Lucara Diamond Corporation announced that it would develop an open pit plan for its Karowe diamond mine in Letlhakane after the completion of the current feasibility study on the project.
This week the mine announced to its shareholders that production samples carried out in February recovered 13 562 carats with a total of 79 052 tonnes of ore processed. The samples returned 9.5 percent carats of diamond larger than 10.8 carats and 47 diamonds were greater than 10.8 carats.
Lucara Diamond Mine Chief Executive, Eira Thomas highlighted that the Karowe mine plan is dominated by South Lobe ore, with the high grade, high value (EM/PK) unit becoming increasingly prevalent as they mine deeper. “We now understand that some of Karowe’s large, high value diamonds originated from the EM/PK(S) unit including the historic 1109 carat Lesedi La Rona and the 813 carat Constellation which sold for a record US$63 million,” said Thomas.
He said the resource update supports the continued recovery of large high value diamonds from the South Lobe throughout its remaining open pit mine life and the likelihood for underground mining until at least 2036. “Feasibility work assessing the potential for underground mining, including hydrogeological and geotechnical drilling together with several mining trade off studies is ongoing,” explained Thomas.Since declaring production in July 2012, the mine has produced an average of 320 000 carats
of diamonds per annum from open pit operations which are expected to continue until 2026 and underground operations are expected to end in 2036.
The Karowe Mine has been in commercial production since July 2012. The mine has produced and sold over two million carats from 13.9 million tonnes of processed kimberlite at an average sales price of $US 606/carat. Karowe is firmly established as one of the world’s foremost producer of large and high value diamonds.
Ongoing development capital requirements for the Karowe underground project are estimated at $178-million. The total all-in on-site unit operating costs, after the start of commercial production, are estimated at $54.18/t treated, comprising mining costs of $31/t, processing costs of $11.82/t, and engineering costs of $2.05/t. Ongoing underground development is estimated at $4.82/t processed.