Time filter

Source Type

Highlands Ranch, CO, United States

Lee J.,Newmont Mining Corporation | Acar S.,Newmont Mining Corporation | Doerr D.L.,Newmont Mining Corporation | Brierley J.A.,Brierley Consultancy LLC
Hydrometallurgy | Year: 2011

Column testing was conducted to evaluate the potential for copper extraction from composited samples of Newmont Mining Corporation's Yanacocha Verde deposit in Peru. The Mineral Liberation Analysis (MLA) revealed that the composites contained various amount of copper sulfide minerals. Comparative bioleaching was conducted with consortia of mesophilic iron-oxidizing bacteria containing species of Acidithiobacillus and Leptospirillum for bioleaching at ambient laboratory temperature (20-22 °C) and with a mix of a thermophilic archaea culture containing Acidianus, Metallospheara and Sulfolobus at 65 °C. Enargite- and covellite-rich composites exhibited low copper extraction ranging from 7.3% to 27.1% based on column head/residue assays from columns after more than 300 days of bioleaching at room temperature with mesophilic bacteria. Chalcocite rich composites responded to mesophilic bacteria bioleaching with extractions ranging from 50 to 90% based on head/residue assays. High copper recovery from secondary chalcocite and low copper recovery from the primary copper minerals enargite and covellite are consistent with the performance of mesophilic bacteria. Thermophilic archaea proved advantageous for bioleaching primary enargite and covellite at 65 °C with copper extractions ranging from 60 to 98% over 335-346 days. Copper extractions from chalcocite-rich composites using thermophilic archaea were similar to those with room temperature mesophilic bacteria bioleaching. Semiquantitative XRD analysis and Mineral Liberation Analysis (MLA) were performed for mineralogical investigation with respective heads, and mesophilic and thermophilic residues. MLA confirmed only chalcocite leached under mesophilic conditions with partial leaching of covellite; and all copper minerals were leached under thermophilic conditions. © 2010 Elsevier B.V. All rights reserved. Source

Brierley J.A.,Brierley Consultancy LLC
Mineral Processing and Extractive Metallurgy: 100 Years of Innovation | Year: 2014

The author has selected noteworthy events in the historical development of biohydrometallurgy. The events are categorized as discovery of the microbial process for biooxidation of pyrite; demonstration that sulfide mineral biooxidation and bioleaching are conducted by numerous types of microbes composing a consortium; definition of how microbes oxidize sulfide minerals; and development of commercial plants for economic use of biohydrometallurgy. The latter topic is considered for heap and stirred-tank reactor systems. Possible future developments are contemplated. Source

Brierley C.L.,Brierley Consultancy LLC
Hydrometallurgy | Year: 2010

Bioleaching, also referred to as minerals biooxidation, and bioremediation have been widely employed commercially for heap and dump bioleaching of secondary copper sulfide ores, sulfidic-refractory gold concentrates and treatment of acid rock drainage. Technical and commercial challenges, identified in this paper, remain for bioleaching of primary sulfides and complex ores. New frontiers for the technology exist in processing massive sulfides, silicate-locked minerals and in the more distant future in-situ leaching. Decommissioning of cyanide heap leach operations and stabilizing mine wastes using biotechnology are opportunities requiring intensive and focused research, development and engineering efforts. © 2010 Elsevier B.V. All rights reserved. Source

Brierley C.L.,Brierley Consultancy LLC | Brierley J.A.,Brierley Consultancy LLC
Applied Microbiology and Biotechnology | Year: 2013

This review presents developments and applications in bioleaching and mineral biooxidation since publication of a previous mini review in 2003 (Olson et al. Appl Microbiol Biotechnol 63:249-257, 2003). There have been discoveries of newly identified acidophilic microorganisms that have unique characteristics for effective bioleaching of sulfidic ores and concentrates. Progress has been made in understanding and developing bioleaching of copper from primary copper sulfide minerals, chalcopyrite, covellite, and enargite. These developments point to low oxidation-reduction potential in concert with thermophilic bacteria and archaea as a potential key to the leaching of these minerals. On the commercial front, heap bioleaching of nickel has been commissioned, and the mineral biooxidation pretreatment of sulfidic-refractory gold concentrates is increasingly used on a global scale to enhance precious metal recovery. New and larger stirred-tank reactors have been constructed since the 2003 review article. One biooxidation-heap process for pretreatment of sulfidic-refractory gold ores was also commercialized. A novel reductive approach to bioleaching nickel laterite minerals has been proposed. © Springer-Verlag Berlin Heidelberg 2013. Source

Discover hidden collaborations