Efficient flotation recovery of azurite with a novel ammonium dithiocarbamate–xanthate system: Experimental and mechanistic study

Abstract

This study innovatively exploits the synergistic effect of ammonium dithiocarbamate (ADTC) and xanthate collectors to achieve efficient flotation recovery of azurite. Comprehensive surface characterization techniques—including field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS), focused ion beam-transmission electron microscopy (FIB-TEM), and X-ray photoelectron spectroscopy (XPS)—combined with density functional theory (DFT) calculations revealed that the NH₂CS₂^– group in ADTC spontaneously reacts with Cu atoms on the azurite surface, forming a scaly product film approximately 17.89 nm thick. Further confirmation by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and contact angle tests demonstrated that ADTC pretreatment significantly enhances the adsorption capacity of xanthate collectors on azurite and markedly improves surface hydrophobicity, thereby effectively boosting its flotation performance. The novel ADTC-KBX activation-flotation system developed herein remarkably alters the surface morphology and chemical properties of azurite, ultimately achieving a high flotation recovery rate of 97.06 %. This provides an innovative solution for the efficient recovery of azurite resources.