Victor Roberto Parra Sanchez

@udec.cl

Departamento de Ingeniería Metalúrgica/Metallurgical Engineering Department
Universidad de Concepción

Victor Roberto Parra Sanchez


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https://researchid.co/vparras84

RESEARCH, TEACHING, or OTHER INTERESTS

Chemical Engineering, Metals and Alloys, Geology
11

Scopus Publications

Scopus Publications

  • Distribution of Copper, Iron, and Sulfur in Copper Concentrate Particles during Oxidation under Simulated Flash Smelting Conditions
    Manuel Pérez-Tello, Valeria de la Paz-Ojeda, Víctor R. Parra-Sánchez, Eugenia A. Araneda-Hernández, Madrioly C. Fernández-Sagredo, Eduardo A. Villagrán-Guerra
    Minerals, 2024
    The distribution of copper, iron, and sulfur during the oxidation of La Caridad copper concentrate particles under simulated flash smelting conditions was studied in a laboratory reactor. Six wet-sieved size fractions and the unsieved copper concentrate were oxidized at 1123 K and 40% and 70% O2 by volume in the process gas during the experiments. Samples of partially oxidized particles were collected at 0.2, 0.8, and 0.9 m from the point of entry and analyzed in a QEMSCAN® unit to determine the elemental composition within the population of particles. The distribution of the major elements during oxidation was strongly dependent upon the size and chemical composition of the initial particles. Overall, the copper content tended to increase and sulfur content decreased along the reactor length within all sizes. In contrast, the distribution of iron did not follow a general trend, as it was found to increase, decrease, or remain unchanged depending on the particle size. This finding may represent a key feature to further investigate the reaction path followed by particles during flash smelting, especially those associated with particle fragmentation. In general, the larger the particle size was, the larger the change in the content of the major elements within the particle population. Based on the experimental results, particles within a size fraction of <45 µm tended to follow a reaction path consisting of rapid melting followed by the collision and coalescence of reacting droplets during flight. In contrast, particles within the fraction of 45–53 µm tended to react individually. The oxidation behavior of the unsieved concentrate particles showed a combination of both reaction paths.
  • Effect of Glue, Thiourea, and Chloride on the Electrochemical Reduction in CuSO4–H2SO4 Solutions
    Érika D. Nevárez-Llamas, Eugenia A. Araneda-Hernández, Víctor R. Parra-Sánchez, Eduardo A. Villagrán-Guerra
    Metals, 2023
    The effect of glue, thiourea, and chloride on the kinetics of copper reduction in CuSO4–H2SO4 solutions of copper composition, and temperatures like those used in the copper electrorefining plants, were studied. The kinetic study was conducted by determining the kinetic parameters i0 and β under the activation control of the Tafel approximation, which is applied to polarization curves obtained via linear voltammetry. The results show that the incorporation of glue and thiourea decreases the exchange current density, while chloride does not significantly affect the kinetic parameters. The data on the fraction of the surface covered by glue and thiourea fitted to the Temkin adsorption isotherm indicate that the mechanism of action during the reduction of copper to low overpotentials is the adsorption of these additives on the electrode surface. The adsorption of additives reduces the cathodic area available for Cu2+ adsorption and lateral diffusion of Cu atoms to continue the reduction process and the growth of the crystalline deposit. The kinetic study was complemented with a comprehensive analysis of the effect of the additives on the morphological and textural characteristics of the deposits. The results of this work contribute to the understanding of the mechanisms of the main additives used during the copper electrorefining process.
  • Experimental Determination of the Conversion Rate of Molten White Metal by Supplying Individual Air Bubbles
    Maximiliano F. Roa-Jofré, Víctor R. Parra-Sánchez, Gonzalo A. Reyes-Alcántara, Eugenia A. Araneda-Hernández, Eduardo R. Balladares-Varela, Roberto A. Parra-Figueroa, Camila V. Mora-Vilches
    Metals, 2022
    The conversion of copper sulfide mattes lacks fundamental kinetic information for understanding the process. This work presents the results of the experimental measurement of the rate of oxidation of molten white metal by supplying individual air bubbles. The bubbles were characterized from information collected during the experiments and through theoretical and empirical correlations. Conversion tests were carried out at different temperature conditions and injection dynamics of the oxidizing gas. The results indicate that the conversion is controlled by the transport of oxygen into the bubble. A dependency between the characteristics of the injector and the shape, size and surface of the bubbles was identified. The oxidation rate of the white metal depended on the characteristics of the bubbles and the oxygen available for conversion. The results of this research provide relevant information to improve the operation of industrial conversion furnaces by controlling gas injection through the tuyeres. The criterion for improving conversion systems is the balance between the retention of the bubbles in the molten white metal and their size, such that the availability of oxygen for the conversion is guaranteed.
  • A radiometric technique for monitoring the desulfurization process of blister copper
    Alejandro Vásquez, Francisco Pérez, Maximiliano Roa, Ignacio Sanhueza, Hugo Rojas, Victor Parra, Eduardo Balladares, Roberto Parra, Sergio Torres
    Sensors Switzerland, 2021
    In this paper, a novel optical technique for following the progress of the blister copper desulfurization process is presented. The technique is based on the changes observed in the continuous spectrum of the visible–near-infrared (VIS–NIR) radiation that the blister melt emits while the chemical reactions of the sulfur elimination process are taking place. Specifically, the proposed technique uses an optical probe composed of an optical fiber, a collimating lens, and a quartz tube, which is immersed in the melt. This optical probe provides a field of view of the blowing zone where the desulfurization reaction occurs. The experimental results show that the melt VIS–NIR total irradiance evolves inversely to the SO2 concentration reported by a gas analyzer based on differential optical absorption spectroscopy. Furthermore, the blister copper spectral emissivity as well as the total emissivity observed throughout the process show strong correlation with the sulfur content during desulfurization reaction.
  • Erratum: On the detection of spectral emissions of iron oxides in combustion experiments of pyrite concentrates (Sensors, (2020) 20, 1284, 10.3390/s20051284)
    Carlos Toro, Sergio Torres, Víctor Parra, Rodrigo Fuentes, Rosario Castillo, Walter Díaz, Gonzalo Reyes, Eduardo Balladares, Roberto Parra
    Sensors Switzerland, 2020
    The authors wish to make the following corrections to this paper [...]
  • On the detection of spectral emissions of iron oxides in combustion experiments of pyrite concentrates
    Carlos Toro, Sergio Torres, Víctor Parra, Rodrigo Fuentes, Rosario Castillo, Walter Díaz, Gonzalo Reyes, Eduardo Balladares, Roberto Parra
    Sensors Switzerland, 2020
    In this paper, we report on the spectral detection of wustite, Fe(II) oxide (FeO), and magnetite, Fe(II, III) oxide (Fe3O4), molecular emissions during the combustion of pyrite (FeS2), in a laboratory-scale furnace operating at high temperatures. These species are typically generated by reactions occurring during the combustion (oxidation) of this iron sulfide mineral. Two detection schemes are addressed: the first consisting of measurements with a built-in developed spectrometer with a high sensitivity and a high spectral resolution. The second one consisting of spectra measured with a low spectral resolution and a low sensitivity commercial spectrometer, but enhanced and analyzed with post signal processing and multivariate data analysis such as principal component analysis (PCA) and a multivariate curve resolution—the alternating least squares method (MCR-ALS). A non-linear model is also proposed to reconstruct spectral signals measured during pyrite combustion. Different combustion conditions were studied to evaluate the capacity of the detection schemes to follow the spectral emissions of iron oxides. The results show a direct correlation between FeO and Fe3O4 spectral features intensity, and non-linear relations with key combustion variables such as flame temperature, and the combusted sulfide mineral particle size.
  • Spectral characterization of copper and iron sulfide combustion: A multivariate data analysis approach for mineral identification on the blend
    Walter Díaz, Carlos Toro, Eduardo Balladares, Victor Parra, Pablo Coelho, Gonzalo Reyes, Roberto Parra
    Metals, 2019
    The pyrometallurgical processes for primary copper production have only off-line and time-demanding analytical techniques to characterize the in and out streams of the smelting and converting steps. Since these processes are highly exothermic, relevant process information could potentially be obtained from the visible and near-infrared radiation emitted to the environment. In this work, we apply spectral sensing and multivariate data analysis methodologies to identify and classify copper and iron sulfide minerals present in the blend from spectra measured during their combustion in a laboratory drop-tube setup, in which chemical reactions that take place in flash smelting furnaces can be reproduced. Controlled combustion experiments were conducted with two industrial concentrates and with high-grade mineral species as well, with a focus on pyrite and chalcopyrite. Exploratory analysis by means of Principal Component Analysis (PCA) applied on the spectral data depicted high correlation features among species with similar elemental compositions. Classification algorithms were tested on the spectral data, and a classification accuracy of 95.3% with a support vector machine (SVM) algorithm with a Gaussian kernel was achieved. The results obtained by the described procedures are shown to be very promising as a first step in the development of a predictive and analytical tool in search of fitting the current need for real-time control of pyrometallurgical processes.
  • Neutralization and co-precipitation of heavy metals by lime addition to effluent from acid plant in a copper smelter
    Eduardo Balladares, O. Jerez, F. Parada, L. Baltierra, C. Hernández, E. Araneda, V. Parra
    Minerals Engineering, 2018
  • Evolution of size and chemical composition of copper concentrate particles oxidized under simulated flash smelting conditions
    Manuel Pérez-Tello, Víctor R. Parra-Sánchez, Víctor M. Sánchez-Corrales, Agustín Gómez-Álvarez, Francisco Brown-Bojórquez, Roberto A. Parra-Figueroa, Eduardo R. Balladares-Varela, Eugenia A. Araneda-Hernández
    Metallurgical and Materials Transactions B Process Metallurgy and Materials Processing Science, 2018
  • The Role of Expansion and Fragmentation Phenomena on the Generation and Chemical Composition of Dust Particles in a Flash Converting Reactor
    Cirilo Andrés Duarte-Ruiz, Manuel Pérez-Tello, Víctor Roberto Parra-Sánchez, Hong Yong Sohn
    Metallurgical and Materials Transactions B Process Metallurgy and Materials Processing Science, 2016
  • Compositional fragmentation model for the oxidation of sulfide particles in a flash reactor
    Víctor Roberto Parra-Sánchez, Manuel Pérez-Tello, Cirilo Andrés Duarte-Ruiz, Hong Yong Sohn
    Metallurgical and Materials Transactions B Process Metallurgy and Materials Processing Science, 2014