Lesedi Unclaimed

Lesedi uses a drilling method known as continuous coring for mining exploration. In this method the core produced by the cutting action of the bit goes straight into the rod string. Water is pumped down to the bit on the outside of the rod string and returns to the drill via the inside of the rods. The water pressure from the return water is enough to push the core to the top of the rod string where it is retrieved by the driller. Continuous coring results in much higher levels of productivity as there is no down-time when core is retrieved from the core barrel. It is important to note that continuous coring works very well in relatively homogeneous rock formations such as those found in the South African gold and platinum. It is not successful as a technique in badly fractured and faulted ground.