The activation mechanism of metal ions on spodumene flotation from the perspective of in situ ATR-FTIR and ToF-SIMS

Abstract

• Fe 3+ , Mg 2+ , and Ca 2+ exhibited strong activation ability for the spodumene flotation . • The activation ability of Ca 2+ and Mg 2+ to spodumene is stronger than that of Fe 3+ . • The metal ions provided more active sites for the adsorption of NaOL. • The colloidal complexes of metal ions and NaOL strengthened the spodumene flotation. The existence of metal ions is inevitable in the spodumene ore beneficiation and the study of their interaction mechanism with spodumene is of great significance for the spodumene flotation. In this work, the effect of Fe 3+ , Mg 2+ , and Ca 2+ on the flotation behavior of spodumene with NaOL was investigated through micro-flotation experiments. The flotation results showed that Fe 3+ , Mg 2+ , and Ca 2+ exhibited strong activation ability at pH 6.5, 10.9, and 12.1, respectively, and the activation ability of Mg 2+ and Ca 2+ toward spodumene was superior compared to that of Fe 3+ . The activation mechanism of metal ions was explored by the Visual MINTEQ model, in-situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results of species distribution calculated by the Visual MINTEQ model and in situ ATR-FTIR demonstrated that NaOL adsorbed more strongly onto spodumene in the presence of Mg 2+ and Ca 2+ compared with that of Fe 3+ , resulting in better activation of Mg 2+ and Ca 2+ . In addition, XPS and ToF-SIMS analyses revealed that the activation of spodumene by metal ions works in two ways. It not only provides more active sites for the adsorption of NaOL, but also interacts with NaOL to form the colloidal complexes and then adsorbed on the spodumene surface.