Recovery of vanadium with melamine in acidic medium.

Many hydro-metallurgical methods are developed to recover vanadium, while ammonium salt precipitation possesses the final step and it has threatened the environment. The key point is to find a new compound to replace ammonium salts without reducing vanadium recovery efficiency. Some compounds with -NH function groups have attracted our attention as they have similar function groups with ammonium salts. In this paper, the adsorption of vanadium with melamine is conducted. The results show that high adsorption efficiency can be achieved in a short time and melamine displays great performance in the recovery of all concentrations of vanadium. Response surface methodology (RSM) is used to optimize the reaction conditions and order the parameters: reaction temperature > concentration of vanadium > dosage of melamine > reaction time. 99.63% vanadium is adsorbed under optimized conditions: n(melamine)/n(V) = 0.6, reaction time of 60 min, 10 g/L vanadium solution and reaction temperature of 60°C. The successful application of melamine in the recovery of vanadium provides a new way for the utilization of melamine and also a glorious future for -NH compounds in the recovery heavy metals.