Selective separation of hematite and chlorite by eco-friendly inhibitor syringic acid and its mechanism

In this work, using syringic acid (SA) as a novel eco-friendly inhibitor and dodecylamine (DDA) as a collector in a cationic reverse flotation system, the effect of SA on the flotation separation of hematite and chlorite was investigated. Micro-flotation experiments and artificial mixed mineral experiments were conducted to study the flotation behavior of hematite and chlorite in the presence of SA. The adsorption mechanism of SA on the surfaces of hematite and chlorite was analyzed through methods such as Zeta potential, AFM, FTIR, XPS testing, and DFT calculations. Flotation experiments showed that after adding SA, the recovery rate of hematite was 88.87%, and that of chlorite was 7.01%, effectively achieving the separation of hematite and chlorite. Mechanism analysis indicated that SA could form complexes with Fe atoms, selectively adsorb on the surface of hematite, hinder the adsorption and capture of DDA on hematite, and suppress the flotation of hematite without affecting the surface properties of chlorite. Therefore, SA can serve as apotential selective inhibitor for the separation of hematite and chlorite.