DSpace Repository :: Browsing by Author "Reyes-Bozo, Lorenzo"

Browsing by Author "Reyes-Bozo, Lorenzo"

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A combined photovoltaic and novel renewable energy system: An optimized techno-economic analysis for mining industry applications
(01/04/2017) Vyhmeister, Eduardo; Muñoz, Cristina Aleixendri; Bermúdez, José Miguel; Pina Moya, Javier; Fúnez Guerra, Carlos; Rodríguez Mayor, Lourdes; Godoy Faúndez, Alex; Higueras, Pablo; Clemente-Jul, Carmen; Valdés-González, Héctor; Reyes-Bozo, Lorenzo
The productivity of the mining industry in Chile, currently the main driver of Chilean economy, is closely tied to foreign demand for ores. Ore-processing is known for involving energy–intensive processes, such as comminution, concentrating and cathodic processes. As mining activities take place in the arid north of Chile, they are affected by water scarcity. Water shortage has forced the industry to pump desalinated seawater up to mining sites over 2000 m above sea level, further increasing electricity consumption. Given these energy needs, and the fact that electrical energy supply in the north of Chile is based on fossil fuels, it is important to consider the use of renewable energies as environment-friendly and economic alternatives. The aim of this work is to evaluate, by an optimized techno-economic analysis, the use of photovoltaic and a novel wind-based technology to supply at least 10% of the current and the predicted electrical energy requirements of the mining industry in the Antofagasta region. A combination of an optimization problem and technical evaluation was performed using Matlab to obtain the optimal number of solar and wind-based technology units in a case study. Total energy generation from a novel wind-based technology unit is 67,616 MWh/y, corresponding to 14.45·106 Nm3 (1298 t) of hydrogen and 7.41·106 Nm3(10,323 t) of oxygen after electrolytical transformation. Considering a 65% efficiency of the combined cycle fed with hydrogen and oxygen, 28,133 MWh/y of electrical energy would be obtained. For the cases studied the cost of energy from the combined system was estimated to be between 0.255 US$/kWh and 0.273 US$/kWh, slightly higher than the average energy regional cost. According to the analysis, the renewable energy system could be a sustainable alternative to supply economic green energy to the mining industry in Chile.
A Conceptual Model Considering Multiple Agents for Water Management
(2022-06-30) Rivadeneira Tassara, Benjamín; Valdés González, Héctor; Fúnez Guerra, Carlos; Reyes-Bozo, Lorenzo
In Chile, as in many other areas of the world, water supplies have been poorly managed and water availability is decreasing. In order to manage water resources more sustainably and equitably, it is necessary to understand and predict their supply and use considering the characteristics of a particular zone. This study aimed to develop a conceptual model for water management in the Libertador Bernardo O’Higgins Region in Chile. The model considers the water needs of industries with production activities, human consumption, and the ecological flow of each sub-basin in the area. The results show that the proposed model contributes to the understanding of the critical variables, their agents, and the interaction between the hydric demands, which enables the prioritization of human consumption and the ecological flow. Furthermore, the cross-analysis between the offer and demand indicates that current and predicted consumption levels will only be sustainable up to the year 2031. The findings may be of use to decision-makers seeking to improve water management plans in this area and elsewhere, and to others interested in modeling water management in different areas.
Adsorption of biosolids and their main components on chalcopyrite, molybdenite and pyrite: Zeta potential and FTIR spectroscopy studies
(2015) Reyes-Bozo, Lorenzo; Escudey, Mauricio; Vyhmeister, Eduardo; Higueras, Pablo; Godoy Faúndez, Alex; Salazar, José Luis; Valdés-González, Héctor; Wolf-Sepúlveda, German; Herrera-Urbina, Ronaldo
Zeta potential measurements were used to assess the electrokinetic characteristics of chalcopyrite, molybdenite and pyrite in the presence of biosolids and their main components (humic acids, glucose and serum albumin) as well as a commercial collector (Aero 6697). Fourier transform infrared spectroscopy (FTIR) was then used to gain a deeper understanding of the interaction of these compounds with these sulfide minerals. It aims to achieve a better understanding of the surface chemistry of sulfide-water interfaces that improve froth flotation at industrial scale in the step of copper sulfide ore concentration. Zeta potential results show that hydrogen and hydroxide ions are potential determining ions for each sulfide mineral studied. The addition of 50 g/t biosolids or all the other chemicals used in this investigation shift the isoelectric point of chalcopyrite. Under the same conditions, only humic acid significantly affects the zeta potential of molybdenite, making it more negative in the pH range investigated, and shifting its isoelectric point about 6 pH units. These compounds seem to have a poor affinity with pyrite surfaces because their zeta potential is slightly modified. FTIR spectroscopy characterization shows that biosolids and their main components can interact with chalcopyrite, molydenite and pyrite surfaces through a complex mechanism involving chemical or physical linkages. The results reported here seem to indicate that biosolids may be used as new environment-friendly froth flotation agents to concentrate copper and molybdenum sulfide minerals. (C) 2015 Elsevier Ltd. All rights reserved.
Assessment of the floatability of chalcopyrite, molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores
(2014) Reyes-Bozo, Lorenzo; Higueras, Pablo; Godoy Faúndez, Alex; Sobarzo, Francisco; Sáez-Navarrete, César; Vásquez-Bestagno, Jorge; Herrera-Urbina, Ronaldo
Biosolids and representative compounds of their main components – humic acids, sugars, and proteins – have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite – both valuable sulphide minerals present in these ores – as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that of a commercial collector (Aero 6697 promoter). Biosolids show more affinity for pyrite. The copper recovery (85.9%) and copper grade (6.7%) of a rougher concentrate obtained using humic acids as main collector for the flotation of a copper sulphide ore from Chile, were very similar to those of a copper concentrate produced by froth flotation under the same conditions with a xanthate type commercial collector. This new and feasible end-use of biosolids and humic acids should be new environment-friendly organic froth flotation agents for greening the concentration of copper sulphide ore. Now, further research is needed in order to scale current laboratory assays to operational mining scales to determine efficiencies to industrial scale.
Effect of biosolids and their main components in the concentration of copper sulphide ores
(2014) Godoy Faúndez, Alex; Reyes-Bozo, Lorenzo; León Higueras, Pablo; Herrera-Urbina, Ronaldo
The copper mining industry in Chile and perhaps in other countries as well is faced with the challenge to implement the best practices in order to achieve a sustainable and more environmentfriendly growth. Relationships between mining industry and society have been historically complex due to its environmental impacts. Whereas the ore grade has declined continuously, this has involved an intensive energy and water consumption thus increasing operational costs at different stages of the concentration process. In the case of copper sulphide ore concentration, froth flotation is the main technology used worldwide. The amount of the different chemical reagents used in flotation plants (i.e., collectors, depressants, frothers and modifiers) affects significantly production costs and has a negative effect on the environment as well. The objective of this research work was to evaluate the use of biosolids and their main components (i.e., glucose, proteins and humic substances) as more environment-friendly flotation collectors for chalcopyrite and molybdenite. For this purpose, microflotation tests were conducted in a modified Hallimond tube. In addition, FTIR and zeta potential experiments were performed to investigate the interaction of biosolids with these sulphide minerals. Biosolids and their main components may interact through physical and chemical ways due to different affinities with such sulphide minerals as chalcopyrite, pyrite and molybdenite, which are present in copper sulphide ores. In alkaline pHs, biosolids and their main components make the zeta potential of the sulphide minerals investigated more negative. These results may provide important information concerning the behavior of the main sulphide minerals in the concentration of copper sulphide ores at industrial scale, wherein mill processes could affect their surfaces properties. Therefore, biosolids and their main components may open an opportunity to be used in copper sulphide flotation plants to partially replace conventional reagents, which are more hazardous and less environment-friendly.
Electromobility in forest transport. Is it feasible? Perceptions regarding implementation in the chilean industry
(2022) Valdés-González, Héctor; Larenas-Barra, Sebastián; Méndez-Dedes, Luis; Reyes-Bozo, Lorenzo; Sandoval-Yáñez, Claudia
Este trabajo examina las distintas impresiones y perspectivas relacionadas con la implementación de electromovilidad en el transporte de rollizos con ca-miones de capacidad de carga de hasta 45 tonela-das en el sector forestal de la octava y decimosexta región de Chile. El objetivo de este trabajo es esta-blecer los aspectos críticos que los actores claves de la industria forestal identifican y perciben para una correcta implementación de camiones eléctricos de alto tonelaje. Para esto se propone un estudio me-todológico de tipo cualitativo con un diseño no ex-perimental basado en entrevistas semiestructuradas dirigidas a actores del sector forestal de la zona es-tudio. Se utiliza una muestra por conveniencia apli-cada a 4 empresarios del rubro, 3 ejecutivos de empresas forestales principales y 2 representantes de distribuidores de camiones. Los datos muestran que actualmente hay poco conocimiento, derivado de la inexistencia de proyectos y plataformas de di-fusión específicos que consideren la tecnología en el rubro, pero, por el contrario, demuestran que existe una buena disposición por parte de los actores para implementar planes piloto con miras a la sustentabi-lidad económica que se le proyecta a la electromo-vilidad. Se evidencia una concentración de aspectos críticos que es necesario abordar para implementar la electromovilidad en el transporte forestal y que, atendi-dos por un trabajo público-privado, permitirían al rubro y al país obtener los beneficios económicos y ambien-tales de esta tecnología.
Greening Chilean copper mining operations through industrial ecology strategies
(2014) Reyes-Bozo, Lorenzo; Godoy Faúndez, Alex; Herrera-Urbina, Ronaldo; Higueras, Pablo; Salazar, José Luis; Valdés-González, Héctor; Vyhmeister, Eduardo; Antizar-Ladislao, Blanca
Sawdust was used as cheap sorbent for the remediation of a diesel and oil fuel-contaminated mining soil whereas biosolids were evaluated as collectors and frothers in froth flotation of copper sulphide ores. The use of these waste materials in copper sulphide ore mining and mineral processing may have a positive impact on the cleaner production of copper from its natural raw sources and may decrease the deleterious effect that mining operations have on the environment. Mixtures of oil fuel contaminated mining soil and sawdust were treated in an aerobic reactor at 50.0% humidity for several days. A significant decrease (over 60.0%) of Volatile Organic Compounds (VOCs) content in these mixtures was obtained after one-month of treatment. Rougher flotation of copper sulphide ores using biosolids – from wastewater treatment plants – and humic acids – a component of biosolids – as collector and frother yielded a copper sulphide concentrate with a copper grade and copper recovery of 0.8% and 26.0%, and 3.5% and 29.7%, respectively. Biosolids and humic acids have shown to be potential candidates to partially substitute traditional organic chemicals used in industrial flotation of copper sulphide ores. This possibility opens up an alternative for greening copper sulphide ore flotation by using more environment-friendly flotation reagents. Based on these results, a conceptual model based on industrial ecology and cleaner production principles is proposed for greening the overall copper sulphide ore processing.
Metodologías ágiles: un análisis de los desafíos organizacionales para su implementación
(2022) Valdés-González, Héctor; Flores-Cerna, Fernando; Sanhueza-Salazar, Víctor-Manuel; Reyes-Bozo, Lorenzo
Este trabajo analiza las principales brechas que influyen en las PyMEs TI (pequeñas y medianas empresas de tecnología de la información) con metodología tradicional, al iniciar la implementación de metodologías ágiles para la gestión de proyectos. El objetivo de esta investigación es determinar las principales brechas existentes antes de implementar metodologías ágiles en una PyME TI con metodología tradicional para la gestión de proyectos. Para lograrlo se propone una aproximación cualitativa a las opiniones de tres gerentes, dos ingenieros de proyecto y seis analistas programadores de la empresa, basada en entrevistas semiestructuradas, considerando una muestra por conveniencia, para entender las dificultades existentes en la empresa de estudio, contrastando dicha realidad mediante encuestas dirigidas a 29 profesionales de áreas TI de otras organizaciones. Los resultados del análisis revelan que las principales brechas para la implementación de metodologías ágiles en la PyME son la cultura organizacional en desacuerdo con la agilidad, la falta de compromiso de la gerencia y la resistencia al cambio. Se concluye que la propuesta resulta ser efectiva para conocer las principales brechas a resolver antes de comenzar la implementación de una metodología ágil en una PyME TI, permitiendo alinear a la organización con la agilidad.
Modeling and energy-based model predictive control of high pressure grinding roll
(2019) Vyhmeister, Eduardo; Reyes-Bozo, Lorenzo; Rodriguez-Maecker, Roman; Fúnez-Guerra, Carlos; Cepeda-Vaca, Fernando; Valdés-González, Héctor
Even though semiautogenous grinding mills and ball mills are normally used in grinding processes, the industry is driven to decrease cost by increasing efficiencies and decreasing energy consumption. High Pressure Grinding Rolls (HPGR) are seen as an energy-efficient alternative but their developments in modeling and control have received relatively little attention. In this work a model and a control scheme for HPGR is presented that considers the total energy consumed as one of the main controlled variable. First, the model was generated by using literature-reported information of a specific manufacturer and lithology. The dynamic representation of the treatment capacity, product granulometric distribution (reported as 80% percentile), compression energy, and rolling energy were considered as the most important model output variables. Second, model validation was performed with considerable positive results (based on assessment of estimation errors). Finally, the model was used to generate a multiple input multiple output control scheme. As result, it was observed that the model had a correct representation of the phenomena involved and that the peripheral velocity and pressure used in the HPGR are useful manipulated variables to control the energy consumed by the equipment in an MPC scheme.
Use of humic substances in froth flotation processes
(2019) Reyes-Bozo, Lorenzo; Vyhmeister, Eduardo; Godoy-Faúndez, Alex; Higueras, Pablo; Fúnez-Guerra, Carlos; Valdés-González, Héctor; Salazar, José Luis; Herrera-Urbina, Ronaldo
Continual growing demand for metals in regular and emerging markets has led to an increasing use of chemicals and reagents in ore processing. This trend force to incur in an increasing use of commodities which inevitable leads to higher operational costs and environmental concern. The chemicals and reagents used in flotation processes especially invoke high costs of handling and disposal due to their hazardous nature, but until now, few studies have been carried out to seek possible alternatives. In order to develop a cheaper and greener processes, these hazardous materials should be replaced by more sustainable products, by-products, or wastes generated by other industries. Biosolids, cheaper and greener than chemical frothers and collectors, have been tested successfully in flotation processes. Studies of removal rates and froth flotation kinetics have been carried out independently, nevertheless a deeper understanding of the tradeoffs involved between the rates and kinetics should be obtained. This work evaluates the use of different collectors (conventional collector (CC), biosolids (and their main components), and mixtures of CC and biosolids main components) in the froth flotation of copper sulfide ores. Tests were carried out in Denver Cells, at fixed collector, frother, and pH levels, in order to estimate metallurgical and kinetic parameters. In rougher flotation tests, biosolids show to be the most efficient non-CCs, achieving Cu recoveries of 64.1%. CC achieved 76.2% Cu recoveries while none of the pure biosolids main components achieved Cu recoveries over 60%. In the kinetics studies, only the partial replacement of CC (by 50% of Humic Acids (HAs) or biosolids) allowed a similar copper recovery once compared with CC (~81% Cu to be obtained with a fast kinetic constant of ~0.88 min−1). For molybdenum, partial replacement of CC produced better recovery and kinetics constants (k of 0.83 min−1 and R∞ of 66.10% for 50% CC - 50% HAs; k of 0.90 min−1 and R∞ of 61.79% for 50% CC - 50% biosolids). Results show that different combinations of biosolids - CC or HAs - CC could achieve optimal flotation conditions. As evaluated, an optimal combinations would allow considerable reductions in energy and chemical consumption.
Vapor-Liquid equilibria modeling using gray-box neural networks as binary interaction parameters predictor
(2017) Vyhmeister, Eduardo; Rodríguez-Pino, Jonathan; Reyes-Bozo, Lorenzo; Galleguillos-Pozo, Rosa; Valdés González, Héctor; Rodríguez-Maecker, Roman
Simulations of vapor-liquid equilibrium (VLE) are widely used given their impact on the scale, design, and extrapolation of different operational units. However, due to a number of factors, it is almost impossible to experimentally study each of the VLE systems. VLE simulations can be developed using representations that are strongly dependent on the nature and interactions of the compounds forming mixtures. A model that helps in predicting these interactions would facilitate simulation processes. A Gray Box Neural Network Model (GNM) was created as Binary Interaction Parameters predictors (BIP), which are estimated using state variables and information from pure components. This information was used to predict VLE behavior in mixtures and ranges not used in the mathematical formulation. The GNM prediction capabilities (including temperature dependency) showed an error level lower than 5% and 20% for mixtures considered and not considered in the training data, respectively.

Browsing by Author "Reyes-Bozo, Lorenzo"

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