Recovery and separation of Mo(VI) and Re(VII) from Mo-Re bearing solution by gallic acid-modified cellulose microspheres

Abstract It is significant to develop an effective adsorbent for the separation of Mo(VI) and Re(VII) owing to congenital isomorphism. Herein, gallic acid-functionalized microcrystalline cellulose microspheres (MCGA) were synthesized via radiation technology. Batch and column experiments were systematically performed to evaluate the separation behaviors for Mo(VI) and Re(VII). It was discovered that MCGA showed higher adsorption capacity and stronger affinity for Mo(VI) than Re(VII) under the tested condition. The separation of Mo(VI) and Re(VII) could be easily achieved by MCGA, exhibiting a separation factor (βMo/Re) in the range of 5.23 - 735.53. Significantly, the dynamic column experiment revealed that the MCGA could selectively recover Mo(VI) from a simulated leaching solution of molybdenite. In addition, different eluents can achieve the stepwise elution of Mo(VI) and Re(VII). With increasing temperature, Mo(VI) and Re(VII) could be more easily separation from the solution. Ultimately, the capture of Mo(VI) by MCGA was attributed to the formation of hydrogen bond and complexes between the adjacent phenolic hydroxyl group and metal ions, while Re(VII) was mainly associated with MCGA by hydrogen bond. Moreover, the excellent adsorption properties indicated that MCGA is a candidate for separation of Mo(VI) and Re(VII) from Mo-Re bearing solution.