De Beers started to reinvestigate the Orapa field and subsequently discovered more than 40 additional kimberlites in the general area. In addition, they have re-sampled some of the first phase kimberlites and have commenced operations at the Damtshaa Mine in the Orapa area, mining kimberlites BK9, BK12 and in future BK15 and parts of BK1. They have also studied the alluvial potential associated with the main AK1 pipe and may also mine alluvials. De Beers have explored other areas in Botswana, finding a cluster of kimberlites in the west (Okwa valley) with Mark Scowcroft supervising the programme in the field. In the southeast another programme discovered the Martin’s Drift kimberlites. Two ages of kimberlites were discovered in this field, including the main, nonmagnetic cluster of 1333 Ma. De Beers eventually attempted to mine the older kimberlites. After a five year period.

First discovered in 1966, the Orapa Regime (cluster) consists of Orapa, Letlhakane and Damtshaa Mines, which are open-pit operations using traditional truck and shovel methods, and clustered in a radius of under 25km in the Central District of Botswana.

The ore produced at Damtshaa is processed at a processing plant at its sister mine, the Orapa diamond mine, about 20 km (12 mi) distant. The Damtshaa mine is also managed from the Orapa mine

The tonnes mined from A/K1 pit feed two processing plants, Orapa 1 and Orapa 2. The concept of diamond processing, entails stages of comminution to progressively reduce the particle size of the ore, and screen it into a feed size envelope desirable for the concentration process. A major outcome of the comminution process is diamond liberation; a process whereby the locked-up stones are released from the host rocks. Once the diamonds are liberated, they can now be separated from the gangue material into a concentrate by the Dense Medium Separation process.

Liberation is the fundamental activity of any diamond processing operation. The state of liberation in a plant, while not measurable, is diagnosed by the level of grind (fracture) completed by the plant at any given sub-stage of comminution. The total grind conducted by the plant is achieved by a combination of comminution equipment and recycle such that all material is reduced to below a desired size.

The combination of the comminution stages is also known as feed preparation. Subsequently, diamond concentration is achieved through a process known as dense medium separation (DMS). A concentrate is formed by utilizing the density differentials between the gangue or host rock and the diamonds. The final recovery stage is done by using x-ray machines in a separate plant, known as the ‘recovery plant’.