Exploration Development

Surface diamond drilling will show wether a mineralized area has enough potential to become an orebody. Surface work is followed by underground development and detailed drilling definition from the workings to outline the area with greater precision, and to confirm that mineralization is constant and the tonnage and grade estimates are correct. Only then can the developer make production plans.

Surface diamond drilled holes can tell only part of the situation. A mineralized zone might have the chances of being irregular, or of swelling or pinching, and a very big quantity of diamond drilling is needed to fill in the information between the primary holes that the developer drills. Drilling holes from the surface sooner or later becomes forbiddingly expensive, and it is up to the mine developer to decide whether or not to continue the exploration from underground. If exploration is permitted, an access ramp or a suitably sized exploration shaft is driven, permitting crews to get closer access to the orebody.

The crews drive crosscuts or drifts from the ramp or shaft, and drilling areas are excavated at regular intervals to have the underground drills accommodated. The mineralized body is afterwards drilled from underground to get a precise estimate of tonnage and grade.

Up to this point in the program of exploration, the only samples taken from the orebody have been the drill cores. However, it is possible to get much bigger bulk samples of the ore by actual mining once underground. The material which is mineralized that is removed during this operation gives a bulk sample for metallurgical testing,it is first done at bench scale in a laboratory and finally at pilot scale in an actual mill. The testing is used to determine the method of extraction that will recover the most amounts of metal from the ore.