Chitosan as an Eco-Friendly Alternative for Silicate Depressant in Phosphate Flotation

Abstract

The quest for environmentally friendly reagents in froth flotation processes has gained significant importance for minimizing ecological impacts. This research investigates the utilization of chitosan polymer as a green depressant for silicate minerals in the direct flotation of phosphate minerals. To understand the behaviour of the flotation feed, zeta potential measurements were conducted to assess the electrical properties of mineral surfaces in the presence and absence of chitosan polymer. Furthermore, the effects of chitosan dosage, pulp pH, and flotation time on the flotation recoveries and concentrate grade of phosphates were studied. Comparative analyses were performed by comparing the flotation recoveries of phosphate minerals achieved using chitosan polymer with those obtained when employing a commercial silicate dispersant, sodium silicate. The findings revealed that at a dosage of 300g/ton, the recovery of phosphate minerals reached approximately 70% when using chitosan polymer, whereas the recovery was only around 40% with the same dosage of sodium silicate dispersant. These outcomes demonstrate the potential of chitosan as an effective and sustainable silicate depressant in the phosphate flotation process under specific conditions.