Name of the Project
Karowe underground expansion project (UGP).

Location
North-central Botswana.

Project Owner/s
Canadian diamond mining company Lucara Diamond Corp.
 
Project Description
The operating Karowe openpit diamond mine is a conventional load-and-haul operation, with operations expected to terminate in mid-2025 at an elevation of 713 metres above sea level (masl). 

The underground development is expected to extend Karowe's mine life beyond 2040 and is designed to support a 2.7-million-tonne-a-year mining operation and processing plant, which will be focused on the South Lobe of the AK06 kimberlite.

The project will involve the extraction of an estimated 400 vertical metres of the South Lobe from 310 masl (700 m below surface) to the bottom of the depleted openpit about 710 masl (300 m below surface).

The project will include an 8.5 m completed internal-diameter production shaft, about 767 m deep and equipped to hoist a nominal 7 400 t/d of ore and additional development waste; and a 6 m completed internal-diameter unequipped ventilation shaft with a planned final depth of 729 m.

Total life-of-mine (life-of-mine) diamond recoveries are estimated at 6.8-million carats.

Potential Job Creation
None stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Preproduction capital costs for the underground project are estimated at $683-million.

Planned Start/End Date
Capital will be expended over an eight-year preproduction construction and commissioning period until the second half of 2027. Full-scale underground production is planned for the first half of 2028.

Latest Developments
Lucara is reviewing the mining method for the UGP, along with the project’s cost estimates and schedule.
The UGP has progressed well, reaching the bottom of the production shaft in late July and achieving 2 067 lost-time injury-free days.

The ore extraction review has focused on further understanding the orebody geomechanics and on modelling potential caving scenarios that affect ore extraction levels, with point designs to be included in an updated technical report.

The company has initiated detailed engineering of the lateral development portion of the UGP and is finalising an updated LoM plan based on the results of the simulation work.

Lucara has said that the review of the mining method does not impact on the ongoing development of the UGP. The company continues to advance the UGP according to plan towards the lateral development phase of the project.

UGP development work is continuing with the equipping of the production shaft, commissioning of the shaft conveyances, progressing underground infrastructure development near the shafts and advancing the lateral development towards the kimberlite.

In the quarter ended September 30, 2025, $22.7-million was spent on the UGP to primarily advance production shaft sinking and develop the 310 level to interconnect shafts, as well as 285-level station development that included significant concrete work, pump installations and other station civil works.

Expenditures also included completing key electrical and power installations at the 355 level and 470 level, as well as ongoing lateral development and surface infrastructure activities.

In terms of ventilation shaft third-quarter developments, the company has completed 184.5 m of lateral development at the 310 level, and is advancing the 310 level lateral development towards holing into the production shaft.
Lucara has started stage modifications and equipping stage assembly on the production shaft, having completed 7.8 m of lateral development.

The company is continuing the adjudication and review of underground lateral development tender documents.

Winder installations, including rack and cable installations in the man-and-material winder building, have been completed.
Lucara has also completed the fencing of evaporator pond and pipeline installation, in addition to having advanced mining engineering, focusing on underground infrastructure and finalising drilling level plans.

Activities planned in the fourth quarter of this year include the ventilation shaft, where the company has said it will complete the 310 level station development and 310 level lateral development connecting to the production shaft, as well as complete the blasting of the ore pass to the 285 level.

In terms of the ventilation shaft, Lucara aims to complete 310 level to 285 level tip construction and the installation and commissioning of the substation. It also plans to complete sinking to 285 level and continue 310 level and 285-level lateral development.

In terms of the production shaft, the company aims to complete stage modification for shaft equipping, continue with shaft equipping and complete loading pocket structure steel installation, install the shaft bottom spillage and deflection wall, and complete station steel construction at the 285 level and 310 level.

Key Contracts, Suppliers and Consultants
JDS Energy & Mining (technical report).

Contact Details for Project Information
Lucara Diamond Corp, tel +1 604 674 0272 or email info@lucaradiamond.com.