Designing Flotation Process for Lead-Zinc ore from Nepal

Abstract

The paper deals with the development of a process based on froth flotation for the concentration of a lead-zinc ore from Ganesh-Himal region of Nepal. A detailed chara-cterisation and flotation studies were carried out under the varying process conditions. The ore was predomionantly made up of sphalerite and pyrite in association with sub-ordinate amount of galena, minor amount of pyrrhotite and chalcopyrite with dolomite as the major gangue. Under the optimum process conditions the rougher lead and zinc recovery were 96.3% and 90.8% respectively. Regrinding followed by three stage cleaning of the lead rougher conc-entrate resulted in cleaner concentrate assaying 79.11 % Pb with 83.4% recovery. Similarly two stage cleaning of the zinc rougher concentrate produced cleaner concentrate analysing 60.08% Zn with 80.4% recovery. Based on the studies undertaken a process flow-sheet for the conc-entration of the ore to individual lead and zinc concen-trates has been recommended.