Chilean Copper Research Articles

HeathcliffWalks

Heathcliff<i>Walks</i>

Being a chilean copper union leader: between social struggle and loyalty to machismo

In this article, we analyze the experience of the production (or genesis) of female subjectivity within a framework of the copper mining industry in northern Chile. We choose a biographical methodology that allows us to magnify the life story of a female union leader working in a male-dominated field in Chile. The findings show that female miners are under constant tension of subordination and subversion as members and leaders of a union that, until recently, had been dominated by males. Likewise, these women have had to search for validation while working during complex periods of female emancipation characterized by, on the one hand, grants of autonomy, and on the other hand, a means for domination caused by gender and labor gaps in the workplace.

Gateways or backdoors to development? Filtering mechanisms and territorial embeddedness in the Chilean copper GPN’s urban system

AbstractThis paper analyses the role played by different urban nodes in the Chilean copper mining Global Production Network (GPN), and how filtering mechanisms act in favour of the capital city, limiting the territorial embeddedness of extractive industry in resource peripheries. In doing so, we make three contributions to the literature. First, in addition to observing gateway cities (those connecting the mining hinterlands to the global economy), we propose an intermediate category in urban hierarchies which we label the “backdoor city” (those that can perform one or more functions of a gateway city but lack chances for value capture and sustainable development outcomes). Second, we analyse the filtering mechanisms that work to the detriment of resources peripheries. Third, we analyse how these mechanisms reduce the territorial embeddedness of mining activity across the Chilean urban hierarchy. Our main results show that the capital city of Santiago stands out as the only gateway city in the country, and Antofagasta acts as a backdoor city for the Chilean resource peripheries where the extractive activity is weakly embedded, limiting their development opportunities.

Development of an irradiance-based weather derivative to hedge cloud risk for solar energy systems

For large energy consumers transitioning to high shares of solar energy, irradiance variability causes volatility in power generation and energy expenditures. Volatility in an end user’s cash flow is harmful to their financial health, especially in abnormally cloudy years. This paper explores the utility of an irradiance-based weather derivative in mitigating cloud weather risk and measures the effectiveness of the developed derivative by applying it to a case study of two Chilean copper mines. Weather derivatives are financial instruments tied to an underlying weather variable that act as an insurance for the contract holder, executing indemnity payments based on an index value. This research develops a contract with a combined index based on monthly sums of irradiance and cloudy day sequencing to mitigate a solar mine’s weather risk. The design and evaluation of contracts are based on LEELO, a linear optimization model outputting optimal sizes of solar photovoltaic, battery storage, and power-to-gas systems, as well as the operation of these systems for a given mine’s load, irradiance and technology costs. Results indicate contracts are effective in cloudier climates with increasing utility for mines installing solar energy systems until the year 2030. After 2030 batteries begin to become a more cost-effective risk-hedging mechanism as they become more affordable.

Empirical analysis of Chile's copper boom and the Dutch Disease through causality and cointegration tests

Over the period 1990–2018, Chile has experienced the great copper boom manifested in an initial phase of the strong expansion of the productive base, followed by a period of high copper prices derived from the supercycle. Over this period, Chile has achieved great social progress in poverty and wealth indicators that have allowed it to decouple its progress from that of its peers in the region. However, it is valid to ask whether, as a consequence of the mining boom, Chile has suffered from an industrial weakening and other negative effects as a result of the Dutch Disease (DD), jeopardizing the country's long-term economic progress. This paper proposes a methodology to evaluate whether the Chilean copper boom induced the DD symptoms in its economy through Granger-causality, cointegration, and impulse-response function over a vast set of socioeconomic variables. According to the authors' knowledge, the approach implemented allowed for the broadest empirical DD evaluation in the Chilean economy taking into account four crucial aspects: i) the political and economic regime established and consolidated along the 1990–2018 period; ii) the full Chilean copper industry expansion cycle; iii) the complete supercycle of the commodity prices; iv) data availability. The results suggest that the copper mining industry has not only allowed the country to enjoy an income surplus but actually levered the country's development. The proven success over the last three decades of Chile's mining development and windfall management should be a strong argument in favor of the model continuity and as a valid benchmark for macroeconomic management purposes by other countries in similar macroeconomic and idiosyncratic contexts.

Equivalent availability index for the performance measurement of haul truck fleets

This article presents a model of performance analysis for a truck fleet system in an openpit mine, considering special characteristics of haul fleets. In these systems, the expected availability of each piece of equipment and its operating capacity are the fundamental variables to construct a global fleet performance function. Our analytical algorithm considers heterogeneous fleets with known individual characteristics of transport capacity and failure and repair behavior. The results converge to a new indicator denominated “Equivalent Availability” (EA), which arises from the need to evaluate the capacity of the truck fleet to operate at a lower payload than required using different combinations of equipment to achieve an availability goal. EA is a key indicator to determine the productive capacity of a process, and for selecting equipment and their combinations to achieve production objectives. To exemplify the potentialities of the EA, a case study is implemented in a Chilean copper truck fleet mining process.

Natural resource rent allocation, government quality, and concession design: The case of copper in Chile

Rent allocation is key to natural-resource rich countries' development. A life cycle model is used to study optimal rent allocation considering the uncertainties derived from government quality and rent measurement. Chile's private copper industry is used as a case study. Results show that between 1988 to 2018 roughly USD 161.7 billion of copper rent has been allocated to the private sector, which accounts for 62.6% of the total rent generated by the industry. Given the quality of Chile's government (i.e., level of accountability, political stability, effectiveness, regulatory quality, control over corruption, and adherence to the rule of law), rent allocation has likely been suboptimal and institutional change is likely warranted.

Surface properties of copper-sulfide minerals with sodium-hydrosulfide activation

The surface properties of slightly oxidized chalcocite, bornite, and chalcopyrite with sodium hydrosulfide (NaHS) treatment were investigated by solid analyses of X-ray photoelectron spectroscopy, solution analyses, and zeta potential measurements. NaHS is known as a flotation activator for copper-oxide minerals by sulfurizing their surfaces. This study focused on the surface properties before/after sulfurization by the NaHS at several NaHS dosages and alkaline pHs. Iron leaching and precipitates of copper–iron-sulfide minerals have also been investigated. The analysis results showed that NaHS sulfurized the oxidized copper species, CuO and CuSO4, to copper sulfide, but oxidized iron species, Fe2O3 and Fe(OH)3, were not sulfurized by NaHS. These oxidized iron species dissolved into solutions as complex ion, Fe(HS)20, then Fe(HS)20 was decomposed by dissolved oxygen and reprecipitated as Fe2O3. The results of chalcocite showed that Cu2S was generated on the surfaces with NaHS treatment at any pH. The bornite and chalcopyrite results indicated that Fe2O3 was produced on bornite surfaces with an increase in pH, whereas the chalcopyrite surfaces were covered as the pH decreased. A flotation test was conducted using a Chilean copper ore that contained chalcocite, bornite, and chalcopyrite, and the flotation recovery of each mineral was consistent with the surface sulfurization at several NaHS dosages and pHs.

Selective Extraction of Cobalt and Copper from Chilean Mine Water by Ion Exchange Resin

Heavy metal-containing waste has become one of heavy environmental problems. Processing of such waste accumulated at waste dumps to extract valuable components is commercially beneficial activity and, in addition, decreases environmental impact. In this study, Lewatit MonoPlus TP 207 (TP 207) ion exchange resin was evaluated for its suitability for selective removal of cobalt (Co) and copper (Cu) from mine waste waters, generated by heap leaching waste materials at a Chilean copper mine. In series of laboratory scale fixed-bed ion exchange column tests, the effects of process parameters, such as waste water flow rate and regenerant (sulfuric acid) concentration, were studied in both waste water treatment by the ion exchange resin process and the resin regeneration (metals eluting) process. The regeneration process tests were performed using 1 % and 10 % sulfuric acid. The best separation of the metals (in the eluting process) was achieved with regeneration of TP 207 resin using 1 % sulfuric acid at flow rate of 1 bed volume per hour (BV/h).

Transparency on greenhouse gas emissions from mining to enable climate change mitigation

The climate change impacts of mining are often not fully accounted for, although the environmental impact of mineral extraction more generally is widely studied. Copper mining can serve as a case study to analyse the measurable pathways by which mining contributes to climate change through direct and indirect greenhouse gas emissions. For example, mining, processing and transportation require fuel and electricity, and the decomposition of carbonate minerals, employed to reduce environmental impacts, also releases carbon dioxide. Overall, we estimate that greenhouse gas emissions associated with primary mineral and metal production was equivalent to approximately 10% of the total global energy-related greenhouse gas emissions in 2018. For copper mining, fuel consumption increased by 130% and electricity consumption increased by 32% per unit of mined copper in Chile from 2001 to 2017, largely due to decreasing ore grade. This trend of increasing energy demand to produce the same quantity of some metals compounds the problems of increased metal demand due to the pressures of new technologies and increasing population. For green technologies to be implemented effectively, it is necessary that the mining industry and regulators accurately and transparently account for greenhouse gas emissions to implement mitigation strategies. Direct and indirect greenhouse gas emissions from mining for green technologies need to be accurately and transparently accounted for, as highlighted by a case study of Chilean copper mining.

Analyzing the potential for solar thermal energy utilization in the Chilean copper mining industry

Copper mining is the largest industry and energy consumer in Chile, utilizing heat from imported fossil fuels of which Chile is not a producer. The goals for decarbonization present opportunities to analyze how the Chilean industry can become sustainable with significant shares of renewable energy including solar heat. The present study analyzes the integration of solar heating to the copper refining process in order to gain insights on the technical, economical, and emissions performance of solar heating systems for the largest copper mining operations in Chile. The solar technologies considered in the analysis are flat plate, evacuated tube, and parabolic trough collectors. The results are validated by comparing with publicly available data from existing solar heating plants in copper mining facilities showing that solar plants are able to supply partially the thermal energy demand, although at different costs in terms of capital and operation and maintenance requirements. The economic analysis indicates that with current fossil fuel prices, solar heating technologies are a valid alternative for cost and emissions reduction in copper mining. Flat plate collectors show the lowest cost for solar heat when compared to evacuated tube and parabolic trough systems considering identical sets of technical and financial parameters. The parametric and sensitivity analysis indicate that the conditions under which solar heating is competitive with traditional fossil-fired heaters. which might still be required as backup systems in order to provide heat in a 24/7 regime, and in all the cases analyzed, a substantial reduction in CO2 emissions can be achieved.

Reducing GHG global emissions from copper refining and sea shipping of Chile's mining exports: A world win-win policy

Chile is the largest copper producing country of the world; and almost 50% of the copper it exports to the rest of the world is exported as copper concentrates to be smelted and refined abroad. However, 70% of the weight of these exported copper concentrates is gangue (valueless and undesirable material associated to the copper content in these exported concentrates). In this paper analyze and quantify the contribution Chile could make to the ongoing world efforts to reduce climate change and global warming, if it adopts a trading policy eliminating its exports of copper concentrates and replacing them with the greater value added exports of the refined copper obtained from smelting and refining those concentrates in Chile. This policy would allow a significant reduction of greenhouse gases (GHG) emitted every year to the global atmosphere. This reduction would occur through two channels: 1. avoiding the combustion of more than 600,000 tons of diesel oil currently used to transport by sea almost 6,600,000 tons of the gangue incorporated in Chile's copper concentrate exports; and, 2. using Chile's cleaner technology for smelting and refining copper concentrates instead of the dirtier technologies of the countries currently importing, smelting and refining the Chilean copper concentrates. For the first time, using data for 2014, we estimate the total net reduction in GHG emissions to the global atmosphere that the proposed trade policy would imply. We calculate the distance of the nautical routes used for the 919 shipments of concentrates exported by Chile that year; and we perform sensitivity analysis for 4 scenarios, employing two alternative values for two key parameters. Additionally, we compare the GHG emission performances of the copper smelting and refining metallurgic technologies employed in Chile and in every one of the 22 countries that import and smelt and refine Chilean concentrates. Our estimates for the 2 most extreme scenarios indicate that, if instead of exporting copper concentrates in 2014, Chile would had exported only refined copper, it would had contributed with a total net reduction of GHG emissions emitted to the global atmosphere of 2,227,047 and 2,799,279 ton CO2-eq tons that year, which are equivalent to approximately 5.6% of the total amount of GHG emissions that would had made Chile fully carbon neutral that year. This is a significant contribution regarding Chile's commitment to the Paris Agreement as well as in terms of the required world efforts to reducing GHG emissions from sea shipping.

Improving the productivity of the copper mining process in the Chilean copper industry

This paper presents a linear programming model used for decision making in the mining process of copper concentration from sulphide minerals. The developed model enables the decision maker to select the types of ore to be used in the mix to maximize the metallurgical recovery and the copper grade at the end of the process. The model is of the mixture model of minerals with added economic variables such as processing costs, electric power and others. The process has four sub-processes that are crushing the ore, crushing the crushed ore, flotation of the ground ore to obtain copper concentrate and drying, in which the water is extracted. The model uses a set of variables whose size varies according to the number of lots of minerals and the number of planning days considered. The model may be considered a considerable problem when a long period of time is planned, but has only been implemented with 3.000 variables and 2.000 constraints. The developed model is being implemented in the National mining company, which buys ore from small producers to produce copper concentrate and then melt and refine it to obtain high grade copper. The generated model produces savings of the order of thousand dollars per day, when compared to the current methods of allocating minerals, which represents millions of dollars per year. It also produces a benefit due to the fact that lower operating costs are obtained, with estimate savings of the order of 5% of the current cost.

Assessment of the use of lignosulfonates to separate chalcopyrite and molybdenite by flotation

Molybdenum is the most important by-product of Chile's copper mining industry, and during the last decade gained international relevance because of its high price At mining deposits, copper and molybdenum are extracted together and then separated in a process consisting of several stages of flotation using sodium hydrosulfide (NaHS) as key reagent. However, environmental issues related to the potential emissions of toxic hydrosulfide gas (H2S), and bad odors make necessary the development of new environmentally friendly processes that incorporate non-toxic reagents. In this work, we hypothesize that a selective separation of chalcopyrite and molybdenite by flotation can be achieved by using lignosulfonates instead of NaHS. This approach was evaluated by testing the effect of lignosulfonates, produced by reacting kraft lignin with sodium sulfite and formaldehyde, and commercially available lignosulfonates, on molybdenite and chalcopyrite flotation. Chemical characterization of lignosulfonates was performed by determination of molecular mass, elemental analysis, fourier transform infrared, and mass spectroscopy with inductively coupled plasma. Also, interactions between molybdenite and lignosulfonates were studied through measurements of electrophoretic mobility. The main conclusions of the work are that molybdenite flotation can be depressed by the action of lignosulfonates, and such depressing effect increases with pH because of the interactions between lignosulfonates with the metallic calcium sites existing on the surface of the mineral particles. The experimental results also indicate that lignosulfonates can depress chalcopyrite flotation when sodium isopropyl xanthate is used as a collector, but this effect can be completely mitigated by using potassium amyl xanthate as a collector, thus, making it possible the potential separation of both minerals.

Elements of logistics: Along the line of copper

Examining the conduits of production and circulation that link the extraction of copper in Chile to its storage and use in China, this article explores the political dimensions of the logistical te...

Uranium and molybdenum recovery from copper leaching solutions using ion exchange

This work shows the technical feasibility to recover uranium and molybdenum from industrial copper leaching solutions (PLS). Both were obtained as by-products from hydrometallurgical operations of the Chilean copper mining industry, using the ion exchange technique. This process recovered uranium and molybdenum, without disturbing or changing the normal operation of the overall copper production process. Uranium concentration was 17 mg/L, while molybdenum concentration was 50 mg/L. Four different anionic resins were tested, along with the influence of impurities over the breakthrough and saturation points achieved. In a first instance, two resins were chosen based on their Langmuir parameters, namely, maximum load capacity (Qmax) and separation factor (RL): L-MP62 and M43. The overall dynamic process consisted in a pre-conditioning step for the resin, using a weak hydrochloric acid solution. Next, the copper PLS solution feeds the fixed bed of the ion exchange column. Once the PLS solution saturates the anionic resin, a hydrochloric solution extracts uranium, and a sodium hydroxide solution extracts molybdenum. The final products were purified elution solutions with 500 mg/L uranium and 800 mg/L molybdenum, respectively.

Economic potential of new ore products in processing plant operations: A case study from midsize prospects, Atacama Chile

This paper proposes a methodology to evaluate the economic potential of mining prospects with a 'multi-product' approach. The National Mining Company (ENAMI) is a Chilean producer traditionally engaged in copper, silver and gold production and commercialization. Using this methodology it has been possible to identify other commodities with greater geological, market and technological potential. Prospects studied were valued using economic-mining criteria such as the cut-off grade, marginal cut-off grade and equivalent grade. In this work, thirteen commodities were analyzed and seven of them stand out: molybdenum, lithium, iron, bismuth, tungsten, rare earths (REE) and titanium. For every commodity, it is essential to know the geological characteristics of the prospect, the mining and processing technologies, the purchase point closest to the prospect and the market for these commodities. The sources of information are public bodies specialized in these matters, such as the National Geology and Mining Service, SERNAGEOMIN; the Chilean Copper Commission, COCHILCO. Sixteen ENAMI prospects were valued based on the proposed methodology and six of them presented the greatest economic potential: Salado Norte, Cerro Negro, Pazota, Pastenes, Laura–Laurita and Carmen Sur

Museums and mining technologies

ABSTRACTThis article has a twofold purpose, first to explore how the founding of museums helps the mining industry to create a new way to look at what becomes natural in landscapes that are intervened by mining operations, and second to analyze how this new way of looking at the landscape ignites a process of recontextualization having a material impact on the territories. As part of this discussion, this article reveals how the technologies of mining production have evolved, facilitating the companies’ material production, and how the mining museum becomes a fundamental part of this technological development. This article looks at two mining museums owned or funded by the Chilean copper mine Los Pelambres, the ‘Museum of Copper and Sustainable Development’, located in Los Vilos next to Los Chungungos dock, and the ‘Andróniko Luksic Mining Center’, located in the engineering department at the Pontificia Universidad Católica in Santiago. These museums are funded by the mining company Los Pelambres and one of them is currently managed by the company.

Increasing and Diminishing Returns – Africa’s Opportunity to Develop

Marshall’s observation also applies to today’s migration patterns: from countries where most activities are subject to constant or diminishing returns to countries whose key economic activities are subject to increasing returns to scale. Diminishing returns occur when one factor of production is limited by nature, which means that it occurs in agriculture, mining, and fisheries. Normally the best land, the best ore, and the richest fishing grounds are exploited first, and – after a point – the more a country specializes in these activities, the poorer it gets. OECD (2018) shows how this occurs in Chilean copper mining: every ton of copper is produced with a higher cost than the previous ton. In Alfred Marshall’s theory, the ‘Law of Diminishing Returns’ is juxtaposed with ‘The Law of Increasing Returns’, also called economies of scale. Here we find the opposite phenomenon; the larger the volume of production, the cheaper the next unit of production becomes. Traditionally economies of scale were mainly found in manufacturing industry, and increasing returns combined with technological change has for centuries been the main driving force of economic growth. Increasing returns creates imperfect competition, market power and large barriers to entry for challengers – companies or nations – making it difficult for them to enter these industries. In contrast to the rents produced under conditions of increasing returns, raw materials – commodities – on the other hand, are subject to perfect markets, and productivity improvements spread as lowered prices. This is the essence of the theory which explains why former World Bank Chief Economist Justin Yifu Lin was correct when he asserted that ‘Except for a few oil-exporting countries, no countries have ever gotten rich without industrialization first’ (Lin 2012 : 350).

Electrokinetic remediation of manganese and zinc in copper mine tailings.

The scope of this work is to determine the effect of initial acidity and electric field intensity on the Electrokinetic Remediation of manganese and zinc from mine tailings from a Chilean copper mine. To achieve this objective, experiments were carried out focusing on the effect of the applied electric field (1 and 2 V cm-1), the H2SO4 concentration during pretreatment (1 and 2 mol L-1) and the interaction between these factors in manganese and zinc concentration. From the obtained results, manganese and zinc can be removed from the analyzed tailings, with the maximum net removal 31.88% and 17.95%, respectively. The enhancement of electromigration was proven by an Analysis of Variance with a significance level of 10% for the soluble and total metal concentration in the cathodic zone, where total concentration was increased to 24% and 11% for zinc and manganese, respectively.