Mineralogical and flotation characteristics of lead-zinc ore with a particular reference to effects of oxidation

The present paper deals with the mineralogical and flotation characteristics of two lead-zinc ore samples (S1 and S2) from Ganesh-Himal region of Nepal. The two samples assayed 2.47% & 3.53% Pb and 13.6 & 13.45% Zn respectively. The ore was predominantly made up of spahlerite and pyrite in association with subordinate amounts of galena, minor amounts of pyrrhotite and chalcopyrite. Dolomite was the main gangue. The modal analysis showed the probability of fair liberation of sulphides from gangues around 210 micron but the locking of galena with sphalerite and other sulphides continued to finer sizes. However, sample S2 showed the presence high content of mineral fines and oxidised mineral phases. Detailed flotation studies carried out on the samples under varying process conditions resulted in reasonably high recovery of lead and zinc bearing minerals for sulphidic sample (S1) but recovery from oxidised sample (S2) was not satisfactory. Use of new alkyl quinoline based chelating type collector found helpful in improving flotation results.