Copper Mine In Chile Research Articles

The nationalization of the large-scale copper mines in Chile: successful investment or financial failure?

AbstractBetween 1967 and 1971, the Chilean government nationalized its large-scale copper mining industry. While this process is widely considered successful given the demonstrated long-term state capacity to profitably operate the assets, the discussion on its net financial convenience has usually been disregarded. Aiming to improve the understanding of this case of resource nationalism, this paper follows two complementary approaches. First, we provide a systematic review of the historical background, development, and short-term impact of the Chilean nationalization, consolidating at the same time the available financial data on fiscal inflows and outflows as part of this process. Secondly, we perform an ex-post NPV assessment using a 10% discount rate over the annual cash flows that the government has perceived from the nationalized mining operations from 1967 to 2022 and compare it with a hypothetical counterfactual scenario in which these mines would have remained privately owned. This yields a higher NPV of the Nationalization compared to the counterfactual. Considering that discount rates above 11.1% or operational cost reductions by 4.5% indicate a net financial loss, the results suggest that, purely from a financial perspective, the nationalization process was marginally positive for the government. We expect that this analysis provides support for a thoughtful mineral policy that contributes to sustainable human and economic development in resource-rich countries.

Commodity price and fatalities in mining – Evidence from copper regions in Chile

On October 13th, 2010, the world was glued to the TV screen to watch the rescue of the 33 miners that spent 69 days trapped 700 m underground in a Chilean copper mine. While the 33 miners were rescued alive, 43 copper miners died in Chile the same year due to accidents in mining operations – the most significant number of mining fatalities in more than 20 years. The same year, copper reached its highest average annual price in history. Does this mean that high commodity prices induce a higher number of fatal accidents in mining operations? This paper addresses this question using 21 years of accident data in copper mines in Chile. We find that when the international price of copper surpasses approx. $5200/tonne, there is a strong positive correlation with the number of fatalities in copper mining. Scrutinizing such findings, we observe that the relationship mainly occurs with companies’ direct employees, while the number of deaths within contractors does not vary along with the copper price. Our results suggest that in the wave of high commodity prices, mining operations intensify their production processes, including rushing to bring back medium-sized operation sites that have previously been in care and maintenance, and which negatively affects the safety of operations.

Error reduction in long-term mine planning estimates using deep learning models

The long-term mine planning model (LTMP) and short-term mine planning model (STMP) are two approaches that describe the ore content in a mine; they are essential intangible resources that determine a mining operation and its feasibility. These models are obtained with geostatistical methods and, given their nature, are prone to discrepancies with one another. To reduce these differences, we studied the performance of deep learning (DL)-based models in ore grade estimation for a copper mine in Chile. Specifically, feedforward neural network (FNN), one-dimensional (1D) convolutional neural network (CNN), and long short-term memory (LSTM) models were analyzed. The experiment consisted of a dataset with 732,870 samples, obtained after data cleaning and selection. The use of spatial information in the samples was also studied, adding contextual information for estimation. This led to a dataset of 545,768 samples that were used to evaluate 1D CNN and LSTM models. Architecture tuning was performed by the k-fold cross-validation (CV) method, and hyperparameters such as the number of layers, number of neurons, activation function, and kernel size were optimized. The resulting hyperparameters were used to perform a final evaluation. Performance was measured based on the mean absolute error (MAE), mean squared error (MSE), and coefficient of determination (R2) metrics. A baseline is created using LTMP and STMP estimates to quantify the improvement in the performance of DL-based models. The experimental results revealed the ability of DL-based models to significantly improve copper grade estimates provided by standard mining industry methods in the context under study. For MSE in the final tests, FNN improved by 21%, CNN by 37%, and LSTM by 39% over baselines.

An Economic Evaluation of the Health and Agricultural Damages Caused by Copper Mining in Chile

AbstractThis study assesses the environmental damage caused by copper mining on surface water bodies in Chile. The few official records on the discharges and concentrations of arsenic and copper only allow for identifying the impacts of some mining operations in the regions of Coquimbo, Valparaíso, and O’Higgins. The economic valuation is carried out through the impact pathway approach, which relates copper production, discharges, concentrations, and dose-response coefficients to establish effects on health and agriculture. The results show that the economic damage due to water pollution occurs mainly in the regions of Coquimbo and O’Higgins. The above is explained because the greatest externalities are generated in agricultural areas, while the damage to health is low because of the small population exposed (97.6% versus 2.4%). Finally, total damages represent 0.43%, 0.26%, and 0.0001% of copper sales in the mining operations analyzed in the regions of Coquimbo, O’Higgins, and Valparaíso, respectively.

Microbial responses are unreliable indicators of copper ecotoxicity in soils contaminated by mining activities

Metal contamination of soil has become a serious environmental problem worldwide. Many studies have attempted to infer metal ecotoxicity from soil microbial responses. However, much of the data from these studies tends to be inconsistent and difficult to interpret. We hypothesized that microbial response would be a useful indicator of metal toxicity in soils contaminated by copper mining in Chile. Eighty-four topsoils (0–20 cm) were collected from three areas historically contaminated by copper mining (total Cu: 46–1106 mg kg−1, soluble Cu: 0.05–2.3 mg kg−1, pCu2+: 6.3–10, pH: 5.1–7.8, organic matter: 1.1–10%, clay: 0–28%). Based on soil metal concentrations and ecotoxicity thresholds, Cu was expected to be toxic to microorganisms in the studied soils, while the effects of other metals (total Zn: 79-672, As: 1.9–60, Pb: 19-220, Cd: 0.4–5.1 mg kg−1) were expected to be minor. Soil microbial responses (microbial biomass and numbers, nitrogen mineralization and nitrification, and community-level physiological profiles) were also measured. The results showed that the different responses of soil microbes were not correlated with each other. Furthermore, the soil microbial responses were mainly influenced by the physicochemical properties of the soil, not by the metal concentrations in the soil. The effect of copper on the microbial response was either stimulating (positive) or toxic (negative). Of the soil microbial responses measured in this study, only the microbial biomass was useful for calculating dose-response curves. However, the microbial biomass response was not consistent among the different soil copper pools (total copper, soluble copper, and activity of free Cu2+ ions). It is important to emphasize that the thresholds obtained for copper toxicity cannot be adopted in a robust manner because of the different microbial responses in different sampling areas. Thus, in the copper-contaminated soils under study, microbial response was found to be an unreliable indicator of metal toxicity.

The use of solar energy in the copper mining processes: A comprehensive review

The copper mineral processing industry faces complex scenarios with increased demand, highly variable energy prices, falling ore grades that increase energy consumption, and increasing concern about the industry's carbon footprint. To reduce the risk imposed by these scenarios, the industry is looking at the use of renewable energy sources. Considering that the most important copper mines in Chile are situated in regions with high radiation levels, solar energy has the potential to be an attractive and sustainable source of energy. This paper provides an overview of the current solar technologies and how they have been applied to address some of the challenges faced by the copper mining industry today. It describes the use of solar thermal and solar photovoltaic technologies to produce power and heat for the copper mining processes. Indeed, solar photovoltaic technologies can be used to produce electricity for the comminution machines, electro-refineries and water pumping while solar thermal technologies are useful for electricity generation, heat production, thermal leaching and drying of copper concentrate. The review also analyzes, from a broader perspective, the potential of these technologies in the operation and design of new solar copper mineral processes. It is concluded that there several feasible options to integrate solar energy into the copper mining processes.

Обоснование условий применения автоматизированных систем управления открытыми горными работами строительства комплекса циклично-поточной геотехнологии в карьере с помощью имитационного моделирования

The simulation modeling approach described in the article is intended to assess the efficiency of geo-technologies and can be applied: 1) to evaluate the implementation of smart geotechnologies with digital transformation of the mining systems; 2) to select the mining and transportation management system as well as the preferred logistic scheme of the mine. This approach makes it possible to make more reasonable investment decisions based on an objective quantitative assessment. Simulation modeling should be based on the results of geotechnical justification of structural parameters of the pit walls and benches in operating and limit states. Transition to automated systems to control smart geotechnologies in programmable mode and timely inclusion of the In Pit Crushing and Conveying (IPCC) technology into the transport scheme helps to: 1) remove people from the working zones inside the open pit; 2) significantly reduce the ore mining costs; 3) advance to a higher level of technology in developing the deposits; 4) process ores that were previously considered substandard. As an example, the assessment results are provided of the implementation of new rock mass transportation technologies at the Codelco copper mine in Chile in the Radomiro Tomic open pit.

Selection Criteria for Sustainable Suppliers in the Supply Chain of Copper Mining in Chile

The objective of this research was to identify the criteria for the selection of sustainable suppliers in the supply chain of copper mining located in the Antofagasta region in Chile, through the information obtained in the application of a survey managers mining companies in 2018. The research results show that mining companies use economic, environmental and social criteria in the selection of sustainable suppliers, which are consistent with the research carried out by Dickson (1966) and Zimmer, Frohling and Schultmann ( 2016). However, the differentiation that mining companies make in the evaluation of criteria when it comes to suppliers of goods or service providers stands out as an important finding. In the case of suppliers of goods, economic criteria are valued more preferably, such as: quality, delivery on time, price, historical performance and previous sales. On the other hand, when it comes to service providers, environmental and social criteria, such as: occupational health and safety management and environmental management, are valued with greater importance.

Rock lithological classification by hyperspectral, range 3D and color images

Mine operations in the future will require automatic rock characterization at many different stages, since it can be used to supervise and optimize various processes in the laboratory as well as at the mine locations for planning and exploitation. Different methods for classifying rocks based on image analysis have been proposed in the past. In this paper, we report the use of hyperspectral sensors in the classification of rock lithology. The lithology provides information about the chemical composition of the rock, and its physical properties. According to our literature review, this is the first time hyperspectral sensors have been employed in rock type classification. Additionally, it is the first time the use of three different technologies in rock type classification has been reported: hyperspectral sensors, laser range and a color camera. We use two hyperspectral sensors, one has sensibility within the visible and near-infrared range of 400–1000 nm, and the second has sensibility within the short-wavelength infrared range of 900–2500 nm. The range and high definition color images are used to perform accurate segmentation of the rock samples. Images are tessellated into sub-images in which various features from the three sensor types are extracted. In a first stage, the sub-images are classified by using a support-vector machine (SVM) classifier with the extracted features as inputs. In a second stage, the rock segmentation is used to perform a voting process among all the sub-images of each rock and improve the classification. The method was tested using a database with 13 lithologies from a copper mine in Chile. The results show that lithological classification performance obtained by using hyperspectral images greatly exceeds the performance of the color and range images. The achieved classification performance was 98.62% using sub-image classification and 99.95% using a voting process among sub-images. The number of features was also reduced by using the CMIM (Conditional Mutual Information Maximization) feature selection method, achieving a performance of over 99% with using only 3% of the total number of features.

Statistical testing of availability for mining technological systems with air quality constraints

AbstractWe develop a mining technology statistical model showing that even environmentally sustainable mining can be still very profitable. We put constraints on mining activities for elevated levels of particulate matters (eg, PM2.5 and PM10) in the air. We show that upper quantiles (eg, 95%) of productivity slightly decrease with respect to maximal number of failures, and this high‐productivity feature is robust with respect to variation of underlying statistical parameters. We illustrate the model on two currently active mining sites, the Chuquicamata copper mine in Chile and the opencast coal mine Libouš in the Czech Republic. Two generic working scenarios have been obtained. We show that, under very realistic conditions for both countries, the Czech Republic and Chilean mining companies can regulate mining activities for high thresholds of air pollutants without a substantial loss of productivity. Sensitivity analysis with respect to parameters is provided.

Copper mining in Chile and its regional employment linkages

This article gauges employment interactions among different economic sectors of relevant copper-producing regions in Chile, such as Tarapacá, Antofagasta, Atacama, Coquimbo, and O′Higgins. To that end, concordance measures of employment during peaks and troughs, and rolling correlations are computed. The estimation results show that the strength of employment co-movement of mining & quarrying with other economic sectors—within a given region and across regions —varies among the geographic locations under analysis. In particular, employment linkages between the Antofagasta and Metropolitan Regions have weakened over time.In addition, this article provides background information on the world copper market and Chile's mining sector. In particular, time series of copper production and labor productivity of private and state-owned mining firms operating in Chile are presented. Specifically, historical figures show that falling ore grades have had as a counterpart an increase in electricity costs per metric ton of refined copper during 2001–2015. This is specially the case for concentrator plants, which experienced an 87.1%-increase in electricity costs during that time period.

Hybrid Stripmap–ScanSAR Interferometry: Extension to the X-Band COSMO-SkyMed Data

This letter aims to investigate the applicability of the hybrid stripmap–ScanSAR differential synthetic aperture radar interferometry to data collected by the X-band RADAR sensors of the Italian COSMO-SkyMed (CSK) constellation. The presented analysis relies on the experiments carried out on two sets of stripmap and ScanSAR CSK images collected over the Chuquicamata copper mine in Chile and the Mojave Desert in Southern California, respectively. As a result of our investigation, a spurious phase modulation has been recognized in the generated hybrid stripmap–ScanSAR interferograms along the azimuth direction. This effect is due to the specific staggered topology of the used active phased array antennas that introduces half-wavelength residuals during the electronic antenna steering in the elevation plane. A straightforward solution to compensate for such spurious phase modulation effects has been provided, and the achieved results demonstrate its effectiveness. The outcomes of our analysis may be relevant in the perspective of the future CSK Second Generation Program.

Genetic Basis of Metal Resistance in <i>Acidiphilium</i> sp. DSM 27270 (Yenapatur)

Acidiphilium sp. DSM 27270 (Yenapatur) forms part of a microbial consortium isolated from copper mines in Chile, that is currently used in state of the art industrial-scale biotechnology. Its taxonomic assignment is still tentative and is metal resistance and homeostatic responses poorly characterized. Here we report the genomic taxonomy evaluation of the Yenapatur strain and the preliminary characterization of its metal resistance and homeostatic responses. The genome of Yenapatur was re-assembled, annotated and compared to other sequenced strains of the genus. Genomic signatures were derived to better define the taxonomy of the strain. The minimum inhibitory concentrations of diverse cations and anions (Cu (II), Fe (II), Mg (II), Mn (II), Zn (II), Al (III), As (III), Fe (III), chloride and nitrate) were determined. Known resistance determinants were profiled in the genome of Yenapatur and publically available sequenced Acidiphilium strains. Results are presented and discussed under the light of the operational conditions in which Yenapatur thrives.

Increasing the value of heterogeneous ore deposits by high-resolution deposit-modelling and flexible extraction techniques

Continued profitability in mineral resource extraction is challenged by depressed prices and decreasing grades, combined with increased extraction and processing costs, as well as the increasing depth and complexity of available deposits. A standard industry response to these challenges has been to adopt economies of scale; however, this approach is proven to have limitations in the current cost/price environment. Improved precision and accuracy in ore routing can overcome these challenges to a larger extent, but in order to achieve this, a new tool set consisting of high resolution data capture and modelling, coupled with flexible, real-time, online in-pit mineral classification appears to be required. This paper examines preliminary developments in measuring and modelling deposit heterogeneity at two copper mines in Chile. This examination is then followed by the development and use of a data model to evaluate the opportunity to introduce selective partitioning of ores through in-pit sensing and decision support tools prior to conventional processing in leach or flotation circuits. The results of this study suggest that the value proposition for the use of in-mine sensors for classifying and segregating valuable ore from waste, and to improve the accuracy of dispatch to the leaching, milling, or waste disposal stages, is significant.

Failure Analysis of Slurry Pump Impeller Fractured at Collahuasi Mine

Abstract This work presents the analysis of a fractured impeller used in slurry pumps at the Collahuasi copper mine in Chile. Although the impeller must run more than 1 800 h, it was fractured under working conditions before having reached 1 500 h, generating a catastrophic failure of the pumping system. The microstructure of the impeller material was analyzed by optical microscopy, scanning electron microscopy (SEM) and microhardness. The composition of the impeller material was studied by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. It was found that the impeller material corresponds to cast iron with high content of chromium, typically called white cast iron, which usually exhibits high wear and corrosion resistance. After analyzing the overall failure, we conclude that the fracture was mainly produced by the existence of high-impact materials in the slurry pulp, which produced an imbalance of the impeller rotation.

Anomalously high arsenic concentration in a West Antarctic ice core and its relationship to copper mining in Chile

Abstract Arsenic variability records are preserved in snow and ice cores and can be utilized to reconstruct air pollution history. The Mount Johns ice core (79°55′S; 94°23′W and 91.2 m depth) was collected from the West Antarctic Ice Sheet in the 2008/09 austral summer. Here, we report the As concentration variability as determined by 2137 samples from the upper 45 m of this core using ICP-SFMS (CCI, University of Maine, USA). The record covers approximately 125 years (1883–2008) showing a mean concentration of 4.32 pg g−1. The arsenic concentration in the core follows global copper mining evolution, particularly in Chile (the largest producer of Cu). From 1940 to 1990, copper-mining production increased along with arsenic concentrations in the MJ core, from 1.92 pg g−1 (before 1900) to 7.94 pg g−1 (1950). In the last two decades, environmental regulations for As emissions have been implemented, forcing smelters to treat their gases to conform to national and international environmental standards. In Chile, decontamination plants required by the government started operating from 1993 to 2000. Thereafter, Chilean copper production more than doubled while As emission levels declined, and the same reduction was observed in the Mount Johns ice core. After 1999, arsenic concentrations in our samples decreased to levels comparable to the period before 1900.

Determination of bulk density, methods and impacts, with a case study from Los Bronces Mine, Chile

Mineral resource and ore reserve estimates are founded on two sources of data: tonnage and grade. The tonnage is a product of volume and density; both of which are estimates. Density impacts numerous operational factors, which include, but are not limited to, mine design, mine planning, equipment selection and operational performance. Hence, density is a significant parameter and its determination requires similar care as the measurement of grade. This paper provides an overview of methods used to determine density within the Anglo American Group. It is not the purpose of this paper to identify a preferred method, but to highlight the importance of choosing the best suited practice for a project or mine site. In addition, a case study comparing two different density determination methods applied to the same rock samples from the Los Bronces Copper mine in Chile was undertaken and the results of that study are presented here. Selecting the most appropriate method to determine density and comparing results from two or more techniques against each other, together with other suitable quality control procedures, is considered to be essential for mining operations and exploration projects in order to reduce risk and to improve operational performance, which in turn increases profit margin.

Application of bioleaching to copper mining in Chile

Background: Bioleaching of minerals is a process that allows the treatment of insoluble sulfides and insoluble oxides via hydrometallurgy, as opposed to the more traditional technology of pyrometallurgy. Bioleaching presents several technological, environmental and economic advantages as compared with pyrometallurgy, as well as some limitations. Results: In this work a general panorama of copper mining and biomining, the influence of the most relevant operating variables and their present and future situation in Chile are presented and discussed. Conclusions: Today, Chile plays an important role in the development and commercial application of bioleaching to copper ores. This background information allows predicting a brilliant future for this technology in Chile, as has been forecasted in the last years.

Student attitudes to socially responsible business: a case study of mine workers in Chile

PurposeGiven the proliferation of United Kingdom (UK) media headlines around the recent financial meltdown and the subsequent allocation of blame to government, bankers, the Bank of England and the Financial Services Authority, it is clear that there is disquiet amongst the public as to how the crisis has been handled. Business schools, both in the UK and worldwide, have been accused of failing to address issues of governance in their curricula. Can the assumption be made that current curricula will have prepared students to evaluate this key concept critically? This paper seeks to address these issues.Design/methodology/approachTaking a case study approach, this work sets out to explore the attitudes of a cohort of 43 final‐year undergraduate students studying in a UK business school. It focuses on an analysis of their written work on the sourcing of copper from Chile and its procurement by the UK Royal Mint for coinage.FindingsThe findings indicate that students valued the inclusion of corporate social responsibility in its widest context, and would welcome earlier inclusion within their curricula.Originality/valueThis is a timely point in their academic studies, as the students are preparing for study at Master's level or for the job market. The coursework required research into the production process of raw material at the copper mines in Chile, as well as the ethical decision‐making process of a UK governmental agency. Although this is a small‐scale study, it does offer some interesting insights into student perspectives. The paper concludes with recommendations for future curriculum development.

Gender relations and masculinity in northern Chile mining areas: ethnography in schoperías

This paper deals with an ethnography aimed at describing and ­understanding the gendered organization of schoperia life and masculinity in northern Chile. Schoperias are characterized physically and socially and the effects these ­premises have on gender relations and masculinity assigned to them by waitresses and clients are studied. Schoperias are beer halls, mainly for men, ­served by women, located in cities near copper mines in Chile. They are strongly ­gendered and classed places. Schoperias are reference scenarios for men and their performance; they are premises that privilege masculine socialization and heterosexual ­hegemonic masculine performance. Paradoxically, they are at the same time unique places where male friendship and complicity take place, allowing homosociability and the expression of a certain type of affection and feelings among men.