New insights into the dispersion mechanism of citric acid for enhancing the flotation separation of fine siderite from hematite and quartz

In this work, citric acid was employed as a specialized dispersant to eliminate the strong heterocoagulation of fine siderite with hematite or quartz. The dispersion performance of citric acid was investigated by flotation experiments and kinetics analysis. Zeta potential measurement, Fourier transform infrared (FT-IR) spectroscopy, atomic force microscope (AFM) imaging and force detection technology, and turbidity measurement were conducted to probe the adsorption and dispersion mechanism of citric acid. The flotation results and kinetics analysis indicated that both the recovery and content of hematite/quartz in the concentrate decreased apparently after adding citric acid, resulting in an increase in the kinetic selectivity index (KSI) for separating fine siderite from hematite/quartz. Zeta potential measurement, FT-IR analysis, and AFM imaging demonstrated that citric acid could strongly attach to siderite and hematite surfaces whereas weakly on the quartz surface. AFM force measurement and turbidity analysis confirmed that the repulsive force between siderite and hematite or quartz caused by citric acid promoted the dispersion of different minerals, as further supported by the notable increases in the turbidity of the minerals suspension. Our findings provided new insights into the dispersion mechanism of citric acid for enhancing the flotation separation of fine siderite from hematite and quartz.

Automated summary

The study demonstrates that citric acid can effectively disperse the strong heterocoagulation between fine siderite, hematite, and quartz, thereby enhancing the separation selectivity of different minerals.