Adsorption study of 3-tetradecylamine propyl amidoxime onto rhodochrosite surface: Implications for rhodochrosite-calcite flotation separation

Rhodochrosite and calcite have similar physicochemical characteristics and floatability, making it difficult for conventional flotation collectors to effectively separate the two minerals. In this paper, a novel 3-tetradecylamine propyl amidoxime (TPA) collector with selective and excellent collection capability for rhodochrosite has been investigated. The micro-flotation experiments showed that the flotation performance of TPA is superior to that of the commonly used sodium oleate (NaOL) collector, and the separation of rhodochrosite and calcite can be achieved under neutral conditions. At a slurry pH of 7 and a dosage of 2.0 x 10-4 mol/L, TPA provided a recovery of 88.5% for rhodochrosite and only 15.0% for calcite. The mechanism of interaction between TPA and minerals was examined by contact angle, Zeta potential tests and Fourier transform infrared (FTIR) analysis, which indicated that TPA selectively adsorbed on the surface of rhodochrosite rather than calcite. Finally, the adsorption behavior of TPA molecules on the surface of rhodochrosite was confirmed by Density functional theory (DFT) calculation to be through electrostatic interaction. This paper provides a novel collector for the flotation separation of rhodochrosite from calcite with excellent collecting ability and selectivity, which is sig-nificant for the efficient utilization of manganese ore resources.