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In this work, the effect of the pre-treatment of bornite concentrate with a sodium chloride–sulfuric acid mixture prior to leaching with chloride solutions was evaluated. The influence of the dosage of NaCl and the resting time in the copper solution was evaluated. The solid residues of the pre-treatment were characterized by XRD to evaluate the changes that took place in the bornite. The experimental results show that as the sitting time and the amount of sodium chloride added are increased, the dissolution of the sulfide species also increased. The pre-treatment affects Cu preferentially because it has greater mobility than iron in the bornite crystal lattice. The pre-treatment promotes the formation of soluble Cu and Fe species. The efficiency of the pre-treatment depends largely on the formation of hydrochloric acid in the mixture at the particle level, due to the ease with which it diffuses through the bornite particles, achieving greater penetration of the pre-treatment.
Patricio Navarro; Cristian Vargas; Fabiana Bahamonde; Matías Gómez; Daniel Espinoza; Rossana Sepúlveda; Jonathan Castillo. Effect of Pre-Treatment with Sodium Chloride/Sulfuric Acid on the Bornite Concentrate Leaching in Chloride Medium. Metals 2020, 10, 1674 .
AMA StylePatricio Navarro, Cristian Vargas, Fabiana Bahamonde, Matías Gómez, Daniel Espinoza, Rossana Sepúlveda, Jonathan Castillo. Effect of Pre-Treatment with Sodium Chloride/Sulfuric Acid on the Bornite Concentrate Leaching in Chloride Medium. Metals. 2020; 10 (12):1674.
Chicago/Turabian StylePatricio Navarro; Cristian Vargas; Fabiana Bahamonde; Matías Gómez; Daniel Espinoza; Rossana Sepúlveda; Jonathan Castillo. 2020. "Effect of Pre-Treatment with Sodium Chloride/Sulfuric Acid on the Bornite Concentrate Leaching in Chloride Medium." Metals 10, no. 12: 1674.
In this study, weak acid in the curing and leaching stages of copper ore was incorporated, and we analyzed its effect on the dissolution of copper and final impurities. The weak acid corresponds to a wastewater effluent from sulfuric acid plants produced in the gas treatment of copper smelting processes. This effluent is basically water with high acidity (pH-value low at 1), which contains several toxic elements and some valuable metals. The results indicated that there is no positive or negative effect on the incorporation of the weak acid in the curing stage, while the case of the leaching stage is favored. Toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) toxicity tests were performed on the solid leaching residues, determining that they accomplish the stability ranges of the impurities (Pb, Cd, Hg, Cr, Ba, Se, As, and Ag).
Giselle Araya; Norman Toro; Jonathan Castillo; Danny Guzmán; Alexis Guzmán; Pía Hernández; Ricardo I. Jeldres; Rossana Sepúlveda. Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters. Metals 2020, 10, 627 .
AMA StyleGiselle Araya, Norman Toro, Jonathan Castillo, Danny Guzmán, Alexis Guzmán, Pía Hernández, Ricardo I. Jeldres, Rossana Sepúlveda. Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters. Metals. 2020; 10 (5):627.
Chicago/Turabian StyleGiselle Araya; Norman Toro; Jonathan Castillo; Danny Guzmán; Alexis Guzmán; Pía Hernández; Ricardo I. Jeldres; Rossana Sepúlveda. 2020. "Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters." Metals 10, no. 5: 627.
The entrainment of the organic phase in the aqueous applied to typical solutions in a solvent extraction of copper process was studied. The organic phase used is composed of the commercial extractant LIX 984-N diluted in Shellsol 2046 AR. The aqueous phase contains 6 g/L of Cu2+, at pH 2 and 20 ºC. The variables studied were: mixing speed of 400 to 1000 rpm; mixing time of 3 to 30 minutes; initial pH of the electrolyte 2, 3, and 4; percentage of extractant in the organic phase 10 to 30% v/v; and copper concentration in the aqueous phase 1 to 6 g/L. It was determined that the entrainment of the organic phase in the aqueous is determined by the physical properties of the phases in equilibrium and by the system’s hydrodynamics, and it is a phenomenon that involves the advancing speed of the interphase (or dispersion band) and the displacement speed of the organic drops.
Patricio Navarro Donoso; Cristian Vargas Riquelme; Jonathan Castillo; Rossana Sepúlveda. Experimental study of phase entrainment in copper solvent extraction. DYNA 2020, 87, 85 -90.
AMA StylePatricio Navarro Donoso, Cristian Vargas Riquelme, Jonathan Castillo, Rossana Sepúlveda. Experimental study of phase entrainment in copper solvent extraction. DYNA. 2020; 87 (213):85-90.
Chicago/Turabian StylePatricio Navarro Donoso; Cristian Vargas Riquelme; Jonathan Castillo; Rossana Sepúlveda. 2020. "Experimental study of phase entrainment in copper solvent extraction." DYNA 87, no. 213: 85-90.
The unique properties of ionic liquids (ILs) drive the growing number of novel applications in different industries. The main features of ILs are high thermal stability, recyclability, low flash point, and low vapor pressure. This study investigated pure chalcopyrite dissolution in the presence of the ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate, [BMIm]HSO4, and a bromide-like complexing agent. The proposed system was compared with acid leaching in sulfate media with the addition of chloride and bromide ions. The results demonstrated that the use of ionic liquid and bromide ions improved the chalcopyrite leaching performance. The best operational conditions were at a temperature of 90 °C, with an ionic liquid concentration of 20% and 100 g/L of bromide.
Marcelo Rodríguez; Luís Ayala; Pedro Robles; Rossana Sepúlveda; David Torres; Francisco Raul Carrillo-Pedroza; Ricardo I. Jeldres; Norman Toro. Leaching Chalcopyrite with an Imidazolium-Based Ionic Liquid and Bromide. Metals 2020, 10, 183 .
AMA StyleMarcelo Rodríguez, Luís Ayala, Pedro Robles, Rossana Sepúlveda, David Torres, Francisco Raul Carrillo-Pedroza, Ricardo I. Jeldres, Norman Toro. Leaching Chalcopyrite with an Imidazolium-Based Ionic Liquid and Bromide. Metals. 2020; 10 (2):183.
Chicago/Turabian StyleMarcelo Rodríguez; Luís Ayala; Pedro Robles; Rossana Sepúlveda; David Torres; Francisco Raul Carrillo-Pedroza; Ricardo I. Jeldres; Norman Toro. 2020. "Leaching Chalcopyrite with an Imidazolium-Based Ionic Liquid and Bromide." Metals 10, no. 2: 183.
Chalcocite is the most important and abundant secondary copper ore in the world with a rapid dissolution of copper in an acid-chloride environment. In this investigation, the methodology of surface optimization will be applied to evaluate the effect of three independent variables (time, concentration of sulfuric acid and chloride concentration) in the leaching of pure chalcocite to extract the copper with the objective of obtaining a quadratic model that allows us to predict the extraction of copper. The kinetics of copper dissolution in regard to the function of temperature is also analyzed. An ANOVA indicates that the linear variables with the greatest influence are time and the chloride concentration. Also, the concentration of chloride-time exerts a significant synergic effect in the quadratic model. The ANOVA indicates that the quadratic model is representative and the R2 value of 0.92 is valid. The highest copper extraction (67.75%) was obtained at 48 h leaching under conditions of 2 mol/L H2SO4 and 100 g/L chloride. The XRD analysis shows the formation of a stable and non-polluting residue; such as elemental sulfur (S0). This residue was obtained in a leaching time of 4 h at room temperature under conditions of 0.5 mol/L H2SO4 and 50 g/L Cl−.
Norman Toro; Williams Briceño; Kevin Pérez; Manuel Cánovas; Emilio Trigueros; Rossana Sepúlveda; Pía Hernández. Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water. Metals 2019, 9, 780 .
AMA StyleNorman Toro, Williams Briceño, Kevin Pérez, Manuel Cánovas, Emilio Trigueros, Rossana Sepúlveda, Pía Hernández. Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water. Metals. 2019; 9 (7):780.
Chicago/Turabian StyleNorman Toro; Williams Briceño; Kevin Pérez; Manuel Cánovas; Emilio Trigueros; Rossana Sepúlveda; Pía Hernández. 2019. "Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water." Metals 9, no. 7: 780.
The effect of NaCl on the leaching of white metal from a Teniente Converter was investigated in NaCl-H2SO4 media under environmental conditions. The copper dissolution from white metal was studied using ferric ions in the range of 1–10 g/L, NaCl in the range of 30–210 g/L, and sulfuric acid in the range of 10–50 g/L. The test without NaCl produced a dissolution of 55%; through the addition of NaCl, the dissolution increased to nearly 90%. The effect of sulfuric acid on the copper dissolution was not significant in the studied range, as the excess sulfuric acid simply increased the iron precipitation. The positive effect of NaCl seems to be related to the action of chloro-complex oxidizing agents in relation to the Cu+2/Cu+ couple. A simplified two-stage mechanism is proposed for the leaching of white metal. In the first stage, the white metal produces covellite and Cu2+, and in the second stage it produces elemental sulfur and Cu2+. The first stage is very rapidly compared to the second stage.
Jonathan Castillo; Rossana Sepúlveda; Giselle Araya; Danny Guzmán; Norman Toro; Kevin Pérez; Marcelo Rodríguez; Alessandro Navarra. Leaching of White Metal in a NaCl-H2SO4 System under Environmental Conditions. Minerals 2019, 9, 319 .
AMA StyleJonathan Castillo, Rossana Sepúlveda, Giselle Araya, Danny Guzmán, Norman Toro, Kevin Pérez, Marcelo Rodríguez, Alessandro Navarra. Leaching of White Metal in a NaCl-H2SO4 System under Environmental Conditions. Minerals. 2019; 9 (5):319.
Chicago/Turabian StyleJonathan Castillo; Rossana Sepúlveda; Giselle Araya; Danny Guzmán; Norman Toro; Kevin Pérez; Marcelo Rodríguez; Alessandro Navarra. 2019. "Leaching of White Metal in a NaCl-H2SO4 System under Environmental Conditions." Minerals 9, no. 5: 319.
In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.
Norman Toro; Nelson Herrera; Jonathan Castillo; Cynthia M. Torres; Rossana Sepúlveda. Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I. Minerals 2018, 8, 565 .
AMA StyleNorman Toro, Nelson Herrera, Jonathan Castillo, Cynthia M. Torres, Rossana Sepúlveda. Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I. Minerals. 2018; 8 (12):565.
Chicago/Turabian StyleNorman Toro; Nelson Herrera; Jonathan Castillo; Cynthia M. Torres; Rossana Sepúlveda. 2018. "Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I." Minerals 8, no. 12: 565.
The aim of this work was to study the synthesis and electrochemical properties of Ti 2 wt %-Si alloys prepared by mechanical alloying (MA) and heat treatment. The MA process was performed under Ar atmosphere. The structural, morphological, and compositional evolutions during the milling and subsequent heat treatment were investigated by X-ray diffraction, energy-dispersive spectroscopy, and scanning electron microscopy. The electrochemical behavior was evaluated by open circuit potential and linear sweep voltammetry measurements. The results showed that the MA process promotes the formation of a supersaturated α-Ti-Si solid solution. During heat treatment, the Si remaining in the mechanically alloyed powders and the Si from the α-Ti-Si supersaturated solid solution reacted with Ti to form Ti-Si intermetallic compounds. These compounds have a fine and homogeneous distribution in the α-Ti matrix, which cannot be achieved by conventional casting methods. Additionally, the electrochemical evaluations revealed that the mechanically alloyed and heat-treated Ti 2 wt %-Si powders have better corrosion resistance in 1.63 M H2SO4 than the pure Ti and MA Ti-Si samples. This is likely due to the particular microstructure produced during the milling and subsequent heat treatment.
Danny Guzmán; Carolina García; Álvaro Soliz; Rossana Sepúlveda; Claudio Aguilar; Paula Rojas; Iñigo Iturriza; Carmen Luno-Bilbao. Synthesis and Electrochemical Properties of Ti-Si Alloys Prepared by Mechanical Alloying and Heat Treatment. Metals 2018, 8, 417 .
AMA StyleDanny Guzmán, Carolina García, Álvaro Soliz, Rossana Sepúlveda, Claudio Aguilar, Paula Rojas, Iñigo Iturriza, Carmen Luno-Bilbao. Synthesis and Electrochemical Properties of Ti-Si Alloys Prepared by Mechanical Alloying and Heat Treatment. Metals. 2018; 8 (6):417.
Chicago/Turabian StyleDanny Guzmán; Carolina García; Álvaro Soliz; Rossana Sepúlveda; Claudio Aguilar; Paula Rojas; Iñigo Iturriza; Carmen Luno-Bilbao. 2018. "Synthesis and Electrochemical Properties of Ti-Si Alloys Prepared by Mechanical Alloying and Heat Treatment." Metals 8, no. 6: 417.
Rossana Sepúlveda; Jonathan Castillo; Andrea Plaza; José Sánchez; Alejandra Torres; Julio Romero. Improvement of recovery performance in the solvent extraction of Cu(II) using [bmim][Tf 2 N] and a β-diketone as extractant and its stripping with supercritical carbon dioxide. The Journal of Supercritical Fluids 2017, 128, 26 -31.
AMA StyleRossana Sepúlveda, Jonathan Castillo, Andrea Plaza, José Sánchez, Alejandra Torres, Julio Romero. Improvement of recovery performance in the solvent extraction of Cu(II) using [bmim][Tf 2 N] and a β-diketone as extractant and its stripping with supercritical carbon dioxide. The Journal of Supercritical Fluids. 2017; 128 ():26-31.
Chicago/Turabian StyleRossana Sepúlveda; Jonathan Castillo; Andrea Plaza; José Sánchez; Alejandra Torres; Julio Romero. 2017. "Improvement of recovery performance in the solvent extraction of Cu(II) using [bmim][Tf 2 N] and a β-diketone as extractant and its stripping with supercritical carbon dioxide." The Journal of Supercritical Fluids 128, no. : 26-31.
Rossana Sepúlveda; Julio Romero; Jose Sanchez-Marcano. Copper removal from aqueous solutions by means of ionic liquids containing a β-diketone and the recovery of metal complexes by supercritical fluid extraction. Journal of Chemical Technology & Biotechnology 2014, 89, 899 -908.
AMA StyleRossana Sepúlveda, Julio Romero, Jose Sanchez-Marcano. Copper removal from aqueous solutions by means of ionic liquids containing a β-diketone and the recovery of metal complexes by supercritical fluid extraction. Journal of Chemical Technology & Biotechnology. 2014; 89 (6):899-908.
Chicago/Turabian StyleRossana Sepúlveda; Julio Romero; Jose Sanchez-Marcano. 2014. "Copper removal from aqueous solutions by means of ionic liquids containing a β-diketone and the recovery of metal complexes by supercritical fluid extraction." Journal of Chemical Technology & Biotechnology 89, no. 6: 899-908.
Jonathan Castillo; María Teresa Coll; Agustín Fortuny; Patricio Navarro Donoso; Rossana Sepúlveda; Ana María Sastre. Cu(II) extraction using quaternary ammonium and quaternary phosphonium based ionic liquid. Hydrometallurgy 2014, 141, 89 -96.
AMA StyleJonathan Castillo, María Teresa Coll, Agustín Fortuny, Patricio Navarro Donoso, Rossana Sepúlveda, Ana María Sastre. Cu(II) extraction using quaternary ammonium and quaternary phosphonium based ionic liquid. Hydrometallurgy. 2014; 141 ():89-96.
Chicago/Turabian StyleJonathan Castillo; María Teresa Coll; Agustín Fortuny; Patricio Navarro Donoso; Rossana Sepúlveda; Ana María Sastre. 2014. "Cu(II) extraction using quaternary ammonium and quaternary phosphonium based ionic liquid." Hydrometallurgy 141, no. : 89-96.
The aim of this work is the experimental and theoretical characterization of the mass transfer in a membrane-based dense gas extraction of metal ions from aqueous solutions using a hollow fiber contactor. Extractions of Cu(II) were conducted in a single fiber membrane contactor operating under steady state conditions. Aqueous CuSO4 solutions were treated using a CO2 phase containing 1,1,1-trifluoro-2,4-pentanedione (TFA) or 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HFA) at 40 °C and pressures ranged between 70 and 90 bar. Experiments show that the use of dense CO2 as extraction solvent of Cu(II) ions reaches extraction efficiencies valued up to 98.7%. Simultaneously, a mass transfer model was proposed correlating an effective rate function of the complex formation at the aqueous-CO2 interface. The highest extraction efficiencies were observed at higher pressures and lower pH values, which could confirm that a high content of protons is required to facilitate and stabilize the formation complex by means of keto-enol tautomerism. This work represents the first step in order to propose a novel intensified operation, which could be applied for high valued metals or hazardous materials.
Hugo Valdes; Rossana Sepúlveda; Julio Romero; Fernando Valenzuela; Jose Sanchez-Marcano. Near critical and supercritical fluid extraction of Cu(II) from aqueous solutions using a hollow fiber contactor. Chemical Engineering and Processing - Process Intensification 2013, 65, 58 -67.
AMA StyleHugo Valdes, Rossana Sepúlveda, Julio Romero, Fernando Valenzuela, Jose Sanchez-Marcano. Near critical and supercritical fluid extraction of Cu(II) from aqueous solutions using a hollow fiber contactor. Chemical Engineering and Processing - Process Intensification. 2013; 65 ():58-67.
Chicago/Turabian StyleHugo Valdes; Rossana Sepúlveda; Julio Romero; Fernando Valenzuela; Jose Sanchez-Marcano. 2013. "Near critical and supercritical fluid extraction of Cu(II) from aqueous solutions using a hollow fiber contactor." Chemical Engineering and Processing - Process Intensification 65, no. : 58-67.