnol”, 43:961-966, (1995).
3. [3] Rawlings, D.E., “Microbially Assited Dissolution of Minerals and its Use in the Mining Industry”, Pure Appl. Chem., V:76, 4:847-859, (2004).
4. [4] Ndlovu, S., “Biohydrometallurgy for Sustainable Development in the African Minerals Industry”, Hydrometallurgy, Article in Press., (2007).
5. [5] Brierley, L.C., “Bacterial Oxidation: Master Key to Unlock Refractory Gold Ores?”, Engineering & Mining Journal, May, (1995).
6. [6] Rawlings, D.E., Dew, D. and Plessis, C.D., “Biomineralization of Metal Containing ores and Concentrates, Trends in Biotechnology”, V.21, 1:38-44, January, (2003).
7. [7] Brierley, L.C. ve Briggs, A.P., “Selection and Sizing of Biooxidation Equipment and Circuits”, Mineral Processing Plant Design, Practice, and Control, Edited by Andrew, L. Mular, Doug, N. Halbe, Derek, J., published by SME, (2002).
8. [8] Norris, P.R., “Thermophiles and Bioleaching, Biomining: Theory, Microbes and Industrial Processes”, ed. D.E. Rawlings, Chapter 12. (1997).

9. [9] Seifelnassr, A.A.S., and Abouzeid, A.Z.M., “New Trends in Mineral Processing: Exploitation of Bacterial Activities”, Ore Dressing, 4:18-41, (2000).
10. [10] Spencer, A.P., “Influence of Bacterial Culture Selection on the Operation of a Plant Treating Refractory Gold Ore”, Int. J. Miner. Processing,. 62:217–229, (2001).
11. [11] Brandl, H., “Microbial Leaching of Metals”, Zürich, Switzerland, http://www.infomine.com, (2005).
12. [12] Çelik, H., “Refrakter Altın Cevherlerinin/Konsantrelerinin Ön İyileştirilmesinde Biyooksidasyon Yönteminin Kullanımı”, MADENCİLİK, Cilt 44, 3:35-46, Eylül, (2005).
13. [13] Deng, T.L., Liao, M.X., Wang, M.H., Chen, Y.W. and Belzile, N., “Investigation of Accelerating Parameters for the Biooxidation of Low Grade Refractory Gold Ores”, Minerals Engineering, 13:1543-1553, (2000).
14. [14] Bouffard, S.C. and Dixon, D.G., “Heap Biooxidation of Refractory Gold Ores: Current State of the Art”, Mineral Processing & Extractive Metall. Rev., 25:159-192, (2004).
15. [15] Dresher, W.H., “Copper Applications in Mining and Extraction”, http://www.copper.org/innovations/2004/05/
16. [16] Brierley, J.A. and Brierley, C.L., “Present and Future Commercial Applications of Biohydrometallurgy”, Hydrometallurgy, 59:233-239, (2001).
17. [17] Brierley, J.A, “Response of Microbial Systems to Thermal Stress in Biooxidation Heap Pretreatment of Refractory Gold Ores”, Hydrometallurgy, 71:13-19, (2003).
18. [18] McCready, R.G. and Gould, W.D., “Bioleaching of Uranium”, Ehrlich, H.L. and Brierly, C.L. (Eds.), Microbial Mineral Recovery, McGraw-Hill, New York, p.107, (1990).
19. [19] Williams, T., Hunter, C. and Arnall, B., “Pacific Ore Technology’s Bacterial Leaching of Chalcopyrite”, http://www.pacificore.com.au/oploads/media/POTCopper_paper.pdf, (2007).
20. [20] Brombacher, C., Bachofen, R. and Brandl, H., “Biohydrometallurgical Processing of Solids: a Patent Review”, Appl. Microbiol. Biotechnol, 48:577-587, (1997).
21. [21] İnternet (a), Lesson 12: topic. BIOMIMING, http://www.rocw.raifoundation.org /.../MscBioinformatics/enviraomentalbiotechnology/lecture_notes/lecture-12.pdf, (2007).
22. [22] Harvey, T., “It’s a bug’s life”, World Mining Equipment, March, (2005).
23. [23] Sampson, M.I., Van der Merwe, J.W., Harvey, T.J. and Bath, M.D., “Testing the Ability of a Low Grade Sphalerite Concentrate to Achieve Autothermality During Biooxidation Heap Leaching”, Minerals Engineering, 18:42-437, (2005).
24. [24] Petersen, J. and Dixon, D.G., “Thermophilic Heap Leaching of a Chalcopyrite Concentrate”, Minerals Engineering, 15:777-785, (2002).
25. [25] Johansson, C., Shrader, V., Suissa, J., Adutwum, K. and Kohr, W., “Use of the GEOCOAT Process for the Recovery of Copper from Chalcopyrite”, Presented at IBS Biomin ’99 in Madrid, Spain, (1999).
26. [26] Harvey, T.J., Shield, J.W., Richard, M. and Crowell, P.E., “GEOCOAT Biooxidation Demonstration at Ashanti Goldfields Obuasi Operations”, Ghana, West Africa, Presented at Randol Gold Forum, Denver, Colorado, May, (1999).
27. [27] İnternet (b), Geobiotics Technologies, http://www.geobiotics.com, (2008).
28. [28] Harvey, T.J., Holder, N. and Stanek, T., “Thermophilic Bioleaching of Chalcopyrite Concentrates with GEOCOAT Process”, Presented at Alta Nickel/Cobalt-Copper Conference, Perth, Australia. (2002a).
29. [29] Harvey, T.J., Van der Merwe, J.W. and Afewu, K., “The Application of the GeoBiotics GEOCOAT Biooxidation Technology for the Treatment of Sphalerite at Kumba Resources Rosh Pinah Mine”, Minerals Engineering, 15:823-829, (2002b).
30. [30] İnternet (c), Refractory Gold-Bacox, http://www.mintek.co.za, (2004).