Separation of indium from iron in a rotating packed bed contactor using Di-2-ethylhexylphosphoric acid

• IS–RPB as a novel reactor was employed for the separation of indium and iron.
• The separation tests were carried out with In rich solution.
• The separation factor of In(III)/Fe(III) excess of 3000.
• IS–RPB has a good application foreground in solvent extraction.

In order to separate In(III) and Fe(III) from the sulfate leaching solution, solvent extraction with Di-2-ethylhexylphosphoric acid (D2EHPA) was investigated using a Impinging Stream–Rotating Packed Bed (IS–RPB) contactor in laboratory scale. The effects of operating parameters, such as feed solution pH, flow rate ratio, the high gravity factor, the concentration of D2EHPA, initial iron concentration, stripping solution concentration were examined. The experimental results showed that the IS–RPB was effective in the separation of In(III) and Fe(III)under favorable operating conditions. The extraction and stripping efficiency as high as 99% could be achieved, at a separation factor in excess of 3000. Compared with other mixing devices, IS–RPB contactor has better micromixing characteristics, which has a good application prospect.