Research Center Cientifico Tecnologico Para la Mineria

Chile

Research Center Cientifico Tecnologico Para la Mineria

Chile

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Jeldres R.I.,University of Antofagasta | Arancibia-Bravo M.P.,University of Antofagasta | Reyes A.,Research Center Cientifico Tecnologico para la Mineria | Aguirre C.E.,University of Antofagasta | And 3 more authors.
Minerals Engineering | Year: 2017

The use of seawater in the flotation of copper-molybdenum sulphide ores is becoming increasingly important. However, the complex chemistry by the presence of calcium and magnesium hydroxyl-complexes interferes with the recovery of molybdenite. This study analyzes the impact of pre-treated seawater with calcium and magnesium removal on the floatability of copper-molybdenum sulphide ores. The pretreatment was carried out by a mixture of Na2CO3 and CaO, which promotes the precipitation of calcium and magnesium ions. Three different conditions were compared, (i) flotation in seawater at pH 11.5; (ii) flotation in pretreated seawater with calcium and magnesium removal at pH 11.5; and (iii) flotation in seawater at natural pH, i.e. pH ≈ 7.6. While the copper recovery was similar in all cases, the recovery of molybdenum at high alkaline condition was notably increased when seawater harness was reduced. On the other hand, a high pyrite depression was reached because the oxidizing atmosphere at pH 11.5 allows Fe(OH)3 formation. © 2017 Elsevier Ltd


Ghorbani Y.,University of Antofagasta | Kuan S.H.,University Tunku Abdul Rahman | Kuan S.H.,Research Center Cientifico Tecnologico Para la Mineria
International Journal of Mining, Reclamation and Environment | Year: 2016

Chile is the principal producer of copper with a total of 5.8 million tonnes fine copper production in 2013. Chilean mining industry currently faces a projected increase in waste production, depleting water resources in the arid mining regions of the north and a lack of fossil fuel energy sources. In this study, a review of the historical background of environmental practices in Chile is presented, focused between 1970 and 2010. A review of the current state of sustainable development, comprising energy, water, stakeholder participation, environmental impacts and institutional decentralisation in the mining industry is presented. © 2016 Taylor & Francis


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: ENV.2013.6.5-4 | Award Amount: 1.13M | Year: 2013

Bi-regional cooperation between the EU, its Member States and Latin America has focussed on the environment since the 1st EU-LAC Summit in Rio de Janeiro and the creation of the Strategic Partnership in 1999. Within political dialogue and the subsequent EU-LAC summits, the environment has always been a priority, focusing on climate change, sustainability, biodiversity, natural resources and hazards. At the technical level, numerous projects and initiatives have been implemented with EU and Latin American funding focussing on climate change mitigation, loss of biodiversity, natural hazards, desertification, sustainable management of raw materials, and water and waste management, amongst many others. These projects are complemented with development and cooperation projects funded by the EU, as well as research and development projects funded under bilateral EU-LAC schemes or regional environmental initiatives. However, this results in a wide array of initiatives and projects oriented towards scientific development of specific topics or isolated small scale development projects. This approach misses the opportunity to create a structured exchange that goes beyond purely content issues and which could create a strategic input to the political dialogue. The ENSOCIO-LA project aims at establishing sustainable and integrated research and innovation cooperation between the EU and Latin American in the environment field, concretely in climate change, resource efficiency and raw materials, as well as at improving dissemination and the exploitation of research results in this area by different user groups. This will be achieved through networking and twinning of existing multilateral and bilateral projects funded by different sources, through the development of efficient interaction schemes between science, industry and users and the joint elaboration of future research priorities and joint activities.


Galvez E.D.,Research Center Cientifico Tecnologico Para la Mineria | Galvez E.D.,Católica del Norte University | Cruz R.,University of Antofagasta | Robles P.A.,University of Antofagasta | And 2 more authors.
Minerals Engineering | Year: 2014

Water is widely used as a solvent in the mining industry and is employed in hydrometallurgical processes and for mineral concentration. Because of the global increase in metal production, the demand for water, including fresh water, is expected to increase continually. In arid and semi-arid regions such as northern Chile, the scarcity of fresh water has led to increased dependence on other sources such as sea water and triggered efforts towards optimization of the use of fresh water. In copper concentration plants, approximately 40-60% of the total amount of water lost is retained in slurries in the tailings. In this paper, we present a method for optimizing the design of dewatering systems that employ hydrocyclones and thickeners. Mathematical models were generated to determine the maximum water recovery rate and the corresponding system structure for given equipment sizes, and to determine the minimum cost of the equipment and the corresponding system structure for given water recovery rates. The models were based on mixed integer nonlinear programming. Several case studies were performed. The model predictions were consistent with the results of an experimental study of an actual dewatering system in a copper concentrator plant. © 2014 Elsevier Ltd. All rights reserved.


Lucay F.,Research Center Cientifico Tecnologico Para la Mineria | Lucay F.,Católica del Norte University | Mellado M.E.,Research Center Cientifico Tecnologico Para la Mineria | Cisternas L.A.,University of Antofagasta | And 3 more authors.
International Journal of Mineral Processing | Year: 2012

Several methods for the design of separation circuits have been presented in the literature. These methodologies can be classified as those that use either heuristics or mathematical optimization techniques. However, none of these methods is currently used in industry. This is, the former is very simple to incorporate the complexities of the problem and the latter requires that the designer has more specialized training. In this work, we use sensitivity analysis to analyze and design separation circuits. We study the effect of each stage on the general circuit by identifying the relationships between recovery at each stage and global recovery of the circuit. Based on these results, we propose a novel methodology to analyze and design separation circuits. This new method is a hybrid because it uses mathematical analysis and the designer's experience. An example is provided for flotation separation in copper mining. © 2012 Elsevier B.V. All rights reserved.


Mellado M.E.,Research Center Cientifico Tecnologico Para la Mineria | Galvez E.D.,Católica del Norte University | Cisternas L.A.,University of Antofagasta
International Journal of Mineral Processing | Year: 2011

In this paper we present some considerations on the computation of optimal flow rates for the heap leaching process of solid reactants from porous pellets. We use a model already published by authors, which is suitable in applications where the scale-up is necessary. This approach allows to obtain better flow rates. Novelty of this approach is the simple form of the models and the easy way to compute good flow rates as used in actual operations in industry, for instance, alternate flows. We propose, also, an exponentially decreasing flow rate which is optimal from the mathematical point of view and the model being used. Due to the model simplicity, they can be used without mathematical complexities. We present a brief sensibility analysis to identify important operation variables that are relevant to change usual constant flow rates of lixiviant agents. Through simple optimization and case studies, we find better flow rate to minimize the acid and water consumed in the process under consideration. © 2011 Elsevier B.V. All rights reserved.


Trujillo J.Y.,University of Antofagasta | Cisternas L.A.,Research Center Cientifico Tecnologico para la Mineria | Cisternas L.A.,University of Antofagasta | Galvez E.D.,Católica del Norte University | And 2 more authors.
Chemical Engineering Research and Design | Year: 2014

Although the process of heap leaching is an established technology for treating minerals, such as copper, gold, silver, uranium and saltpeter, as well as remediating soil, no studies to date have investigated process optimization. This work presents a methodology for the design and planning of heap leaching systems to optimize the process. This methodology consists of the creation of a superstructure that represents a set of alternatives to search for the optimal solution; from this superstructure, a mixed integer nonlinear programming (MINLP) model was generated, and a BARON-GAMS solver was used to find the optimal solution. This method was applied to the extraction of copper from systems with one, two and three heaps, and the effects of copper price, ore grade and other variables were analyzed for each system. From the results, it can be concluded that this methodology can be used to optimize heap leaching processes, including planning and design issues. © 2013 The Institution of Chemical Engineers.


Galvez E.D.,Católica del Norte University | Galvez E.D.,Research Center Cientifico Tecnologico Para la Mineria | Moreno L.,Institute of Chemical Technology | Moreno L.,University of Antofagasta | And 4 more authors.
Minerals Engineering | Year: 2012

Antofagasta, Chile, has one of the most important deposits of saltpetre in the world, which is called caliche. These deposits are mainly composed of nitrate, halite, sodium anorthite, and quartz. Minor species include anhydrite, glauberite, loeweite, calcite, polyhalite, probertite, and gypsum. Recently, several operations began to use heap leaching for the extraction of saltpetre. Modelling the heap leaching of caliche is not straightforward because of the many minerals and their different dissolution rates. Moreover, caliche may have a large fraction of soluble minerals, approximately 40%, which causes the heap to slump. In this work, we present two models. The first, which is a phenomenological model, is an extension of the model published by Valencia et al. (2008). The system is modelled as a column comprised of N small columns, and in each of these small columns, the height of the solids varies with time when the soluble minerals are dissolved. The liquid in each small column has the same composition (well-stirred reactor). The second model, which is an analytical model, is an extension of that published by Mellado et al. (2009) for low-grade minerals, such as copper and gold, which considers that the leaching phenomenon occurs on different scales of size and time. However, in this work, the time scale at the particle level is based on the Bruner and Tolloczko dissolution model. The objective of this work is to test the suitability of the analytical model as a tool for use in optimisation, for which the model needs to be solved many times. The phenomenological model was used to generate simulated experimental data. The results show that the analytical model may be a useful tool in optimisation. © 2011 Elsevier Ltd. All rights reserved.


Mellado M.E.,Research Center Cientifico Tecnologico para la Mineria | Casanova M.P.,University of Concepción | Cisternas L.A.,Research Center Cientifico Tecnologico para la Mineria | Cisternas L.A.,University of Antofagasta | And 2 more authors.
Computers and Chemical Engineering | Year: 2011

In this paper we present analytical models suitable for scaling up the heap leaching process of solid reactants from porous pellets. The models are based on first order ordinary differential equations together with some constitutive relations derived from models based on ordinary and partial differential equations and other relations based on insight. The models are suitable for applications in which the scale-up is neccesary. This approach allows to obtain accurate solutions for actual industry heap leaching operations. Novelty of this approach is the simple form of the models and its accuracy as compared with more complex models. Due to the models simplicity, they can be used for analysis, design, control and optimization of heap leaching processes without mathematical complexities. The models include the effect of heap height, particle sizes, flow rates, and several operation-design variables. Finally, some numerical experiments which confirm our theory are presented. © 2010 Elsevier Ltd.


Meier L.,University of the Frontier | Perez R.,University of the Frontier | Azocar L.,University of the Frontier | Rivas M.,Research Center Cientifico Tecnologico para la Mineria | And 2 more authors.
Biomass and Bioenergy | Year: 2015

The use of photosynthetic CO2 reduction capacity of microalgae can be used for biogas upgrading. Such process would convert CO2 contained in the biogas into microalgal biomass, generating two products: upgraded biogas and biomass. Growth rate of Nannochloropsis gaditana was determined in atmospheres containing different levels of CH4 and CO2. Results showed no effect of CH4 rich atmosphere over microalgal development. CO2 inhibition was observed only when microalgae culture was exposed to atmospheres containing 9% of CO2. Direct contact of the biogas and the microalgal culture is not a feasible way to upgrade biogas, due to oxygen desorption to the gas phase. A two-stage process, involving a photobioreactor connected with a gas/liquid mass transfer unit showed to be an efficient way to remove CO2 from the biogas, keeping low levels of oxygen in the upgraded biogas. © 2014 Elsevier Ltd.

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