공지 • Jan 08
Lucara Diamond Corp. Announces Updated Feasibility Study for Karowe Under Underground Project
Lucara Diamond Corp. announced the results of an updated technical report (the "Report") for the updated Feasibility Study ("FS" or "Study"), prepared in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") on its Underground Project ("UGP" or "Project") at the Karowe Diamond Mine ("Karowe") located in Botswana. The UGP at Karowe is expected to extend the mine life, as confirmed previously in the published 2023 underground feasibility study ("2023 FS"), and to generate revenue and cashflow to 2038, extending benefits to the Company, its employees, shareholders, communities surrounding the mine, and to Botswana. The Report provides an update to the 2023 FS and 2021 financed base case to reflect changes to capital expenditure, project schedule, and applied mining technical solutions for the Project. Pre-production capital costs for the UGP until production starts in H1 2028 are estimated at $779 million (over an eight-year pre-production construction and commissioning period), of which more than $436 million has been spent on the Project over five and a half years to date;. Karowe is a world-class mine, and the following significant modifications: Project construction progress (surface infrastructure and underground development) to September 30, 2025, and in particular the achievement of successfully reaching both production and ventilation shaft bottoms and lateral development connecting the two shafts; Re-baselining the UGP schedule and, as a result, the open pit mine and processing facility production plans; Geological model updates incorporating pit mapping and drillhole data from five core holes (1,781 m) drilled between July and September 2025; Hydrogeological and geomechanical model updates; Mine design, method, and schedule updates; Bulk mining by Long Hole Shrinkage (LHS) drill and blast mining methods from 310 metres above sea level ("masl") (700 metres below surface) to 490 masl (520 metres below surface), after which geotechnical modelling indicates the kimberlite will cave unassisted to the bottom of the open pit at 665 masl (350 metres below surface); Both empirical and state-of-the-art numerical modelling were applied by external industry specialists to assess the cavability of the kimberlite pipe, and the overall integrity and performance of the new hybrid mine design. A comprehensive Ground Control Management Plan has also been updated with the new design, informing all the detailed ground support designs, along with a Cave Management Plan, which sets out the details around cave performance monitoring and operational responses to a range of possible cave behaviors. The underground mine will be situated primarily within the granitic basement, where groundwater is expected to report to mine workings through open joints and structures, of which several have been encountered and successfully grouted to date. Groundwater at Karowe is highly saline and is regularly tested to inform equipment and piping specifications and water management plan updates for safe disposal of excess mine water. Geotechnical evaluations and predictive modeling performed in 2024 focused on optimising the orientation, spacing, size, and overall geotechnical stability of the 2023 FS mine design and defining Cave Management Plans. The result of this work suggested design opportunities to improve structural stability at the extraction level, and more importantly, a strong potential for unassisted block caving above 500 masl. Hydraulically coupled cave simulations were performed to confirm the location, rate, and evolution of free caving within the South Lobe and has led to the introduction of the block caving mining method after an initial LHS campaign opens the cave back to the required geomechanical conditions using shorter stoping horizons than previously planned in the 2023 FS. The approximately $436 million of capital incurred to date relates primarily to permanent infrastructure, underground shaft development, and long-lead installations that are required under both the original and updated mine plans.