Recovery of indium from liquid crystal displays of discarded mobile phones using solvent extraction

Abstract One of the greatest challenges in the development of hydrometallurgical processes for the recovery of indium from secondary sources is the fact that the leaching step generally results in very dilute solutions. Therefore, this diluted indium solution must be concentrated before being sent to a subsequent step such as recovery of the metal by electrowinning. The aim of the present work was to apply solvent extraction using bis(2-ethylhexyl) phosphate (D2EHPA) in order to maximize the indium concentration in the solution. Firstly, the extraction and stripping steps were investigated using a synthetic solution. After definition of the best conditions using a synthetic solution, a real solution obtained from the leaching of discarded LCDs was employed.