Selective particle agglomeration-driven flotation enhancement of spodumene by a novel collector–micro/nanobubble synergistic system under high-altitude conditions

High-altitude flotation environments are characterized by low temperature and low atmospheric pressure, which adversely affect reagent performance, bubble–particle interactions, and froth stability, thereby limiting the efficient recovery of spodumene resources. To improve spodumene flotation under such conditions, a novel flotation strategy combining a sodium oleate/lauramidopropyl hydroxysultaine (NaOL/LHS) mixed collector with micro–nanobubbles (MNBs) was developed. The flotation behavior of spodumene and albite under different temperature and pressure conditions was investigated through single mineral and artificially mixed mineral flotation experiments. In addition, turbidity measurements and microscopic observations were employed to reveal the role of MNBs in particle agglomeration. The results showed that the NaOL/LHS mixed collector exhibited good selectivity for the flotation separation of spodumene from albite under simulated high-altitude conditions. The introduction of MNBs further enhanced flotation performance, particularly under low-temperature and low-pressure conditions. At 5 °C, the flotation recovery and Li 2 O grade in the MNBs system increased by 7.20% and 0.66%, respectively. At 60 kPa, the flotation recovery increased from 26.45% to 33.32%, corresponding to an increase of 6.87%. Agglomeration analyses revealed that the NaOL/LHS collector promoted the selective agglomeration of spodumene particles, while MNBs further accelerated floc formation and strengthened particle–bubble interactions. As a result, the flotation recovery of spodumene was significantly improved. These findings demonstrate that the synergistic NaOL/LHS–MNBs system provides an effective approach for enhancing spodumene flotation under high-altitude conditions, and that selective particle agglomeration is an important mechanism responsible for the improved flotation performance.