Critical evaluation of most suitable underground mining method for Kahatagaha underground graphite mine - a case study

Abstract

Lanka has been a well-known natural vein graphite supplier to the world since 1820. This reputation is mainly due to its extremely high purity, the purity being above 99% carbon as in-situ status and no other country in the world has vein graphite deposits for commercial mining now. Vein graphite is mined at Kahatagaha, Bogala, Ragedara and also from a few smaller underground mines in Sri Lanka. For decades, the Kahatagaha graphite mine has been practising the ‘open stope mining method’ and this method itself does not require extensive mine support because high strength of host rock inside the mine. It can be thought that the behaviour of graphite veins especially inclined in nature and stable host rock could be the main factors to select above mentioned mining method. But, this mining method causes many practical issues now so that mine production, miners` safety and underground work supervision are badly affected. This research includes the study of the current mining method adopted at Kahatagaha graphite mine and its suitability compared with other mining methods used for narrow vein mining and proposing a mining method which is more suitable, safer, and more economical compared to the current practising method.