What is the scope of De Beers’ investment into the Venetia Underground Project?
We committed US$2-billion in replacing the open mine with a new underground mine. This will approximately double the life of the mine to the middle of the 2040s.
When do you expect to start producing diamonds?
We start intersecting the kimberlite orebodies in the 2020s. The first significant production will be in 2021, on a smaller component of the mine. The open pit will halt all operation in 2023 and from then on, the underground will become the main source. The open pit is currently mining three distinct kimberlite pipes. The underground mine will mine two of those.
How many jobs have been created?
We have about 750 people on the project. At our peak, the numbers will increase to about 2 000 to 2 500 people – these will decrease as the project execution comes to an end.
The underground mine will not significantly change the number of De Beers’ employees on the mine, although there might be different contractors that are required on the underground operation from those we used on the open pit because of the changed nature of the mining.
We forecast that we will stay at similar employment levels as before. We currently have approximately 1 350 employees, excluding contractors. The situation with contractors is very dynamic, and changes as workload alters. It is not consistent work over the life of the mine.
Are local businesses involved?
Some portions of the project are unique, and require established experienced contractors to deliver. We have gone on a campaign to try to build to establish as many local SMMEs as possible. There are a few success stories, such as our partnership with a company called Renuna for accommodation. Smaller local building contractors are also helping us to develop structures on site.
How long is the tunnel from the surface to the mine?
We are developing three access points. The decline is 2.5 km and the vertical depth is about 400 m. The decline assists with developing the top of the mine. The decline will be completed this month and we have started with lateral development towards ore bodies. The two vertical shafts, which are about 550 m below the surface, will eventually be 1 km in depth.
At what speed are the vertical shafts being developed?
We are currently achieving approximately 40-45 m per month.
What are some of the key challenges you face in this project?
Some of the key challenges we have is obtaining specialist skills required for shaft sinking. We are competing with a project in Mongolia and one in Zambia. Obtaining the correct skills set within the SA environment is tricky, including the skills set that we require for the operational phase of the underground mine.
Are there any new techniques being used on the project?
The shaft sinking methodology we are employing through Murry & Roberts is the first of its kind in South Africa. We awarded it to Murray & Roberts based on the safety associated with its method. The old method did concrete lining concurrently with development. We do everything in line, making sure we don’t expose people to people working on top of them. This affects the advance rate, but it is a significantly safer method.
From a safety record perspective, we are doing well compared to other similar projects in SA. Shaft sinking is typically associated with severe accidents. While we have not yet achieved our goal of zero harm, we have progressed significantly on our journey.
Christoffel Kühn has Master’s degrees in mechanical engineering and project management from the universities of Potchefstroom and Pretoria which he has put into practice in Southern Africa, South America and Australia. Starting as an engineer on a gold mine, he has since delivered several capital projects in the mining industry. His experience includes engineering and project management, project development and techno-economic evaluation. Kühn’s previous post was head of the project management support and review department at Anglo American.