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.