Production Potential of Collapsed Blocks

Currently not all areas are mineable at Nchanga underground mine due to high stress ground conditions that have led to the collapse of a certain number of blocks. The main purpose of this study was to recommend modification to block caving at the underground mine, ensure that it meets anticipated production levels and address the adverse ground conditions, of the intensely fractured orebody. Excavations of current methods are driven close to the incompetent orebody. Determination of the appropriate method based on criteria of selection techniques, together with the analysis of operating costs and safety. Reclamation of ore in the collapsed blocks entirely depended on maximizing revenue, recovery of the mineral and safe working environment for equipment and personnel. On recommendation of a suitable method, extent of the collapsed blocks was another aspect considered. The proposed methods of extraction were variants of block caving, further shortlisted based on the extent of collapse. Economic appraisal of both the recommended and current mining methods employed included extraction, recovery, development, reclamation costs, revenue estimation and revenue raised from finished copper.