Papers by Antonio Pagliero
Optimal Precipitation Hardening Conditions in Lead Base Anodes for Copper Electrowinning
Materials Science Forum, 2010
ABSTRACT The suitable yield stress of Pb-0 07%Ca-1.3%Sn anodes of 6 mm thickness for copper elect... more ABSTRACT The suitable yield stress of Pb-0 07%Ca-1.3%Sn anodes of 6 mm thickness for copper electrowinning is achieved by means of deformation and precipitation hardening processes, being its useful life dependant of this yield stress. In such sense the objective of the present work is to optimize the precipitation hardening, finding for this purpose the best cooling conditions of the anodes in the molds and of the hot rolling temperature. The results show that increasing cooling rate of ingots from natural cooling the precipitation hardening is enhanced, with increases of 10% and 12.5 % on the yield stress and working life of the anodes respectively, and that a minimum of 45 days of ageing is necessary to reach stable conditions for the precipitation hardening, with precipitates formation as CaSn(3). The hot roll temperature as not significant effect on the precipitation hardening of the anodes
Influence of the Impurities on Cathodic Copper on the Ductility of Copper Wires
Materials Science Forum, Jan 31, 2012
Abstract The main characteristic of cathodic copper is the concentration of impurities because it... more Abstract The main characteristic of cathodic copper is the concentration of impurities because it depends on mechanical characteristics, ie ductility, of the derived copper wires. The standard mechanical tests that evaluate their ductility, are quick elongation and spiral ...
Revista Colombiana De Materiales, May 16, 2014
El presente trabajo trata sobre el estudio de materiales porosos de acero inoxidable 316 L y graf... more El presente trabajo trata sobre el estudio de materiales porosos de acero inoxidable 316 L y grafito, de diferentes espesores (L) y porosidad ( ), y tiene como objetivo general establecer una metodología de trabajo con este tipo de material con fines electroquímicos, realizando una caracterización que incorpora una estimación del área electroactiva vía técnicas electroquímicas, y análisis de un depósito metálico en el interior del material. Para análisis cinético, se trabajó con la técnica de voltametría y la reacción electrocatalítica Fe 2+ /Fe 3+ , mientras que para análisis de depósito, se utilizó microscopía SEM y análisis de imágenes con Software Scentis Struers. Para acero inoxidable poroso ( = 78.73, L = 0.62 mm) la superficie específica estimada fue de 11150 m 2 /m 3 . Para el grafito ( = 0.89, L= 2 mm) se estimó la superficie especifica de 23530 m 2 /m 3 con base en mediciones de propiedades físicas. En ambos tipos de electrodos se observó en el interior heterogeneidad en la distribución del depósito de Cu, con zonas preferenciales de crecimiento.
Los ánodos base plomo (composición nominal 1.3% Sn, 0.07% Ca) de 6 mm de espesor utilizados en la... more Los ánodos base plomo (composición nominal 1.3% Sn, 0.07% Ca) de 6 mm de espesor utilizados en la electroobtención de cobre, si cumplen con el estándar de calidad mecánico requerido, suelen tener una vida útil de 4 a 5 años. Al cabo de ese período su espesor y por consiguiente su rigidez han disminuido fuertemente como consecuencia de su oxidación en las celdas, lo que los hace más propensos a sufrir deformaciones en operación, incompatibles con la buena marcha del proceso, ya que generan fundamentalmente sobretensiones y cortocircuitos, afectando la calidad del cobre catódico. Si los ánodos no poseen las propiedades mecánicas requeridas, las deformaciones en éstos se presentan al poco tiempo de operación en las celdas de electroobtención, normalmente antes del primer año de uso, lapso en el que se liberan los esfuerzos residuales generados durante el proceso de fabricación del ánodo (laminado) y por la posterior soldadura de la barra conductora de cobre en su zona superior. En tal ...
Study of precipitation hardening in lead calcium tin anodes for copper electrowinning
Materials Science and Technology, 2010
ABSTRACT A suitable yield stress for Pb anodes with 0.07% Ca and 1.3% Sn of 6 mm thickness for co... more ABSTRACT A suitable yield stress for Pb anodes with 0.07% Ca and 1.3% Sn of 6 mm thickness for copper electrowinning is achieved by means of deformation and precipitation hardening processes, their useful life being dependent on this yield stress. The objective of the present work was to optimise the precipitation hardening, by finding the best cooling conditions for the anodes in the moulds and the optimum hot rolling temperature. The results show that increasing the cooling rate of ingots beyond the rate of natural cooling enhances the precipitation hardening. At least 45 days of aging are necessary to reach stable conditions for the precipitation hardening, with precipitates formation as CaSn(3). The hot rolling temperature does not have a significant effect on the precipitation hardening of the anodes.
Electric field and potential determination for electrowinning cells with bipolar electrodes by finite difference models
Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242), 1998
This paper is a contribution to the electric modeling of electrochemical cells. Specifically, cel... more This paper is a contribution to the electric modeling of electrochemical cells. Specifically, cells for a new copper electrowinning process, which uses bipolar electrodes, are studied. Electrowinning is used together with solvent extraction and has gained great importance, due to its significant cost and environmental advantages, as compared to other copper reduction methods. Current electrowinning cells use unipolar electrodes connected
Modeling the electric field and potential of an electrowinning cell with bipolar floating electrodes
IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200), 1998
ABSTRACT An electric model for electrolysis cells used in copper electrowinning processes is deve... more ABSTRACT An electric model for electrolysis cells used in copper electrowinning processes is developed. It is applied to the analysis of cells, using series configurations of bipolar floating electrodes. This technology has been used in several fields of electrochemistry, but has not yet been applied by the copper industry. Its main advantage is that, for the same copper production, the cell requires a much lower DC current, as compared to conventional electrolysis cells, which use a parallel configuration of unipolar electrodes. This feature allows it to be supplied from a modular and compact PWM rectifier instead of a bulk and high current thyristor rectifier. Finite difference algorithms in two dimensions are derived to obtain the graphical distribution of the potential and the electric field inside the cell, and around the bipolar electrodes. The proposed modeling algorithms are implemented in the MATLAB software package. Different geometrical distributions of the floating electrodes in the cell are analyzed
Multicircuit approach for electrolytic cells, a novel method to force current balance in electrowinning plants
ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543), 2000
ABSTRACT
Anodic slimes formation in copper electrowinning
Revista de Metalurgia, 2004
Revista de Metalurgia, 2007
Optimal Operational Conditions during Production of Lead-Calcium-Tin Anodes for Improve Their Mechanical Properties
Materials Science Forum, 2005
Optimal Precipitation Hardening Conditions in Lead Base Anodes for Copper Electrowinning
Materials Science Forum, 2010
ABSTRACT The suitable yield stress of Pb-0 07%Ca-1.3%Sn anodes of 6 mm thickness for copper elect... more ABSTRACT The suitable yield stress of Pb-0 07%Ca-1.3%Sn anodes of 6 mm thickness for copper electrowinning is achieved by means of deformation and precipitation hardening processes, being its useful life dependant of this yield stress. In such sense the objective of the present work is to optimize the precipitation hardening, finding for this purpose the best cooling conditions of the anodes in the molds and of the hot rolling temperature. The results show that increasing cooling rate of ingots from natural cooling the precipitation hardening is enhanced, with increases of 10% and 12.5 % on the yield stress and working life of the anodes respectively, and that a minimum of 45 days of ageing is necessary to reach stable conditions for the precipitation hardening, with precipitates formation as CaSn(3). The hot roll temperature as not significant effect on the precipitation hardening of the anodes
Performance of Intercell Bars for Electrolytic Applications: A Critical Evaluation
Young/Electrometallurgy, 2003
Influence of the Impurities on Cathodic Copper on the Ductility of Copper Wires
Materials Science Forum, 2012
Abstract The main characteristic of cathodic copper is the concentration of impurities because it... more Abstract The main characteristic of cathodic copper is the concentration of impurities because it depends on mechanical characteristics, ie ductility, of the derived copper wires. The standard mechanical tests that evaluate their ductility, are quick elongation and spiral ...
Materials Characterization, 2001
The objective of this work is the study of mechanical and metallurgical characteristics of variou... more The objective of this work is the study of mechanical and metallurgical characteristics of various leadcalcium -tin anodes for copper electrowinning, to determine a relationship between properties and distortions during their operation in the cell in order to set quality standards for new anodes that guarantee absence of distortions. The mechanical tests consist of measurement of hardness, s o yield strength between room temperature and 80°C by means of compression tests, and tensile strength through tensile tests. The metallurgical characterization is aimed at determining the size and shape of the grains. It is observed that the anodes that do not undergo deformation in the cell show throughout the temperature range and during equivalent time of use an average yield stress higher than that of those anodes that undergo deformation. This can be explained by the fact that, in the case of the first anodes, the final temperature of rolling corresponds to cold rolling and, consequently, deformation hardening occurs during their fabrication. The deformed anodes, however, were hot rolled. D
IEEE Transactions on Industry Applications, 2000
This paper presents a current-source connection for electrolytic cells facilities, enlarging actu... more This paper presents a current-source connection for electrolytic cells facilities, enlarging actual production boundaries. Specifically, the aim of production-level increase, quality improvement, and costs reduction in electrowinning and electrorefining plants have been limited by the current-density (CD) dispersion. In fact, the cathodes of a plant designed to operate with a nominal 320 A/m 2 CD per cathode, usually presents CDs in a range between 220 and 420 A/m 2 (±31% variations). Industrial tests performed in a copper ER plant proved that the proposed connection halves dispersion. It has been estimated that a 15% earnings increase should be obtained with the increase of efficiency, quality, and production.
Technological Improvement in Copper Electrometallurgy: Optibar Segmented Intercell Bars (Patent Pending)
Canadian Metallurgical Quarterly, 2005
Copper electrowinning using segmented intercell bars for improved current distribution
Canadian Metallurgical Quarterly, Nov 30, 2002
... l'obtention de cuivre pur (> 99.999% Cu) à partir de min-erais d&... more ... l'obtention de cuivre pur (> 99.999% Cu) à partir de min-erais d'oxyde de cuivre est LIX ... et le contrôle continu de la distribution de courant dans l'ensemble des cellules. ... Electrodeposition processes are employed throughout the world for obtaining several metals such as Cu and ...
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Papers by Antonio Pagliero