The Voorspoed kimberlite pipe is an oval body with maximum dimensions of 490mx350m at the 30m level - the approximate average deplh of the present open pit. Three types of kimberlite have been identified, but Types 2 and 3 kimbedite folm only a small percentage of the total pipe area. Type 1 kimberlite is extremely hard and resistanl to weathering.

The total area of the pit at this level is 12,5 hectares, but almosi half of this area is taken up by a huge mass of barren basalt rock. The actual area ofthe kimbedite on the 30m level is 6,55 hectares.

The most outstanding geological feature of the pipe is the huge mass of lava which occupies the southern half ofthe pipe at the surface. This lava is of Stormberg age and is an enormous inclusion which slumped downwards along the southern edge of the pipe from higher (eroded) levels.

At present, very little of the country rock at Voorspoed is available. lt has been ascertained that Karoo sediments overlie Ventersdorp lava at Voorspoed, but the depth and nature ofthe contacl between the two are unknown.

De Beers Voorspoed mine is an open-pit kimberlite mine that is situated 30 kilometres northeast of Kroonstad in the Free State, South Africa. It currently mines at a depth of 150 metres. The mine was expected to produce over ten million carats during the life of the mine using standard drill and blast techniques. As is the case with mines such projections are continuously reviewed and Voorspoed is no exception.

The plant includes the installation of high pressure rolls crushers to replace the relatively dated rod milling process used before, and two new secondary crushers, replacing the older technology cone crushers. The efficiency improvements have been achieved with the addition of a coarse Dense Medium Separation (DMS) Plant and by converting the existing DMS plant to a fines DMS plant, thus allowing for a more efficient DMS process. This will feed correctly prepared diamond bearing kimberlite to a new final recovery plant that includes the latest X-Ray diamond recovery technology. Much of the technology installed at Finsch was developed by DebTech, the De Beers Group’s technology research and manufacturing division based in the south of Johannesburg.