Separation of indium and iron by solvent extraction

Indium is associated in trace amounts in several kinds of zinc and aluminum ores, and has therefore been recovery as a byproduct in these industries. Together with this metal iron is found in high concentration. esent work investigates the separation of indium and iron by solvent extraction using a Replicate Two-Factor Factorial Design. The experimental work was carried out using synthetic solutions of iron and indium from sulfuric media. The chosen concentrations of these elements were based on the expected liquor composition to be industrially processed. The organic solution was prepared with the extractant di(2-ethylhexyl) phosphoric acid (D2EHPA) diluted in isoparafin. The main parameters studied were: extractant concentration, acidity of the aqueous phase and contact time. The tests were made in separatory funnels at a temperature of about 25°C using 1:1 phase ratio (O/A). sults showed that D2EHPA can be effectively used to separate indium and iron from acid solutions. It was possible to obtain an aqueous extract with a high concentration of indium with practically no iron, the indium recovery reaching nearly 90% with only about 3% iron impurity.