Effect of activated carbon on the bioleaching of chalcopyrite concentrate

doi:10.1016/S0301-7516(98)00026-X

International Journal of Mineral Processing

Volume 55, Issue 2, December 1998, Pages 87-94

https://doi.org/10.1016/S0301-7516(98)00026-X Get rights and content

Abstract

The effect of the addition of activated carbon on the bioleaching of chalcopyrite concentrate, which contained pyrite, sphalerite and galena as sulfide gangue minerals, has been investigated using Thiobacillus ferrooxidans. The addition of activated carbon accelerated the dissolution of copper from the chalcopyrite concentrate. The recovery of copper increased with increase in the amount of activated carbon and with decrease in particle size of activated carbon. In the chemical control, activated carbon also enhanced the dissolution rate of copper and zinc from the chalcopyrite concentrate. These results indicated that the enhanced rate of leaching could be attributed to the galvanic interactions between activated carbon and chalcopyrite or sphalerite. The presence of Thiobacillus ferrooxidans could accelerate the galvanic interactions.

Introduction

Bioleaching of chalcopyrite concentrate by Thiobacillus ferrooxidans has been investigated intensively by many investigators. However, the dissolution rate is extremely slow. For example, the dissolved copper from a chalcopyrite concentrate was 18% after 30 days of bioleaching. Some attempts have been made to improve the dissolution rate of copper in the bioleaching of chalcopyrite concentrate. The addition of silver ion was found to enhance the copper dissolution in the bioleaching of chalcopyrite concentrates (Sukla et al., 1990; Ahonen and Tuovinen, 1990) Nakazawa et al. (1995)reported that the presence of silver chloride accelerated copper extraction in the bioleaching of chalcopyrite concentrate.

Wan et al. (1984)showed that the dissolution rate of chalcopyrite in the ferric sulfate leaching was enhanced by the formation of chalcopyrite/carbon aggregates. They suggested that the conductive carbon particles change the conductivity of the reaction product layer and such a phenomenon accounts for the increase in leaching rate.

The purpose of this work is to study the effect of the addition of activated carbon, which is electrically conductive, on the bioleaching of chalcopyrite concentrate.

Section snippets

Materials and method

Chalcopyrite concentrate used in this study was obtained from Hanaoka mine in Japan. The particle size was −200 mesh. The X-ray diffraction analysis showed that the patterns of pyrite, sphalerite and galena besides the pattern of chalcopyrite. The chemical analysis of chalcopyrite concentrate is as follows; Cu: 20.39%; Fe: 30.22%; Zn: 4.98%; Pb: 4.46%.

A strain of Thiobacillus ferrooxidans used in this study was isolated from an acid mine water at abandoned Matso mine in Japan and cultured in 9K

Results and discussion

Fig. 1 shows the bioleaching of chalcopyrite concentrate in the presence and absence of activated carbon with particle size of −400 mesh at the initial pH of 1.3. The copper leaching was accelerated by the addition of activated carbon. The yields of copper leaching were 18, 33 and 42% for the 0, 0.1 and 0.5 g activated carbon additions, respectively, after 19 days of leaching. The concentration of ferrous iron was negligible with the addition of 0.1 g activated carbon even at the first day of

Conclusion

The addition of activated carbon accelerated copper dissolution in the bioleaching of chalcopyrite concentrate using Thiobacillus ferrooxidans.

In the chemical control, the dissolution of chalcopyrite and sphalerite was enhanced in the presence of activated carbon. It could be due to galvanic interactions between activated carbon and these minerals. In the bioleaching of chalcopyrite concentrate, Thiobacillus ferrooxidans could enhance the galvanic interaction between chalcopyrite and activated

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Citation Excerpt :
In addition to the solution redox potential, Dixon et al. (2008) adjusted other experimental parameters including the pyrite to chalcopyrite ratio, pH, and temperature for the galvanic leaching process, and achieved copper recoveries of 98% from chalcopyrite within 4 hours (Dixon et al., 2008). Additionally, adding catalysts such as Ag+ (Xia et al., 2018; Yuehua et al., 2002), activated carbon (Liang et al., 2010; Nakazawa et al., 1998), and Cl− (Chang-Li et al., 2012), as well as implementing electrochemical leaching process with thermophilic iron- and sulfur-oxidising microbes (Hedrich et al., 2018; Huang et al., 2018; Peng et al., 2019), which regenerate Fe3+, oxidise the interfering S0 layer, and decrease solution pH, also effectively alleviate the passivation and promote leaching (Fig. 5B). Other electrochemical approaches for enhancing the metal extraction include using a working electrode for converting the surface of chalcopyrite to a less refractory mineral phase such as chalcocite (CuS2) (Tanne and Schippers, 2019) and for promoting the activity of leaching microbes (Blake et al., 1994; Yunker and Radovich, 1986).
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Effect of activated carbon on the bioleaching of chalcopyrite concentrate

Abstract

Introduction

Section snippets

Materials and method

Results and discussion

Conclusion

Hydrometallurgy

Int. J. Min. Proc.

The influence of different variables on the bioleaching of sphalerite

Biorecovery

Role of bacteria in the alteration of sulfide minerals

J. Met.

Effect of chloride ions on the bacterial leaching of sulfide minerals with the addition of silver ions

Shigen-to-Sozai