Extraction and Separation of Iron and Aluminum Ions from Acid Leaching Solution of Fly Ash

The extraction and separation of iron and aluminum ions from acid leaching solution of fly ash were carried out in the composite extraction system with N503 and TBP as extractants, n-octanol as modifier and kerosene as diluent. The effects of concentration of HCl in aqueous phase, concentration of chlorine ion and volume fraction of N503 in organic phase on the extraction were examined. And stripping of iron from the iron-loaded organic phase with low HCl solution was conducted and the optimum conditions were obtained by the countercurrent experiments. The results showed that over 99.8% of iron was extracted, but aluminum almost remained unchanged, from the extraction system of 30%(?) N503, 10%(?) TBP, 10%(?) n-octanol and 50%(?) kerosene under the conditions of initial iron concentration at 0.96 mol/L, aluminum concentration 0.22 mol/L, extractant phase ratio O/A 2:1 and five extraction stages. 0.01 mol/L HCl solution was used as stripping solution, under the stripping conditions of phase ratio O/A at 3:1 and six stripping stages, the iron concentration in the final stripping solution reached 1.8 mol/L. In addition, the FT-IR spectra of both the pure and iron-loaded phases were also presented.