A novel adsorbent was prepared by NH4HCO3-modifying nanoalumina dioxide and was employed for the separation/preconcentration of ReVII ions from aqueous solution. It was found that ReVII ions could be adsorbed quantitatively (above 94%) on modified nano-Al2O3 in the pH range of 2.0–3.0, while only 8.3% of ReVII ions were adsorbed on unmodified nano-Al2O3. Effects of the pH, concentration of elution solution, and interfering ions on the recovery of ReVII were systematically investigated. Adsorption kinetics for ReVII was found to be very fast, and equilibrium was reached within 5 min following the pseudo-second-order model with observed rate constants (k 2) of 14.44 g·mg–1·min–1 at 298 K. The overall rate process appeared to be influenced by both external mass transfer and intraparticle diffusion. The sorption data could be well interpreted by the Langmuir model with a maximum adsorption capacity of 1.94 mg·g–1 of ReVII on modified nano-Al2O3. Moreover, the thermodynamic parameters showed the spontaneous and endothermic nature of the adsorption process. Finally, modified nano-Al2O3 as the sorbent was successfully applied to the separation of ReVII from the ore samples with satisfactory results.