Flotation Behavior of Lepidolite Using Conventional Amine and Gemini Collectors

Lepidolite flotation was investigated using Armeen C, a conventional primary amine, and a cationic Gemini surfactant (hexanediyl-α,ω-bis(dimethyldodecylammonium bromide), 12-6-12) (HBDB), as collectors. Microflotation tests, electrophoretic mobility measurements, adsorption isotherms, and dynamic foamability experiments were conducted to compare their performance and interaction mechanisms. HBDB produced high lepidolite recoveries at relatively low concentrations of 25–75 mg/L, particularly between pH 5 and 9, whereas Armeen C required higher dosages of 100–300 mg/L to achieve comparable recoveries over a broader pH range. Electrophoretic mobility and adsorption results confirmed the interaction of both collectors with the lepidolite surface, although Armeen C showed stronger charge reversal and higher adsorption density. In contrast, HBDB exhibited substantially stronger foamability, with DFI values ~7.2–7.8 higher than those of Armeen C. These results indicate that HBDB can enhance lepidolite flotation through efficient surface hydrophobization and strong froth stabilization.