Electron Microprobe and Mineralogical Study on Cobalt Bearing Sulphide from the Kalyadi Copper Mine, Hassan District, Karnataka

Cobalt mineralisation in the Kalyadi copper-Cobalt deposit in the Hassan district, Karnataka, is mostly in sulphidic banded, feldspathic cherty quartzite. Electron microprobe study conducted on sulphide concentrates from this deposit revealed that cobalt up to 3.21 wt% is present exclusively in pyrite grains, whereas it is absent in chalcopyrite and arsenopyrite. From this, it infers that pyrite crystallized first, followed by chalcopyrite and arsenopyrite with most cobalt present in the mineralizing system replacing Fe in the paragenetically early-Formed pyrite,thereby rendering the system deficient in cobalt during later crystallization of chalcopyrite and arsenopyrite.