Modern Mining November 2019

The Karowe mine, which is located in the Orapa Kimberlite Field (photo: Lucara).

Lucara prepares to go underground at Karowe

a stand-alone underground (UG) scenario and a combined open pit underground LoM scenario with the underground operation mining the South Lobe of the AK6 kimberlite resource from the base of the planned open pit. All underground mined kimberlite will be processed at the existing Karowe processing plant over a 13-15 year period following the cessation of the current open-pit operations. Highlights of the FS (based on the combined open pit underground scenario) include a LoM pro- duction of 7,8 million carats; pre-production capital costs of US$514 million for the underground project; an after-tax NPV 5% of US$718 million; and average LoM operation costs of US$28,43 per tonne of ore processed. Eira Thomas, Lucara’s President and CEO, com- mented: “Lucara is highly encouraged by the results of the Karowe Underground feasibility study which has outlined a much larger economic opportunity than first envisaged in the 2017 PEA and represents an exciting, world-class growth project for our com- pany. Diamond deposits are rare and getting rarer. In this context, we are extending a mine that is in a class of its own, having produced 15 diamonds in excess of 300 carats, including two greater than 1 000 carats, in just seven years of production.

The Karowe diamond mine in Botswana is likely to transition into an underground operation. The mine’s owner, Canada’s Lucara Diamond Corp, recently announced the results of a positive underground Feasibility Study (FS), which indicate that going underground could double the mine life, extending operations out to 2040. Based on the positive results of the FS, Lucara says it will commence advancement of detailed engineering immediately, in parallel with project permitting, arranging project financing and long lead item procurement.

K arowe is one of the world’s most prolific pro- ducers of large, high value, type IIA diamonds and the only diamond mine in recorded history to have produced two +1 000 carat diamonds. Over its relatively short life, it has produced 2,5 mil- lion carats and generated US$1,5 billion in revenue. It is widely regarded as one of the world’s most suc- cessful diamond mines and the extension of its life would be a welcome shot in the arm for Botswana’s mining industry, which has seen some significant setbacks over the past several years, including the closure of the BCL operation in Selebi-Phikwe. The Karowe Underground FS contemplates both

26  MODERN MINING  November 2019