A novel activation approach for promoting chrysocolla flotation: Performance and mechanism

Abstract

Chrysocolla is an important copper oxide mineral. However, owing to the unique structure of chrysocolla, effective recovery of chrysocolla using conventional sulfidization xanthate flotation methods proves challenging. In this work, the effects of Pb2+ on the surface properties, sulfidization, activation, hydrophobicity, and floatability of chrysocolla were systematically investigated in a sulfidization xanthate system. Compared to the direct sulfidization flotation results, the flotation recovery of chrysocolla significantly increased from 7.84% to 69.46% after Pb2+ stepwise activation. The results of X-ray photoelectron spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) analyses indicated that Pb species and sulfidization products on chrysocolla surfaces obviously increased in the Pb2+ stepwise activation system, the content of highly reactive PbS components on the surface of chrysocolla was higher, and the stability of sulfidization products on the chrysocolla surface was stronger than that in a single Pb2+ activation system. The results of contact angle, Fourier-transform Infrared (FTIR), and adsorption amount characterizations showed that more xanthate components were adsorbed on the surface of chrysocolla after Pb2+ stepwise activation, and the hydrophobicity of chrysocolla surface was significantly enhanced. Therefore, Pb2+ stepwise activation not only enhanced the sulfidization of chrysocolla surface but also improved the reactivity and hydrophobicity of mineral surfaces, thus realizing the effective recovery of silicic copper oxide minerals, which are extremely difficult to float.