Flocculation of flotation tailings in presence of silicate gel and polymer

Abstract

Flotation tailings were successfully flocculated in the presence of cationic polyacrylamide and silica gel. The effects of various parameters such as polymer weight, charge density, and pH on the rate of flocculation were also investigated in the current study. The flocculation mechanism of the flocculant on tailings was investigated using zeta potential and Fourier transform infrared (FTIR) measurements. The results obtained reveal that 1) sodium silicate gel, used as a binder for the consolidation of tailings form primary flocs, acts as an anchor and the adsorption of polymer flocculant on these anchors results in the formation of larger flocs and, consequently, enhanced settling rate; 2) flocculation in the presence of silica gel and polymer has a faster settling rate than single-polymer flocculation owing to the mechanisms of charge neutralization and bridging as identified using zeta potential and FTIR measurements. A pilot level study was conducted to investigate the influence of processed water on the flotation of scheelite. The results show that the proposed tailing disposal method could improve scheelite recovery by 2% (approximately) and could reduce the daily operation costs of the plant by approximately 108.57 USD.

Keywords

silica gel / polymer / flocculation / tailings disposal

References

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