Selective separation of wolframite from calcite by froth flotation using a novel amidoxime surfactant: Adsorption mechanism and DFT calculation

Wolframite was separated and extracted from calcite by using a new type of amidoxime surfactant − 3-dodecylamine propyl amidoxime (DPA) as a flotation collector. • A novel amidoxime surfactant DPA was synthesized by lab. • DPA was first introduced in flotation for separation of wolframite from calcite. • DPA has superior selective adsorption performance at wolframite interface. • The wolframite recovery was 96% and calcite only 2 % at pH 7 and 2 × 10 -4 mol/L DPA. This study concentrated on the adsorption features and mechanism of a novel amidoxime surfactant 3-dodecylamine propyl amidoxime (DPA) used as a new wolframite collector on wolframite and calcite surfaces. The flotation experiment showed that DPA collector has a remarkable flotation separation effect on wolframite and calcite. Additionally, the results of the contact angle and zeta potential measurements, and FTIR spectral analysis revealed that the DPA had produced strong electrostatic adsorption on the surface of wolframite, but almost no adsorption on calcite. The results of the DFT calculation showed that DPA had a strong effect on the wolframite surface mainly through the positive charged –C(NOH)N + H 3 group. It provides a new idea for the flotation separation of wolframite and calcite.