Stripping of Fe<SUP>3+</SUP> Extracted with Versatic Acid 10

The stripping of Fe3+ extracted in organic phase with Versatic Acid 10 was investigated. Principal results obtained are as follows;H2SO4 was found to be the most reactive stripping agent among H2SO4, HCl and HClO4 when the stripping rates were compared at the same pH level. By introducing SO2 into the stripping reactor, the stripping rates were greatly increased in all acidic solutions. This is due mainly to the reduction of Fe3+ stripped from an organic phase to Fe2+ in an aqueous phase. The lowering of pH in the aqueous phase caused by the dissolution of SO2 may assist the acceleration of stripping process. When the stripping was made by using HCl or HClO4 aqueous solution, the stripped species were almost reduced to 100% Fe2+. On the other hand, the percentage of Fe3+ in a stripped aqueous H2SO4 solution increased with the lowering of initial pH value of stripping solution. The enhanced stripping rate may be attributed to the shift of equilibrium based on the rapid reduction of Fe3+ to Fe2+ in an aqueous phase.