Sulfidization flotation of azurite using 2-amino-5-bromo-1, 3, 4-thiadiazole as a novel sulfidizing agent: An experimental and mechanistic study

In this study, 2-Amino-5-bromo-1, 3, 4-thiadiazole (ATD) was firstly introduced as a novel sulphidizing agent to improve the floatability of azurite. Micro-flotation tests and contact angle experiments demonstrated that the addition of ATD significantly enhanced the hydrophobicity of the azurite surface and increased its recovery to 98.97 %. To elucidate the facilitation mechanism, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS) were conducted. XPS and TOF-SIMS analyses revealed that ATD chemically interacted with copper sites on the azurite surface, forming stable copper-ATD complexes. This interaction promoted the subsequent adsorption of butyl xanthate (NaBX), as evidenced by the enhanced surface coverage and uniform distribution observed in the 2D distribution of ion fragments in TOF-SIMS, as well as in SEM imaging and EDS analysis. The combined characterizations confirmed that ATD acts as an effective sulphidizing agent to activate azurite flotation. Consequently, the proposed ATD-assisted sulfidization flotation offers a promising strategy for the effective recovery of azurite. This work provides both experimental and mechanistic insights into the role of ATD in oxide copper mineral processing.