Zhi Lei, Heng Zhang, Hao Tang, Yong-Chun Luo*, Peng-Fei Xu*
http://10.1016/j.jece.2025.117093
Abstract
The flotation separation of chalcopyrite from talc presents a significant challenge due to its analogous surface characteristics. This study investigated the selective depression of talc in the presence of chalcopyrite using a novel modified chitosan (CSMA), achieving effective mineral separation. CSMA possesses a porous architecture compared to unmodified chitosan (CS), which facilitates enhanced interaction with mineral surfaces. Flotation tests revealed that CSMA significantly inhibited talc flotation while exerting minimal impact on chalcopyrite recovery. Morphological and elemental changes were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES), atomic force microscopy (AFM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM). These analytical results confirm that CSMA adsorbs onto the talc surface. In addition, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations collectively indicate that CSMA exhibits enhanced reactivity, primarily through hydrogen bonding and hydrophobic interactions with the talc surface. This investigation elucidates the mechanism by which carboxymethyl chitosan acts as an effective depressant in the flotation separation of copper sulfide minerals, thereby establishing a foundation for the environmentally friendly recovery of these minerals.