“…capacitors, resistor, batteries), comminuting, in some cases a thermal treatment, chemical leaching, solution purification and metals recovery. Reagents like the inorganic acids (sulfuric acid, hydrochloric acid and nitric acid), organic acids (citric acid, oxalic acid) or solution with alkaline character (ammonium and sodium hydroxide) have been used for base metals leaching, afterwards a subsequent leaching on the solid suspension has been applied with chemicals such as cyanide, thiosulfate, thiourea and halides for the precious metals recovery (Birloaga et al, 2013;Jianfeng et al, 2009;Kim et al, 2011;Lee et al, 2011;Oishi et al, 2007;Kamberović et al, 2011;Zhou and Qiu, 2010;Zhu et al, 2011;Fogarasi et al, 2013;Fogarasi et al, 2014;Yang et al, 2011a,b). Many hydrometallurgical attempts were tried to extract copper from the composition of WPCBs, this ''red gold'' being considerate the major metallic element in the composition of these wastes.…”