title: Closed circuit recovery of copper, lead and iron from electronic waste with citrate solutions.
abstract: An integral closed circuit hydrometallurgical process is presented for base metal recovery from electronic waste. The leaching medium consists of a sodium citrate solution, from which base metals are retrieved by direct electrowinning, and the barren solution is recycled back to the leaching stage. This leaching-electrowinning cycle was repeated four times. The redox properties of the fresh citrate solution, as well as the leach liquors, were characterized by cyclic voltammetry to determine adequate conditions for metal reduction, as well as to limit citrate degradation. The leaching efficiency of electronic waste, employing the same solution after four complete cycles was 71, 83 and 94% for copper, iron and lead, respectively, compared to the original leach with fresh citrate solution.
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: D002951:Citrates / Q000737:chemistry; D003300:Copper / Q000302:isolation & purification*; D059029:Electronic Waste; D007501:Iron / Q000302:isolation & purification*; D007854:Lead / Q000302:isolation & purification*; D059027:Recycling / Q000379:methods; D012996:Solutions / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D002951:Citrates; D012996:Solutions; D007854:Lead; D003300:Copper; D007501:Iron
keywords: Citrate solutions; Closed-circuit leaching/electrowinning; Copper; Electronic waste; Iron; Lead