An updated mineral resource estimate on TSX-listed Lucara Diamond’s Karowe mine, in Botswana, supports the continued recovery of large, high-value diamonds from the South Lobe throughout the remaining life of the openpit and the likelihood for underground mining until at least 2036, CEO Eira Thomas said on Tuesday.
The mineral resource estimate, which was completed by Mineral Services Canada, shows the remaining indicated mineral resource for the mine’s AK06 kimberlite includes 7.9-million carats, hosted in 57.85-million tonnes at an average grade of 13.7 carats per hundred tonnes (cpht).
The indicated mineral resource for the South Lobe of the AK06 kimberlite increased by 54% to 6.78-million carats as a result of the conversion of inferred mineral resources to a depth of 400 metres above sea level.
The results of the updated mineral resource estimate will be used for mine planning and to support the preparation of current feasibility-level studies for the potential development of an underground mine, after the depletion of the current openpit mine.
Going forward, the Karowe mine plan is dominated by South Lobe ore, with the high-grade, high-value (EM/PK(S)) unit becoming increasingly prevalent with deeper mining, said Thomas.
The 1 109 ct Lesedi La Rona and the 813 ct Constellation are some of the large, high-value diamonds already recovered from the EM/PK(S)S unit.
“Feasibility work assessing the potential for underground mining, including hydrogeological and geotechnical drilling, together with several mining trade-off studies, is ongoing,” Thomas added.