title: Electrochemical oxidation of cyanide on 3D Ti-RuO2anode using a filter-press electrolyzer.
abstract: The novelty of this communication lies in the use of a Ti-RuO2anode which has not been tested for the oxidation of free cyanide in alkaline media at concentrations similar to those found in wastewater from the Merrill Crowe process (100 mg L-1KCN and pH 11), which is typically used for the recovery of gold and silver. The anode was prepared by the Pechini method and characterized by SEM. Linear sweep voltammetries on a Ti-RuO2rotating disk electrode (RDE) confirmed that cyanide is oxidized at 0.45 < E < 1.0 V vs SHE, while significant oxygen evolution reaction (OER) occurred. Bulk oxidation of free cyanide was investigated on Ti-RuO2meshes fitted into a filter-press electrolyzer. Bulk electrolyzes were performed at constant potentials of 0.85 V and 0.95 V and at different mean linear flow rates ranging between 1.2 and 4.9 cm s-1. The bulk anodic oxidation of cyanide at 0.85 V and 3.7 cm s-1achieved a degradation of 94%, with current efficiencies of 38% and an energy consumption of 24.6 kWh m-3. Moreover, the degradation sequence of cyanide was also examined by HPLC.
authors.affiliation: Universidad de Guanajuato, Departamento de Ingeniería Geomática e Hidráulica, Av. Juárez 77, Zona Centro, 36000, Guanajuato, Guanajuato, Mexico. Electronic address: t.perezsegura@ugto.mx.
authors.forename: Tzayam
authors.initials: T
authors.lastname: Pérez
authors.affiliation: Universidad de Guanajuato, Departamento de Ingeniería Geomática e Hidráulica, Av. Juárez 77, Zona Centro, 36000, Guanajuato, Guanajuato, Mexico.
authors.forename: Rosa L
authors.initials: RL
authors.lastname: López
authors.affiliation: Universidad de Guanajuato, Departamento de Ingeniería Geomática e Hidráulica, Av. Juárez 77, Zona Centro, 36000, Guanajuato, Guanajuato, Mexico. Electronic address: jlnm@ugto.mx.
authors.forename: José L
authors.initials: JL
authors.lastname: Nava
authors.affiliation: Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia-Facultad de Ingeniería, Av. Sierra Leona 550, 78210, San Luis Potosí, San Luis Potosí, Mexico. Electronic address: ilazaro@uaslp.mx.
authors.forename: Isabel
authors.initials: I
authors.lastname: Lázaro
authors.affiliation: Minera San Xavier S.A. de C.V., 78440, Cerro de San Pedro, San Luis Potosí, Mexico. Electronic address: Guillermo.Velasco@newgold.com.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Velasco
authors.affiliation: Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia-Facultad de Ingeniería, Av. Sierra Leona 550, 78210, San Luis Potosí, San Luis Potosí, Mexico. Electronic address: rcruz@uaslp.mx.
authors.forename: Roel
authors.initials: R
authors.lastname: Cruz
authors.affiliation: Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia-Facultad de Ingeniería, Av. Sierra Leona 550, 78210, San Luis Potosí, San Luis Potosí, Mexico. Electronic address: learsi@uaslp.mx.
authors.forename: Israel
authors.initials: I
authors.lastname: Rodríguez
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003486:Cyanides / Q000737:chemistry*; D004566:Electrodes; D004572:Electrolysis; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D062065:Wastewater; D018508:Water Purification / Q000379:methods*
chemical_list: D003486:Cyanides; D006046:Gold; D010100:Oxygen; D012428:Ruthenium; D012834:Silver; D014025:Titanium; D062065:Wastewater
keywords: Cyanide oxidation; Filter-press electrolyzer; Liquid chromatographic analysis; Mining wastewater treatment; Ruthenium dioxide anode