Controllable recovery of ammonium substituted polyoxovanadate acid compound (ASPOVC) from aqueous/leaching solution by primary amines

The recovery of polyoxovanadate acid compounds has got increasing attention because of both sustainable necessities and material applications. In this paper, we proposed a recovery strategy of ammonium substituted polyoxovanadate acid compounds (ASPOVC) by solvent extraction from leaching/aqueous solution. It is noted that the state of the compound (solid or liquid) is possibly controllable by the type of amines (branched or linear amine chains), enlarging application fields of these compounds. Subsequently, the compounds were characterized by comprehensive techniques, from which the molecular structures with hydrogen bonds were described. The solubility parameters were calculated, and solid ASPOVC was the biggest among the four compounds, explaining formation reasons of different states. The amine extractants performed well-efficiency (more than 98.5%) for reutilization. This approach is believed to be promised for a sustainable recovery for high-value vanadium materials from waste water. (C) 2018 Elsevier Ltd. All rights reserved.