Jwaneng diamond mine is situated in South Central Botswana, about 160 miles southwest of Gaborone. Debaswana, a partnership between De Beers Company and the Government of Botswana, owns the mine.
Mining is conducted on three kimberlite pipes extended in an area of 520,000 square metres at ground level, and a satellite deposit.
The Jwaneng diamond pipe has a current depth of 300m, which is expected to reach 675m. It was discovered in 1972 and reached full production in July 1982. The mine was officially inaugurated in August 1982.
Jwaneng open-pit mine geology, reserves and production
The Jwaneng open pit mine consists of Paleoproterozoic-aged sedimentary rocks occuring as a collection of tilted and displaced blocks with dolomites at the base.
Jwaneng is the eighth biggest diamond mine in the world with an estimated reserves of 88.3Mct (70.1Mt grading 1.26ct/t diamond) as of December 2012. The mine has an average production rate of 12 to 15 million carats per year.
Mining activities at the Jwaneng mine
The kimberlite deposits at Jwaneng are mined as a series of cut-downs into the earth. P&H 250XP blast-hole machines are used for the drilling. Approximately 58.72 million tonnes of ore was moved to the surface in 2010.
In-pit crushing method is applied at the mine. The recrushing plant processes the primary crushed ore and prepares it for diamond recovery. The dense-medium cyclones separate the waste from the diamonds after the secondary crushing.
The mining fleet includes the advanced Komatsu 930 haul trucks and Bateman semi-mobile crushers. Gemcom integrated mine production and management system is used for the ore transportation. The ore is carried to the processing plant using 250t payload capacity dump trucks.
Processing plant at the Jwaneng diamond mine
The ore produced at Jwaneng is processed at the Aquarium project, a dense media separation-based processing plant. The plant processed 22.35 million carats in 2010.
The Aquarium processing plant comprises of Completely Automated Recovery Plant (CARP) and Fully Integrated Sort House (FISH). The Aquarium facility applies laser and x-ray sorting technology for diamond recovery.
The ore concentrate from the Main Treatment Plant and the Recrush Plant is treated at the CARP facility. The FISH facility handles the diamonds recovered by the CARP facility.
Construction activities undertaken at the Botswanan mine
Major construction activities include the construction of the Cut 8 expansion project, Jwaneng Resource Expansion Project, and a modular tailings treatment plant.
The construction of $3bn Cut-8 expansion project began in 2010. It is expected to extend the mine life to 2028 and provide access to 95 million carats of diamonds. Jwaneng will feature among the top super-pit mines in the world upon completion of the Cut-8. The infrastructure and plant upgrades for the expansion project were completed in September 2012.
The construction of modular tailings treatment plant commenced in 2013. It will have a capacity to treat 2.5Mtpa and is expected to produce 18 million carats in 20 years. The plant is expected to be fully operational in 2014.
The Jwaneng Resource Expansion Project is expected to increase the mine depth to 850m below the surface.
Contractors involved with the Jwaneng mine development
SRK Consultants were awarded the contract for conducting detailed probabilistic stability analysis for the Cut 8 project.
The engineering, procurement and construction management (EPCM) services contract for installing the mine surface infrastructure was awarded to Fluor. The contractual scope also included the earthworks, civil construction, pilings, structural steel erection and electrical installation.
Majwe, a joint venture of Leighton Africa, Basil Read Mining and Bothakga Burrow, was awarded the contract for providing mining services for the Cut 8 Phase 2. The contract services included mine scheduling, drilling and blasting, waste removal and limited ore mining.
Otraco was awarded the contract for tyre-management services. Komatsu provided 16 930E haul trucks and other ancillary machinery for the Jwaneng’s Cut 8 project.
Kentz was awarded the contract for the procurement, fabrication, erection of structural steel, and cladding for buildings and conveyors.
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