Details of Award
NERC Reference : NE/R007675/1
In situ pilot-scale demonstration of a novel mineral processing biotechnology for recovering metals from lateritic ores (International)
Grant Award
- Principal Investigator:
- Professor DB Johnson, Bangor University, Sch of Natural Sciences
- Grant held at:
- Bangor University, Sch of Natural Sciences
- Science Area:
- Earth
- Overall Classification:
- Unknown
- ENRIs:
- Environmental Risks and Hazards
- Natural Resource Management
- Pollution and Waste
- Science Topics:
- Earth Engineering
- Extremophiles
- Earth Resources
- Technol. for Environ. Appl.
- Abstract:
- Nickel and cobalt are two key metals used by modern civilization in a host of applications. Cobalt, in particular, is categorized as a "strategic metal" in view of its great importance to the development of "green technologies" (such as energy storage in batteries used, for example in new generation electric and hybrid vehicles) and also because of the fact that much of its production is concentrated in parts of the world perceived to be potentially unstable. Most of the nickel and cobalt produced from mining primary ores originates from reduced (sulfidic) minerals, though the bulk of accessible global reserves of nickel (in particular) is contained in oxidized ores, most notably laterites, which are widely distributed throughout (mostly) tropical regions. Although technologies exist for extracting valuable metals from lateritic ores, these mostly operate at high temperatures and pressures and are therefore highly energy consuming and have large carbon footprints. Recently, a microbiological mechanism for extracting nickel and cobalt from limonitic laterites, which operates at atmospheric pressure and ambient (30 - 40C) temperatures has been described and demonstrated at laboratory scale. Biomining is often considered to be a "green" approach for obtaining metals, and has been used for over 50 years to obtain copper. The novel technology developed at Bangor University in conjunction with the mining industry has greatly extended the range of metal ores that can be bioprocessed. Limonitic ores from mines located in different parts of the world (including Asia, Africa and South America) have been trialed in the frame of a current NERC-sponsored project (which focuses specifically on cobalt) and all have been shown to be amenable to bioprocessing using this new approach (referred to as "reductive mineral dissolution"). Among these was material from a new mining enterprise in Brazil, located in Piaui state, the owners of which are active members of the NERC project consortium. The Piaui mine has not yet become a full-scale operation, and the bioprocessing option has several perceived major advantages of what is currently envisaged as the operating protocol (leaching with concentrated sulfuric acid in heaps). These include: (i) eliminating the need to transport in large amounts of concentrated acid to the remote mine site (both costly and hazardous); (ii) removing the need to purchase an acid-generating plant for long-term sulfuric acid generation (the cost of which is equivalent to ~25% of the total capital cost of the mine); (iii) the potential to enhance both rates and extents of metal extraction from the ore. The original reductive mineral dissolution protocol has been fine-tuned in the current NERC project to minimize or eliminate the need to use acid to neutralize the alkalinity generated when minerals in the limonite ores dissolve. Instead the acid is generated in situ from elemental sulfur by specialized bacteria. There is a perfectly timed opportunity to scale up the reductive mineral dissolution approach from laboratory to pilot scale, and this is greatly facilitated by the fact that large columns required for this are already in place at the Piaui mine site. The project will involve firstly producing sulfur colonized by the specialized bacteria used in the process, shipping this from the UK to the mine at Piaui where it will be combined with the ore (and additional sulfur) and packed into a large (4 m high) column. This, and a control (acid-leached) column will be operated in re-circulation flow mode for 6-7 months, by which time most of the metals will have been extracted. The columns will then be dis-assembled and, if results are as anticipated, used for the next stage in the process (heap leaching; beyond the scope of the current project). This demonstration plant will provide essential data that will help promote the application of this novel biomining approach to laterite mines throughout the world.
- NERC Reference:
- NE/R007675/1
- Grant Stage:
- Completed
- Scheme:
- NC&C
- Grant Status:
- Closed
- Programme:
- Innovation Follow on
This grant award has a total value of £99,492
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | Exception - Other Costs | DA - Investigators | DI - Staff | DA - Estate Costs | DI - T&S |
|---|---|---|---|---|---|---|
| £1,774 | £18,028 | £33,264 | £13,436 | £21,838 | £3,652 | £7,500 |
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