Adsorption Capability of Calcined Gibbsite for V, Sr, and Mo from a Complex Solution System

Abstract

In this study, we have modified gibbsite, one of the mineral forms of aluminum hydroxide, by calcination at 400°C (GB400) to be used as an adsorbent. Properties of pristine gibbsite and GB400 have been investigated. Adsorption of V, Sr, and Mo onto GB400 and the effect of contact time and pH in solution on the adsorption process have been investigated using the adsorption isotherms. Desorption process and the selective adsorption and desorption of the metal ions in binary or ternary solution systems have also been monitored. Adsorption isotherms for V, Sr, and Mo were fitted well using the Langmuir equation in comparison to the Freundlich equation. Adsorption equilibrium for V, Sr, and Mo were attained within 12 h, 10 − 20 min, and 10 − 20 min, respectively. These data can be well described with a pseudo-second-order model than a pseudo-first-order model. V, Sr, and Mo adsorbed onto GB400 were easily desorbed (recovered) using hydrochloric acid or sodium hydroxide solutions of different concentrations. GB400 exhibits selective adsorption and desorption capacities in binary and ternary solution systems, which indicate that GB400 could be used for the selective recovery of rare metals from ternary (complex) solution systems.