title: Copper leaching from electronic waste for the improvement of gold recycling.
abstract: Gold recovery from electronic waste material with high copper content was investigated at ambient conditions. A chemical preliminary treatment was found necessary to remove the large quantities of copper before the precious metal can be extracted. For this purpose inorganic acids (HCl, HNO3and H2SO4) and two organic substances EDTA and citrate, were tested. The effect of auxiliary oxidants such as air, ozone and peroxide hydroxide was studied. In pretreatments with peroxide and HCl or citrate, copper extractions greater than 90% were achieved. In the second leaching stage for gold recovery, the solid residue of the copper extraction was contacted with thiourea solutions, resulting in greater than 90% gold removal after only one hour of reaction.
authors.affiliation: Universidad Autónoma Metropolitana - Iztapalapa, Depto. Ingeniería de Procesos e Hidráulica, San Rafael Atlixco 186, Col. Vicentina, C.P. 09340 México D.F., Mexico; Universidad Pedagógica y Tecnológica de Colombia, Fac. Ingeniería, Escuela de Metalurgia, Avenida central del norte Km 4, Edif. de Ingeniería 201, Tunja, Colombia. Electronic address: robinson.torres@uptc.edu.co.
authors.forename: Robinson
authors.initials: R
authors.lastname: Torres
authors.affiliation: Universidad Autónoma Metropolitana - Iztapalapa, Depto. Ingeniería de Procesos e Hidráulica, San Rafael Atlixco 186, Col. Vicentina, C.P. 09340 México D.F., Mexico.
authors.forename: Gretchen T
authors.initials: GT
authors.lastname: Lapidus
mesh_terms: D000388:Air; D005591:Chemical Fractionation; D002951:Citrates / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D059029:Electronic Waste; D006046:Gold / Q000302:isolation & purification*; D006851:Hydrochloric Acid / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000032:analysis; D010126:Ozone / Q000737:chemistry; D059027:Recycling / Q000379:methods*; D013890:Thiourea / Q000737:chemistry
chemical_list: D002951:Citrates; D008670:Metals; D010126:Ozone; D006046:Gold; D003300:Copper; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D013890:Thiourea; D006851:Hydrochloric Acid
keywords: Copper; Electronic waste; Gold; Leaching