Extracting Transition Metals from HCl Solutions by Means of Polypropylene Glycol 425

A solution is proposed for processing printed circuit boards that contain a wide range of non-ferrous and precious metals. Ni(II), Zn(II), Al(III), and Fe(III) ions are extracted from acidic mixed solutions in a system based on polypropylene glycol 425 and sodium chloride. A basic technological scheme for processing of used printed circuit boards is developed, based on the composition of printed circuit boards and experimental data on extraction of non-ferrous metals ions from mixed solutions with different contents of sodium chloride in the system. The proposed technological scheme includes stepwise acid leaching of metals; extraction in an environmentally friendly system based on polypropylene glycol 425 and sodium chloride; and the precipitation of metal hydroxides, which allows complex processing of printed circuit boards metal fraction.