Karowe Diamond Mine

Client: Boteti Diamonds
Location: Botswana
Value: USD$ 126 million
Scope: Engineering, Procurement and Construction Management

Boteti Diamonds (a subsidiary of Lucara Diamond Corporation) contracted DRA Global to provide an underground study and complete EPCM service for the design and construction of a diamond milling, DMS and Recovery plant and associated crushing, screening and thickener systems for the AK06 (Karowe) Mine located in central Botswana. DRA commissioned the project and subsequently operated the plant on an outsourced basis until 2020.

Karowe Underground Study /

The mining scope of the 2.5Mtpa Concept Study was conducted by DRA Global, and the team were responsible for: Geotechnical, Mining, Engineering, Project Schedule and cost estimation including operating cost, initial and sustaining capital.

The underground study was used to determine the optimal open pit to underground transition point, the execution of various trade-off studies on the underground access method, mining method and submission of a comprehensive life of mine schedule. The aim of the underground study is to ensure a steady plant production rate during transition from open pit to underground mining and to thereafter extend the overall life of the mine. As an existing mining operation, the key infrastructure aspects of this project were focused on the underground access infrastructure, water management and the expansion of existing facilities for power supply and tailings.

Karowe EPCM /

The $126 million AK06 diamond plant was designed to process 2.5 million tonnes of ROM kimberlite ore per annum with a single 200tph DMS module. The concentrate material from the DMS is subsequently treated through a 2.5tph wet X-ray Recovery for material reduction and diamond winning.

A unique feature of the AK06 mine is the autogenous (or AG) milling technology utilised as part of the circuit previously seen only in northern hemisphere diamond plants. AG mills can accomplish the same size reduction work that normally takes multiple stages of crushing, screening and grinding methods which accounts for its popularity.

After a successful commissioning, Boteti approached DRA Global to complete the Phase 2 upgrade of the Karowe process plant. DRA Global again utilised impediment innovative engineering design to integrate specialised X-ray technology into a new diamond recovery circuit that identified and recovered carbon-specific diamondiferous material. This unique XRT technology enhanced Boteti’s ability to recover larger diamonds, prior to the DMS, while mitigating the risk of downstream damage. This technology enabled Boteti to recover the second largest diamond ever found, a 1,111 carat diamond. This diamond is the largest diamond to be found using modern processing technology.