Aggregation relations and flotation behavior of the depressant pectin on talc, chlorite, and serpentine and its mechanism of action

In this study, pectin was used as an environmentally friendly depressant to study its flotation behavior and aggregation effect on key magnesium silicate gangue minerals commonly found in nickel ore, such as talc, chlorite, and serpentine. The interaction mechanisms between pectin and minerals were explored using a series of techniques, including IC-FBRM particle size analysis, adsorption tests, scanning electron microscopy (SEM) tests, FTIR analysis, XPS analysis, and zeta potential measurements. Results from flotation experiments, IC-FBRM tests, and SEM observations indicate that under natural conditions, serpentine tends to aggregate with talc, but the three mixed minerals still exhibit floatability. At low dosages of pectin, serpentine and chlorite tend to aggregate together. Further increasing the pectin dosage reduces the recovery rate to 0%. FTIR and XPS analyses reveal that the –OH groups in pectin chemically interact with Mg atoms in chlorite. Zeta potential results show that pectin causes a significant downward shift in the zeta potential of chlorite.