Preparation of functional polytertiary amine macroporous resin and its adsorption and separation properties for tungsten and molybdenum

Abstract

Separation of tungsten (W) and molybdenum (Mo) is a key challenge for the efficient and high-value-added utilization and recycling of W and Mo resources. The clean and recyclable separation technology has been the research focus in this field. To improve the effectiveness of W-Mo adsorption and separation and avoid sulfurization in the ion exchange method, a functional polytertiary amine macroporous resin (TA12-MR) was designed and prepared first time. Optimal synthesis conditions were determined by optimizing preparation time, temperature, and modifier addition, FTIR, XRD, SEM and BET characterizations revealed that TA12-MR exhibited enriched amine groups, dense structure and abundant pores. After optimizing the adsorption conditions, QWMax reached 743.6 mg·g−1, βMoW reached 20.1 at pH = 7.4, T = 25 °C, t = 4 h, n(CTAB)/n(Mo) = 0.5). The adsorption isotherms and kinetics fitting results indicated that the adsorption of W and Mo was a monolayer spontaneous chemically adsorption. The mechanism was found to be a combination of electrostatic adsorption and chemisorption. Firstly, W migrated near N which on TA12-MR, followed by HWO4− replaced Cl− for ion exchange and coordinated with N. The adsorption property remained high with QW = 849 mg·g−1, QMo = 85 mg·g−1, after ten adsorption–desorption cycles. It is an environmentally friendly and high recyclable method without sulfurization and H2S generation. TA12-MR is expected to be a clean, efficient, reusable, and green material, which can be applied to the efficient separation and comprehensive recovery of W and Mo secondary resources, to provide support for solving the problem of W-Mo separation.