Recuperação de metais em placas de circuito impresso

Abstract

The growth and technological upgrades, which occur uncontrollably each day, lead to an increase in the production and consumption of new electro/electronic devices, as a consequence, the growth of waste produced by the disposal of such equipment (e-waste). Disposal of this waste may pose a great risk to the environment because it contains toxic chemicals. The development of techniques with the objective of recovering the metals present in the electronic waste is of extreme importance, aiming at the economic power generated and also the reduction in environmental impacts. The highest concentration of the metals present in the electronic equipment are found in the printed circuit board, with this, the accomplishment of this work has as objective the separation, identification and recovery of the metals present in printed circuit boards of obsolete computers, where starting from alkaline leaching (NaOH 2 mol/L) and acid (HCl 12 mol/L and HNO3 14 mol/L) the metals were oxidized, separated into three different solutions (hydroxides, chlorides and metal nitrates) and characterized by inductive plasma coupled emission spectrometry (ICPAES). From the three solutions, different methods were applied to recover the metals: dehydration of the solution of metal hydroxides (aluminum oxide): electrowinning solution of metallic chlorides (copper, tin and lead); and the reaction of the solution of metallic nitrates with NH4OH (nitrate of tetramincupre (II)). The solid materials obtained are analyzed by X-ray fluorescence, with yields of up to 94.74% copper, 70.21% tin and 37.55% recovered lead.