The effect of sodium silicate as pH modifier and depressant in the froth flotation of molybdenite ores

Abstract

In flotation of porphyry molybdenite ores or copper-molybdenite ores using oil collector, a molybdenite (M0S2) concentrate has mainly been separated by combination of sodium silicate (Na2SiO3 and lime (CaO) at about pH 9-11. In this research, the role of sodium silicate and the effect of collector (kerosene) in flotation of Dong-won molybdenite ores from Korea have been observed. It was confirmed that sodium silicate could adjust the pH of pulp to 11. Furthermore, flotation efficiency using sodium silicate was better more than that using lime in the alkaline conditions (pH 9.5-Il). It was demonstrated that sodium silicate could be used not only as pH modifier but also as depressant/dispersant of slime. Also Mo grade of 54.1% and recovery of 92.5% were successfully obtained at 75 g/t kerosene and 1.25 kg/t Na2SiO3 (pH 10).© 2010 The Japan Institute of Metals .