Mineralogical evaluation of Zinc-lead ore from Ganesh Himal region of central Nepal

Abstract

The zinc-lead mineralization in the Ganesh-Himal range is a part of crystalline Kathmandu Nappes of Main Central Thrust Zone, which belongs to the wide schuppen zone between Nawakot metasediments and Ganesh Himal regions. The host rock is crystalline dolomitic limestone in which zinc-lead minerals are mostly disseminated. Microscopic and X-ray mineralogy indicate that the ore minerals are predominantly made up of sphalerite and iron sulfides (pyrite and pyrrhotite) and galena, with minor to traces of chalcopyrite and magnetite. Dolomite is the major gangue mineral in association with amphibole, biotite, calcite and carbonates of lead and zinc. The mineralogical study indicates possibility of preconcentration of values at coarser size (60 mesh) but fine grind at around -100+200 mesh is needed to recover different sulfide minerals.