Flotation enhancement of spodumene with a β-amino-hydroxamate surfactants

In view of the combination of dodecylamine and hydroxamate can improve the flotation recovery of spodumene, a novel beta-amino-hydroxamate surfactant, i.e., N-(3-(dodecylamino)) hydroxamic acid (DAHA), was designed and introduced into spodumene flotation. The micro-flotation performance indicated that DAHA performed excellent collecting ability toward spodumene, and 2.0 x 10-4 mol/L of DAHA floated out about 90.2% of spodumene, while that of sodium oleate (NaOL) was only about 57.4%. The zeta potential of DAHA-treated spodumene revealed the effective chemisorption of hydroxamate group on spodumene surface. FTIR and XPS recommended that the hydroxamate group in DAHA chelated with surface Al sites to form five-membered hydroxamate-(O,O)Al complexes. The affinity of DAHA on spodumene spontaneously enhanced by the protonated amino group (-NH3+), which facilitated the chelation of hydroxamate with the surface Al atoms and strengthened the hydrophobicity of spodumene.