Mineralogical Characterisation of the Complex Sulphide Ores from Askot, Pithoragarh District, U.P

Sphalerite, galena, chalcopyrite and arsenopyrite are the dominant ore minerals with minor amounts of pyrrhotite, cubanite, marcasite, pyrite and chalcocite. Bornite, stibnite, native bismuth and silver are present in trace quantities. Chemical analyses of the samples reveal variations in different metal values. Sphalerite, galena, chalcopyrite and arsenopyrite are analysed by Scanning Electron Microscope coupled with EDAX analyser to decipher the distribution of valuable elements in them.

The ore needs grinding to 45 microns to liberate 91.70% of galena, 94.49% of sphalerite, 95.31% of chalcopyrite and 98.45% of composite galena-chalcopyrite-sphalerite. This suggests that by physical beneficiation, individual concentrates of Pb, Cu and Zn with good recoveries may be difficult to obtain, but a bulk concentrate of these three metals can be produced.