Easier extraction of rare earth elements (REEs) by Janus particle

Deep treatment of wastewater containing low concentration rare earth elements (REEs) is significant for environmental remedy and full utilization of resources. Effective extraction of such system at a high phase ratio remains challenging. A new strategy is proposed to perform the highly efficient extraction by using the paramagnetic Janus particle (PJP) as the functional solid surfactant. A larger interface area is provided by forming the emulsion in the presence of PJP, facilitating a faster mass transfer. The ion contained extractant emulsion droplets stabilized with the PJP can be easily collected from the aqueous phase with a magnet. Taking neodymium (Nd3+) contained aqueous solution (100 ppm) as the model of low concentration wastewater, a high extraction efficiency over 99% can be achieved within a short time. The PJP can be easily isolated from the extractant by using a stronger magnet, which can preserve the same capability as the original one.