Bioleaching of marmatite using moderately thermophilic bacteria

Abstract

The process of bioleaching marmatite using moderately thermophilic bacteria was studied by comparing marmatite leaching performance of mesophiles and moderate thermophiles and valuating the effect of venting capacity as well as pulp density on marmatite leaching performance of moderate thermophiles. The results show that moderate thermophiles have more advantages over mesophilies in bioleaching marmatite at 45 °C and the pulp density of 50 g/L, and the zinc extraction efficiency reaches 93.1% in 20 d. Aeration agitation can improve the transfer of O₂ and CO₂ in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. Under the venting levels of 50, 200 and 800 mL/min, the zinc extraction efficiencies by moderate thermophiles are 57.8%, 92.5% and 96.0%, respectively. With the increase of pulp density, the total leaching amount of valuable metals increases, however, the extraction efficiency decreases due to many reasons, such as increasing shear force leading to poorly growth condition for bacteria, etc. The zinc extraction decreases remarkably to 58.9% while the pulp density mounts up 20%.

Keywords

marmatite / moderate thermophilies / zinc / bioleaching

References

[1] DongY.. Probe into processing the zinc sulphide concentrate bearing high content of iron [J]. Yunnan Metallurgy, 2000, 29(4): 26-29

[2] EhrlichH. L.. Past, present and future of bioleaching [J]. Hydrometallurgy, 2001, 59(2/3): 127-134

[3] GarciaO. J., BighamJ. M., TuovienO. H.. Sphalerite oxidation by Thiobacillus ferrooxidans and Thiobacillus thiooxidans [J]. Can J Microbiol, 1995, 41(7): 578-584

[4] BoonM., SnijderM., HansfordG. S., HeijnenJ. J.. The oxidation kinetics of zinc sulphide with Thiobacillus ferrooxidans [J]. Hydrometallurgy, 1998, 48(2): 171-186

[5] ZawaH., SatoH.. Bacterial leaching of cobalt-rich ferromanganese crusts [J]. Int J Miner Process, 1995, 43(3/4): 255-265

[6] BattagliaF., MorinD., OllivierP.. Dissolution of cobaltiferous pyrite by Thiobacillus ferrooxidans and Thiobacillus thiooxidans: Factors influencing bacterial leaching efficiency [J]. J Biotechnology, 1994, 32(1): 11-16

[7] MasonL. J., RiceN. M.. The adaptation of Thiobacillus ferrooxidans for the treatment of nickel-iron sulphide concentrates [J]. Mineral Engineering, 2002, 15(11): 795-808

[8] ZhangG.-j., FangZ.-heng.. Behavior of Fe and S in bioleaching of pentlandite [J]. Trans Nonferrous Met Soc China, 2002, 12(1): 160-163

[9] TuovinenO. H., BhattiT. M., BighamJ. M., HallbergK. B., GarciaO.Jr, LindströmE. B.. Oxidative dissolution of arsenopyrite by mesophilic and moderately thermophilic acidophiles [J]. Appl Environ Microbiol, 1994, 60(9): 3268-3274

[10] DeveciH., AkcilA., AlpI.. Bioleaching of complex zinc sulphide using mesophilic and thermophilic bacteria: Comparative importance of pH and iron [J]. Hydrometallurgy, 2004, 73(3/4): 293-303

[11] ShiS.-Y., FangZ.-heng.. Comparison of bioleaching of marmatite flotation concentrates with Acidithiobacillus ferrooxidans and a moderately thermophilic strain [J]. The Chinese Journal of Process Engineering, 2005, 5(4): 384-388

[12] WuC.-b., ZengW.-m., ZhouH.-b., FuB., HuangJ.-f., QiuG.-z., WangD.-zuo.. Bioleaching of chalcopyrite by a mixed culture of moderately thermophilic microorganisms [J]. Journal of Central South University of Technology, 2007, 14(4): 474-478

[13] ZhouH.-b., LiuX., FuB., HuoQ., ZengW.-m., LiuJ.-s., QiuG.-z., ChenX. H.. Isolation and characterization of Acidithiobacillus caldus from several typical environments in China [J]. Journal of Central South University of Technology, 2007, 14(2): 163-169

[14] BaileyA. D., HansfordG. S.. Oxygen mass transfer limitation of batch bio-oxidation at high solids concentration [J]. Minerals Engineering, 1994, 7(2/3): 293-303

[15] TormaA. E., WaldenC. C., DuncanD. L. W., BranionR. M. R.. The effect of carbon dioxide and particle surface area on the microbiological leaching of a zinc sulfide concentrate [J]. Biotechnology and Bioengineering, 1972, 14(5): 777-786

[16] ShiS.-y., FangZ.-heng.. Bioleaching of marmatite concentrate in magnetic stirring reactor [J]. Nonferrous Metals, 2005, 57(2): 62-65