Modern Mining July 2015

feature COUNTRY FOCUS – BOTSWANA The new XRT building at Karowe diamond mine.

Innovative XRT circuit now in operation at Karowe

Construction of the US$55 million plant upgrade and optimisation project at Lucara’s Karowe diamond mine in Botswana’s Orapa Kimberlite Field (OKF) has been complet- ed on time and on budget. Lucara’s Gaborone-based COO, Paul Day, gave a presentation on the mine at the recent Botswana Resource Sector Conference in Gaborone and also discussed the upgrade project with Modern Mining’s Arthur Tassell on the sidelines of the conference. He says that early results from the XRT technology installed as part of the upgrade are extremely encouraging, with the circuit thus far meeting all Lucara’s expectations.

to 420 000 carats a year, the mine has met this objective easily and in fact produced just over 430 000 carats in 2014. While the overall carat production level has thus far been in line with estimates, what was not foreseen at the plan- ning and design stage of the mine was that the orebody would have the ability to deliver large diamonds on a regular basis. “Over the past 29 months, Karowe has pro- duced 70 stones of over 100 carats, including 12 of over 200 carats, and one of over 300,” says Day. “The plus 300-carat stone, which was recovered earlier this year, is a 341,9 carat Type IIa diamond of exceptional quality. It could well rank as the biggest gem-quality diamond ever recovered in Botswana. There is some anec- dotal evidence of a 372-carat stone having been produced in the past but this – if the rumours are true – was apparently of poor quality.” Giving the background to the upgrade proj- ect, Day says the plant as originally configured and built was designed to treat the weathered and transitional ore near surface. “It was well understood from day one that as mining pro- gressed the plant would have to be modified

C ommissioned in 2012, Karowe – which exploits the AK6 kimberlite first discovered in the early 1970s – has been a spectacular success for Vancouver-based Lucara Dia- mond Corp, which acquired the project from De Beers and African Diamonds in two sepa- rate deals signed in 2009 and 2010 respective- ly. Designed to produce approximately 400 000

28  MODERN MINING  July 2015