title: Determination of the potential gold electrowinning from an ammoniacal thiosulphate solution applied to recycling of printed circuit board scraps.
abstract: The use of electrochemical techniques in the selective recovery of gold from a solution containing thiosulphate, ammonia, and copper, obtained from the leaching of printed circuit boards from mobile phones using ammoniacal thiosulphate, are shown in this work. First, cyclic voltammetry tests were performed to determine the potential of electrodeposition of gold and copper, and then, electrowinning tests at different potentials for checking the rates of recovery of these metals were performed. The results of the cyclic voltammetry show that copper deposition occurs at potentials more negative than -600 mV (Ag/AgCl), whereas the gold deposition can be performed at potentials more positives than -600 mV (Ag/AgCl). The results of electrowinning show that 99% of the gold present in solutions containing thiosulphate and copper can be selectively recovered in a potential range between -400 mV (vs Ag/AgCl) and -500 mV (vs Ag/AgCl). Furthermore, 99% of copper can be recovered in potentials more negative than -700 mV (vs Ag/AgCl).
authors.affiliation: LACOR-PPGE3M, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil angelakasper@globo.com.
authors.forename: Angela C
authors.initials: AC
authors.lastname: Kasper
authors.affiliation: Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Carrillo Abad
authors.affiliation: Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: García Gabaldón
authors.affiliation: LACOR-PPGE3M, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil.
authors.forename: Hugo M
authors.initials: HM
authors.lastname: Veit
authors.affiliation: Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Valentín
authors.initials: V
authors.lastname: Pérez Herranz
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D040421:Cell Phone; D003300:Copper / Q000032:analysis*; D059029:Electronic Waste / Q000032:analysis*; D006046:Gold / Q000032:analysis*; D010084:Oxidation-Reduction; D059027:Recycling / Q000379:methods*; D013885:Thiosulfates / Q000737:chemistry*
chemical_list: D013885:Thiosulfates; D006046:Gold; D000641:Ammonia; D003300:Copper
keywords: Printed circuit boards; cyclic voltammetry; electrolysis studies; gold; gold electrowinning; thiosulphate