Development and commercial demonstration of the BioCOP™ thermophile process

doi:10.1016/j.hydromet.2006.03.049

Hydrometallurgy

Volume 83, Issues 1–4, September 2006, Pages 83-89

https://doi.org/10.1016/j.hydromet.2006.03.049 Get rights and content

Abstract

The paper describes the engineering development of the BioCOP™ Process, from pilot-scale to full-scale commercial demonstration at the Chuquicamata Mine in Chile, with a design production rate of 20 000 t copper per annum.

BioCOP™ Process is owned by BHP Billiton. The BioCOP™ Process has been specifically developed for treatment of concentrates not suitable for commercial smelting due to the content of deleterious elements, such as arsenic, which is harmful to the environment. The process utilises thermophilic microorganisms operating at temperatures up to 80 °C to leach copper sulphide mineral concentrates. The copper is subsequently recovered by conventional solvent extraction and electrowinning, producing a high value copper metal product.

The paper describes the importance of staged development to ensure correct definition of scale-up criteria for commercial plant design. The design and operation of the Commercial Demonstration Plant is also described a “World First” for bioleaching using thermophilic microorganisms for commercial treatment of primary copper sulphide concentrates.

Introduction

The commercialisation of a new technology entails a large number of risks. Many of these risks can be mitigated by the manner in which the technology is developed from the conceptual stage to a commercial operation. The types of risks that can be easily reduced revolve around the physical characteristics of the process and its requirements. There are a considerable number of other risks when commercialising a new technology. These range from the unforeseen to simple problems of human nature, such as focusing on the novel to the detriment of support unit operations.

This paper leads you through the initial stages of development of the BioCOP™ technology through to the construction of a 200 t per day (tpd) prototype plant at Chuquicamata in Chile.

Section snippets

The concept

The first bioleach laboratory tests were performed in the seventies and possibly even before. BHP Billiton's Johannesburg Technology Centre (JTC), then known as Genmin Process Research, was very involved with the subsequent development and commercialisation of BIOX® process. The BIOX® process utilised mesophilic microorganisms (± 40 °C) to oxidise sulphide minerals to liberate gold in refractory sulphide gold concentrates. The minerals involved were mainly pyrite, pyrrohtite and arsenopyrite.

Laboratory test phase

The first laboratory tests on a copper concentrate were performed at JTC in 1995. Batch type tests involve slurrying a concentrate sample at a predetermined percent solids in a small agitated reactor vessel. The slurry is then pH-stabilised, inoculated and process parameters such as dissolved oxygen are monitored and controlled. The results of these laboratory tests start to give an understanding of the process.

Results of laboratory tests and start of thermophile technology

Initial tests showed that the standard mesophile (40 °C) culture was very successful at oxidising secondary sulphide minerals, but was not effective for primary copper sulphide minerals especially chalcopyrite. Oxidation of chalcopyrite stopped at a relatively low oxidation value (30%–60%) and additional leach time failed to improve recovery. The mesophile technology still has applications, but for concentrates with high chalcopyrite, something new was needed.

A thermophilic microorganism was

Results of piloting

The first thermophile pilot trials on a copper concentrate began in 1995 in a small test unit with reactors of 10 L each. In 1997, the first of two larger pilot units was constructed. This unit consisted of two 240-L stirred tanks operating in parallel as primary reactors. These overflowed to four 140-L stirred tanks operating in series as secondary reactors. Each reactor was equipped with independent temperature control and independent gas mass flow meters. The gas flow meters allowed mixing

Determining scale-up parameters – 5-m³ reactor and ITR facility

There were two projects to look at the engineering requirements for an industrial plant. The first was a 5-m³ single reactor built and operated at JTC's facility in Randburg, Gauteng, South Africa. Later, a second much larger project known as the Industrial Test Reactor Facility (ITR) was built at the Pering mine, Reivilo, Northwest Province, South Africa. The ITR facility consisted of a 50-m³ and 300-m³ reactor.

20KTPA cathode prototype plant

A joint venture company called Alliance Copper Limited was formed between BHP Billiton and Codelco. The purpose of Alliance Copper was to exploit the BioCOP™ technology. The BioCOP™ encompasses both mesophile and thermophile technologies. Of the two processes, mesophile operations are well understood and it is the thermophile process that required prototyping for confidence.

Pilot plant test work had been carried out at the Codelco mine of Chuquicamata in Chile since 1997. BHP Billiton conducted

Acknowledgements

Many thanks to the personnel from BHP Billiton Johannesburg Technology Centre through whose work this technology came into existence. Many thanks to the personnel of Alliance Copper through whose dedication the Prototype plant continues to be a source of pride and thanks to our joint venture partner Codelco for their efforts.

Reference (1)

Milestone for Bioleaching
Mining Journal
(2001 March 9)

Cited by (98)

Continuous bioreactor leaching of nickel sulfide concentrates with moderately thermophilic bacteria and archaea
2024, Minerals Engineering
A commercial process for bioreactor leaching of a nickel concentrate by-product of talc mining has been described previously. It was developed and operated (2016–2018) at about 45–46 °C. Further features of bioleaching that concentrate have now been investigated in laboratory-scale reactors with continuous feeds of up to 10% (w/v) solids and an emphasis on temperatures at and a few degrees above that of the commercial process. The sulfur-oxidizing At. caldus was more abundant than the sulfide mineral-oxidizing S. thermosulfidooxidans and Atm. siderophilum at 48 °C but was essentially lost with a 3 °C temperature rise, simultaneously with a rise in pH and in iron precipitation from solution, without adversely affecting nickel leaching. The relative abundance among bacteria was similar between two reactors operated in series but there was more than a fourfold increase in the relative abundance of the ferrous-iron oxidizing, heterotrophic archaeon Ac. cupricumulans in the secondary reactor, most likely in response to an increase in the acidity as the sulfide concentrate oxidation proceeded.
Chalcocite (bio)hydrometallurgy—current state, mechanism, and future directions: A review
2022, Chinese Journal of Chemical Engineering
There has been a strong interest in technologies suited for mining and processing of low-grade ores because of the rapid depletion of mineral resources in the world. In most cases, the extraction of copper from such raw materials is achieved by applying the leaching procedures. However, its low extraction efficiency and the long extraction period limit its large-scale commercial applications in copper recovery, even though bioleaching has been widely employed commercially for heap and dump bioleaching of secondary copper sulfide ores. Overcoming the technical challenges requires a better understanding of leaching kinetics and on-site microbial activities. Herein, this paper reviews the current status of main commercial biomining operations around the world, identifies factors that affect chalcocite dissolution both in chemical leaching and bioleaching, summarizes the related kinetic research, and concludes with a discussion of two on-site chalcocite heap leaching practices. Further, the challenges and innovations for the future development of chalcocite hydrometallurgy are presented in the end.
Biobeneficiation of bulk copper-zinc and copper-nickel concentrates at different temperatures
2021, Minerals Engineering
Citation Excerpt :
Chalcopyrite is known to be highly refractory to the attack of mesophilic microorganisms, while an increase in the efficiency of chalcopyrite bioleaching at elevated temperatures has been shown by different authors (D'Hugues et al., 2002; Hedrich et al., 2018). A process using a thermophilic community (78 °C) of acidophilic archaea to recover copper from the arsenic-containing chalcopyrite concentrate was commercialized in Chile (Batty and Rorke, 2006). Bioleaching of chalcopyrite is known to be more efficient at a relatively low redox potential (<600 mV vs. SHE) (Cordoba et al., 2008; Zhao et al., 2015b).
One of the problems associated with polymetallic ore concentration is the separation of bulk concentrates, which is difficult due to the textural and structural characteristics of mineral particles. In this paper, we proposed selective bioleaching of zinc and nickel from bulk copper-zinc and copper-nickel sulfide concentrates, respectively, to extract these metals into solution and to produce high-grade copper concentrates. In the copper-zinc concentrate, zinc occurred in sphalerite (ZnS). In the copper-nickel concentrate, nickel occurred in pentlandite ((Ni,Fe)₉S₈) and violarite (FeNi₂S₄). In both concentrates, which also contained pyrite (FeS₂) and pyrrhotite (Fe_1-xS), copper occurred in chalcopyrite (CuFeS₂). Bioleaching of the concentrates by acidophilic microbial communities at 30 and 40 °C was compared. Bioleaching at increased temperature was characterized by the higher intensity of the process. Complete removal of zinc from the copper-zinc concentrate occurred within 15 days at 30 °C and 4 days at 40 °C, while the copper content in the bioleach residue increased by 7.5 and 5.9%, respectively. Nickel leaching was less efficient: 67.6% at 30 °C and 86.7% at 40 °C after 22 days of the process. At the same time, the copper content in the bioleach residue increased by 2.7 and 5.7%. Dissolution of violarite proceeded more rapidly than that of pentlandite. More efficient zinc and nickel leaching from the concentrates at 40 °C could be associated with a higher microbial diversity in the communities formed at this temperature. An increase in the proportion of bacteria of the genera Sulfobacillus and Ferrimicrobium, as well as archaea of the families Ferroplasmaceae and Cuniculiplasmataceae, was shown. At both temperatures, Acidithiobacillus and Leptospirillum bacteria prevailed during the biooxidation of both, the copper-zinc and copper-nickel concentrates.
Copper and critical metals production from porphyry ores and E-wastes: A review of resource availability, processing/recycling challenges, socio-environmental aspects, and sustainability issues
2021, Resources, Conservation and Recycling
Porphyry ores and E-wastes/WEEE are two of the most important copper-bearing materials on the planet. Over 60% of world copper output comes from porphyry copper ores while E-waste(s) is globally the largest copper-bearing waste category since the 1980s. They also contain critical elements for low-carbon technologies essential in the clean energy transition's success. In this review, a critical analysis of ore distribution/processing, metal extraction, E-waste generation and E-waste recycling is presented, focusing on identifying challenges and how to address them with emerging technologies and sustainable socio-environmental strategies. Access to ore deposits is a major hurdle for mine development while the absence of a consistent E-waste classification and legislation, including poor collection rates, remains serious problems in E-waste recycling. As lower grade porphyry ores are exploited, difficulties in processing/extraction due to mineralogical complexities, very fine particles and the generation of “dirty” concentrates will become more prevalent. For E-wastes recycling, current trends are to develop smaller, more mobile, and eco-friendly hydrometallurgical alternatives to pyrometallurgy that can handle localised compositional and feed variabilities. Finally, more sustainable mine waste management strategies, including better LCIA tools with spatial and temporal dimensions, are needed to limit socio-environmental impacts of resources exploitation and maintain the sector's SLO.
Biohydrometallurgy of Chalcopyrite
2021, Biohydrometallurgy of Chalcopyrite
Sustainability assessment of bioleaching for mineral resource recovery from MSWI ashes
2021, Circular Economy and Sustainability: Volume 2: Environmental Engineering
About 46 million tons of combustion ashes from municipal waste are produced annually at the global level. These materials are equivalent to low-grade ores for metal recovery, as well as there is an opportunity to recover secondary raw materials for reuse in sustainable applications, as the circular economy demands. Bioleaching has the potential to be further developed into affordable biotechnology for resource recovery in waste management. The chapter provides information on the mineralogy and geochemistry of fly and bottom ashes from Municipal Solid Waste Incineration (MSWI), then examines bioleaching experiments that facilitate resource extraction and recovery from these anthropogenic materials. The analysis of strengths and weaknesses of this biomining-biotechnology allow assessing the sustainability of bioleaching as a drive for further challenges and opportunities.

View all citing articles on Scopus

View full text