Enhance selective separation of vanadium and iron from acid-leaching solution with sulfamic acid modified resin

Abstract

To address the problems of low saturated adsorption capacity of the chelate resin and enhance selective separation of vanadium and iron when vanadium shale acid leaching solution was treated by ion exchange resin, DS418 resin, an innovative resin was prepared by surface modification of D418 resin with sulfamic acid. FTIR, XPS and the frontier molecular orbital theory show that the amino and the sulfamic acid are under a sulfonamide reaction, removing a molecule of H2O and connecting S and N. The adsorption rate of V on DS418 resin was 94.17 % when the concentration of modifier was 1.35 mol/L, the modified liquid–solid ratio was 6.5 g/mL and the modification temperature was 41℃. When pH = 1.8, the adsorption rate of V was increased by 12 %, the adsorption rate of Fe was reduced by 34 % compared with the D418 resin, and the saturated adsorption capacity of DS418 resin reached 112.36 mg/g, was twice as much as the D418 resin. After 10 cycles of adsorption–desorption experiments, the adsorption rate of DS418 resin for V was 92.19 %, and the desorption rate was 98.37 %. The adsorption mechanism of V was changed from single anion exchange to synergistic adsorption of anion exchange and electrostatic interaction. DS418 resin had a higher affinity for V than Fe. This research is expected to achieve efficient recovery of V and guide the selection and design of special resin for V extraction.