Recovery of valuable metals from polymetallic mine tailings by natural microbial consortium

ABSTRACT

Possibilities for the recovery of non-ferrous and precious metals from Kapan polymetallic mine tailings (Armenia) were studied. The aim of this paper was to study the possibilities of bioleaching of samples of concentrated tailings by the natural microbial consortium of drainage water. The extent of extraction of metals from the samples of concentrated tailings by natural microbial consortium reached 41–55% and 53–73% for copper and zinc, respectively. Metal leaching efficiencies of pure culture Leptospirillum ferrooxidans Teg were higher, namely 47–93% and 73–81% for copper and zinc, respectively. The content of gold in solid phase of tailings increased about 7–16% and 2–9% after bio-oxidation process by L. ferrooxidans Teg and natural microbial consortium, respectively. It was shown that bioleaching of the samples of tailings could be performed using the natural consortium of drainage water. However, to increase the intensity of the recovery of valuable metals, natural consortium of drainage water combined with iron-oxidizing L. ferrooxidans Teg has been proposed.

GRAPHICAL ABSTRACT

KEYWORDS:

• Polymetallic mine tailings
• bioleaching
• microbial consortium
• iron-oxidizing bacteria
• extraction of non-ferrous and precious metals

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Arevik Vardanyan http://orcid.org/0000-0001-8715-5870

Additional information

Funding

This work was supported by the SCS-BMBF-2012 12GE-005 Grant of the Ministry of Education and Science of Armenia and the German Federal Ministry of Education and Research.