Name of the Project
Karowe diamond mine underground expansion.
Location
Botswana.
Project Owner/s
Lucara Diamond Corp.
Project Description
The Karowe mine is an existing conventional drill-and-blast openpit operation, with diesel excavators and trucks providing an average of 2.6-million tonnes a year of kimberlite feed for the mill. The openpit mine operation is expected to terminate in mid-2025, ending at an elevation of about 700 m above sea level.
The combined openpit and underground indicated resource is estimated at 54.27-million tonnes at 15.3 carats per hundred tonnes for a contained diamond resource of 8.3-million carats, excluding stockpiles effective 01 July 2019.
The feasibility on the proposed project has focused on the substantial resources remaining below the economic extents of the openpit.
Longhole shrinkage underground bulk mining has been selected to provide early access to higher-value ore and allow for a short payback period.
The underground project is designed to access the South lobe kimberlite resource below the current planned bottom of the openpit, which is expected to be at about 700 m above sea level, to a depth of 310 m above sea level.
Access to the South lobe underground will be through two vertical shafts – production and ventilation – of about 765 m and 715 m respectively.
All underground mined kimberlite will be processed at the existing Karowe processing plant over a 13- to 15-year period, following the cessation of the current openpit operations, which is expected to occur in 2025.
Life-of-mine production (remaining openpit and underground) is estimated at 7.8-million carats.
The underground expansion is expected to extend Karowe’s mine life by 15 years.
Potential Job Creation
Not stated.
Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at a 5% discount rate, of $718-million, with a payback of 2.8 years, for the combined openpit and underground mine.
Capital Expenditure
Preproduction capital costs for the underground project are estimated at $513.7-million.
Planned Start/End Date
Based on construction starting in mid-2020, ore from underground mining will seamlessly integrate into current operations providing mill feed in 2023, with a ramp-up to 2.7-million tonnes a year to the processing plant by 2026.
Latest Developments
Lucara Diamond has mandated five international financial institutions for a secured project financing package of up to $220-million to fund the underground expansion of the Karowe mine.
The syndicate comprises ING Bank, Natixis, Société Générale, London Branch, Africa Finance Corporation and Afreximbank.
The debt package will supplement cash flows from continued operations of the Karowe openpit over the next five years, extending Karowe's mine life from 2025 until at least 2040.
Lucara is targeting completion of the project financing package by midyear, with full project sanction thereafter.
Key Contracts, Suppliers and Consultants
None stated.
Contact Details for Project Information
Lucara Diamond Corp investor and public relations, tel +1 604 674 0272 or email info@lucaradiamond.com.