Scandium extraction from sulfuric acid solutions by mixtures of D2EHPA and MTAA sulfate in toluene

Abstract

The extraction of scandium from solutions of the waste of sulfuric-acid leaching from the magnetic separation of titanomagnetites via toluene solutions of equinormal mixtures of D2EHPA and MTAA sulfate has been studied. The conditions for scandium quantitative extraction from solutions containing 2.0–3.0 mol/L of H₂SO₄ and 5–10 mg/L of Sc have been determined with the saturation of the organic phase up to 300–450 mg/L with respect to Sc. It has been shown that the two-stage reextraction of scandium from the saturated organic phase by alkaline-carbonate solutions containing 12 wt % of Na₂CO₃ + 1 wt % of NaOH allows scandium and accompanying impurities of nonferrous and rare metals to be completely converted into a solid that forms a rough scandium concentrate containing 4–8 wt % of Sc, which can be used to prepare high-purity scandium oxide.