Adsorption Mechanism of Amidoxime Collector on the Flotation of Lepidolite: Experiment and DFT Calculation

Abstract

Lepidolite is an important mineral resource of lithium. With the increase in awareness of low-carbon and green travel, the demand for lithium has increased dramatically. Therefore, how to increase the output of lithium has to turn into high precedence. In this paper, amidoxime (DPA) was synthesized and used for the efficient collection of lepidolite. Dodecylamine (DA), a commonly used collector of lepidolite ore, was used for comparison. The collecting performances of DA and DPA for lepidolite were studied by the micro-flotation experiment, and the adsorption mechanism of DPA on lepidolite was verified by contact angle, zeta potential tests, FTIR spectra, and density functional theory (DFT) calculations. The results of flotation experiments showed that at the same collector dosage (3 × 10–4 mol/L), the recovery of lepidolite could reach 90%, while the recovery of lepidolite with DA was only 52.5%, and to achieve the maximum recovery of DA (77.5%), only half of the DPA was added. The contact angle test results showed that DPA could effectively improve the hydrophobicity of lepidolite than DA. FTIR spectra and zeta potential tests suggested that DPA molecules were adsorbed on the lepidolite surface by electrostatic attraction. DFT calculations revealed that DPA reacted with the nucleophilic reagent (lepidolite) by the reactive site of the −CH2NH­(CH2)2C­(NOH)­N+H3 group and more easily absorbed on the surface of lepidolite than DA. Therefore, our new finding will provide an important prospect for the sustainable development and utilization of lithium resources.

Application of Quantum Chemistry in the Study of Flotation Reagents

“…Lepidolite is another crucial mineral resource of lithium, for which a few quantum chemical studies of flotation reagents are available. For example, Huang et al [250] synthesized amidoxime as a collector for the efficient collection of lepidolite and compared it with a commonly used collector, DDA, to understand the collecting performances and adsorption mechanism of amidoxime using experimental and computational methods. The results suggested that amidoxime is adsorbed on the lepidolite surface via electrostatic attraction through the −CH 2 NH(CH 2 ) 2 C(NOH)N + H 3 group as the adsorption site.…”

Surface Structure Analysis and Formaldehyde Removal Mechanism of Lotus Shell Biochar: An Experimental and Theoretical Perspective

“…As a well-established method in quantum chemistry, density functional theory (DFT) has been used to obtain insights into the microscopic mechanisms of pollutant–material interfaces. − HCHO-molecularly imprinted polymers have been designed and synthesized for HCHO removal with the assistance of DFT calculations . Both experimental studies and DFT calculations have been conducted to identify the adsorption behavior of HCHO on resin-based carbons and amine-modified diatomite. , The integration of experimental and DFT methods has emerged as a crucial strategy to identify the fundamental mechanisms involved.…”