A hydrazine amidoxime crosslinked polyacrylonitrile resin for efficient extraction of gallium from vanadium-containing waste solution

The conventional Ga(III) adsorption resins suffer from complex synthesis procedure and low raw material utilization rate. In this study, homogeneous porous amidoxime resins were developed using microfluidic and non-solvent-induced phase separation methods, and subsequent modification by crosslinking and grafting. The adsorption results show that the static adsorption capacity of Ga(III) and V(V) under 0.5 mg/mL, 25 °C at 60 min was 25.97 mg/g and 8.09 mg/g, respectively. Ga(III) adsorption followed the pseudo-second-order model, reaching a saturation adsorption capacity of 38.61 mg/g. The Langmuir model effectively described Ga(III) adsorption, with a maximum capacity of 92.1 mg/g. The mechanism showed Ga(III) adsorption was solely influenced by the oxime group. The separation factor for Ga(III) and V(V) was 120, and desorption efficiencies for Ga(III) and V(V) were 89.79% and 6.81% in the 1 M HCl and 0.2 M thiourea solution at 10 min, respectively. Furthermore, the hydrazine amidoxime crosslinked polyacrylonitrile resins maintains a gallium adsorption capacity of 19.40 mg/g after five times, which are promising for separating Ga(III) and V(V) in waste solutions.