Property and mechanism on sorption of molybdenum from tungstate solution with a porous amine resin

The sustainable development of tungsten and molybdenum resources requires a new clean and recyclable separation technology. This work proposes a recyclable clean separation technology of tungsten and molybdenum with a porous amine resin. The resin was well prepared by assembling amine groups on trioctylamine (TOA) and the porous resin matrix D301 by the dipping method. Here, pH 7.8, temperature 25 °C, and reaction time 240 min was used as optimum condition, resulting in the highest sorption capacity 236 mg g−1, and it has a good cycle performance, exhibiting a retention rate of 90% after five cycles. Experimental spectroscopy combined theoretical calculation confirmed that this sustainable sorption behavior is substantially related to the amine functional groups on the resin. Experimental spectroscopy illustrated that the Cl− ions in the amine resin and the MoS42− ions were subjected to ion exchange. Theoretical investigations further confirm that the sorption site is at the N atoms, the sorption behavior is chemical binding with the binding energy −0.055 Ha, and the bonding method is the s orbit of the N atoms in the amine resin hybridized with the s orbit of the S atoms in the amine resin. Owing to such an excellent performance in the selective sorption of molybdenum from the tungstate solution, the amine resin is greatly promising in the tungsten and molybdenum waste recovery field.