2 July 2010 – Bateman Engineering has commenced the engineering and procurement (EP) on the Maxi phase of the innovative greenfields Trekkopje project in the heart of Namibia’s Namib Desert, some 65 km north-east of the coastal town of Swakopmund.
The French nuclear giant AREVA, through its subsidiary AREVA Resources Namibia and AREVA Processing Namibia Pty (Ltd), is developing the world’s first uranium mine to utilise an alkaline heap leach process.
Due to the pioneering nature of this alkaline leach application, AREVA is developing the Trekkopje project in three distinct phases, the Mini, Midi and Maxi projects, covering, respectively, the technology demonstrator, and industrial and full scale process development stages. The Midi project, for which Bateman Engineering was the EPCM contractor, is currently being handed over to AREVA.
Bateman Engineering’s scope of work for the Maxi project comprises the EP, related to the conveying of in-pit primary-crushed run-of-mine ore, the comminution circuit, agglomeration, heap irrigation, reclaiming, interface management and site infrastructure (laboratory facilities, services and utilities).
The Maxi project is currently on schedule to ensure that the first ore stacking will start in the first quarter of 2012, with engineering 40% and procurement 50% complete.
The Trekkopje deposit is a very large, shallow and low grade uranium resource. The life of the mine is estimated to be 12 to 14 years mining at a rate of 36.4 million t/yr, an average of 100,000 t/day. The expected production of U3O8 is 3,200 t/yr, with the equivalent UO4 (yellowcake) tonnage slightly higher.
An integrated procurement strategy has been employed, using combined AREVA and Bateman vendor databases. Before commencing procurement, an intensive value engineering exercise ensured that the plant design was optimal in respect of Capex, Opex and functionality. This focused on reducing the installed redundancy and specifying tight equipment specifications that would maximise the equipment availability and plant utilisation.
While the procurement strategy was developed to ensure that all procurement was done from the best available global vendors and contractors, the strategy also aimed to maximise the social footprint of AREVA in Namibia by using, where possible, Namibian contractors.
As with Bateman Engineering, AREVA is committed to world class safety standards and this has been emphasised by incentivising a strong safety culture for all contractors involved on the project.
The Trekkopje Maxi Project will be an open pit mining operation, followed by crushing, screening, agglomeration and a carbonate / bicarbonate heap leach process, which is in turn followed by ion-exchange UO4 recovery. The majority of the spent ore is planned to be stacked into the mined areas of the pit with associated ongoing rehabilitation.
The heap leach pad will comprise 30 cells in total, of which about 22 will be active at any given time, while the remainder will be in various stages of construction (stacking), demolition (reclaiming), or maintenance per the OOHLP (On-Off Heap Leach Pad) method.
Prior to leaching, as much chloride material as possible will be removed from the four most recently stacked cells in a two-stage washing process, with the water being recovered for re-use in the washing process.
During the basic heap leach process, uranium in the ore is dissolved by a solution of sodium carbonate and sodium bicarbonate reagents. The pregnant liquor solution is pumped from the pond to the back-end plant where uranium is recovered through various ion exchange, elution and precipitation processes, and the final product produced is yellowcake.
Once the leach cycles are completed, the ore is removed from the pad with a reclaimer system and disposed via a spent ore facility.
CONTACT
Jon Kock, General Manager
Business Development, Sub-Saharan Africa
+27-11-899-9111
enquiries@bateman.com
